Reference for Non-newtonian Perihelion advance of Mercury
greywolf42
many angels and so few pins.
Long before the recent Mercury threads begain, I twice requested anyone on
these newsgroups asking for a citation or source for our current (modern)
values of the perihelion advance of Mercury. No one has responded. A
couple of people have asked for current citations in the recent spate of
posts. But -again- no one has provided any.
A couple of responders attempted to pass off Le Verrier's late 1800's work
and lunar-ranging data. Both are irrelevant to the question. (Le Verrier
based his work on inferior and superior conjuction times -- and of course he
didn't include corrections for the bending of light at superior
conjunction). But most simply asserted that the evidence "had to be" good,
or scientists wouldn't believe it.
So I again ask for a citation. Does ANYONE know where the current work is?
Just to be clear, by "current" I mean subsequent to the Mariner "surprise"
(when an irritating spacecraft found that the physical mass of Mercury was
twice what had been predicted by GR*). Actually, I'll take anything from
1950 on.
* Yes I KNOW that Mercury's mass is not included in the single calculation
for Mercury's perihelion advance. But it is contained in the entire system.
(Mercury's mass affects the other 8 planets to varying degrees -- and vice
versa).
greywolf42
ubi dubium ibi libertas
Steve Carlip
> Long before the recent Mercury threads begain, I twice requested anyone on
> these newsgroups asking for a citation or source for our current (modern)
> values of the perihelion advance of Mercury.
> [...] Does ANYONE know where the current work is?
Try:
I.I. Shapiro et al., Phys. Rev. Lett. 28 (1972) 1594 (radar ranging results)
J.D. Anderson et al., Acta Astronautica 5 (1978) 43 (optical and radar data)
Steve Carlip
Chris Hillman
On Tue, 20 Mar 2001, greywolf42 (aka etherman?) wrote:
> I've been amused watching the posts on Mercury's perihelion advance. So
> many angels and so few pins.
>
> Long before the recent Mercury threads begain, I twice requested anyone on
> these newsgroups asking for a citation or source for our current (modern)
> values of the perihelion advance of Mercury. No one has responded.
Sheesh, I -said- just yesterday: the modern value
42.98 seconds per century
and is accurate to one part in 10^(-4). This value uses radar ranging to
Mercury from 1966 to 1955. And I gave a reference to a paper by Will
which has citations to the primary literature. So there you go.
Chris Hillman
Home Page: http://www.math.washington.edu/~hillman/
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
NOTE TO WOULD-BE CORRESPONDENTS: I have installed a mail filter which
deletes incoming messages not from the "*.edu" or "*.gov" domains, but
also deletes messages from some bad actors whose emails happen to be in
the "*.edu" domain and "passes" messages from a few friends with email
addresses in other domains.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
greywolf42
news:Pine.OSF.4.21.01032...@goedel2.math.washington.edu...
>
>
> On Tue, 20 Mar 2001, greywolf42 (aka etherman?) wrote:
>
> > I've been amused watching the posts on Mercury's perihelion advance. So
> > many angels and so few pins.
> >
> > Long before the recent Mercury threads begain, I twice requested anyone
on
> > these newsgroups asking for a citation or source for our current
(modern)
> > values of the perihelion advance of Mercury. No one has responded.
>
> Sheesh, I -said- just yesterday: the modern value
>
> 42.98 seconds per century
I didn't ask what the "modern value" was.
>
> and is accurate to one part in 10^(-4).
I didn't ask what the claimed "accuracy" (sic, precision) was.
>This value uses radar ranging to Mercury from 1966 to 1955.
I presume you mean from 1955 to 1966.
> And I gave a reference to a paper by Will
> which has citations to the primary literature. So there you go.
>
> Chris Hillman
>
> Home Page: http://www.math.washington.edu/~hillman/
Wow! I was supposed to know that Will had a citation to something that
might include the calculations? So, what is this "primary literature"
citation? Not a claim that you have a reference that might have a useful
citation....
greywolf42
greywolf42
"Steve Carlip" <car...@dirac.ucdavis.edu> wrote in message
news:99880f$jdb$1...@woodrow.ucdavis.edu...
> greywolf42 <min...@sim-ss.com> wrote:
>
> > Long before the recent Mercury threads begain, I twice requested anyone
on
> > these newsgroups asking for a citation or source for our current
(modern)
> > values of the perihelion advance of Mercury.
>
> > [...] Does ANYONE know where the current work is?
>
> Try:
>
> I.I. Shapiro et al., Phys. Rev. Lett. 28 (1972) 1594 (radar ranging
results)
I don't believe that Physical Review Letters can POSSIBLY include the
calculations and/or data. They don't publish long papers. (I'll send $25
to the first to prove me wrong by providing a copy to me.)
> J.D. Anderson et al., Acta Astronautica 5 (1978) 43 (optical and radar
data)
>
> Steve Carlip
I'll try the latter. Thanks. (I'll also send $25 to anyone kind enough to
save me a trip to the UC library by posting the paper here.)
greywolf42
News Reader
"greywolf42" <min...@sim-ss.com> wrote in message news:8cLt6.1244$ei1.3...@nntp3.onemain.com...
I would have a snoop around the jpl web site www.jpl.nasa.gov . They produce accurate
ephemerides for all the planets so they got their primary data from somewhere.
I did a quick search on their site for "mercury, emphemerides" and it came up with a
gazillion articles. I dont have time to go through them myself to see if any are
relevant to your question. Feel free to have a look yourself.
Regards
greywolf42
"News Reader" <al...@hotmail.com> wrote in message
news:3ab8...@clear.net.nz...
Thanks. I could dig around and maybe find something. The point was -- of
course -- that dozens of "relativists" repeatedly stated that the
non-newtonian perihelion advance was experimentally confirmed (to one part
in 10,000 -- which is 1 part in 100,000 of total advance). Rather than
shoot in the dark and try to "guess" what references they had in mind, I've
asked them to be specific. If none of those relativist has any reference at
hand, they're just talking religion.
Steve Carlip
> "Steve Carlip" <car...@dirac.ucdavis.edu> wrote in message
> news:99880f$jdb$1...@woodrow.ucdavis.edu...
>> greywolf42 <min...@sim-ss.com> wrote:
>> > Long before the recent Mercury threads begain, I twice requested
>> > anyone on these newsgroups asking for a citation or source for
>> > our current (modern) values of the perihelion advance of Mercury.
>> Try:
>> I.I. Shapiro et al., Phys. Rev. Lett. 28 (1972) 1594 (radar ranging
> results)
> I don't believe that Physical Review Letters can POSSIBLY include the
> calculations and/or data.
Hmm. The Shapiro paper is based on 350 radar time-delay measurements
of Mercury and over 500 measurements of Venus. Are those measurements
the ``data'' you want? In what form? You'll also need some detailed analysis
of the workings of the Arecibo and Haystack observatories. In what form
would you expect that to be published?
The Anderson paper uses 44,000 observations, includingsomething like
38,000 optical observations from the US Naval Observatory, about 5000
radar observations of Mercury, Venus, and Mars, 803 Mariner 9 data points,
and a bunch of data from Pioneer 9 and 10. Do you propose to reanalyze
this?
How do you propose to incorporate corrections to limb biases for Mercury
and Venus? How about the shape of the planets, which affects radar
delays? How about Solar corona time delay? Will you include corrections
from major asteroids? Which ones?
And exactly what ``calculations'' would you expect such a paper to show?
One more question. In the past, you've been rather enthusiastic about the
``Pioneer effect,'' which was also reported in Physical Review Letters in
a paper that didn't ``include the calculations and/or data.'' Have you asked
for that data? Do you trust the results of those calculations? I ask because
the first author on the Pioneer paper is the same J.D. Anderson who is the
first author of the paper on Mecury's perihelion that I cited, and E.L. Lau
is also an author of both. If you're willing to accept one result without
demanding the details of the ``calculations and/or data,'' shouldn't you
treat the other the same?
Steve Carlip
Steve Carlip
Vern
I may be wrong, but I got the impression that greywolf just wanted the GR
calculations (field equations, maybe?) which were used to show that GR
matches the observed advance. If not, I would be interested in what
equations are used to derive the GR-figured advance.
Vern
Chris Hillman
On Tue, 20 Mar 2001, greywolf42 wrote:
[snip tendentious carping]
> >This value uses radar ranging to Mercury from 1966 to 1955.
>
> I presume you mean from 1955 to 1966.
I meant 1966 to 1995.
> > And I gave a reference to a paper by Will
> > which has citations to the primary literature. So there you go.
>
> Wow! I was supposed to know that Will had a citation to something that
> might include the calculations?
Why don't you read the paper? It's free.
Chris Hillman
Home Page: http://www.math.washington.edu/~hillman/
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Chris Hillman
On Wed, 21 Mar 2001, Vern wrote:
> I may be wrong, but I got the impression that greywolf just wanted the
> GR calculations (field equations, maybe?) which were used to show that
> GR matches the observed advance.
That is not the impression I received.
> If not, I would be interested in what equations are used to derive the
> GR-figured advance.
I assume you are saying you would like to see a derivation of the
"extra-Newtonian precession" of the perihelia of Mercury as predicted by
gtr. That can be found in almost any gtr textbook; try this reading list
http://math.ucr.edu/home/baez/RelWWW/reading.html#gtr
or the full length graduate level course notes listed here:
http://math.ucr.edu/home/baez/RelWWW/grad.html#gr
A slightly simplified version of the derivation (precession of pericenter
of a nearly circular orbit) is given in detail in
http://math.ucr.edu/home/baez/PUB/line
If you find any of this confusing, you can ask in sci.physics.research or
sci.astro.research, which are both moderated groups. Post to them the
same way you would post to an unmoderated group, but expect to wait
several days to a week before your post appears.
Vern
> > If not, I would be interested in what equations are used to derive the
> > GR-figured advance.
>
> I assume you are saying you would like to see a derivation of the
> "extra-Newtonian precession" of the perihelia of Mercury as predicted by
> gtr. That can be found in almost any gtr textbook; try this reading list
>
> http://math.ucr.edu/home/baez/RelWWW/reading.html#gtr
>
> or the full length graduate level course notes listed here:
>
> http://math.ucr.edu/home/baez/RelWWW/grad.html#gr
>
> A slightly simplified version of the derivation (precession of pericenter
> of a nearly circular orbit) is given in detail in
>
> http://math.ucr.edu/home/baez/PUB/line
>
> If you find any of this confusing, you can ask in sci.physics.research or
> sci.astro.research, which are both moderated groups. Post to them the
> same way you would post to an unmoderated group, but expect to wait
> several days to a week before your post appears.
Vern (new):
Thanks.
> NOTE TO WOULD-BE CORRESPONDENTS: I have installed a mail filter which
> deletes incoming messages not from the "*.edu" or "*.gov" domains, but
> also deletes messages from some bad actors whose emails happen to be in
> the "*.edu" domain and "passes" messages from a few friends with email
> addresses in other domains.
What's up with this?
Vern
greywolf42
> greywolf42 <min...@sim-ss.com> wrote:
>
> > "Steve Carlip" <car...@dirac.ucdavis.edu> wrote in message
> > news:99880f$jdb$1...@woodrow.ucdavis.edu...
> >> greywolf42 <min...@sim-ss.com> wrote:
>
> >> > Long before the recent Mercury threads begain, I twice requested
> >> > anyone on these newsgroups asking for a citation or source for
> >> > our current (modern) values of the perihelion advance of Mercury.
>
> >> Try:
>
> >> I.I. Shapiro et al., Phys. Rev. Lett. 28 (1972) 1594 (radar ranging
> > results)
>
> > I don't believe that Physical Review Letters can POSSIBLY include the
> > calculations and/or data.
>
> Hmm. The Shapiro paper is based on 350 radar time-delay measurements
> of Mercury and over 500 measurements of Venus. Are those measurements
> the ``data'' you want?
Possibly. That number of observations is on the same order as Le Verrier in
1873.
> In what form?
In whatever form they are in.
> You'll also need some detailed analysis
> of the workings of the Arecibo and Haystack observatories. In what form
> would you expect that to be published?
Somewhere referenceable.
> The Anderson paper uses 44,000 observations, includingsomething like
> 38,000 optical observations from the US Naval Observatory, about 5000
> radar observations of Mercury, Venus, and Mars, 803 Mariner 9 data points,
> and a bunch of data from Pioneer 9 and 10. Do you propose to reanalyze
> this?
It depends on the description of the "analysis" that WAS done. The point
is, that the data SHOULD be referenceable.
> How do you propose to incorporate corrections to limb biases for Mercury
> and Venus? How about the shape of the planets, which affects radar
> delays? How about Solar corona time delay? Will you include corrections
> from major asteroids? Which ones?
The ones that affect the results.
> And exactly what ``calculations'' would you expect such a paper to show?
The ones necessary to allow verification of the results. Like any good
scientific paper.
> One more question. In the past, you've been rather enthusiastic about the
> ``Pioneer effect,'' which was also reported in Physical Review Letters in
> a paper that didn't ``include the calculations and/or data.'' Have you
asked
> for that data?
Not yet.
> Do you trust the results of those calculations?
No. I don't "trust" anything. "Trust" is part of religion, not science.
> I ask because
> the first author on the Pioneer paper is the same J.D. Anderson who is the
> first author of the paper on Mecury's perihelion that I cited, and E.L.
Lau
> is also an author of both. If you're willing to accept one result without
> demanding the details of the ``calculations and/or data,'' shouldn't you
> treat the other the same?
No one has yet claimed that the Pioneer data is good to 1 part in 100,000.
And the Pioneer paper would have to be orders of magnitude less complicated
by assumptions than the Mercury paper.
> Steve Carlip
Thank you for making my point, Steve. There are a tremendous number of
assumptions built into the calculations of the determination of the orbit of
Mercury and it's precession. There is no way to validly claim a 1 part in
10,000 precision in the value of the GR perihelion advance.
I was going to look for things like the assumptions about the shape and
density of the solar wind, solar oblateness, timing corrections and chi
squared paths of Mercury.
Poor old LeVerrier had to work by angles and time alone. Now with modern
technology, we get to add distance.
But, you see, I'm just a bit suspicious of yet "another" super-duper, claim
of high-precision confirmation of GR.
You've just shown it is not possible by your list of assumptions I'd have to
make. Just like anyone would have to make.
When LeVerrier first did his thing, the non-planetary precession was 38
arcseconds per century. And it was all accounted for by the disk of dust
and gas (not planetisimals) in the ecliptic. (At least according to the
Astronomers of the time.) There was "no" anomaly for Einstein to "fix". In
part because there were no good measurements of mass of either Mercury or
Venus (or Mars). That is, there was evidence of sufficient flattened matter
in the solar system to account for 38 arcseconds. So Einstein needed to ADD
42 to the 38 known. But this was "fixed" by simply claiming the mass did
not exist!
Now LeVerrier did not "correct" for bending of light at superior
conjunction. But that coincidentally did not affect the results. Then
radar ranging was begun, and GR validated!
Then "whoopsie!" Mariner found Mercury to be twice the mass predicted by
GR. Yet nothing changed in the claims regarding the results of the
"measurement" or confirmation of GR.
In short, the process of determining the perihelion advance is long and
involved. It is NOT a direct measurment. There are dynamic and transient
effects. And it all has to be based on the masses of all 9 of the planets,
the Sun and the gas and dust in the solar system. Which are determined
using -- wait for it -- GR. At least in "geometrized" units. Of course
they have to be "geometrized" -- because the value of G is only known to 3
decimal places.
The evaluation of the slowing of Pioneer is not nearly so complex. And
because it is NOT just one spacecraft or one speed. But multiple
spacecraft. Versus only one Mercury. Far simpler. More "experiments."
Oh, and just in case you don't know. I do feel that there would be some
perihelion advance of Mercury, on the order of the GR prediction. It is the
direct consequence of finite speed of gravitational propagation (known since
Gerber, 1898). However, since I'm aware that the Sun is not a perfect
sphere (and neither is the matter in the space around it, etc) I don't
believe that GR/finite grav speed is the source of "all" of the
non-planetary differences.
The solar system is a messy place.
greywolf42
>
> On Tue, 20 Mar 2001, greywolf42 wrote:
>
> [snip tendentious carping]
Carping? I was pointing out that you didn't bother to read the post before
you shot off a set of irrelvant answers. I asked for the source of your
values and you responded with a flat statement of claimed values.
Specifically:
"I twice requested anyone on these newsgroups asking for a citation or
source for our current
(modern) values of the perihelion advance of Mercury."
To which you responded: "Sheesh, I -said- just yesterday: the modern value
42.98 seconds per century and is accurate to one part in 10^(-4)."
> > > And I gave a reference to a paper by Will
> > > which has citations to the primary literature. So there you go.
> >
> > Wow! I was supposed to know that Will had a citation to something that
> > might include the calculations?
>
> Why don't you read the paper? It's free.
>
> Chris Hillman
>
Nice of you to snip the question so it's not obvious that you are weaseling.
The correct quote is:
"Wow! I was supposed to know that Will had a citation to something that
might include the calculations? So, what is this "primary literature"
citation? Not a claim that you have a reference that might have a useful
citation...."
Note the difference. I did not ask for general references about GR theory.
Such as Will's paper. Specifically, I requested a primary source. That is,
the basis for your claims about the value and precision of perihelion
advance. You apparently aren't aware of one. That doesn't stop you from
parroting an unsubstantiated claim that you happen to like.
Of course I can go literature searching and find something, somewhere. But
it won't be the sources that the posters in this group are referring to. So
rather than waste my time, I thought I'd ask those who claim to know -- like
yourself. What I continue to find is that there's nothing behind the claims
but wishful thinking. Or rather that those making the claims don't know
what the basis of the claim is.
So I ask again. WHAT is the primary literature reference (one that can be
checked) for your claimed value and precision for Mercury's non-newtonian
perihelion advance.
Matthew Nobes
> "Steve Carlip" <car...@dirac.ucdavis.edu> wrote in message
> news:99arnq$lhv$2...@woodrow.ucdavis.edu...
[snip, the subject is the Pioneer "effect"]
> > Do you trust the results of those calculations?
>
> No. I don't "trust" anything. "Trust" is part of religion, not science.
Okay. I'm going to take that *very* seriously. (I should add that this
statement is patently false, in practice sceince could never progress if
present researchers didn't trust the results of past researchers).
[snip to this]
> ... Mariner found Mercury to be twice the mass predicted by GR.
I don't trust you. Please provide evidence for this claim. And rememebr
I'm applying your methods here. So to start I want
1) a primary reference showing the GR prediction of the mass of Mercury
2) details on the Mariner spacecraft. How am I supposed to know if it was
sending back reilable data? A sample of raw data from some test run
would be a good start
3) all of the raw data, from Mariner, relvent to the mass determination
4) full details of how the mass of Mercury is extracted from the above
data
5) A demonstration that this affects the perhilon shift computation
This ought to be a good start. Now I won't be sent on any "wild goose
chases" I want primary references in all cases. I would of course also
like to see an actual Mariner spacecraft launched. I mean, in the end,
how am I supposed to trust that all of these events weren't just faked?
Who wants to bet that Mr. Mingst can't provide the level of proof for his
claims that he demands of others?
--
"It was one thing to say, along the banks of |Matthew Nobes
the Sea of Galilee, `Love thy neighbour.' It |c/o Physics Dept.
is a different thing to say it in today's |Simon Fraser University
world. Not that it is any less `true'; but |8888 University Drive
it has a different meaning in terms of |Burnaby, B.C., Canada
practice and in terms of what men can manage" |pastureh.phys.sfu.ca
-Robert Oppenheimer |
greywolf42
"Matthew Nobes" <man...@fraser.sfu.ca> wrote in message
news:Pine.GSO.4.30.010322...@fraser.sfu.ca...
> On Wed, 21 Mar 2001, greywolf42 wrote:
>
> > "Steve Carlip" <car...@dirac.ucdavis.edu> wrote in message
> > news:99arnq$lhv$2...@woodrow.ucdavis.edu...
> [snip, the subject is the Pioneer "effect"]
> > > Do you trust the results of those calculations?
> >
> > No. I don't "trust" anything. "Trust" is part of religion, not
science.
>
> Okay. I'm going to take that *very* seriously. (I should add that this
> statement is patently false, in practice sceince could never progress if
> present researchers didn't trust the results of past researchers).
????? Whatever happened to independent verification? That's how science is
supposed to be self-correcting. If you don't check, repeat, verify and
question; then you don't have science. No self-correction, no science.
>
> [snip to this]
> > ... Mariner found Mercury to be twice the mass predicted by GR.
>
> I don't trust you. Please provide evidence for this claim. And rememebr
> I'm applying your methods here. So to start I want
>
> 1) a primary reference showing the GR prediction of the mass of Mercury
Ummm, that's what I was asking for. Can you read?
> 2) details on the Mariner spacecraft. How am I supposed to know if it was
> sending back reilable data? A sample of raw data from some test run
> would be a good start
Goodness..
>
> 3) all of the raw data, from Mariner, relvent to the mass determination
>
> 4) full details of how the mass of Mercury is extracted from the above
> data
>
> 5) A demonstration that this affects the perhilon shift computation
>
> This ought to be a good start. Now I won't be sent on any "wild goose
> chases" I want primary references in all cases. I would of course also
> like to see an actual Mariner spacecraft launched. I mean, in the end,
> how am I supposed to trust that all of these events weren't just faked?
That is up to you -- personally. I leave it to your scientific judgement.
Of course, you could simply request the primary claims by GR. Then -- by
your definition -- you'd have everything you asked for. Of course, my
statement was based on a single quote (I'll dig it out of one of my
beginning Astro texts this weekend, if you insist.)
But first I want to find out if you are claiming this didn't happen.
> Who wants to bet that Mr. Mingst can't provide the level of proof for his
> claims that he demands of others?
I never made such a demand. I did not demand that level of proof (to
start). I merely wanted to see the primary literature that you are all
claiming.
Matthew Nobes
>
> "Matthew Nobes" <man...@fraser.sfu.ca> wrote in message
> news:Pine.GSO.4.30.010322...@fraser.sfu.ca...
> > On Wed, 21 Mar 2001, greywolf42 wrote:
> >
> > > "Steve Carlip" <car...@dirac.ucdavis.edu> wrote in message
> > > news:99arnq$lhv$2...@woodrow.ucdavis.edu...
> > [snip, the subject is the Pioneer "effect"]
> > > > Do you trust the results of those calculations?
> > >
> > > No. I don't "trust" anything. "Trust" is part of religion, not
> > > science.
> >
> > Okay. I'm going to take that *very* seriously. (I should add that this
> > statement is patently false, in practice sceince could never progress if
> > present researchers didn't trust the results of past researchers).
>
> ????? Whatever happened to independent verification? That's how science is
> supposed to be self-correcting. If you don't check, repeat, verify and
> question; then you don't have science. No self-correction, no science.
My point is that you seem to take such independent verification to silly
extremes when it comes to claims you don't like.
> > [snip to this]
> > > ... Mariner found Mercury to be twice the mass predicted by GR.
> >
> > I don't trust you. Please provide evidence for this claim. And rememebr
> > I'm applying your methods here. So to start I want
> >
> > 1) a primary reference showing the GR prediction of the mass of Mercury
>
> Ummm, that's what I was asking for.
No. You were asking for the reference to the perhilion shift calculation.
Your claim above implies that there is a GR prediction of the *mass* of
Mercury that's something different.
> Can you read?
Ad hominum
> > 2) details on the Mariner spacecraft. How am I supposed to know if it was
> > sending back reilable data? A sample of raw data from some test run
> > would be a good start
>
> Goodness..
Well according to you scientists shouldn't "trust" anything. You have
made a claim, I don't trust it. Since part of the claim invovles the
Mariner spacecraft I think it would be a good idea to verify that it
worked properly.
Since I can't "trust" the NASA engineers I'd best look into this myself.
> > 3) all of the raw data, from Mariner, relvent to the mass determination
> >
> > 4) full details of how the mass of Mercury is extracted from the above
> > data
> >
> > 5) A demonstration that this affects the perhilon shift computation
> >
> > This ought to be a good start. Now I won't be sent on any "wild goose
> > chases" I want primary references in all cases. I would of course also
> > like to see an actual Mariner spacecraft launched. I mean, in the end,
> > how am I supposed to trust that all of these events weren't just faked?
>
> That is up to you -- personally. I leave it to your scientific judgement.
Well I'm just following your maxim above.
> Of course, you could simply request the primary claims by GR.
I just did.
> Then -- by your definition -- you'd have everything you asked for.
> Of course, my statement was based on a single quote (I'll dig it out
> of one of my beginning Astro texts this weekend, if you insist.)
So you "trusted" the author of a textbook?
That seems a bit strange in light of your comments above.
> But first I want to find out if you are claiming this didn't happen.
Well according to what you said above I certainly can't "trust" that it
did just cause somebody says so.
> > Who wants to bet that Mr. Mingst can't provide the level of proof for his
> > claims that he demands of others?
>
> I never made such a demand. I did not demand that level of proof (to
> start). I merely wanted to see the primary literature that you are all
> claiming.
And Dr. Carlip gave you two references. You claimed that at least one
wasn't good enough. You even have strange expectations about large radio
telescopes, as evidenced by this exchange
"You'll also need some detailed analysis of the workings of the Arecibo
and Haystack observatories. In what form would you expect that to be
published?" -- Dr. Carlip
"Somewhere referenceable." --You
Do you think that there's some book out there entitled "How to work the
Arecibo observatory"?
My point is that it requires *years* of training to become familier with
the workings of these complicated things (another good example are
particle accelerators). The users of these things *have* to trust that
they are working correctly.
greywolf42
> On Fri, 23 Mar 2001, greywolf42 wrote:
>
> >
> > "Matthew Nobes" <man...@fraser.sfu.ca> wrote in message
> > news:Pine.GSO.4.30.010322...@fraser.sfu.ca...
> > > On Wed, 21 Mar 2001, greywolf42 wrote:
> > >
> > > > "Steve Carlip" <car...@dirac.ucdavis.edu> wrote in message
> > > > news:99arnq$lhv$2...@woodrow.ucdavis.edu...
> > > [snip, the subject is the Pioneer "effect"]
> > > > > Do you trust the results of those calculations?
> > > >
> > > > No. I don't "trust" anything. "Trust" is part of religion, not
> > > > science.
> > >
> > > Okay. I'm going to take that *very* seriously. (I should add that
this
> > > statement is patently false, in practice sceince could never progress
if
> > > present researchers didn't trust the results of past researchers).
> >
> > ????? Whatever happened to independent verification? That's how
science is
> > supposed to be self-correcting. If you don't check, repeat, verify and
> > question; then you don't have science. No self-correction, no science.
>
> My point is that you seem to take such independent verification to silly
> extremes when it comes to claims you don't like.
Sure. If you define "silly" as being verifiiable in case of need (Not
always.), instead of "trusting" experiments that confirm your pet theory and
"distrusting" those that don't.
> > > [snip to this]
> > > > ... Mariner found Mercury to be twice the mass predicted by GR.
> > >
> > > I don't trust you. Please provide evidence for this claim. And
rememebr
> > > I'm applying your methods here. So to start I want
> > >
> > > 1) a primary reference showing the GR prediction of the mass of
Mercury
> >
> > Ummm, that's what I was asking for.
>
> No. You were asking for the reference to the perhilion shift calculation.
> Your claim above implies that there is a GR prediction of the *mass* of
> Mercury that's something different.
>
> > Can you read?
>
> Ad hominum
Goodness, that wasn't ad hominem! That was a rhetorical question. I could
have re-stated the sentence "That's what I was asking for." But it didn't
work the first time. Ad hominem would have been my calling you a
tendentious, misrepresentative fool. Your attempt at irony (returning one
of my favorite phrases) failed because you misused the term.
> > > 2) details on the Mariner spacecraft. How am I supposed to know if it
was
> > > sending back reilable data? A sample of raw data from some test
run
> > > would be a good start
> >
> > Goodness..
>
> Well according to you scientists shouldn't "trust" anything. You have
> made a claim, I don't trust it. Since part of the claim invovles the
> Mariner spacecraft I think it would be a good idea to verify that it
> worked properly.
>
> Since I can't "trust" the NASA engineers I'd best look into this myself.
If that's what you need to do, in your own scientific judgement. The point
being that ALL observations are supposed to be either repeatable or
documented and available. So we can check if we need to.
One does not get to invoke "it's too complex, so we have to trust" in
Science.
My point is that all of the "references" deal with theory and wishful
thinking. This is not experiment.
> > > 3) all of the raw data, from Mariner, relvent to the mass
determination
> > >
> > > 4) full details of how the mass of Mercury is extracted from the above
> > > data
> > >
> > > 5) A demonstration that this affects the perhilon shift computation
> > >
> > > This ought to be a good start. Now I won't be sent on any "wild goose
> > > chases" I want primary references in all cases. I would of course
also
> > > like to see an actual Mariner spacecraft launched. I mean, in the
end,
> > > how am I supposed to trust that all of these events weren't just
faked?
> >
> > That is up to you -- personally. I leave it to your scientific
judgement.
>
> Well I'm just following your maxim above.
Excellent. That should keep you out of trouble for a long time. Even
though you have misunderstood or misrepresented the "maxim" of scientific
evidence.
> > Of course, you could simply request the primary claims by GR.
>
> I just did.
No, you requested primary evidence for me to prove to you that GR is wrong.
Primary claims that GR is "accurate to 1 part in 10,000" is what claims "by"
GR mean.
> > Then -- by your definition -- you'd have everything you asked for.
> > Of course, my statement was based on a single quote (I'll dig it out
> > of one of my beginning Astro texts this weekend, if you insist.)
>
> So you "trusted" the author of a textbook?
No, I did not "trust" him. Nor did I "distrust" him. The statement implies
that something must have changed in the calculations before and after
Mariner to explain the "increase." That's why I have been asking for
primary literature. So I can see whether his representation was correct or
GR is a bunch of hooey perpetuated by observation-adjusting theorists.
> That seems a bit strange in light of your comments above.
It is completely consistent with my "maxim." Instead of determining which
view is correct by social standing of the author (my degree of "trust") or
social conformity of the consequences, I go looking for observational or
experimental data.
> > But first I want to find out if you are claiming this didn't happen.
>
> Well according to what you said above I certainly can't "trust" that it
> did just cause somebody says so.
Please quit weaseling. Are you claiming that it didn't happen (Mercury
found to be significantly higher mass than predicted by GR)?
> > > Who wants to bet that Mr. Mingst can't provide the level of proof for
his
> > > claims that he demands of others?
> >
> > I never made such a demand. I did not demand that level of proof (to
> > start). I merely wanted to see the primary literature that you are all
> > claiming.
>
> And Dr. Carlip gave you two references. You claimed that at least one
> wasn't good enough. You even have strange expectations about large radio
> telescopes, as evidenced by this exchange
>
> "You'll also need some detailed analysis of the workings of the Arecibo
> and Haystack observatories. In what form would you expect that to be
> published?" -- Dr. Carlip
>
> "Somewhere referenceable." --You
>
> Do you think that there's some book out there entitled "How to work the
> Arecibo observatory"?
What I expect is that the information claimed to back up a bald statement
that GR is confirmed to 1 part in 10,000 in the perihelion advance of
Mercury can be traced back to actual observations and documentation.
Without that the claim is pure theoretical puffery.
If one made assumptions about how Arecibo works in order to support the 1
part in 10,000, then -- yes -- I would expect at least a description of how
such assumptions were made based on the operation of Arecibo radio
telescope.
> My point is that it requires *years* of training to become familier with
> the workings of these complicated things (another good example are
> particle accelerators). The users of these things *have* to trust that
> they are working correctly.
That's right! The special plead. "Only those trained are smart enough to
understand."
Welcome to the Church of Relativity. You must have "P(hD)riests" to
interpret the writings for you!
Bennett Standeven
> > Since I can't "trust" the NASA engineers I'd best look into this myself.
>
> If that's what you need to do, in your own scientific judgement.
So, how exactly is this different from "'trusting' experiments that confirm
your pet theory and 'distrusting' those that don't"?
[...]
> > > Of course, you could simply request the primary claims by GR.
> >
> > I just did.
>
> No, you requested primary evidence for me to prove to you that GR is
wrong.
> Primary claims that GR is "accurate to 1 part in 10,000" is what claims
"by"
> GR mean.
How would "primary claims by GR" demonstrate that Mariner is working
properly,
or tell us the mass of Mercury.
> > > Then -- by your definition -- you'd have everything you asked for.
> > > Of course, my statement was based on a single quote (I'll dig it out
> > > of one of my beginning Astro texts this weekend, if you insist.)
> >
> > So you "trusted" the author of a textbook?
>
> No, I did not "trust" him. Nor did I "distrust" him. The statement
implies
> that something must have changed in the calculations before and after
> Mariner to explain the "increase."
Not necessarily; the textbook author could have simply screwed up.
greywolf42
Bennett Standeven <be...@worldinter.net> wrote in message
news:PnXu6.30$k25...@newsfeed.slurp.net...
Because you go looking at the evidence, rather than taking statements on
faith.
>
> [...]
> > > > Of course, you could simply request the primary claims by GR.
> > >
> > > I just did.
> >
> > No, you requested primary evidence for me to prove to you that GR is
> wrong.
> > Primary claims that GR is "accurate to 1 part in 10,000" is what claims
> "by"
> > GR mean.
>
>
> How would "primary claims by GR" demonstrate that Mariner is working
> properly,
> or tell us the mass of Mercury.
Who knows in advance of looking? All one can do is trace back that amazing
claim that GR is validated to 1 part in 10,000 by Mercury's perihelion
advance, to see if there's any scientfic support for it.
For those who are ignorant of the complexities of these claims and
measurements, herewith is a synopsis of how these claims are made and
(perhaps) validated:
Directions to the planet Mercury (and other planets) were tremendously
important to navigators. If one had access to an exact ephemerides of
various astronomical events (such as transits and rising of Mercury), then
one could fix both one's time and position of longitude. Thus avoiding
rocks and other marine hazards.
In order to develop these ephemerides, observations of the planets over many
years were plugged into the Keplerian orbits of the planets. The orbits of
the planets (relative to Earth, of course) were then plotted as best as
could be. Now these ellipses rotate a bit. According to Newton's
graviational relationship, there will be some "swing" in the alignment of
the orbits. And this must be taken into account when building our
ephemerides. Newton's law predicts that all 9 planets affect the orbits of
each other -- based on their relative masses.
Unfortunately, a planet cannot be placed upon a scale. Thus, all planetary
and solar mass measurements were relative (given as fractions of the solar
mass). All of these interactions had to be averaged out to get a decent fit
to observations. For Mercury, based solely on a spherical sun, totally
empty space, and the nine planets, a value of (I recall) 520 arcseconds per
century was calculated by Newtonian methods. But the "best average" of the
positions of the planets was 38 arcseconds per century more than this value.
This is the "non-newtonian" amount.
So even if we know exactly (to 1 part in whatever you want) where the orbits
of all the planets are and will be, this is only a first step. And has no
bearing on GR whatsoever. These are just measurements.
Now comes the fun part. What are the masses of the planets? In astronomy,
the only way we can measure the mass of an object is to either find or put
something in orbit around the body. All the major planets have convenient
moons -- except Mercury and Venus.
So until Mariner looped by Mercury, we had know way of verifying it's mass.
But GR had to make predictions for both Mercury and Venus sans confirming
data. Otherwise there was no way to claim that the "true" value of
Mercury's NNPA was 43 arcseconds/century.
Now to make those predictions, GR theorists have to make assumptions or
measurements of every mass in the solar system to precisions of 1 part in
100,000. And we only know "G" to 1 part in 1,000. The oblateness of the
Sun "could be" sufficient to account for those 43 arcseconds all by itself.
Or it could be inhomogeneities in the solar wind. ANY deviation from purely
spherical system mass will make itself felt.
So I want to check those assumptions and claims. I seriously doubt that
I'll need to delve into the details of radar-ranging. Because that was a
red herring in the first place. All that fixes is the measured planetary
orbits. It doesn't touch on the theoretical predictions made by GR.
What I fully expect to find is that the GR theorists are relying on
"geometrized" mass. Which is not measured independently, but is CALCULATED
by first assuming GR. I expect this because -- with a value for "G" good to
only one part in 1,000 -- there is no possible way to measure a perihelion
advance of 1 part in 100,000.
So if one ASSUMES GR to determine the "geometrized" mass, it is no surprise
that GR "is good" to 1 part in 100,000. One has assumed what one tried to
prove.
But -- I could be wrong.
So could somebody (preferably those making the 1 in 10,000 claim) PLEASE
explicitly identify your source?
>
> > > > Then -- by your definition -- you'd have everything you asked for.
> > > > Of course, my statement was based on a single quote (I'll dig it out
> > > > of one of my beginning Astro texts this weekend, if you insist.)
> > >
> > > So you "trusted" the author of a textbook?
> >
> > No, I did not "trust" him. Nor did I "distrust" him. The statement
> implies
> > that something must have changed in the calculations before and after
> > Mariner to explain the "increase."
>
> Not necessarily; the textbook author could have simply screwed up.
>
Precisely!!!! "The statement implies..." clearly identifies that this was
the stated opinion of the textbook author. He could have simply screwed up.
Or the claim about GR precision is falsified. Now, how do we -- as
scientists -- determine which is the case? By looking at the evidence. Not
by seeing who has more letters after their name.
So, tell us. Do you claim that Mercury's mass was NOT found to be
significantly higher than GR predicted? That what the author claimed was
never true?
Matthew Nobes
?? But you do the same thing. Pioneer supports your theory (or Paul's)
right? Until Dr. Carlip called you on it I've never seen you in any way
question the Pioneer results.
My point is simple. With many of today's experiments there is *no*
possibility that an indepdent researcher can verify everything. You have
to trust at some point. For example, say you wanted to reevaulate the
Pioneer data. You still have to trust that the data is being given to you
in unaltered form.
> > > > [snip to this]
> > > > > ... Mariner found Mercury to be twice the mass predicted by GR.
> > > >
> > > > I don't trust you. Please provide evidence for this claim. And
> > > > rememebr I'm applying your methods here. So to start I want
> > > >
> > > > 1) a primary reference showing the GR prediction of the mass of
> > > > Mercury
> > >
> > > Ummm, that's what I was asking for.
> >
> > No. You were asking for the reference to the perhilion shift calculation.
> > Your claim above implies that there is a GR prediction of the *mass* of
> > Mercury that's something different.
> >
> > > Can you read?
> >
> > Ad hominum
>
> Goodness, that wasn't ad hominem! That was a rhetorical question. I could
> have re-stated the sentence "That's what I was asking for." But it didn't
> work the first time. Ad hominem would have been my calling you a
> tendentious, misrepresentative fool. Your attempt at irony (returning one
> of my favorite phrases) failed because you misused the term.
Your retorical question is insulting. Furthermore you dodge the main
point which is:
> > No. You were asking for the reference to the perhilion shift calculation.
> > Your claim above implies that there is a GR prediction of the *mass* of
> > Mercury that's something different.
> > > > 2) details on the Mariner spacecraft. How am I supposed to know if it
> > > > was sending back reilable data? A sample of raw data from some
> > > > test run would be a good start
> > >
> > > Goodness..
> >
> > Well according to you scientists shouldn't "trust" anything. You have
> > made a claim, I don't trust it. Since part of the claim invovles the
> > Mariner spacecraft I think it would be a good idea to verify that it
> > worked properly.
> >
> > Since I can't "trust" the NASA engineers I'd best look into this myself.
>
> If that's what you need to do, in your own scientific judgement.
But you'll just trust what you read in a textbook?
> The point being that ALL observations are supposed to be either
> repeatable or documented and available. So we can check if we need
> to.
Repeatable is unrealistic in a modern research environment. Documented
implies trust as I pointed out above.
> One does not get to invoke "it's too complex, so we have to trust" in
> Science.
>
> My point is that all of the "references" deal with theory and wishful
> thinking. This is not experiment.
How do you know? You flat out dismissed one of Dr. Carlip's references
sight unseen.
Further how is this different from your claim that Mariner found the mass
of Mecury to be twice that predicted by GR?
> > > > 3) all of the raw data, from Mariner, relvent to the mass
> > > > determination
> > > >
> > > > 4) full details of how the mass of Mercury is extracted from the above
> > > > data
> > > >
> > > > 5) A demonstration that this affects the perhilon shift computation
> > > >
> > > > This ought to be a good start. Now I won't be sent on any "wild goose
> > > > chases" I want primary references in all cases. I would of course
> > > > also like to see an actual Mariner spacecraft launched. I mean,
> > > > in the end, how am I supposed to trust that all of these events
> > > > weren't just faked?
> > >
> > > That is up to you -- personally. I leave it to your scientific
> > > judgement.
> >
> > Well I'm just following your maxim above.
>
> Excellent. That should keep you out of trouble for a long time. Even
> though you have misunderstood or misrepresented the "maxim" of scientific
> evidence.
>
> > > Of course, you could simply request the primary claims by GR.
> >
> > I just did.
>
> No, you requested primary evidence for me to prove to you that GR is wrong.
> Primary claims that GR is "accurate to 1 part in 10,000" is what claims "by"
> GR mean.
I think you are confused about what I am asking. I am not discussing the
perhilion shift (that's why I retitled the thread). I am asking you about
*your* claim, namely
"... Mariner found Mercury to be twice the mass predicted by GR."
I don't belive this, and would hope that you have evidence to back it up.
I would also hope that said evidence is of the quality that you demand of
other claims. Apperently I was wrong, since your sole piece of evidence
seems to be a claim made in a textbook.
Why then do you accepted that claim, but not the PRL that Dr. Carlip
referenced.
> > > Then -- by your definition -- you'd have everything you asked for.
> > > Of course, my statement was based on a single quote (I'll dig it out
> > > of one of my beginning Astro texts this weekend, if you insist.)
> >
> > So you "trusted" the author of a textbook?
>
> No, I did not "trust" him. Nor did I "distrust" him.
Your statement is not really ambigous
"... Mariner found Mercury to be twice the mass predicted by GR."
Do you care to revise it? Otherwise I am going to have to assume that you
trusted in this textbook author.
> The statement implies that something must have changed in the
> calculations before and after Mariner to explain the "increase."
Of what? The perhilion shift? I'm not asking about that. I'm asking you
to back up *your* claim that
"... Mariner found Mercury to be twice the mass predicted by GR."
> That's why I have been asking for primary literature. So I can see
> whether his representation was correct or GR is a bunch of hooey
> perpetuated by observation-adjusting theorists.
Well I'm asking the same thing of your claim.
> > That seems a bit strange in light of your comments above.
>
> It is completely consistent with my "maxim." Instead of determining which
> view is correct by social standing of the author (my degree of "trust") or
> social conformity of the consequences, I go looking for observational or
> experimental data.
Then you are not claiming that
"... Mariner found Mercury to be twice the mass predicted by GR."
B
??
Since you have no observational data to back that up?
> > > But first I want to find out if you are claiming this didn't happen.
> >
> > Well according to what you said above I certainly can't "trust" that it
> > did just cause somebody says so.
>
> Please quit weaseling. Are you claiming that it didn't happen (Mercury
> found to be significantly higher mass than predicted by GR)?
I am holding judgement until you convince me. So far you're doing a lousy
job.
I will trust, for now, that Mariner was launched and preformed up to spec.
So again. Your claim is
"... Mariner found Mercury to be twice the mass predicted by GR."
At the very least to back this up consistent with your maxim
"No. I don't "trust" anything. "Trust" is part of religion, not
science."
I would expect
1) a primary reference showing the GR prediction of the mass of
Mercury
2) details on the Mariner spacecraft. How am I supposed to know if it
was sending back reilable data? A sample of raw data from some
test run would be a good start
[as I mentioned above I'll drop this requirement for now]
3) all of the raw data, from Mariner, relvent to the mass
determination
4) full details of how the mass of Mercury is extracted from the above
data
5) A demonstration that this affects the perhilon shift computation
Let's drop (5) as well since it doesn't bear on your claim directly.
> > > > Who wants to bet that Mr. Mingst can't provide the level of proof for
> > > > his claims that he demands of others?
> > >
> > > I never made such a demand. I did not demand that level of proof (to
> > > start). I merely wanted to see the primary literature that you are all
> > > claiming.
> >
> > And Dr. Carlip gave you two references. You claimed that at least one
> > wasn't good enough. You even have strange expectations about large radio
> > telescopes, as evidenced by this exchange
> >
> > "You'll also need some detailed analysis of the workings of the Arecibo
> > and Haystack observatories. In what form would you expect that to be
> > published?" -- Dr. Carlip
> >
> > "Somewhere referenceable." --You
> >
> > Do you think that there's some book out there entitled "How to work the
> > Arecibo observatory"?
>
> What I expect is that the information claimed to back up a bald statement
> that GR is confirmed to 1 part in 10,000 in the perihelion advance of
> Mercury can be traced back to actual observations and documentation.
Note the words "TRACED BACK" That means you have to start at the
published papers and *WORK* your way back to the level of detail you need.
But you reject the published papers out of hand, since (inevitably) they
don't contain complete information.
> Without that the claim is pure theoretical puffery.
As is
"... Mariner found Mercury to be twice the mass predicted by GR."
> If one made assumptions about how Arecibo works in order to support the 1
> part in 10,000, then -- yes -- I would expect at least a description of how
> such assumptions were made based on the operation of Arecibo radio
> telescope.
Fine. Then what is unreasonable about my requests concerning your claim
"... Mariner found Mercury to be twice the mass predicted by GR."
Including details about the Mariner spacecraft?
> > My point is that it requires *years* of training to become familier with
> > the workings of these complicated things (another good example are
> > particle accelerators). The users of these things *have* to trust that
> > they are working correctly.
>
> That's right! The special plead. "Only those trained are smart enough to
> understand."
It's not a special plead. It's the truth. Do you know how to run the
Stanford linear accelerator on a day to day basis?
> Welcome to the Church of Relativity. You must have "P(hD)riests" to
> interpret the writings for you!
Apparently anonomous textbook authors are good enough when it supports
what you want to say.
greywolf42
Misreprestation and confusion.
First, if you'd bothered to read the start of the thread, you would have
noticed the phrase "I've twice asked". I began asking for backup data for
the NNPA of Mercury over a year ago. When the "Pioneer effect" was first
reported.
To repeat a prior refutation of this claim: No one has claimed the Pioneer
slowing was good to 1 part in 10,000. And there are several spacecraft (not
just Pioneer) all showing the same "anomalous" (to GR) slowing. And the
researchers tried for 18 years to explain the slowing in terms of GR. Any
paper contradicting a paradigm (GR) is subject to a lot more checking than
one that "confirms" the majority opinion.
In the immediate case, a claim was made that GR was verified to 1 part in
10,000. It was the basis of an entire thread. So I asked for the basis for
this laughable claim. All we've gotten is silence and smoke and mirrors.
Wishful thinking.
You don't have to "trust" anything. When there is a question, you go
verify! You don't have to reinvent the wheel to design a car. But when
someone says his car gets 10,000 miles per gallon of gas, you may want to
ask for details.
In this case, no matter how precisely the orbits of the planets are
determined, this doesn't address the question. GR had to make a multitude
of assumptions concerning mass distribution (to 1 part in 100,000)
throughout the solar system to make the claim. And we only know G to 1 part
in 1,000. So I suspect the claim was pure hogwash. But because it's what
the GR-ists want to hear, they all "trusted" those repeated the claim.
So show me I'm wrong. Point me to the original calculation that made the 1
in 10,000 claim for NNPA.
>
> > > > > [snip to this]
> > > > > > ... Mariner found Mercury to be twice the mass predicted by GR.
> > > > >
> > > > > I don't trust you. Please provide evidence for this claim. And
> > > > > rememebr I'm applying your methods here. So to start I want
> > > > >
> > > > > 1) a primary reference showing the GR prediction of the mass of
> > > > > Mercury
> > > >
> > > > Ummm, that's what I was asking for.
> > >
> > > No. You were asking for the reference to the perhilion shift
calculation.
> > > Your claim above implies that there is a GR prediction of the *mass*
of
> > > Mercury that's something different.
> > >
> > > > Can you read?
> > >
> > > Ad hominum
> >
> > Goodness, that wasn't ad hominem! That was a rhetorical question. I
could
> > have re-stated the sentence "That's what I was asking for." But it
didn't
> > work the first time. Ad hominem would have been my calling you a
> > tendentious, misrepresentative fool. Your attempt at irony (returning
one
> > of my favorite phrases) failed because you misused the term.
>
> Your retorical question is insulting.
It was meant to be. Because you were insulting me and other readers by
ignoring a statement of fact.
> Furthermore you dodge the main
> point which is:
>
> > > No. You were asking for the reference to the perhilion shift
calculation.
> > > Your claim above implies that there is a GR prediction of the *mass*
of
> > > Mercury that's something different.
That isn't the main point. The main point is that a claim was made that the
NNPA of Mercury was validated to 1 part in 10,000. Without reference.
>
> > > > > 2) details on the Mariner spacecraft. How am I supposed to know
if it
> > > > > was sending back reilable data? A sample of raw data from some
> > > > > test run would be a good start
> > > >
> > > > Goodness..
> > >
> > > Well according to you scientists shouldn't "trust" anything. You have
> > > made a claim, I don't trust it. Since part of the claim invovles the
> > > Mariner spacecraft I think it would be a good idea to verify that it
> > > worked properly.
> > >
> > > Since I can't "trust" the NASA engineers I'd best look into this
myself.
> >
> > If that's what you need to do, in your own scientific judgement.
>
> But you'll just trust what you read in a textbook?
Nope. I especially don't "trust" textbooks. Too many lies and
misrepresentations in the texts I was given as a downy-cheeked undergrad
Physics student.
But I do tend to trust the descriptions of "surprises" and problems more
than I trust the "perfect confirmations." I haven't found any that were
substantially wrong, yet. (Authorities just love to cover up the "minor"
problems.)
> > The point being that ALL observations are supposed to be either
> > repeatable or documented and available. So we can check if we need
> > to.
>
> Repeatable is unrealistic in a modern research environment.
It's too bad the scientific method is considered obsolete in modern research
environments.
> Documented implies trust as I pointed out above.
????? What did you point out that has any bearing.
> > One does not get to invoke "it's too complex, so we have to trust" in
> > Science.
> >
> > My point is that all of the "references" deal with theory and wishful
> > thinking. This is not experiment.
>
> How do you know? You flat out dismissed one of Dr. Carlip's references
> sight unseen.
>
> Further how is this different from your claim that Mariner found the mass
> of Mecury to be twice that predicted by GR?
See above. I won't repeat it a fourth time.
I didn't notice the title change. And I refuse to be drawn into your
tangential argument.
> I am asking you about *your* claim, namely
>
> "... Mariner found Mercury to be twice the mass predicted by GR."
>
> I don't belive this, and would hope that you have evidence to back it up.
> I would also hope that said evidence is of the quality that you demand of
> other claims. Apperently I was wrong, since your sole piece of evidence
> seems to be a claim made in a textbook.
At least you've stated an opinion that you don't believe it. Although you
don't say why you don't believe it.
The evidence would be what we went looking for, now wouldn't it????
Let's say we find that GR's prediction of Mercury's mass (prior to Mariner)
was X.
And that Mariner found that Mercury's mass (by responding to same in an
orbital tangent) was 1.2 X or greater.
Would you consider that evidence, or not?
>
> Why then do you accepted that claim, but not the PRL that Dr. Carlip
> referenced.
>
> > > > Then -- by your definition -- you'd have everything you asked for.
> > > > Of course, my statement was based on a single quote (I'll dig it out
> > > > of one of my beginning Astro texts this weekend, if you insist.)
> > >
> > > So you "trusted" the author of a textbook?
> >
> > No, I did not "trust" him. Nor did I "distrust" him.
>
> Your statement is not really ambigous
>
> "... Mariner found Mercury to be twice the mass predicted by GR."
>
> Do you care to revise it? Otherwise I am going to have to assume that you
> trusted in this textbook author.
My, my. Such misrepresentation. I do not "trust" the text. I reported a
statement. After which I began asking for actual data. The only way to
verify whether this was the case is to get one's hands on the original data.
Which -- prior to Dr. Carlip -- NO ONE on these groups was willing or able
to provide.
WHO CARES whether I can dig up the old quote?
> > The statement implies that something must have changed in the
> > calculations before and after Mariner to explain the "increase."
>
> Of what? The perhilion shift? I'm not asking about that. I'm asking you
> to back up *your* claim that
>
> "... Mariner found Mercury to be twice the mass predicted by GR."
See the answer immediately below..... You should really learn to read. Or
at least to read before responding.
> > That's why I have been asking for primary literature. So I can see
> > whether his representation was correct or GR is a bunch of hooey
> > perpetuated by observation-adjusting theorists.
>
> Well I'm asking the same thing of your claim.
The answers to both depend on the results of finding the primary data.
>
> > > That seems a bit strange in light of your comments above.
> >
> > It is completely consistent with my "maxim." Instead of determining
which
> > view is correct by social standing of the author (my degree of "trust")
or
> > social conformity of the consequences, I go looking for observational or
> > experimental data.
>
> Then you are not claiming that
>
> "... Mariner found Mercury to be twice the mass predicted by GR."
> B
> ??
After 10 seperate misrepresentations I grow weary...
Snipping the rest... of the waste of bandwidth.....
Matthew Nobes
You are the one who is confused. I have *NO*INTEREST* in discussing the
NNPA of Mercury. AT least no until you have convinced me thatr your claim
is valid.
> First, if you'd bothered to read the start of the thread, you would have
> noticed the phrase "I've twice asked". I began asking for backup data for
> the NNPA of Mercury over a year ago. When the "Pioneer effect" was first
> reported.
And I have now repeatedly asked you to provide the backup data for your
claim. You have not even responded with a starting point (i.e. a paper).
> To repeat a prior refutation of this claim: No one has claimed the Pioneer
> slowing was good to 1 part in 10,000. And there are several spacecraft (not
> just Pioneer) all showing the same "anomalous" (to GR) slowing. And the
> researchers tried for 18 years to explain the slowing in terms of GR. Any
> paper contradicting a paradigm (GR) is subject to a lot more checking than
> one that "confirms" the majority opinion.
>
> In the immediate case, a claim was made that GR was verified to 1 part in
> 10,000. It was the basis of an entire thread. So I asked for the basis for
> this laughable claim. All we've gotten is silence and smoke and mirrors.
> Wishful thinking.
Hogwash. Dr. Carlip provided two references.
But that is irrelveent. I retitled the thread for a reason. I want to
talk about your claim that Marnier found that the mass of Mercury was
twice that predicted by GR. This has *nothing* to do with the perhilion
advance.
> You don't have to "trust" anything. When there is a question, you go
> verify! You don't have to reinvent the wheel to design a car. But when
> someone says his car gets 10,000 miles per gallon of gas, you may want to
> ask for details.
And this is precisly what I'm asking you for. Details on your claim
regarding Mercury's mass.
> In this case, no matter how precisely the orbits of the planets are
> determined, this doesn't address the question. GR had to make a multitude
> of assumptions concerning mass distribution (to 1 part in 100,000)
> throughout the solar system to make the claim. And we only know G to 1 part
> in 1,000. So I suspect the claim was pure hogwash. But because it's what
> the GR-ists want to hear, they all "trusted" those repeated the claim.
>
> So show me I'm wrong. Point me to the original calculation that made the 1
> in 10,000 claim for NNPA.
I have no desire to discuss this. That's why I retitled the thread. I
want you to back up *your* claims.
> > > > > > [snip to this]
> > > > > > > ... Mariner found Mercury to be twice the mass predicted by GR.
> > > > > >
> > > > > > I don't trust you. Please provide evidence for this claim. And
> > > > > > rememebr I'm applying your methods here. So to start I want
> > > > > >
> > > > > > 1) a primary reference showing the GR prediction of the mass of
> > > > > > Mercury
> > > > >
> > > > > Ummm, that's what I was asking for.
> > > >
> > > > No. You were asking for the reference to the perhilion shift
> > > > calculation. Your claim above implies that there is a GR
> > > > prediction of the *mass* of Mercury that's something different.
> > > >
> > > > > Can you read?
> > > >
> > > > Ad hominum
> > >
> > > Goodness, that wasn't ad hominem! That was a rhetorical question. I
> > > could have re-stated the sentence "That's what I was asking for."
> > > But it didn't work the first time. Ad hominem would have been my
> > > calling you a tendentious, misrepresentative fool. Your attempt at
> > > irony (returning one of my favorite phrases) failed because you
> > > misused the term.
> >
> > Your retorical question is insulting.
>
> It was meant to be. Because you were insulting me and other readers by
> ignoring a statement of fact.
What fact am I ignoreing. Did you not make the following claim?
"... Mariner found Mercury to be twice the mass predicted by GR."
Yes or no?
Did you provide a single reference to back up this claim, yes or no?
> > Furthermore you dodge the main
> > point which is:
> >
> > > > No. You were asking for the reference to the perhilion shift
> > > > calculation. Your claim above implies that there is a GR
> > > > prediction of the *mass* of Mercury that's something different.
>
> That isn't the main point. The main point is that a claim was made that the
> NNPA of Mercury was validated to 1 part in 10,000. Without reference.
No that was in the *other* thread. You are of course free to continue
thaqt discussion with others. I want to know about your claim. If you
choose not to defend it, that's fine, but it does say something about how
you treat evidence.
> > > > > > 2) details on the Mariner spacecraft. How am I supposed to know
> > > > > > if it was sending back reilable data? A sample of raw data
> > > > > > from some test run would be a good start
> > > > >
> > > > > Goodness..
> > > >
> > > > Well according to you scientists shouldn't "trust" anything. You have
> > > > made a claim, I don't trust it. Since part of the claim invovles the
> > > > Mariner spacecraft I think it would be a good idea to verify that it
> > > > worked properly.
> > > >
> > > > Since I can't "trust" the NASA engineers I'd best look into this
> > > > myself.
> > >
> > > If that's what you need to do, in your own scientific judgement.
> >
> > But you'll just trust what you read in a textbook?
>
> Nope. I especially don't "trust" textbooks. Too many lies and
> misrepresentations in the texts I was given as a downy-cheeked undergrad
> Physics student.
>
> But I do tend to trust the descriptions of "surprises" and problems more
> than I trust the "perfect confirmations." I haven't found any that were
> substantially wrong, yet. (Authorities just love to cover up the "minor"
> problems.)
So then why do you believe that Marnier found Mercury's mass to be twice
what was predicted?
> > > The point being that ALL observations are supposed to be either
> > > repeatable or documented and available. So we can check if we need
> > > to.
> >
> > Repeatable is unrealistic in a modern research environment.
>
> It's too bad the scientific method is considered obsolete in modern research
> environments.
This is not the case.
Are you suggesting that we should not build the LHC because nobody else
will be able to build a second one for confirmation?
> > Documented implies trust as I pointed out above.
>
> ????? What did you point out that has any bearing.
As I said. *Any* claim relies on trust. Say I wanted to reevaulate the
data from some experiment. I must trust that the data is given to me in
unaltered form.
> > > One does not get to invoke "it's too complex, so we have to trust" in
> > > Science.
> > >
> > > My point is that all of the "references" deal with theory and wishful
> > > thinking. This is not experiment.
> >
> > How do you know? You flat out dismissed one of Dr. Carlip's references
> > sight unseen.
> >
> > Further how is this different from your claim that Mariner found the mass
> > of Mecury to be twice that predicted by GR?
>
> See above. I won't repeat it a fourth time.
You have not addressed the point. You continually dodge the issue by
attempting to discuss the perhilion shift. Try to understand that I do
not want to discuss that. I am questioning your claim about the Marnier
spacecraft.
[snip]
> > I think you are confused about what I am asking. I am not discussing the
> > perhilion shift (that's why I retitled the thread).
>
> I didn't notice the title change. And I refuse to be drawn into your
> tangential argument.
So I should take that as an admission that you have no interest in backing
up yuour claim?
> > I am asking you about *your* claim, namely
> >
> > "... Mariner found Mercury to be twice the mass predicted by GR."
> >
> > I don't belive this, and would hope that you have evidence to back it up.
> > I would also hope that said evidence is of the quality that you demand of
> > other claims. Apperently I was wrong, since your sole piece of evidence
> > seems to be a claim made in a textbook.
>
> At least you've stated an opinion that you don't believe it. Although you
> don't say why you don't believe it.
Becuase you have failed to back it up with any references. You demand
that of others claims.
> The evidence would be what we went looking for, now wouldn't it????
>
> Let's say we find that GR's prediction of Mercury's mass (prior to Mariner)
> was X.
>
> And that Mariner found that Mercury's mass (by responding to same in an
> orbital tangent) was 1.2 X or greater.
>
> Would you consider that evidence, or not?
Not for the claim that Mariner found the mass to be *twice* that
precdicted by GR. What you detialed was 1.2 times that predicted.
I would still want to see the evidence for that contention though.
> > Why then do you accepted that claim, but not the PRL that Dr. Carlip
> > referenced.
> >
> > > > > Then -- by your definition -- you'd have everything you asked for.
> > > > > Of course, my statement was based on a single quote (I'll dig it out
> > > > > of one of my beginning Astro texts this weekend, if you insist.)
> > > >
> > > > So you "trusted" the author of a textbook?
> > >
> > > No, I did not "trust" him. Nor did I "distrust" him.
> >
> > Your statement is not really ambigous
> >
> > "... Mariner found Mercury to be twice the mass predicted by GR."
> >
> > Do you care to revise it? Otherwise I am going to have to assume that you
> > trusted in this textbook author.
>
> My, my. Such misrepresentation. I do not "trust" the text. I reported a
> statement. After which I began asking for actual data. The only way to
> verify whether this was the case is to get one's hands on the original data.
Okay let me try a different tack. Do you belive that
"... Mariner found Mercury to be twice the mass predicted by GR"
> Which -- prior to Dr. Carlip -- NO ONE on these groups was willing or able
> to provide.
>
> WHO CARES whether I can dig up the old quote?
Because, like the perhilion shift measurments/calcuations it can be
subjected to the same scrutiny.
And I CARE, because you demand high levels of evidence for claims which
you are sceptical of, but seem willing to belive claims that support your
view with just the flimisest of evidence. Hell you don't even have a PRL
citation for your claim regarding Marnier. All you've got is a textbook.
Yet you deploy this as if it were a fact.
One more time,
Did you make the following claim
"... Mariner found Mercury to be twice the mass predicted by GR"
Yes or no?
Do you have *any* evidence beyond a textbook quote to back it up, yes or
no?
[snip rest]
Steve Carlip
> Oh, and just in case you don't know. I do feel that there would
> be some perihelion advance of Mercury, on the order of the GR
> prediction. It is the direct consequence of finite speed of
> gravitational propagation (known since Gerber, 1898).
Hmm. You should take this up with Tom Van Flandern.
(You know, by the way, that Gerber's theory gives a value for
the deflection of light in a gravitational field that disagrees very
strongly with experiment, don't you?)
> However, since I'm aware that the Sun is not a perfect sphere
> (and neither is the matter in the space around it, etc) I don't
> believe that GR/finite grav speed is the source of "all" of the
> non-planetary differences.
Of course not. That's why there's been a major effort over the
past 25 years to determine the Sun's oblateness, with direct
observation and via helioseismology. And it's why the standard
models of the Solar System are often redone with the Sun's J_2
as a parameter to be fit rather than an input.
Steve Carlip
Steve Carlip
> "Steve Carlip" <car...@dirac.ucdavis.edu> wrote in message
> news:99arnq$lhv$2...@woodrow.ucdavis.edu...
> I don't "trust" anything. "Trust" is part of religion, not science.
Science is a large and cooperative enteprise. No one can check
everything from scratch. If you are not prepared to ``trust'' the
results of complicated experiments that you are unable to
personally duplicate, or complicated calculations that you have
neither the knowledge nor the facilities to reproduce, then you
will have to get used to standing at the sidelines and being
generally ignored.
That doesn't mean that things don't get checked. First of all,
the computations are checked carefully within collaborations.
You might want to look at Hellings' paper in _General Relativity
and Gravitation, Proc. of the 10th international conference_
(B. Bertotti et al., editors, D. Reidel Publishing Co., 1984) for
a description of some of that cross-checking. Second, the
same calculations are done by different groups. Mercury's
perihelion precession was computed by Morrison and Ward
using optical data; by Shapiro et al. using radar data; and by
Anderson et al. using combined optical, radar, and spacecraft
ranging data.
> There is no way to validly claim a 1 part in
> 10,000 precision in the value of the GR perihelion advance.
Who in the world claimed ``a 1 part in 10,000 precision''? My
goodness! The existing measurements are accurate to about a
half a percent. There are proposals floating around for a Mercury
orbiter, which would eventually (after about eight years, if I recall
correctly) give an accuracy of a part in 10,000 or so.
> I was going to look for things like the assumptions about the
> shape and density of the solar wind, solar oblateness, timing
> corrections and chi squared paths of Mercury.
Much better! Instead of complaining that no one in a newsgroup
has given you a source of raw data (you certainly have a high
opinion of Usenet if this is where you go with such questions!),
you're now talking about some particular aspects that might be
relevant. My suggestion is that you do a back-of-the-envelope
computation to see which of these might be significant at the
.1"/century level, and then ask some more specific questions.
(For instance, Solar oblateness *can* be significant, and there's
been a lot of recent work on this.)
> When LeVerrier first did his thing, the non-planetary precession
> was 38 arcseconds per century.
And when Newcomb did it 25 years later with a lot more data, he
got 43 seconds per century, in good agreement with the modern
results.
Steve Carlip
greywolf42
> greywolf42 <min...@sim-ss.com> wrote:
>
> > "Steve Carlip" <car...@dirac.ucdavis.edu> wrote in message
> > news:99arnq$lhv$2...@woodrow.ucdavis.edu...
>
> > I don't "trust" anything. "Trust" is part of religion, not science.
>
> Science is a large and cooperative enteprise. No one can check
> everything from scratch. If you are not prepared to ``trust'' the
> results of complicated experiments that you are unable to
> personally duplicate, or complicated calculations that you have
> neither the knowledge nor the facilities to reproduce, then you
> will have to get used to standing at the sidelines and being
> generally ignored.
>
> That doesn't mean that things don't get checked. First of all,
> the computations are checked carefully within collaborations.
> You might want to look at Hellings' paper in _General Relativity
> and Gravitation, Proc. of the 10th international conference_
> (B. Bertotti et al., editors, D. Reidel Publishing Co., 1984) for
> a description of some of that cross-checking. Second, the
> same calculations are done by different groups. Mercury's
> perihelion precession was computed by Morrison and Ward
> using optical data; by Shapiro et al. using radar data; and by
> Anderson et al. using combined optical, radar, and spacecraft
> ranging data.
If these are checked, then we are not "trusting" are we? Now one can't
spend one's whole life checking what other people have done. But IF we
decide to check up for some reason (such as seeing a quote that the Mass of
Mercury had been significantly underestimated) then we need to be able to go
find the real numbers. In this case you have mentioned three possible
sources for the values. Presumably one will include an explicit description
of the assumptions used for the physical masses of the planets and the
distribution of non-planetary mass (such as the solar oblateness, solar
wind, and "zodical light", etc) used to determine the "Newtonian". (The
latter part -- of course -- is completely independent of the "optical" or
"radar" data.)
> > There is no way to validly claim a 1 part in
> > 10,000 precision in the value of the GR perihelion advance.
>
> Who in the world claimed ``a 1 part in 10,000 precision''? My
> goodness! The existing measurements are accurate to about a
> half a percent. There are proposals floating around for a Mercury
> orbiter, which would eventually (after about eight years, if I recall
> correctly) give an accuracy of a part in 10,000 or so.
Thank you, Steve. I was just about to post a slam of the entire GR mob on
this newsgroup for letting that wild claim go unchallenged. (I was waiting
a week.) The direct claimant was Chris Hillman, on 3/20/01:
"Sheesh, I -said- just yesterday: the modern value 42.98 seconds per
century and is accurate to one part in 10^(-4). This value uses radar
ranging to Mercury from 1966 to 1955. And I gave a reference to a paper by
Will which has citations to the primary literature. So there you go."
However, if we look at the paper referenced (which I did), we find that Will
only claimed 3 parts in 1,000 for the NNPA of Mercury (Section 3.5).
Hillman couldn't be bothered to even read his own citation. (And Will's
42.98 was the THEORETICAL value, not the observational value.)
Side note: Will is not clear, but I don't believe that he's disagreeing
with your "few percent." It appears Will is referring to geometrized,
theortical precision -- not experimental.
Apparently most of the rest of the group "trusts" Chris Hillman. Matthew
Nobes in particular took me to task for not "trusting" Hillman's statements.
And Mr. Hillman trusts Dr. Will. And Will trusts Shapiro....... A big game
of "science" by the game of "telephone."
You must have missed one of my earlier responses to you. I pointed out that
one of your earlier discussions of the difficulties in getting real numbers
clearly contradicted the 1 in 10,000 claim.
(Chris also "corrected" his values for 1966 to 1995. But again his
reference says 1966 to 1990.)
So you see why I don't trust such claims. You have your criteria for
"trust," and I have mine.
> > I was going to look for things like the assumptions about the
> > shape and density of the solar wind, solar oblateness, timing
> > corrections and chi squared paths of Mercury.
>
> Much better!
Better? No change. You jumped to conclusions, earlier, and assumed that I
was questioning the actual orbital calculations.
> Instead of complaining that no one in a newsgroup
> has given you a source of raw data (you certainly have a high
> opinion of Usenet if this is where you go with such questions!),
> you're now talking about some particular aspects that might be
> relevant. My suggestion is that you do a back-of-the-envelope
> computation to see which of these might be significant at the
> .1"/century level, and then ask some more specific questions.
>
> (For instance, Solar oblateness *can* be significant, and there's
> been a lot of recent work on this.)
True. Will (as usual) selects a theoretical model that allows him to ignore
oblateness. Then states that this theoretical model is "not inconsistent"
with solar seismography data.
> > When LeVerrier first did his thing, the non-planetary precession
> > was 38 arcseconds per century.
>
> And when Newcomb did it 25 years later with a lot more data, he
> got 43 seconds per century, in good agreement with the modern
> results.
>
> Steve Carlip
And neither LeVerrier nor Newcomb corrected for (GR) light curvature by the
Sun-- and superior conjuctions were key in their analyses. And there was no
"deficit" at the time (meaning GR advance is "too high"). As the
non-conglomerated matter giving rise to the "zodiacal light" was sufficient
to cover a major chunk of this value.
greywolf42
ubi dubium ibi libertas
(loosely translated: I'm from Missouri.)
Matthew Nobes
>
> "Steve Carlip" <car...@dirac.ucdavis.edu> wrote in message
> news:99rghr$48o$1...@woodrow.ucdavis.edu...
[snip]
> >
> > Who in the world claimed ``a 1 part in 10,000 precision''? My
> > goodness! The existing measurements are accurate to about a
> > half a percent. There are proposals floating around for a Mercury
> > orbiter, which would eventually (after about eight years, if I recall
> > correctly) give an accuracy of a part in 10,000 or so.
[snip]
> Apparently most of the rest of the group "trusts" Chris Hillman. Matthew
> Nobes in particular took me to task for not "trusting" Hillman's statements.
?? Where did I do that?
I'm attmepting to take you to task for not providing the same level of
backup for your statements that you expect of others. If you want to by
sceptial of the claims of others that's fine by me. All I was asking you
to do was back up your claim about the findings of the Marnier spacecraft
with some level of proof. You have failed to do so, apparently labouring
under the illusion that I was asking about the perhilion shift.
Chris Hillman
[Newsgroup list corrected]
Steve Carlip asked:
> > Who in the world claimed ``a 1 part in 10,000 precision''? My
> > goodness! The existing measurements are accurate to about a
> > half a per cent.
That was me. I somehow misquoted the value given by Will. Apologies to
all. The error was unintentional.
Greywolf42 responded:
> Thank you, Steve. I was just about to post a slam of the entire GR mob on
> this newsgroup for letting that wild claim go unchallenged. (I was waiting
> a week.) The direct claimant was Chris Hillman, on 3/20/01:
>
> "Sheesh, I -said- just yesterday: the modern value 42.98 seconds per
> century and is accurate to one part in 10^(-4). This value uses radar
> ranging to Mercury from 1966 to 1955. And I gave a reference to a paper by
> Will which has citations to the primary literature. So there you go."
>
> However, if we look at the paper referenced (which I did), we find that Will
> only claimed 3 parts in 1,000 for the NNPA of Mercury (Section 3.5).
> Hillman couldn't be bothered to even read his own citation. (And Will's
> 42.98 was the THEORETICAL value, not the observational value.)
IMO, you haven't read Will's paper carefully enough, and in part because
you haven't followed my advice by asking about things like "residuals" and
"unmodeled effects" in sci.astro.research, I think you have seriously
misunderstood the meaning of the phrases "theoretical value" and
"experimental value". Let me try again to summarize the way I understand
the situation (I'd welcome correct from Steve Carlip if I still have
anything wrong):
1. From astronomical observations (the modern measurements are based on
radar ranging from 1966-1990), we can measure the rate of precession of
the perhelia of Mercury's orbit, which turns out to be about 5600 degrees
per century. If you want to know exactly how the measured rate of
precession is computed from the actual variations, you may need to read
some of the primary sources cited in Will's paper and perhaps to write to
those authors. Another poster has already given a clear account of how
these things were done in LeVerrier's time, but the modern method must be
somewhat different. If you do this, I expect you will find the details
are rather technical, especially if you want to get into the detailed
error analysis of the raw data. If you want to follow up on this, I think
you will need to first acquaint yourself with the method of Gauss and
gradually work you way up to more modern methods. You can ask in
sci.astro.research for advice on what books/papers to read to learn about
error analysis in scientific instruments and reducing astronomical
observations to Keplerian orbital parameters, rates of precession, and so
forth. Warning: my impression is that this stuff is ultimately much more
complicated than the classical Newtonian perturbation analysis!
2. Using Newtonian gravitostatics, and modeling the influences of the
major planets, our best measured upper bounds on the Sun's multipole
moments (the quadrupole moment is estimated to be about 1 x 10^(-7) from
helioseismography), and so forth, astronomers can account for all but
about 43 seconds of arc per century of the precession. This Newtonian
perturbation analysis follows the theoretical procedures developed by
Lagrange, Adams, LeVerrier and others, in which small perturbations can be
superimposed -linearly-. I have already cited several times the book
Mathematical Methods of Celestial Mechanics by Arnold et al. which has an
introduction to this classical perturbation theory. Warning: IMO, this
theory is harder to learn than the gtr contribution!
3. Using gtr, we can ignore the complicating effects of the Newtonian
perturbations, treat Mercury as a test particle orbiting in a
Schwarzschild vacuum, and compute the precession of its quasiKeplerian
orbit. This gives 43 seconds per century, the "extra-Newtonian
precession". Because the field is sufficiently weak that we can use the
linearized EFE, it is permissable to simply to add this value to the
already accounted for Newtonian part of the precession, and thus to
declare that the entire precession rate is understood via gtr. (The
Newtonian effects already accounted for still work as advertised in
weak-field slow motion gtr, and can be simply added to the effect which is
new in gtr, the purely relativistic precession.) This is the route
followed in most textbooks, and very similar to the original argument of
Einstein. You can find the details in most textbooks on gtr--- try
different books and you will find different derivations of the same
result, some of which may be clearer to you than others. I think the
argument in the little book by Bose is one of the clearest I have seen,
for example. A simpler derivation of a special case, a nearly circular
orbit, is offered in one of my archived posts on RWW.
4. It is essential to realize that gtr can be embedded using the PPN
formalism in a large class of theories with a number of phenomenological
paramaters, the PPN parameters. One can in effect compute at one go the
predicted "extra-Newtonian" precession for a huge class of competing
gravitation theories, including not only the Brans-Dicke theory but
nonmetric theories. The solar quadropole moment makes a contribution to
this prediction, as shown in equation (36) of Will's paper. The
"theoretical prediction" side of modern tests of gravitation theories use
this PPN formalism to test many theories at once, together with Newtonian
analysis to take care of various known nonrelativistic effects. In gtr,
the PPN parameters beta, gamma which appear in (36) both have the value
unity. Plugging these values and the above mentioned estimate of the
quadrupole moment of the Sun into (36), we find the gtr prediction is
42.99 seconds of arc per century, not 42.98 seconds of arc per century as
I may have incorrectly implied (I forget exactly what I wrote now).
5. By comparing the PPN value for the extra-Newtonian precession (which
as I have stressed, uses our best upper bound for the quadrupole moment of
the Sun--- in the sixties this bound was briefly controversial, but I
think that has not bee the case in a long time) with the measured
precession not accounted for using the classical perturbation analysis, we
can put a bound on the PPN parameter beta which appears in (36). The
current bound is indeed 3 x 10^(-3), as you stated (Table 4 in Will's
paper), not 3 x 10^(-4), as I incorrectly stated in the post you are
critiquing.
> Side note: Will is not clear, but I don't believe that he's disagreeing
> with your "few percent." It appears Will is referring to geometrized,
> theortical precision -- not experimental.
I hope the above clarified the situation. If not, you can find Will's
email address, and you can write to him. (If you refrain from accusing
him of not having taken the trouble to master the stuff he is writing
about, and the question the papers he reads, you are much more likely to
receive a useful reply!)
> Apparently most of the rest of the group "trusts" Chris Hillman.
This is a pretty amusing statement, in a post addressed to Steve Carlip,
who is easily the most expert gravitation theorist who sometimes posts
here. (Compare our publication records in gtr!).
I have two comments:
1. "Most of [regular contributors to] this group" consist of cranks,
crackpots, and trolls who are uninterested in anything but touting their
own crank "ideas".
2. I think the group of readers who are not cranks, crackpots or trolls
generally take the time to read my posts because I always try to give
references to reliable sources of information written by genuine experts
like Clifford Will, and they recognize that these sources are about as
trustworthy as anything ever gets in science.
> Matthew Nobes in particular took me to task for not "trusting"
> Hillman's statements. And Mr. Hillman trusts Dr. Will.
If you want to throw titles around, you can call me Dr. Hillman, and you
can refer to Prof. Will and Prof. Carlip.
> (Chris also "corrected" his values for 1966 to 1995. But again his
> reference says 1966 to 1990.)
Yes, I made a typo, but the range of years I was trying to type was
incorrect, because I again somehow misread Will's paper. Careless of me,
but it doesn't alter the fact that the paper I kept trying to get you to
study is an invaluable guide to the literature on tests of gravitation
theories.
> True. Will (as usual) selects a theoretical model that allows him to
> ignore oblateness.
You really need to study this paper much more carefully. It is true that
you caught me (unintentionally) misquoting the article in two places, but
IMO your own misunderstandings are far more fundamental.
Chris Hillman
Home Page: http://www.math.washington.edu/~hillman/
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
NOTE TO WOULD-BE CORRESPONDENTS: I have installed a mail filter which
deletes incoming messages not from the "*.edu" or "*.gov" domains, but
also deletes messages from some bad actors whose emails happen to be in
the "*.edu" domain and "passes" messages from a few friends with email
addresses in other domains.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Chris Hillman
[Newsgroups corrected]
On Wed, 28 Mar 2001, Steve Carlip wrote:
> And it's why the standard models of the Solar System are often redone
> with the Sun's J_2 as a parameter to be fit rather than an input.
Just a comment for Greywolf, Martin and others who are struggling to
understand this stuff--- this is an instance of what I was trying (not
very coherently, unfortuntely) to explain about how astronomers can and do
choose different ways to construct "theoretical models" to compute
"theoretical values", and these choices imply corresponding choices in how
to reduce (by computation!) raw astronomical data to "observed values" to
be compared with the "theoretical values". I don't happen to know of
books or survey papers which clearly explain this kind of
modeling/data-analysis issue at the beginning graduate level, but as I
keep saying, I bet someone in sci.astro.research would.
greywolf42
.
>
> [Newsgroups corrected]
>
> On Wed, 28 Mar 2001, Steve Carlip wrote:
>
> > And it's why the standard models of the Solar System are often redone
> > with the Sun's J_2 as a parameter to be fit rather than an input.
>
> Just a comment for Greywolf, Martin and others who are struggling to
> understand this stuff---
The only thing we were "struggling" to understand is your inability to read
your own references. Trying to pass off NNPA of Mercury as verified to 1
part in 10,000. But then you main effort is to insult, not educate.
>this is an instance of what I was trying (not
> very coherently, unfortuntely) to explain about how astronomers can and do
> choose different ways to construct "theoretical models" to compute
> "theoretical values", and these choices imply corresponding choices in how
> to reduce (by computation!) raw astronomical data to "observed values" to
> be compared with the "theoretical values". I don't happen to know of
> books or survey papers which clearly explain this kind of
> modeling/data-analysis issue at the beginning graduate level, but as I
> keep saying, I bet someone in sci.astro.research would.
>
> Chris Hillman
Nice try, Chris, but our memories aren't that short.
greywolf42
Joseph Lazio
greywolf> "Chris Hillman" <hil...@math.washington.edu> wrote in
greywolf> message
greywolf> news:Pine.OSF.4.21.010328...@goedel1.math.washington.edu...
>>
>> Just a comment for Greywolf, Martin and others who are struggling
>> to understand this stuff---
greywolf> The only thing we were "struggling" to understand is your
greywolf> inability to read your own references. Trying to pass off
greywolf> NNPA of Mercury as verified to 1 part in 10,000.
I agree. Hillman's recent posting in which he admitted he made a
mistake is clearly part of a clever ruse. He'll attempt to lull us
into agreeing with him, then he'll turn around and change his answer.
greywolf> But then you main effort is to insult, not educate.
Note to Hillman: You've been failing in your effort to insult me as
I've occasionally learned stuff from your postings. You'll have to
increase the vitriol directed at me.
--
Lt. Lazio, HTML police | e-mail: jla...@patriot.net
No means no, stop rape. | http://patriot.net/%7Ejlazio/
sci.astro FAQ at http://sciastro.astronomy.net/sci.astro.html
brian a m stuckless
> to understand this stuff---,
Tweaking or ''matching'' the mathematics of a ''prediction''
to observation, and/or an observed magnitude to a ''prefered''
real number solution, is largely about fudgeing or ''adjusting''
appropriate statistical weights and averages, and specific
observational experimental statistical errors --all of which,
in the case of the perihelion advance of planet Mercury's
orbital precession, far ''out-weigh'' any relevance.
Yours truly,
`````arcsign````` mar 29, 2001
ps.
Mercury does NOT compare with a GR-tivity test particle.
The Newtonian side at the GR-tivity Limit has relevant
omissions, which you can never expect to be addresed
in any ''geometric interpretation''. It would compare well
with a used car salesman telling you it burns oil.
The North Star is still north of the North Pole, --and don't
let any GR-tivity-'crackpot' dupe you into anything different.
Note added newsgroup addresses, above.
^^^^^^^^^in reply to:
Chris Hillman <hil...@math.washington.edu> wrote in article
<Pine.OSF.4.21.010328...@goedel1.math.washington.edu
```snip```
> On Wed, 28 Mar 2001, Steve Carlip wrote:
> > And it's why the standard models of the Solar System are often
> > redone with the Sun's J_2 as a parameter to be fit rather than an
input.
>
> Just a comment for Greywolf, Martin and others who are struggling
> to understand this stuff--- this is an instance of what I was
trying
> (not very coherently, unfortuntely) to explain about how
astronomers
> can and do choose different ways to construct "theoretical models"
> to compute "theoretical values", and these choices imply
corresponding
> choices in how to reduce (by computation!) raw astronomical data to
> "observed values" to be compared with the "theoretical values". I
don't
> happen to know of books or survey papers which clearly explain this
kind
> of modeling/data-analysis issue at the beginning graduate level,
but
> as I keep saying, I bet someone in sci.astro.research would.
>
> Chris Hillman
>
> Home Page: http://www.math.washington.edu/~hillman/
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
rich hammett
Is this english? Do they speak something different in Canadia?
rich
> ^^^^^^^^^in reply to:
--
-remove no from mail name and spam from domain to reply
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
\ Rich Hammett http://home.hiwaay.net/~rhammett
/ hnoa...@eng.spamauburn.edu
\ ..basketball [is] the paramount
/ synthesis in sport of intelligence, precision, courage,
\ audacity, anticipation, artifice, teamwork, elegance,
/ and grace. --Carl Sagan
Steve Carlip
> So you see why I don't trust such claims. You have your criteria for
> "trust," and I have mine.
Just for the record: you should *certainly* not ``trust'' what you read
in a newsgroup! That includes things I write---I try to be fairly
careful, but I certainly don't proofread a message to this group the
way I would proofread a paper, and (as you may have noticed) there
are no referees whose job it is to catch mistakes. Judging relativity
from what you see in a newsgroup is like judging Skakespeare from
what you see in a high school performance.
Newsgroups are also not an especially good place to get the latest
references, since the people most likely to know them don't take
these forums terribly seriously. If you *really* want a reference,
you can try one of the .research groups, which are read more
carefully by more experts. (Try not to write a diatribe; if you want
a reference to Mercury's perihelion, just post a message to, say,
sci.physics.research or sci.astro.research saying, ``Does anyone
have a good up-to-date reference for measurements of Mercury's
perihelion?'') Sooner or later, though, you're going to have to go
to a good library and spend a few days looking at papers.
Steve Carlip
Steve Carlip
> "Steve Carlip" <car...@dirac.ucdavis.edu> wrote in message
> news:99rghr$48o$1...@woodrow.ucdavis.edu...
>> (For instance, Solar oblateness *can* be significant, and there's
>> been a lot of recent work on this.)
> True. Will (as usual) selects a theoretical model that allows him
> to ignore oblateness. Then states that this theoretical model is
> "not inconsistent" with solar seismography data.
I don't know which reference of Will you're referring to here. The
papers of his I've seen have all been rather careful to discuss the
question of Solar oblateness and the limitations it places on tests
of GR.
If you're really interested in following this up, start with J.R. Kuhn
et al., Nature 392 (1998) 155, and look at their figure 2, which has
the eleven most recent measurements of the Sun's oblateness,
with references you can then follow up. For helioseismology, try
F. Pijpers, Mon. Not. R. Astron. Soc. 297, L76 (1998).
> And neither LeVerrier nor Newcomb corrected for (GR) light
> curvature by the Sun
Do you think this is a significant effect? Do the computation---
see what difference this makes in the outcome. If it comes out
significant, first try writing a polite letter to, say, Anderson, and
ask, ``Did you take this into account in your treatment of the
optical measurements?'' If he says no, write up a paper and submit
it to a journal. You'll find that this is much more satisfying than
just complaining on a newsgroup.
Steve Carlip
greywolf42
> greywolf42 <min...@sim-ss.com> wrote:
>
> > Oh, and just in case you don't know. I do feel that there would
> > be some perihelion advance of Mercury, on the order of the GR
> > prediction. It is the direct consequence of finite speed of
> > gravitational propagation (known since Gerber, 1898).
>
> Hmm. You should take this up with Tom Van Flandern.
No need. Tom was merely misusing the "gravitational aberration" argument
that was used to "dis" aether theories in general (as was done by Poincare
and others). But he applied the same false argument to GR. And you did a
good paper on the subject in 1999.
And I say "misusing" because anytime one purports to analyse a dynamic
phenomenon -- and ignores the fact that there are competing processes (in
the case of aether, "drag" -- in the case of GR, "back-action") that counter
the effect.
> (You know, by the way, that Gerber's theory gives a value for
> the deflection of light in a gravitational field that disagrees very
> strongly with experiment, don't you?)
I know that is the party line. But Gerber never did any such calculation.
So it all depends on who "interpreted" Gerber's theory -- and how. But in
this case that is irrelevant. For I'm not referring to Gerber's theory. I
was merely pointing out that the NNPA of Mercury is a consequence of the
finite speed of gravity. ANY theory that contains a finite speed of gravity
that is on the close order of c, will give the correct perihelion advance.
> > However, since I'm aware that the Sun is not a perfect sphere
> > (and neither is the matter in the space around it, etc) I don't
> > believe that GR/finite grav speed is the source of "all" of the
> > non-planetary differences.
>
> Of course not. That's why there's been a major effort over the
> past 25 years to determine the Sun's oblateness, with direct
> observation and via helioseismology. And it's why the standard
> models of the Solar System are often redone with the Sun's J_2
> as a parameter to be fit rather than an input.
>
> Steve Carlip
>
Whether it's a "parameter to be fit" or a "known" does not change the
process. Which -- unavoidably -- presumes that GR is "perfect" (all of the
masses of the planets are "geometrized" in this process). And therefore
claims that GR is "validated" to the measured precision of the orbits.
greywolf42
>
> "Steve Carlip" <car...@dirac.ucdavis.edu> wrote in message
> news:99rghr$48o$1...@woodrow.ucdavis.edu...
> > greywolf42 <min...@sim-ss.com> wrote:
> >
> > > "Steve Carlip" <car...@dirac.ucdavis.edu> wrote in message
> > > news:99arnq$lhv$2...@woodrow.ucdavis.edu...
> >
{snip}
> >
> > Who in the world claimed ``a 1 part in 10,000 precision''? My
> > goodness! The existing measurements are accurate to about a
> > half a percent. There are proposals floating around for a Mercury
> > orbiter, which would eventually (after about eight years, if I recall
> > correctly) give an accuracy of a part in 10,000 or so.
>
> Thank you, Steve. I was just about to post a slam of the entire GR mob on
> this newsgroup for letting that wild claim go unchallenged. (I was
waiting
> a week.) The direct claimant was Chris Hillman, on 3/20/01:
>
> "Sheesh, I -said- just yesterday: the modern value 42.98 seconds per
> century and is accurate to one part in 10^(-4). This value uses radar
> ranging to Mercury from 1966 to 1955. And I gave a reference to a paper
by
> Will which has citations to the primary literature. So there you go."
>
> However, if we look at the paper referenced (which I did), we find that
Will
> only claimed 3 parts in 1,000 for the NNPA of Mercury (Section 3.5).
> Hillman couldn't be bothered to even read his own citation. (And Will's
> 42.98 was the THEORETICAL value, not the observational value.)
>
> Side note: Will is not clear, but I don't believe that he's disagreeing
> with your "few percent." It appears Will is referring to geometrized,
> theortical precision -- not experimental.
>
Note to greywolf42 from greywolf42: Never try to respond to a post early in
the morning without either ingesting some caffeine or reviewing what you
wrote.
Steve said "half a percent." NOT "few percent." 3 parts in 1,000 is close
to half a percent.
My apologies.
{snip}
greywolf42
greywolf42
I did that twice, and a prior poster did that once before this particular
thread. No one bothered to answer.
How "carefully" does an "expert" need to read a simple request? And why
would it matter if it was on a ".research" instead of ".relativity"?
greywolf42
greywolf42
First I need the reference for the primary source of the NNPA. Which I've
repeatedly asked for.
What I was responding to was a bald theoretical claim (from the NNPA
"reference" given by Hillman) that was patently "unscientific."
greywolf42
Chris Hillman <hil...@math.washington.edu> wrote in message
news:Pine.OSF.4.21.010328...@goedel1.math.washington.edu..
.
>
>
> [Newsgroup list corrected]
>
> Steve Carlip asked:
>
> > > Who in the world claimed ``a 1 part in 10,000 precision''? My
> > > goodness! The existing measurements are accurate to about a
> > > half a per cent.
>
> That was me. I somehow misquoted the value given by Will. Apologies to
> all. The error was unintentional.
We all make mistakes. That was my main point. Which I unintentionally
validated by misquoting Dr. Carlip almost immediately, by mentally
transforming "half a percent" to "few percent."
How could it not have occurred to you that 1 part in 10,000 was physically
impossible? Especially when it has been repeatedly pointed out to you?
>
> Greywolf42 responded:
>
> > Thank you, Steve. I was just about to post a slam of the entire GR mob
on
> > this newsgroup for letting that wild claim go unchallenged. (I was
waiting
> > a week.) The direct claimant was Chris Hillman, on 3/20/01:
> >
> > "Sheesh, I -said- just yesterday: the modern value 42.98 seconds per
> > century and is accurate to one part in 10^(-4). This value uses radar
> > ranging to Mercury from 1966 to 1955. And I gave a reference to a paper
by
> > Will which has citations to the primary literature. So there you go."
> >
> > However, if we look at the paper referenced (which I did), we find that
Will
> > only claimed 3 parts in 1,000 for the NNPA of Mercury (Section 3.5).
> > Hillman couldn't be bothered to even read his own citation. (And Will's
> > 42.98 was the THEORETICAL value, not the observational value.)
>
> IMO, you haven't read Will's paper carefully enough, and in part because
> you haven't followed my advice by asking about things like "residuals" and
> "unmodeled effects" in sci.astro.research, I think you have seriously
> misunderstood the meaning of the phrases "theoretical value" and
> "experimental value".
The phrases "theoretical value" and "observational value" (not theoretical)
were mine, not Will's. Will doesn't understand the difference, either.
> Let me try again to summarize the way I understand
> the situation (I'd welcome correct from Steve Carlip if I still have
> anything wrong):
Perhaps YOU should ask things you don't understand from some Astronomers. ;)
>
> 1. From astronomical observations (the modern measurements are based on
> radar ranging from 1966-1990),
Nitpick: You also claimed 1995 for this source last time. But you are
correct here.
> we can measure the rate of precession of
> the perhelia of Mercury's orbit, which turns out to be about 5600 degrees
> per century.
Chris. You and I have got to swear off posting without caffeine.
Please read what you wrote and try again.
Hint: Number is off by a factor of 10. Units are wrong.
And please be sufficiently precise. You are claiming GR validation to
hundredths of an arcsecond per century, so "about 5600" is insufficiently
precise by four orders of magnitude. Please give the correct total
perihelion advance of Mercury value to hundredths of an arcsecond per
century. (Per your claims below).
> If you want to know exactly how the measured rate of
> precession is computed from the actual variations, you may need to read
> some of the primary sources cited in Will's paper and perhaps to write to
> those authors.
That WAS my point. I asked for sources of the primary data. I don't care
to waste my time reading third-hand quotes mangled by theoreticians. Will
rarely bothers with primary data. He tends to reference other
theoreticians.
> Another poster has already given a clear account of how
> these things were done in LeVerrier's time,
That was me.
> but the modern method must be
> somewhat different.
Not in the least. The physical world has not changed. We do get to add
direct measurements of distance from radar ranging. So our calculation of
the ellipses of the planetary orbits are more precise. The method has not
changed.
> If you do this, I expect you will find the details
> are rather technical, especially if you want to get into the detailed
> error analysis of the raw data.
Now why would I want to do that? The "raw data" here are the measurements
that determine the planetary orbits. Which I happen to "accept" (at least
for the moment). What I am asking for are the masses and distributions that
are used to determine the "Newtonian" perihelion advance. The residual of
which is the "non-newtonian perihelion advance" (NNPA).
> If you want to follow up on this, I think
> you will need to first acquaint yourself with the method of Gauss and
> gradually work you way up to more modern methods. You can ask in
> sci.astro.research for advice on what books/papers to read to learn about
> error analysis in scientific instruments and reducing astronomical
> observations to Keplerian orbital parameters, rates of precession, and so
> forth. Warning: my impression is that this stuff is ultimately much more
> complicated than the classical Newtonian perturbation analysis!
You really do disrespect the tools of historical physicists. They are often
the same ones we use -- as in this case.
>
> 2. Using Newtonian gravitostatics,
(sic) gravitodynamics.
> and modeling the influences of the
> major planets, our best measured upper bounds on the Sun's multipole
> moments (the quadrupole moment is estimated to be about 1 x 10^(-7) from
> helioseismography),
Will's description was that he selected a theoretical model that had a value
of the above, and that it was "not inconsistent" with (some)
helioseismography. That was NOT an estimate from measurements.
> and so forth,
Aye, there's the rub! What is included and what is ignored? That is the
question.
> astronomers can account for all but
> about 43 seconds of arc per century of the precession. This Newtonian
> perturbation analysis follows the theoretical procedures developed by
> Lagrange, Adams, LeVerrier and others, in which small perturbations can be
> superimposed -linearly-. I have already cited several times the book
> Mathematical Methods of Celestial Mechanics by Arnold et al. which has an
> introduction to this classical perturbation theory. Warning: IMO, this
> theory is harder to learn than the gtr contribution!
Mainly because real-world physics is harder to do than mathematics.
In this case fitting 10 or 11 variables to the "mass" and orbits of planets
to see what is "left over."
> 3. Using gtr, we can ignore the complicating effects of the Newtonian
> perturbations, treat Mercury as a test particle orbiting in a
> Schwarzschild vacuum, and compute the precession of its quasiKeplerian
> orbit. This gives 43 seconds per century, the "extra-Newtonian
> precession".
Does it give 43 arc-seconds per century, or does it give 42.98 arc-seconds
per century?
> Because the field is sufficiently weak that we can use the
> linearized EFE, it is permissable to simply to add this value to the
> already accounted for Newtonian part of the precession, and thus to
> declare that the entire precession rate is understood via gtr. (The
> Newtonian effects already accounted for still work as advertised in
> weak-field slow motion gtr, and can be simply added to the effect which is
> new in gtr, the purely relativistic precession.) This is the route
> followed in most textbooks, and very similar to the original argument of
> Einstein. You can find the details in most textbooks on gtr--- try
> different books and you will find different derivations of the same
> result, some of which may be clearer to you than others. I think the
> argument in the little book by Bose is one of the clearest I have seen,
> for example. A simpler derivation of a special case, a nearly circular
> orbit, is offered in one of my archived posts on RWW.
>
> 4. It is essential to realize that gtr can be embedded using the PPN
> formalism in a large class of theories with a number of phenomenological
> paramaters, the PPN parameters.
PPN is not essential to this discussion in the least. Although PPN is
"popular," it has no bearing on the direct predictions of GR vs.
observations. It's merely another path.
> One can in effect compute at one go the
> predicted "extra-Newtonian" precession for a huge class of competing
> gravitation theories, including not only the Brans-Dicke theory but
> nonmetric theories. The solar quadropole moment makes a contribution to
> this prediction, as shown in equation (36) of Will's paper. The
> "theoretical prediction" side of modern tests of gravitation theories use
> this PPN formalism to test many theories at once,
Incorrect. PPN is used to determine deviations from GR predictions. The
"map" of GR is taken as the yardstick, and all masses used in these
calculations are determined explicitly from GR.
Totally irrelevant to the question. We aren't discussing competing theories
at the moment.
> together with Newtonian
> analysis to take care of various known nonrelativistic effects. In gtr,
> the PPN parameters beta, gamma which appear in (36) both have the value
> unity. Plugging these values and the above mentioned estimate of the
> quadrupole moment of the Sun into (36), we find the gtr prediction is
> 42.99 seconds of arc per century, not 42.98 seconds of arc per century as
> I may have incorrectly implied (I forget exactly what I wrote now).
???
Your quote was extracted and duplicated at the beginning of this post. Try
scrolling up. You wrote 42.98.
>
> 5. By comparing the PPN value for the extra-Newtonian precession (which
> as I have stressed, uses our best upper bound for the quadrupole moment of
> the Sun-
Warning! Danger, Will Robinson!
That was not the "best upper bound." (Which in itself is an oxymoron.) It
was a value that was "not inconsitent" with (some) measurements.
Please stop trying to "stretch" and "improve" your data through
interpretation.
>-- in the sixties this bound was briefly controversial, but I
> think that has not bee the case in a long time)
See Steve's posts. It is still controversial.
Because people "trust" GR, and no longer pay attention to niggling
discrepancies in observations such as solar oblateness (which GR-ists like
to call "quadrupole moment"), and the apsides of Venus.
> with the measured
> precession not accounted for using the classical perturbation analysis, we
> can put a bound on the PPN parameter beta which appears in (36). The
> current bound is indeed 3 x 10^(-3), as you stated (Table 4 in Will's
> paper),
And repeated in the section on this subject.
>not 3 x 10^(-4), as I incorrectly stated in the post you are
> critiquing.
You've managed to misquote your "misquote."
You stated (see beginning of this post) "1 part in 10,000." You were off by
a factor of 30.
> > Side note: Will is not clear, but I don't believe that he's disagreeing
> > with your "few percent." It appears Will is referring to geometrized,
> > theortical precision -- not experimental.
>
> I hope the above clarified the situation. If not, you can find Will's
> email address, and you can write to him. (If you refrain from accusing
> him of not having taken the trouble to master the stuff he is writing
> about, and the question the papers he reads, you are much more likely to
> receive a useful reply!)
I never asked for Will's opinion. I asked for a primary reference to the
observational NNPA of Mercury. NOT the theoretical value (which is what
Will provides). But so long as you sent me on a wild-goose chase, I thought
I'd point out some errors on Will's part.
> > Apparently most of the rest of the group "trusts" Chris Hillman.
>
> This is a pretty amusing statement, in a post addressed to Steve Carlip,
> who is easily the most expert gravitation theorist who sometimes posts
> here. (Compare our publication records in gtr!).
Glad it helped identify the silliness of "trusting" sources just because
they share your viewpoint.
Of course, no one bothered to question your quote of "1 part in 10,000"
precision for the NNPA of Mercury. They "GR-gang" all trusted you. And had
no concept of the realities of the situation.
>
> I have two comments:
>
> 1. "Most of [regular contributors to] this group" consist of cranks,
> crackpots, and trolls who are uninterested in anything but touting their
> own crank "ideas".
I don't think Luc, Tom, Matthew or others like to be called cranks. (They
are the ones who insist on "trusting" standard sources and texts.)
> 2. I think the group of readers who are not cranks, crackpots or trolls
> generally take the time to read my posts because I always try to give
> references to reliable sources of information written by genuine experts
> like Clifford Will, and they recognize that these sources are about as
> trustworthy as anything ever gets in science.
But none of them bothered to check or counter your obvious error.
My own readings of posts over the past couple years reverses your
conclusion. The posters who references most -- by far -- are Dennis
McCarthy and Paul Stowe (whom you have labelled cranks). GR-ists (when they
bother) usually point to non-specific "texts" on relativity theory.
> > Matthew Nobes in particular took me to task for not "trusting"
> > Hillman's statements. And Mr. Hillman trusts Dr. Will.
>
> If you want to throw titles around, you can call me Dr. Hillman, and you
> can refer to Prof. Will and Prof. Carlip.
Glad to hear you can pile it higher and deeper.
I do happen to know that "Steve Carlip" has a PhD and teaches at UC Davis.
So sometimes I use "Dr". Since "Prof. Will" has a PhD, it is not inaccurate
nor is it imprecise to refer to him as "Dr." You could refer to me as
"Prof." But don't bother. Titles change nothing of substance.
> > (Chris also "corrected" his values for 1966 to 1995. But again his
> > reference says 1966 to 1990.)
>
> Yes, I made a typo, but the range of years I was trying to type was
> incorrect, because I again somehow misread Will's paper. Careless of me,
> but it doesn't alter the fact that the paper I kept trying to get you to
> study is an invaluable guide to the literature on tests of gravitation
> theories.
Nope. It's irrelevant. Because I (and the poster who started this thread)
asked for PRIMARY REFERENCES for the determination of the observational NNPA
of Mercury. What is so hard to understand about this?
>
> > True. Will (as usual) selects a theoretical model that allows him to
> > ignore oblateness.
>
> You really need to study this paper much more carefully. It is true that
> you caught me (unintentionally) misquoting the article in two places, but
> IMO your own misunderstandings are far more fundamental.
>
> Chris Hillman
I understand Will's work far better than you realize. The fact that I find
flaws in it does not mean I don't understand it.
The "misquotes" you made (and continue to make) indicate that you have no
real understanding of the process. You apparently take chunks out of
references you don't really understand. Because when someone points out
your error (as I repeatedly did) you can't seem to see that there might be a
problem.
The problem is mainly that you presented the quote as a know-it-all
("Sheesh"), with no tolerance for "ignorance" of others. And you blew it,
"Doctor."
Steve Carlip
> And I say "misusing" because anytime one purports to analyse a dynamic
> phenomenon -- and ignores the fact that there are competing processes (in
> the case of aether, "drag" -- in the case of GR, "back-action") that counter
> the effect.
The question is how much they ``counter the effect.'' A mere assertion
won't do here---you need to present a concrete model.
>ANY theory that contains a finite speed of gravity
> that is on the close order of c, will give the correct perihelion advance.
This is clearly wrong. I suggest that you get hold of a copy of Roseveare's
book, _Mercury's Perihelion from Le Verrier to Einstein_ and look at
the ``finite speed of gravity'' models described in chapter 6. You can get
a perihelion advance of 6.28" (Weber), 14" (an analogy to Gauss's law),
7" (an analogy to Maxwell's equations), 3.6(k+5)" where k is an arbitrary
undetermined parameter (Ritz), 14.4(1+a)" where a is an arbitrary
undetermined parameter (Levy), 6.8b(b+1)" where b is an arbitrary
undetermined parameter (Oppenheim), or 35" (Surdin).
Steve Carlip
Steve Carlip
> And why would it matter if it was on a ".research" instead of ".relativity"?
For the most part, the people I know who are good physicists and also read
newsgroups---myself included---read sci.physics.relativity mainly for
entertainment, and don't pay much attention most of the time. On the
other hand, we read the .research groups, which screen out the sillier posts,
for research. Further, the .research newsgroups have a lot more expert
readers who don't have the time or inclination to pay attention to an
unmoderated newsgroup.
Remember that when you ask for references, you are asking someone to do
you a favor. It's up to you to do that in a way that elicits a response.
Steve Carlip
Steve Carlip
> First I need the reference for the primary source of the NNPA. Which I've
> repeatedly asked for.
And which I've given you. To repeat:
I.I. Shapiro et al., Phys. Rev. Lett. 28 (1972) 1594 (radar ranging results)
J.D. Anderson et al., Acta Astronautica 5 (1978) 43 (optical and radar data)
L.V. Morrison and C.G. Ward, Mon. Not. Roy. Ast. Soc. 173 (1975) 183
(optical data).
Steve Carlip
Matthew Nobes
>
> Chris Hillman <hil...@math.washington.edu> wrote in message
> news:Pine.OSF.4.21.010328...@goedel1.math.washington.edu..
[snip]
> > I have two comments:
> >
> > 1. "Most of [regular contributors to] this group" consist of cranks,
> > crackpots, and trolls who are uninterested in anything but touting their
> > own crank "ideas".
>
> I don't think Luc, Tom, Matthew or others like to be called cranks. (They
> are the ones who insist on "trusting" standard sources and texts.)
I have done no such thing. I SPECIFICALLY asked you to give me the
primary references for your claim:
"[...]Mariner found Mercury to be twice the mass predicted by
GR."
This claim can be found at
http://groups.google.com/groups?start=10&hl=en&lr=&
safe=off&th=e57d745877d10480&rnum=13&seld=911585939&ic=1
Further, in the message that started that thread you wrote
"Just to be clear, by "current" I mean subsequent
to the Mariner 'surprise' (when an irritating
spacecraft found that the physical mass of Mercury
was twice what had been predicted by GR*)."
(this can be found at http://groups.google.com/groups?
hl=en&lr=&safe=off&th=e57d745877d10480&start=0&ic=1)
Despite my repeated requests for primary sources regarding this claim you
still have not produced one. Why is that Mr. Mingst?
[snip]
> > Yes, I made a typo, but the range of years I was trying to type
> > was incorrect, because I again somehow misread Will's paper.
> > Careless of me, but it doesn't alter the fact that the paper I kept
> > trying to get you to study is an invaluable guide to the literature
> > on tests of gravitation theories.
>
> Nope. It's irrelevant. Because I (and the poster who started this
> thread) asked for PRIMARY REFERENCES for the determination of the
> observational NNPA of Mercury. What is so hard to understand about
> this?
I don't know. Why is it so hard for you to understand that what is good
for the goose is good for the gander. Can you back up your claim with the
same level of evidence you demand of others?
greywolf42
Not if it is in response to a specific claim by another poster. Like "1
part in 10,000".
Or more general claims like "GR has been validated by the NNPA of Mercury."
In both cases is is not a "favor." It is a requirement of science. No
backup, false claim.
> It's up to you to do that in a way that elicits a response.
>
> Steve Carlip
>
Nope. It's up to scientists making such a claim to back it up. Crackpots
and theologians don't need to.
greywolf42
greywolf42
> greywolf42 <min...@sim-ss.com> wrote:
>
Insert snipped context:
==================
> Do you think this is a significant effect? Do the computation---
> see what difference this makes in the outcome. If it comes out
> significant, first try writing a polite letter to, say, Anderson, and
> ask, ``Did you take this into account in your treatment of the
> optical measurements?'' If he says no, write up a paper and submit
> it to a journal. You'll find that this is much more satisfying than
> just complaining on a newsgroup.
==================
Thank you. But since I don't work on-campus, it takes a few days to get to
the library. Point being that I have not had time to read all three. I was
replying to your fault-finding for not knowing by instantaneous osmosis what
the citations the local GR-ists are using to back up their claims.
greywolf42
greywolf42
> greywolf42 <min...@sim-ss.com> wrote:
>
> > And I say "misusing" because anytime one purports to analyse a dynamic
> > phenomenon -- and ignores the fact that there are competing processes
(in
> > the case of aether, "drag" -- in the case of GR, "back-action") that
counter
> > the effect.
>
> The question is how much they ``counter the effect.'' A mere assertion
> won't do here---you need to present a concrete model.
Absolutely not, Steve. Other way around. If you know that there are two
"forces" with opposite direction operating on an orbiting body it is
dishonest to only look at one and claim that a theory you don't like
philosophically is "disproved" when you consider only one of the two.
>
> >ANY theory that contains a finite speed of gravity
> > that is on the close order of c, will give the correct perihelion
advance.
>
> This is clearly wrong. I suggest that you get hold of a copy of
Roseveare's
> book, _Mercury's Perihelion from Le Verrier to Einstein_ and look at
> the ``finite speed of gravity'' models described in chapter 6.
I did. Thanks for the reference, by the way. That's where I got the
information.
> You can get
> a perihelion advance of 6.28" (Weber), 14" (an analogy to Gauss's law),
> 7" (an analogy to Maxwell's equations), 3.6(k+5)" where k is an arbitrary
> undetermined parameter (Ritz), 14.4(1+a)" where a is an arbitrary
> undetermined parameter (Levy), 6.8b(b+1)" where b is an arbitrary
> undetermined parameter (Oppenheim), or 35" (Surdin).
>
> Steve Carlip
>
To get the GR-claimed amount of 42 (at a Vg of c), Surdin would need Vg
approx. c. Levy and Gauss would need approx 3c. The rest would need
approximately 6c.
All on the close order of c. Like I said.
Martin Gradwell
>
> Chris Hillman <hil...@math.washington.edu> wrote in message
>
news:Pine.OSF.4.21.010328...@goedel1.math.washington.edu..
> > we can measure the rate of precession of
> > the perhelia of Mercury's orbit, which turns out to be about 5600
degrees
> > per century.
>
> Chris. You and I have got to swear off posting without caffeine.
>
> Please read what you wrote and try again.
>
> Hint: Number is off by a factor of 10. Units are wrong.
Factor of 10? 5600'', reported as 5600 degrees, is out by a factor of 3600.
>
> And please be sufficiently precise. You are claiming GR validation to
> hundredths of an arcsecond per century, so "about 5600" is insufficiently
> precise by four orders of magnitude. Please give the correct total
> perihelion advance of Mercury value to hundredths of an arcsecond per
> century.
I doubt that Chris is interested in responding to a post in which so many of
his errors are laid bare.
According to "Gravitation" by Misner, Thorne and Wheeler, the total observed
shift per century is 5999''.74, +/- 0''.41.
The other figures given are:
Contribution to shift caused by observer not being in an inertial frame far
from the sun ("general precession" as evaluated in 1947):
5025''.645 +/- 0''.50
Shift per century caused by Newtonian gravitation of other planets: 531''.54
+/- 0''.68
Residual shift per century to be attributed to general relativity plus solar
oblateness: 42''.56 +/- 0''.94
Residual shift if one uses the 1974 value for the "general precession":
41''.4 +/- 0''.90
Note that the MTW text was last revised in 1973 (according to the
copyright), and radar ranging began in 1966, so these figures must be based
on less than eight years of radar measurement. Since the sidereal period of
Jupiter is 11.86 years, the effect of Jupiter's motion on the position of
Mercury over this period (periodic effect, not secular precession) will be
considerable, and any measurement of anomalous precession needs to take this
into account; but MTW (p1111) says: "The periodic effects in the planetary
orbits have not yet (1973) been studied experimentally". It does not say
exactly how the figures have been adjusted to take the periodic effect into
account, but does say that for short-duration experiments "periodic
perturbations in an orbit are of almost as much significance as the
cumulative perihelion shift". Also, over eight years, the total measurable
anomalous precession will be 43'' * 8 / 100 at most, i.e. 3''.44 max.
MTW's description of general precession as being "caused by observer not
being in an inertial frame far from the sun" is unhelpful. In fact it is the
precession of the equinoxes, caused by the interaction between sun, moon and
earth. The positions of the equinoxes will also be subject to periodic as
well as secular variation, which will be important not just in a short term
experiment, but also in any experiment where the positions of the major
planets are significantly different at the end of the experiment, when
compared to the beginning.
..
>
> greywolf42
>
> ubi dubium ibi libertas
>
Martin Gradwell, mtgra...@btinternet.com
http://www.btinternet.com/~mtgradwell/
--
Posted from gadolinium.btinternet.com [194.73.73.111]
via Mailgate.ORG Server - http://www.Mailgate.ORG
Steve Carlip
> "Steve Carlip" <car...@dirac.ucdavis.edu> wrote in message
> news:9a89l5$1l$4...@woodrow.ucdavis.edu...
>> Remember that when you ask for references, you are asking someone
>> to do you a favor.
> Not if it is in response to a specific claim by another poster. Like "1
> part in 10,000".
> Or more general claims like "GR has been validated by the NNPA of
> Mercury." In both cases is is not a "favor." It is a requirement of
> science.
You are apparently confusing ``Usenet'' and ``science.''
> No backup, false claim.
No. No backup, unproven claim.
(Incidentally, I think you've been asked several times to back up your
claim that Mercury's mass was found to be twice the previously thought
value. No backup---does that make this a false claim?)
Steve Carlip
Steve Carlip
> "Steve Carlip" <car...@dirac.ucdavis.edu> wrote in message
> news:9a899h$1l$3...@woodrow.ucdavis.edu...
>> greywolf42 <min...@sim-ss.com> wrote:
>> > And I say "misusing" because anytime one purports to analyse a dynamic
>> > phenomenon -- and ignores the fact that there are competing processes
>> > (in the case of aether, "drag" -- in the case of GR, "back-action") that
>> > counter the effect.
>> The question is how much they ``counter the effect.'' A mere assertion
>> won't do here---you need to present a concrete model.
> Absolutely not, Steve. Other way around. If you know that there are
> two "forces" with opposite direction operating on an orbiting body it is
> dishonest to only look at one and claim that a theory you don't like
> philosophically is "disproved" when you consider only one of the two.
I don't want to quibble over semantics. The main point is that if you want
to propose a new theory, the burden of proof is on *you* to show that it gives
the right predictions. You cannot just say, ``Look, there are two competing
effects. I think they cancel out.''
In this particular case, as I pointed out some time ago, aberration and drag
have different dependences on the mass of the orbiting object, and in general
on its distance from the Sun as well. So it seems extraordinarily improbable
that you'd get cancellation for across the whole Solar System. Once again,
if you think such cancellation is possible, show me calculations in a concrete
model.
>> >ANY theory that contains a finite speed of gravity
>> > that is on the close order of c, will give the correct perihelion
>> > advance.
>> You can get
>> a perihelion advance of 6.28" (Weber), 14" (an analogy to Gauss's law),
>> 7" (an analogy to Maxwell's equations), 3.6(k+5)" where k is an arbitrary
>> undetermined parameter (Ritz), 14.4(1+a)" where a is an arbitrary
>> undetermined parameter (Levy), 6.8b(b+1)" where b is an arbitrary
>> undetermined parameter (Oppenheim), or 35" (Surdin).
> To get the GR-claimed amount of 42 (at a Vg of c), Surdin would need Vg
> approx. c. Levy and Gauss would need approx 3c. The rest would need
> approximately 6c.
> All on the close order of c. Like I said.
What you said is, ``ANY theory that contains a finite speed of gravity that
is on the close order of c, will give the correct perihelion advance.'' What
you seem to be saying now is, ``In any theory that contains a finite speed of
gravity that is on the close order of c, there is a free parameter that I can tune
to a value that gives the correct perihelion advance.'' This is very different.
Unless you have some other reason for expecting a particular value of V_g,
you are now simply stating that these theories make no prediction about
the perihelion advance.
Steve Carlip
greywolf42
> greywolf42 <min...@sim-ss.com> wrote:
>
> > "Steve Carlip" <car...@dirac.ucdavis.edu> wrote in message
> > news:9a89l5$1l$4...@woodrow.ucdavis.edu...
>
> >> Remember that when you ask for references, you are asking someone
> >> to do you a favor.
>
> > Not if it is in response to a specific claim by another poster. Like "1
> > part in 10,000".
>
> > Or more general claims like "GR has been validated by the NNPA of
> > Mercury." In both cases is is not a "favor." It is a requirement of
> > science.
>
> You are apparently confusing ``Usenet'' and ``science.''
No -- only your claim. Regardless of location.
> > No backup, false claim.
>
> No. No backup, unproven claim.
You are more precisely correct.
> (Incidentally, I think you've been asked several times to back up your
> claim that Mercury's mass was found to be twice the previously thought
> value. No backup---does that make this a false claim?)
>
> Steve Carlip
And I've responded ... that I'm on the road and will cite the text when I
can dig it out.
And I've also responded that to do so is irrelevant in this case. As a text
is not a primary source. Which is why I was looking for primary sources
over a year ago. Which started this thread.
greywolf42
greywolf42
Let's take a 'hypothetical' case. Someone comes to you with a new (to them)
LeSagian gravitational model. Your initial response is the Feynman/Mach
argument: "No such theory can work, because dyanmic drag in such a theory
would slow the Earth and cause it to spiral into the sun in around a million
years." Now most students (and many theorists) would give up at this
point -- because there is no self-evident mechanism to counter the drag.
Now let's say that our theorist has come up with some plausible cause for
eliminating the effect of drag in his theory. Your second response is the
Lagrange/Poincare argument. "Well, OK, but because particles take a finite
time to travel, you will have a delayed potential and gravitational
aberration will fling the Earth out of orbit. And by the way, the Earth
will be flung out of orbit faster than it would have decayed! So again,
this type of theory can never work."
Now some more theorists might get discouraged. Of course that was the
intent of only giving half the true situation at a time. To ensure that the
theorist won't "waste his time" on an "impossible" theory. Of course, an
astute theorist might get pissed that you gave him a half-assed argument the
first time. Because if aberration were inevitable -- and of greater
magnitude -- then the Earth would never have spiralled into the sun. You
haven't even been honest enough to give him a "real" problem. You've wasted
his time.
The honest thing to have done in this case is to say something like: "The
dynamics of such a system need to be balanced. A particle-based model will
encounter dynamic drag and also a tendency to accelerate due to aberration.
Your model will have to address whether those two tendencies can balance in
an orbit."
Now a die-hard, unwilling-to-give-up-his-pet-idea theorist, stuck with a
finite speed of gravity (potential), may come up with some really bizarre
claims. Such as "in my theory gravity doesn't 'propagate' at any speed.
The field either exists or it doesn't." These argments attempt to finesse
the problem of the Lagrange argument by simply claiming it doesn't exist.
Of course GR has always suffered from the Lagrange argument. It is not
"particle-based" so there is no obvious primal source for any "back action."
But there is very definitely a finite speed of gravity in GR (a complex
function, but 'c' in the weak-field limit). But the 'problem' was solved
very early on by Emie Noether (1916 if I remember correctly). Einstein was
ecstatic. "Modern" theorists have failed to remember Noether's theorm. And
after someone finally publicly pointed out that GR required a nearly
infinite speed of gravitation to avoid aberration (the same one levelled by
Lagrange against LeSage), you replied with your 1999 paper. Showing that
"velocity-dependent terms" in GR "could" cancel the aberration tendency if
the speed of propagation were on the order of c. And you used Noether's
theorem to do it. ("velocity-dependent" terms such as dynamic drag.)
You are currently making the claim that it is "extraordinarily improbable"
that such a balance can obtain. (In your GR paper, I recall the section "Is
it a miracle?") But at it's core, Noether's theorem is only a re-statement
that energy in a system is conserved -- a rephrasing of the Lagrangian. So
such a balance is not "improbable" at all. Nothing about orbital dynamics
is self-evident. But conservation of energy is tried and true.
So, according to your claim above, most of the current crop of GR supporters
failed. None of them could show you "calculations in a concrete model" that
would account for balance. But you never took them to task for it, even when
they repeated "gravity doesn't propagate, gravitational waves propagate."
I see I've been lecturing again, so I'll repeat the core issue.
It is dishonest to claim that a theory (or type of theory) is disproven by
Feynman's argument (drag). It is dishonest to claim that a (type of) theory
is disproven by Lagrange's argument (aberration). Because you KNOW that
they are contrary tendencies, that balance in some situations. These
arguments -- used singly -- are lies whose purpose is to savage a theory or
theorist and spike honest investigation.
Note the progression of backing and filling in the above thread. Each step
is plausible. Drag, aberration, "unlikely balance", Noether. One didn't
state something that was not strictly true. But it is disingenuous, because
you know each statement is not the whole truth. And the clear purpose is to
mislead the audience.
> >> >ANY theory that contains a finite speed of gravity
> >> > that is on the close order of c, will give the correct perihelion
> >> > advance.
>
> >> You can get
> >> a perihelion advance of 6.28" (Weber), 14" (an analogy to Gauss's law),
> >> 7" (an analogy to Maxwell's equations), 3.6(k+5)" where k is an
arbitrary
> >> undetermined parameter (Ritz), 14.4(1+a)" where a is an arbitrary
> >> undetermined parameter (Levy), 6.8b(b+1)" where b is an arbitrary
> >> undetermined parameter (Oppenheim), or 35" (Surdin).
>
> > To get the GR-claimed amount of 42 (at a Vg of c), Surdin would need Vg
> > approx. c. Levy and Gauss would need approx 3c. The rest would need
> > approximately 6c.
>
> > All on the close order of c. Like I said.
>
> What you said is, ``ANY theory that contains a finite speed of gravity
that
> is on the close order of c, will give the correct perihelion advance.''
What
> you seem to be saying now is, ``In any theory that contains a finite speed
of
> gravity that is on the close order of c, there is a free parameter that I
can tune
> to a value that gives the correct perihelion advance.'' This is very
different.
This is not a different statement. That is why I used the term "on the
close order of c." That means somewhere in the neighborhood of....
You assumed that I meant "for any assumed Vg." The speed of gravity in all
of the above theories -- to get the values you posted -- is "c" by pure
assumption. What I was pointing out was that so long as the speed of gravity
was on the close order of c, any of these theories could give the proper
perihelion advance. That was the point of my statement. Sorry if I wasn't
clear. I thought I was paraphrasing your claims in your 1999 paper very
well. I guess the context threw you off.
> Unless you have some other reason for expecting a particular value of V_g,
> you are now simply stating that these theories make no prediction about
> the perihelion advance.
>
> Steve Carlip
Almost precisely. Ther is no other OBSERVATIONAL reason for expecting a
particular value of Vg.
But please include GR in the list. Ther is no "other" reason for expecting
Vg to be "c" in GR, either.
Bilge
Re: Reference for Non-newtonian Perihelion advance of Mercury to usenet:
[...]
>eliminating the effect of drag in his theory. Your second response is the
>Lagrange/Poincare argument. "Well, OK, but because particles take a finite
>time to travel, you will have a delayed potential and gravitational
>aberration will fling the Earth out of orbit. And by the way, the Earth
>will be flung out of orbit faster than it would have decayed! So again,
>this type of theory can never work."
And why would someone that has considered all of these things not have
a plausible answer for each. If two theories endeavor to explain something,
then either the two are equivalent or else some difference exists that
may, in principle, demonstrate one or the other is wrong. Someone that
has considered the question long enough to pose something plausible will
have considered all of those things.
[...]
>The honest thing to have done in this case is to say something like: "The
>dynamics of such a system need to be balanced. A particle-based model will
>encounter dynamic drag and also a tendency to accelerate due to aberration.
>Your model will have to address whether those two tendencies can balance in
>an orbit."
So, what you are saying is that anyone that wishes to speculate should
be able to obtain a detailed critique with suggestions on how to make their
model compatible with the data regardless of how ill-conceived or how
little effort was made by the author?
[...]
>Of course GR has always suffered from the Lagrange argument. It is not
>"particle-based" so there is no obvious primal source for any "back action."
>But there is very definitely a finite speed of gravity in GR (a complex
>function, but 'c' in the weak-field limit). But the 'problem' was solved
>very early on by Emie Noether (1916 if I remember correctly). Einstein was
>ecstatic. "Modern" theorists have failed to remember Noether's theorm. And
On the contrary. All of modern physics is based upon it.
[...]
>You are currently making the claim that it is "extraordinarily improbable"
>that such a balance can obtain. (In your GR paper, I recall the section "Is
>it a miracle?") But at it's core, Noether's theorem is only a re-statement
>that energy in a system is conserved -- a rephrasing of the Lagrangian. So
>such a balance is not "improbable" at all. Nothing about orbital dynamics
>is self-evident. But conservation of energy is tried and true.
It certainly is not simply a restatement of energy conservation. First
of all, noether's theorem is far more general. Noether's theorem is where
the electromagnetic potential in qed come from, for example. So, is it
also a simple restatement of charge conservation?
[...]
>
>Note the progression of backing and filling in the above thread. Each step
>is plausible. Drag, aberration, "unlikely balance", Noether. One didn't
>state something that was not strictly true. But it is disingenuous, because
>you know each statement is not the whole truth. And the clear purpose is to
>mislead the audience.
Let me phrase noether's theorem in the way that it applies to physics:
"For each contiuous symmetry of the lagrangian, there exists
a conserved current".
Use it to derive the "balance" you insist upon.
Matthew Nobes
My Thanks to Bilge for his post which highlighted these statements
On Thu, 5 Apr 2001, greywolf42 wrote:
> Of course GR has always suffered from the Lagrange argument. It is not
> "particle-based" so there is no obvious primal source for any "back action."
This makes no sense. Back action of what? It's all included in the GR
lagrangain, the action of the field on the particles, and the action of
the particles on the field is all there. Just like the Maxwell--Lorentz
lagrangian.
> But there is very definitely a finite speed of gravity in GR (a complex
> function, but 'c' in the weak-field limit). But the 'problem' was solved
> very early on by Emie Noether (1916 if I remember correctly). Einstein was
> ecstatic.
> "Modern" theorists have failed to remember Noether's theorm.
??? ??? To quote Dennis Mccarthy
"9 iora4g;34909y45yqj3pi5q3jihjhq3 Sorry my head hit the keyboard"
Noether's theorem is perhaps the most importent mathmatical result used by
modern field theorists (classical and quantum). Refutation of your claim
is no further away then any particle physics/field theory textbook.
Checking my backpack, of three books in there, two mention Noether's
theorem, to wit:
"More remarkable still is a relation that exists between symmetries of a
dynamical model and conservation laws, a relation known as Noether's
theorem" -- Quang Ho-Kim and Pham Xuan Yem "Elementary Particles and Their
Interactions" (published 1998), page 12
[Under the heading "Noether's Theorem"]
"Next let us discuss the relationship between symmetries and conservation
laws in classical field theory, summerized in *Noether's Theorem*" --
Michael Peskin and Daniel Schroeder "An Introduction to Quantum Field
Theory" (published 1995) page 17 (emphasis is their's).
I'd wager in my library at home I could find 5-10 more quotes like this,
and upwards of 50 at any modern university library.
> But at it's core, Noether's theorem is only a re-statement that energy
> in a system is conserved -- a rephrasing of the Lagrangian.
This is false. Noether's theorem states that for every symmetry of the
Lagrangian there is a correponding conservation law. A PARTICULAR case of
this is time translation symmetry, which implies conservation of energy.
But Noether's theorem goes way beyond that.
Your comments incidentally are an excellent illustration of my point that
many posters to these newsgroups make elementary errors.
greywolf42
"Bilge" <ro...@radioactivex.lebesque-al.net> wrote in message
news:slrn9crns...@radioactivex.lebesque-al.net...
> greywolf42 said some stuff about
> Re: Reference for Non-newtonian Perihelion advance of Mercury to usenet:
>
> [...]
> >eliminating the effect of drag in his theory. Your second response is
the
> >Lagrange/Poincare argument. "Well, OK, but because particles take a
finite
> >time to travel, you will have a delayed potential and gravitational
> >aberration will fling the Earth out of orbit. And by the way, the Earth
> >will be flung out of orbit faster than it would have decayed! So again,
> >this type of theory can never work."
>
> And why would someone that has considered all of these things not have
> a plausible answer for each. If two theories endeavor to explain
something,
> then either the two are equivalent or else some difference exists that
> may, in principle, demonstrate one or the other is wrong. Someone that
> has considered the question long enough to pose something plausible will
> have considered all of those things.
If you are referring to the hypothetical "expert," that is precisely my
point.
If you are referring to the hypothetical "theorist," you are incorrect.
"Plausible" does not mean correct. Even "solid aether" was "plausible."
And few theorists are omnipotent and think of everything.
> [...]
> >The honest thing to have done in this case is to say something like:
"The
> >dynamics of such a system need to be balanced. A particle-based model
will
> >encounter dynamic drag and also a tendency to accelerate due to
aberration.
> >Your model will have to address whether those two tendencies can balance
in
> >an orbit."
>
> So, what you are saying is that anyone that wishes to speculate should
> be able to obtain a detailed critique with suggestions on how to make
their
> model compatible with the data regardless of how ill-conceived or how
> little effort was made by the author?
Nope. Just that the "experts" not lie by omission (when they do respond),
and waste everybody's time.
> [...]
> >Of course GR has always suffered from the Lagrange
(excuse me.... Laplace. Dyslexics should avoid using Laplace, Lagrange and
LeSage all in the same post.)
> argument. It is not
> >"particle-based" so there is no obvious primal source for any "back
action."
> >But there is very definitely a finite speed of gravity in GR (a complex
> >function, but 'c' in the weak-field limit). But the 'problem' was
solved
> >very early on by Emie Noether (1916 if I remember correctly). Einstein
was
> >ecstatic. "Modern" theorists have failed to remember Noether's theorm.
And
>
> On the contrary. All of modern physics is based upon it.
No one on this group mentioned that Noether's theorem "solved" GR's
problems. They kept trying to state that gravity had "no" speed in GR
(which violates Noether's theorem) -- to avoid Laplace's argument. Until
Dr. Carlip published his 1999 paper, and reminded the crowd.
> [...]
> >You are currently making the claim that it is "extraordinarily
improbable"
> >that such a balance can obtain. (In your GR paper, I recall the section
"Is
> >it a miracle?") But at it's core, Noether's theorem is only a
re-statement
> >that energy in a system is conserved -- a rephrasing of the Lagrangian.
So
> >such a balance is not "improbable" at all. Nothing about orbital
dynamics
> >is self-evident. But conservation of energy is tried and true.
>
> It certainly is not simply a restatement of energy conservation. First
> of all, noether's theorem is far more general. Noether's theorem is where
> the electromagnetic potential in qed come from, for example. So, is it
> also a simple restatement of charge conservation?
"Charge conservation" predates QED by 40 years. It predates Noether's
theorem by 15 years. And I can't think of much more general than energy
conservation. Of course, the point was the use of Noether's theorem in GR.
And the ironic use of the "extraordinarily improbable" possibility of
balance -- for any theory but GR.
> [...]
> >
> >Note the progression of backing and filling in the above thread. Each
step
> >is plausible. Drag, aberration, "unlikely balance", Noether. One
didn't
> >state something that was not strictly true. But it is disingenuous,
because
> >you know each statement is not the whole truth. And the clear purpose
is to
> >mislead the audience.
>
> Let me phrase noether's theorem in the way that it applies to physics:
>
> "For each contiuous symmetry of the lagrangian, there exists
> a conserved current".
That's what I said when I described Noether's theorem. I just used less
pretentious (and possibly less precise) language. "Continuous symmetry of
the lagrangian" translates to "where the flow of energy is closed and
continuous." "Conserved current" means no energy is lost. Taken together,
that means energy is conserved.
Of course, you can substitute other quantities into the mathematical
symbols. And the ink on the page (or phosphors on the screen) don't care.
But the underlying assumption is the same. If you assume energy is
conserved, then energy is conserved. If you assume "X" is conserved, then
"X" is conserved.
But Noether is far more precise and quantified than this simple explanation.
>
> Use it to derive the "balance" you insist upon.
>
???? I'm not sure what you mean by this.
Energy is (at least assumed to be) conserved in all known physics. It is
therefore beholden upon a critic -- who bases his critique on
non-conservation of energy -- to be less cavalier about it.
greywolf42
"Matthew Nobes" <man...@fraser.sfu.ca> wrote in message
news:Pine.GSO.4.30.010406...@fraser.sfu.ca...
> sci.physics added with followups there.
>
> My Thanks to Bilge for his post which highlighted these statements
>
> On Thu, 5 Apr 2001, greywolf42 wrote:
>
> > Of course GR has always suffered from the Lagrange argument. It is not
> > "particle-based" so there is no obvious primal source for any "back
action."
>
> This makes no sense. Back action of what?
Those "velocity-dependent" terms that cancel the "fling" in GR. "Back
action" is used instead of that evil word "force."
> It's all included in the GR
> lagrangain, the action of the field on the particles, and the action of
> the particles on the field is all there. Just like the Maxwell--Lorentz
> lagrangian.
Which is why so many GR-ists insisted that gravity has "no" speed. It
simply is.
I didn't mean "forgot the name." I meant forgot it's uses. Perhaps I was
mistaking those who represent themselves as experts on this usenet for real
"modern physicists."
Point being that "modern physicists" (the ones you point to here) understand
that Noether solved Einstein's GR aberration problem through conservation of
{energy}. Yet those same experts will ignore Noether and apply arguments
wildly contrary to Noether when dealing with an aether theory.
> > But at it's core, Noether's theorem is only a re-statement that energy
> > in a system is conserved -- a rephrasing of the Lagrangian.
>
> This is false. Noether's theorem states that for every symmetry of the
> Lagrangian there is a correponding conservation law. A PARTICULAR case of
> this is time translation symmetry, which implies conservation of energy.
> But Noether's theorem goes way beyond that.
>
> Your comments incidentally are an excellent illustration of my point that
> many posters to these newsgroups make elementary errors.
>
See my reply to "Bilge."
Since you had already read his argument, there was no need to repeat it.
And no need for me to repeat my reply.
Steve Carlip
[On balancing gravitational aberration and drag in LeSage models]
> You are currently making the claim that it is "extraordinarily improbable"
> that such a balance can obtain. (In your GR paper, I recall the section "Is
> it a miracle?") But at it's core, Noether's theorem is only a re-statement
> that energy in a system is conserved -- a rephrasing of the Lagrangian. So
> such a balance is not "improbable" at all. Nothing about orbital dynamics
> is self-evident. But conservation of energy is tried and true.
Noether's theorem, as applied to the particular case of time translation, says
that *total* energy is conserved. In GR, the orbital energy can be carried
off only by gravitational waves---there's nothing else around to participate
in the interaction---and you can combine Noether's theorem with the very
weak quadrupole coupling of gravitational waves to show that aberration and
velocity-dependent forces must nearly cancel.
In a LeSage theory, total energy is perhaps also conserved. (I say perhaps
because you can draw this conclusion from Noether's theorem only if the
full theory is derived from a time translation invariant Lagrangian. Show
me a Lagrangian and I'll make the statement stronger.) But now the system
isn't just the orbiting bodies plus gravitational radiation; it also includes
the LeSage ``ultra-mundame particles'' (or ether, or whatever), and you
have to take into account any extra transfer of energy between the orbiting
bodies and these particles/this medium. The conservation argument that
works for GR can be extended *only* if you can prove that this energy
transfer is very small.
The energy transfer certainly *isn't* small for a typical model. After all,
the whole point of drag is that energy is transferred from the moving body
to the medium exterting the drag. For the balance you want, you would have
to show that the energy transferred to the medium by drag is exactly balanced
by energy transferred from the medium to the orbiting body by aberration.
This is not a conservation argument; it requires a detailed analysis of the
dynamics.
> It is dishonest to claim that a theory (or type of theory) is disproven by
> Feynman's argument (drag). It is dishonest to claim that a (type of) theory
> is disproven by Lagrange's argument (aberration). Because you KNOW
> that they are contrary tendencies, that balance in some situations.
I don't know that they balance in some situations. Show me. Give me a
concrete calculation.
As I said before, the two ``contrary tendencies'' have a different dependence
on the masses and velocities of the orbiting objects. In particular, for a planet
orbiting the Sun, they have a *very* different dependence on the mass of the
Sun, and on the mass of the orbiting body. Work it out!
If you can find any way to get the two effects to cancel, for more than one orbit
at one radius with one mass ratio, I'd like to see it. Once again, this is not a
question about belief, but about the numbers.
[... later in the same post]
> What I was pointing out was that so long as the speed of gravity
> was on the close order of c, any of these theories could give the proper
> perihelion advance. That was the point of my statement. Sorry if I wasn't
> clear. I thought I was paraphrasing your claims in your 1999 paper very
> well. I guess the context threw you off.
Not the context, the content. Your claim is in no way a paraphrase of my paper;
if you think it is, you haven't understood my paper.
>> Unless you have some other reason for expecting a particular value of V_g,
>> you are now simply stating that these theories make no prediction about
>> the perihelion advance.
> Almost precisely. Ther is no other OBSERVATIONAL reason for expecting
> a particular value of Vg.
> But please include GR in the list. Ther is no "other" reason for expecting
> Vg to be "c" in GR, either.
You're simply wrong here. There is no freedom to adjust the speed of gravity
in GR; there is no free parameter to tune.
Steve Carlip
Matthew Nobes
>
> "Matthew Nobes" <man...@fraser.sfu.ca> wrote in message
> news:Pine.GSO.4.30.010406...@fraser.sfu.ca...
> > sci.physics added with followups there.
> >
> > My Thanks to Bilge for his post which highlighted these statements
> >
> > On Thu, 5 Apr 2001, greywolf42 wrote:
> >
> > > Of course GR has always suffered from the Lagrange argument. It is not
> > > "particle-based" so there is no obvious primal source for any "back
> > > action."
> >
> > This makes no sense. Back action of what?
>
> Those "velocity-dependent" terms that cancel the "fling" in GR. "Back
> action" is used instead of that evil word "force."
That's because it's not a force.
> > It's all included in the GR
> > lagrangain, the action of the field on the particles, and the action of
> > the particles on the field is all there. Just like the Maxwell--Lorentz
> > lagrangian.
>
> Which is why so many GR-ists insisted that gravity has "no" speed. It
> simply is.
No. That is not how I understand it at all. There is a field, if it's
static then it is just there. But changes in the field propagate at c.
This is the same as E&M
> > > But there is very definitely a finite speed of gravity in GR (a complex
> > > function, but 'c' in the weak-field limit). But the 'problem' was
> > > solved very early on by Emie Noether (1916 if I remember correctly).
> > > Einstein was ecstatic.
> >
> > > "Modern" theorists have failed to remember Noether's theorm.
> >
> > ??? ??? To quote Dennis Mccarthy
> >
> > "9 iora4g;34909y45yqj3pi5q3jihjhq3 Sorry my head hit the keyboard"
> >
> > Noether's theorem is perhaps the most importent mathmatical result used by
> > modern field theorists (classical and quantum). Refutation of your claim
> > is no further away then any particle physics/field theory textbook.
> > Checking my backpack, of three books in there, two mention Noether's
> > theorem, to wit:
> >
> > "More remarkable still is a relation that exists between symmetries of a
> > dynamical model and conservation laws, a relation known as Noether's
> > theorem" -- Quang Ho-Kim and Pham Xuan Yem "Elementary Particles and Their
> > Interactions" (published 1998), page 12
> >
> > [Under the heading "Noether's Theorem"]
> > "Next let us discuss the relationship between symmetries and conservation
> > laws in classical field theory, summerized in *Noether's Theorem*" --
> > Michael Peskin and Daniel Schroeder "An Introduction to Quantum Field
> > Theory" (published 1995) page 17 (emphasis is their's).
> >
> > I'd wager in my library at home I could find 5-10 more quotes like this,
> > and upwards of 50 at any modern university library.
>
> I didn't mean "forgot the name." I meant forgot it's uses.
I invite you to check my citations for a number of examples of Noether's
theorem in use.
> Perhaps I was mistaking those who represent themselves as experts on
> this usenet for real "modern physicists."
Well I assure you that I know a lot about Noether's theorem, and I
suppose I'd take the label "modern" physicist..
> Point being that "modern physicists" (the ones you point to here) understand
> that Noether solved Einstein's GR aberration problem through conservation of
> {energy}. Yet those same experts will ignore Noether and apply arguments
> wildly contrary to Noether when dealing with an aether theory.
You need a Lagrangain to apply Noether's theorem. Please post the
Lagrangian of your theory, then we'll get to work.
> > > But at it's core, Noether's theorem is only a re-statement that energy
> > > in a system is conserved -- a rephrasing of the Lagrangian.
> >
> > This is false. Noether's theorem states that for every symmetry of the
> > Lagrangian there is a correponding conservation law. A PARTICULAR case of
> > this is time translation symmetry, which implies conservation of energy.
> > But Noether's theorem goes way beyond that.
> >
> > Your comments incidentally are an excellent illustration of my point that
> > many posters to these newsgroups make elementary errors.
> >
>
> See my reply to "Bilge."
>
> Since you had already read his argument, there was no need to repeat it.
> And no need for me to repeat my reply.
Okay
> From min...@sim-ss.com Sat Apr 7 01:11:23 2001
> Date: Fri, 6 Apr 2001 19:26:13 -0700
> From: greywolf42 <min...@sim-ss.com>
> Newsgroups: sci.astronomy, sci.physics.relativity
> Subject: Re: Reference for Non-newtonian Perihelion advance of Mercury
>
> "Bilge" <ro...@radioactivex.lebesque-al.net> wrote in message
> news:slrn9crns...@radioactivex.lebesque-al.net...
>
>> greywolf42 said some stuff about
>> Re: Reference for Non-newtonian Perihelion advance of Mercury to
>>usenet:
[MY SNIP]
>> [...]
>>> Of course GR has always suffered from the Lagrange
>
> (excuse me.... Laplace. Dyslexics should avoid using Laplace,
> Lagrange and LeSage all in the same post.)
>
>>> argument. It is not "particle-based" so there is no obvious primal
>>> source for any "back action." But there is very definitely a finite
>>> speed of gravity in GR (a complex function, but 'c' in the weak-field
>>> limit). But the 'problem' was solved very early on by Emie Noether
>>> (1916 if I remember correctly). Einstein was ecstatic. "Modern"
>>> theorists have failed to remember Noether's theorm.
>>
>> On the contrary. All of modern physics is based upon it.
>
> No one on this group mentioned that Noether's theorem "solved" GR's
> problems. They kept trying to state that gravity had "no" speed in GR
> (which violates Noether's theorem) -- to avoid Laplace's argument.
> Until Dr. Carlip published his 1999 paper, and reminded the crowd.
This doesn't really address Bilgs' point. You stated "'Modern' theorists
have failed to remember Noether's theorem"
As Bilge pointed out that's flat out false.
AS for Dr. Carlip's paper. I thought he was refuting Tom van Flandren's
arguements by summerizing some (little known but uncontroversial) facts
about GR.
Again I assure you that people working in GR know all about Noether's
theorem.
>> [...]
>>> You are currently making the claim that it is "extraordinarily
>>> improbable" that such a balance can obtain. (In your GR paper,
>>> I recall the section "Is it a miracle?") But at it's core,
>>> Noether's theorem is only a re-statement that energy in a system
>>> is conserved -- a rephrasing of the Lagrangian. So such a balance
>>> is not "improbable" at all. Nothing about orbital dynamics
>>> is self-evident. But conservation of energy is tried and true.
>>
>> It certainly is not simply a restatement of energy conservation. First
>> of all, noether's theorem is far more general. Noether's theorem is
>> where the electromagnetic potential in qed come from, for example. So,
>> is it also a simple restatement of charge conservation?
> "Charge conservation" predates QED by 40 years. It predates Noether's
> theorem by 15 years.
So? That doesn't change the fact that oen can use Noether's theorem to
derive conservaion of charge from the Maxwell Lagrangian. Hence Noether's
theorem applies to much more then enegy conservation. That's the point.
> And I can't think of much more general than energy conservation.
Conservation of momentum?
> Of course, the point was the use of Noether's theorem in GR.
Well you've shown that you don't really understand it so why should we
take your comments very seriously?
> And the ironic use of the "extraordinarily improbable" possibility of
> balance -- for any theory but GR.
??? AS I understand Dr. Carlip's paper, and my notes on Jackson's text
the arguements are similar for both Maxwell's theory and GR.
>> [...]
>>>
>>> Note the progression of backing and filling in the above thread.
>>> Each step is plausible. Drag, aberration, "unlikely balance",
>>> Noether.
>>> One didn't state something that was not strictly true. But it is
>>> disingenuous because you know each statement is not the whole truth.
>>> And the clear purpose is to mislead the audience.
>
>> Let me phrase noether's theorem in the way that it applies to physics:
>>
>> "For each contiuous symmetry of the lagrangian, there exists
>> a conserved current".
>
> That's what I said when I described Noether's theorem.
No you said "Noether's theorem is only a re-statement that energy in a
system is conserved -- a rephrasing of the Lagrangian"
This is false on two counts.
1) Noether's theory applies to far more then energy conservation
2) Given the symmetries one can construct an infinity of lagrangains which
will obey them, hence Noether's theorem by itself cannot uniquly determine
the Lagrangian (that's my best guess at what rephrase is supposed to mean
in this context).
> I just used less pretentious (and possibly less precise) language.
That's an understatement
> "Continuous symmetry of the lagrangian" translates to "where the flow
> of energy is closed and continuous."
Only in your fantasy land. The QCD lagranian is invairant under continous
local SU(3) transformations. How does this "tranlate" to "the flow of
energy"?
> "Conserved current" means no energy is lost.
Only in a special case.
> Taken together, that means energy is conserved.
>
> Of course, you can substitute other quantities into the mathematical
> symbols. And the ink on the page (or phosphors on the screen) don't
> care. But the underlying assumption is the same. If you assume energy
> is conserved, then energy is conserved. If you assume "X" is
> conserved, then "X" is conserved.
Again this is not what Noether's theorem says
You assume that the Lagrangian is invariant under time translations this
*implies* that energy is conserved.
> But Noether is far more precise and quantified than this simple
> explanation.
>
>>
>> Use it to derive the "balance" you insist upon.
>>
> ???? I'm not sure what you mean by this.
>
> Energy is (at least assumed to be) conserved in all known physics.
> It is therefore beholden upon a critic -- who bases his critique on
> non-conservation of energy -- to be less cavalier about it.
It is beholden upon somebody who want's to use Noether's theorem in an
arguement to acutuyally produce a Lagrangian to which said theorem can be
applied. Wouldn't you agree?
Bilge
>
>No one on this group mentioned that Noether's theorem "solved" GR's
>problems. They kept trying to state that gravity had "no" speed in GR
>(which violates Noether's theorem) -- to avoid Laplace's argument. Until
>Dr. Carlip published his 1999 paper, and reminded the crowd.
And the main reason noether came up with those two theorems, was to
assist hilbert in obtaining einstein's field equations from an invariance
principle. The theorems basically originate with gr.
[...]
>> It certainly is not simply a restatement of energy conservation. First
>> of all, noether's theorem is far more general. Noether's theorem is where
>> the electromagnetic potential in qed come from, for example. So, is it
>> also a simple restatement of charge conservation?
>
>"Charge conservation" predates QED by 40 years. It predates Noether's
>theorem by 15 years. And I can't think of much more general than energy
>conservation. Of course, the point was the use of Noether's theorem in GR.
Explain how 40 years prior to QED, someone connected charge conservation
to a massless photon. Or else provide a compelling reason for it that
doesn't require lots of ad hoc-ery. I can get it from one symmetry.
Why is energy conservation "basic"? I see nothing that indicates a reason
energy is special without some general principle that gives it a less
ad hoc apperance. You also don't have a good reason to believe otherwise
unless you can state a principle more general that, "because". Friction
doesn't appear to be energy conserving, and based on nothing else, why
would you assume the heat from friction was identeical to the energy loss?
>And the ironic use of the "extraordinarily improbable" possibility of
>balance -- for any theory but GR.
You always have the option of showing otherwise. Since you don't do
so, I see no reason to assume you are correct. But, go for broke. Prove
me incorrect.
[...]
>That's what I said when I described Noether's theorem. I just used less
>pretentious (and possibly less precise) language. "Continuous symmetry of
>the lagrangian" translates to "where the flow of energy is closed and
>continuous." "Conserved current" means no energy is lost. Taken together,
>that means energy is conserved.
Since it also gives you:
1) conservation of momentum from translational invariance
2) conservation of angular momentum from rotational invariance
3) E&M and conservation of charge through phase invariance
4) The weak interaction and the W+/-, Z through weak isospin invariance
5) The strong interaction and gluons through color charge invariance
6) the low lying states in light to medium nuclei throught the
application of isospin invariance to analog nuclei.
7) The prediction of the pi0, pi+ pi- as an isospin triplet.
8) conservation of the stress-energy tensor in gr, which is the
generalization of conservation of energy (differing from your
definition).
9)
and a long list of others, including essentially the entire standard
model.
>
>Of course, you can substitute other quantities into the mathematical
>symbols. And the ink on the page (or phosphors on the screen) don't care.
>But the underlying assumption is the same. If you assume energy is
>conserved, then energy is conserved. If you assume "X" is conserved, then
>"X" is conserved.
>
>But Noether is far more precise and quantified than this simple explanation.
Yeah. I know. That's why I expect (well maybe not quite "expect") you
to make use of that fact and derive results and suggest the tests that
will differentiate it from gr. Noether's theorem gives you a prescription,
since your conservation law will have a symmetry assosciated with it. The
converse of noether's theorems are also true. If you think conservation of
energy is the highlight, you've totally missed the boat.
>>
>> Use it to derive the "balance" you insist upon.
>>
>???? I'm not sure what you mean by this.
>
>Energy is (at least assumed to be) conserved in all known physics. It is
>therefore beholden upon a critic -- who bases his critique on
>non-conservation of energy -- to be less cavalier about it.
I don't know. Who? You have claimed two competing effects cancel to
provide an alternative to gr. Since you claim to base this on something
having to do with noether's theorem, you should have no problem whipping
out the conserved quantity. In fact, these two competing quantities
themselves should have a symmetry and conservation law that exists
independently of anything but the parameters used to describe the effects.
Otherwise, they can't cancel.
Now, go do what you constantly pester other people to do and in all
likelyhood, they will pay more attention to you than you've ever paid
to anyone that's ever done as you've asked. Here's your chance to prove
that everyone else is more closed minded than you are. You even have it
easier. All you need are derivations and an explanation of the tests
suggested by those derivations along with any supporting argument needed
to fill in gaps. Time to put up or shut up.
greywolf42
"Martin Gradwell" <MTGra...@btinternet.com> wrote in message
news:NCBBKLHDOLBDKNHOKBD...@btinternet.com...
>
> greywolf42 <min...@sim-ss.com> wrote in message
> news:d6Lx6.1080$Cx5.2...@nntp3.onemain.com...
> >
> > Chris Hillman <hil...@math.washington.edu> wrote in message
> >
>
news:Pine.OSF.4.21.010328...@goedel1.math.washington.edu..
> ..
> > > we can measure the rate of precession of
> > > the perhelia of Mercury's orbit, which turns out to be about 5600
> degrees
> > > per century.
> >
> > Chris. You and I have got to swear off posting without caffeine.
> >
> > Please read what you wrote and try again.
> >
> > Hint: Number is off by a factor of 10. Units are wrong.
>
> Factor of 10? 5600'', reported as 5600 degrees, is out by a factor of
3600.
According to his source (Will), the total Perihelion advance (observed) is
574 arcseconds per year (that was the factor of 10). I assumed the units
were a seperate issue, and just a typo.
Thanks for the precision. By 5999.74, I presume you mean 5599.74?
5599.74 - 5025.64 = 574.10 "/century.
>
> Note that the MTW text was last revised in 1973 (according to the
> copyright), and radar ranging began in 1966, so these figures must be
based
> on less than eight years of radar measurement. Since the sidereal period
of
> Jupiter is 11.86 years, the effect of Jupiter's motion on the position of
> Mercury over this period (periodic effect, not secular precession) will be
> considerable, and any measurement of anomalous precession needs to take
this
> into account; but MTW (p1111) says: "The periodic effects in the planetary
> orbits have not yet (1973) been studied experimentally". It does not say
> exactly how the figures have been adjusted to take the periodic effect
into
> account, but does say that for short-duration experiments "periodic
> perturbations in an orbit are of almost as much significance as the
> cumulative perihelion shift". Also, over eight years, the total measurable
> anomalous precession will be 43'' * 8 / 100 at most, i.e. 3''.44 max.
Excellent. It's a nice "pre-Mariner" GR case. Note that pre-Mariner,
GR-ists are already claiming validation to tenths of an arcsecond per
century.
Your back of the envelope is not precise, but will serve to illustrate one
point. (Only the Earth's contribution will have a denominator of 100) And
the period of the Planet involved (Mercury) also needs to be included.
I presume the same effects would apply to Venus -- which has a larger effect
on NPA of Mercury than Jupiter -- as well as the other planets. According
to Will "Was Einstein Right?", the total contributions are 277 arcseconds
for Venus, 153 for Jupiter, 90 from Earth, and the other planets "about 10."
Using your rough "smoothing" factor, and not arbitrarily limiting oneself to
Jupiter (as in MTW) gives "at most" 6.5 arcseconds (Venus), 3.6 (Jupiter),
2.1 (Earth) and 0.2 (the rest). For an unexamined uncertainty of up to 12.4
arcseconds per century. (The odds are against all the contributions lining
up, but we are examining "proofs" here.)
Accounting for the periods of the planets, instead of using Earth's value
(100/12 for Jupiter) for a denominator gives 3.2, 43.2, 2.1 and 5.4
(Saturn). A total of 51.9 arcseconds per century. 42 +- 52 arcseconds per
century if we use planetary values. These are reduced by a factor of 0.24
if we account for Mercury's orbital period: 42 +- 13 arcseconds per century.
So when MTW says 531''.54 +/- 0''.68 for "Newtonian", this really means 531
+- 12, and the NNPA is therefore 42 +- 13 arcseconds per century. (Not
precisely chi squared, but it will do for back of the envelope). Especially
as MTW claims this has not been evaluated (as of 1973).
One part in three is hardly the 3 parts in 1,000 level claimed by MTW or
Will.
> MTW's description of general precession as being "caused by observer not
> being in an inertial frame far from the sun" is unhelpful. In fact it is
the
> precession of the equinoxes, caused by the interaction between sun, moon
and
> earth. The positions of the equinoxes will also be subject to periodic as
> well as secular variation, which will be important not just in a short
term
> experiment, but also in any experiment where the positions of the major
> planets are significantly different at the end of the experiment, when
> compared to the beginning.
>
>
> Martin Gradwell, mtgra...@btinternet.com
> http://www.btinternet.com/~mtgradwell/
>
Perhaps I can clarify MTW a bit. When we try to look at the precession in
the orbit of Mercury (to validate GR) we need to look at Mercury's orbit
from a sidereal (external) coordinate system/ reference frame. What we
measure is (unavoidably) relative to the Earth. So to convert our
measurements (on Earth) to those of the background stars (orbits), we need
to correct for the Earth's precession.
Paul Stowe
Steve Carlip <car...@dirac.ucdavis.edu> wrote:
Yes indeed, the aberration is a 'potential' and can act, if and only if,
there is some means for it to 'grab' or act against something. In simpler
terms, to gain the required energy to move these bodies apart, it MUST
come from somewhere...
A 'analogy' is one can push against a sliding surface, if and only if,
there is some friction or means of grabbing against that surface. Thus,
aberration remains an unrealized 'potential' until there is something else
for it to act against. The Le Sage drag IS that something else. This can
be seen if one inspects the retarded potential equation and looks
specifically at the second derivative. But as you elude to, this is a
muti-parameter situation best suited to a full tensor evaluation. I am
currently looking at the issue, in Le Sage's model, orbits may be metastable
EXCEPT at certain orbital positions (a harmonic) which results in Titus-Bode's
observation.
I probably just did a lousy job of explaining this, but I did the best I
could...
> The energy transfer certainly *isn't* small for a typical model. After all,
> the whole point of drag is that energy is transferred from the moving body
> to the medium exterting the drag. For the balance you want, you would have
> to show that the energy transferred to the medium by drag is exactly balanced
> by energy transferred from the medium to the orbiting body by aberration.
> This is not a conservation argument; it requires a detailed analysis of the
> dynamics.
Yes, and when the drag actually exceeds the aberration potential (using up the
'credit' that's in the bank so to speak) the drag then becomes manifest.
>> It is dishonest to claim that a theory (or type of theory) is disproven by
>> Feynman's argument (drag). It is dishonest to claim that a (type of) theory
>> is disproven by Lagrange's argument (aberration). Because you KNOW
>> that they are contrary tendencies, that balance in some situations.
>
> I don't know that they balance in some situations. Show me. Give me a
> concrete calculation.
Yup, we've been working on this. As indicated above on the Titus-Bode's
relationship. But, as you said, it complicated (if it were at all obvious,
well it probably would have been done by now). I've given all the
quanitative elements in discussions but have YET to see any indication that
there is any interest (or even curiosity) in to anyone (besides myself and
Barray) seriously looking into this. Everyone wants to be spoon fed the
final answer without EVERY seriously considering the idea themselves. Even
then, as evidenced by Luc, they will tend to 'want to believe' that the
answer given MUST be flawed, or cooked up in some manner.
> As I said before, the two ``contrary tendencies'' have a different dependence
> on the masses and velocities of the orbiting objects. In particular, for a
> planet orbiting the Sun, they have a *very* different dependence on the mass
> of the Sun, and on the mass of the orbiting body. Work it out!
Yes, I have. I now have the quantitative magnitude of the drag wrt orbital
velocity AND the fling magnitude wrt to orbital radius, and can say that the
fling potential exceeds the drag in the weak limit. Thus, as Barry mentioned,
the result would, even if manifested, be that of orbits spiraling outward
when the propagation velovity is of the order of c.
> If you can find any way to get the two effects to cancel, for more than one
> orbit at one radius with one mass ratio, I'd like to see it. Once again,
> this is not a question about belief, but about the numbers.
>
>[... later in the same post]
>
>> What I was pointing out was that so long as the speed of gravity
>> was on the close order of c, any of these theories could give the proper
>> perihelion advance. That was the point of my statement. Sorry if I wasn't
>> clear. I thought I was paraphrasing your claims in your 1999 paper very
>> well. I guess the context threw you off.
>
> Not the context, the content. Your claim is in no way a paraphrase of my paper;
> if you think it is, you haven't understood my paper.
>
>>> Unless you have some other reason for expecting a particular value of V_g,
>>> you are now simply stating that these theories make no prediction about
>>> the perihelion advance.
>
>> Almost precisely. Ther is no other OBSERVATIONAL reason for expecting
>> a particular value of Vg.
>
>> But please include GR in the list. Ther is no "other" reason for expecting
>> Vg to be "c" in GR, either.
>
> You're simply wrong here. There is no freedom to adjust the speed of gravity
> in GR; there is no free parameter to tune.
Paul Stowe
greywolf42
> greywolf42 said some stuff about
> .
> >
> >No one on this group mentioned that Noether's theorem "solved" GR's
> >problems. They kept trying to state that gravity had "no" speed in GR
> >(which violates Noether's theorem) -- to avoid Laplace's argument.
Until
> >Dr. Carlip published his 1999 paper, and reminded the crowd.
>
> And the main reason noether came up with those two theorems, was to
> assist hilbert in obtaining einstein's field equations from an invariance
> principle. The theorems basically originate with gr.
And your point would be what?
> [...]
> >> It certainly is not simply a restatement of energy conservation. First
> >> of all, noether's theorem is far more general. Noether's theorem is
where
> >> the electromagnetic potential in qed come from, for example. So, is it
> >> also a simple restatement of charge conservation?
> >
> >"Charge conservation" predates QED by 40 years. It predates Noether's
> >theorem by 15 years. And I can't think of much more general than energy
> >conservation. Of course, the point was the use of Noether's theorem in
GR.
>
> Explain how 40 years prior to QED, someone connected charge conservation
> to a massless photon.
Non sequiteur. Charge conservation was postulated by Millikan. I'm not
"connecting" it to a massless photon.
> Or else provide a compelling reason for it that
> doesn't require lots of ad hoc-ery. I can get it from one symmetry.
> Why is energy conservation "basic"?
Because it is assumed in all of physics. One assumes energy conservation
and one assumes momentum conservation.
> I see nothing that indicates a reason
> energy is special without some general principle that gives it a less
> ad hoc apperance.
Energy conservation is an ad hoc assumption?
> You also don't have a good reason to believe otherwise
> unless you can state a principle more general that,
I have no need to state a "more general" principle that "energy is
conserved."
> "because". Friction
> doesn't appear to be energy conserving, and based on nothing else, why
> would you assume the heat from friction was identeical to the energy loss?
Why would I bother with such a silly straw man?
> >And the ironic use of the "extraordinarily improbable" possibility of
> >balance -- for any theory but GR.
>
> You always have the option of showing otherwise. Since you don't do
> so, I see no reason to assume you are correct. But, go for broke. Prove
> me incorrect.
But you are the one making the claim that anything other than GR is
"extraordinarily improbable." I have no way of showing otherwise, since you
have nothing to back up your claim. You made the claim, you back it up.
>
>
> [...]
> >That's what I said when I described Noether's theorem. I just used less
> >pretentious (and possibly less precise) language. "Continuous symmetry
of
> >the lagrangian" translates to "where the flow of energy is closed and
> >continuous." "Conserved current" means no energy is lost. Taken
together,
> >that means energy is conserved.
>
> Since it also gives you:
>
> 1) conservation of momentum from translational invariance
That was also assumed.
> 2) conservation of angular momentum from rotational invariance
That was also assumed.
> 3) E&M and conservation of charge through phase invariance
> 4) The weak interaction and the W+/-, Z through weak isospin invariance
> 5) The strong interaction and gluons through color charge invariance
> 6) the low lying states in light to medium nuclei throught the
> application of isospin invariance to analog nuclei.
> 7) The prediction of the pi0, pi+ pi- as an isospin triplet.
> 8) conservation of the stress-energy tensor in gr, which is the
> generalization of conservation of energy (differing from your
> definition).
> 9)
>
> and a long list of others, including essentially the entire standard
> model.
And all of these are merely plugging different values into the equation that
says:
"If you assume a quantity is conserved, then it is conserved."
>
> >
> >Of course, you can substitute other quantities into the mathematical
> >symbols. And the ink on the page (or phosphors on the screen) don't
care.
> >But the underlying assumption is the same. If you assume energy is
> >conserved, then energy is conserved. If you assume "X" is conserved,
then
> >"X" is conserved.
> >
> >But Noether is far more precise and quantified than this simple
explanation.
>
> Yeah. I know. That's why I expect (well maybe not quite "expect") you
> to make use of that fact and derive results and suggest the tests that
> will differentiate it from gr.
Will differentiate Noether's theorem from GR????
> Noether's theorem gives you a prescription,
> since your conservation law will have a symmetry assosciated with it.
Symmetry is a restatement of assumed conservation.
> The
> converse of noether's theorems are also true.
Huh??? If energy is not conserved, then it is not conserved. Very deep.
> If you think conservation of
> energy is the highlight, you've totally missed the boat.
>
> >>
> >> Use it to derive the "balance" you insist upon.
> >>
> >???? I'm not sure what you mean by this.
> >
> >Energy is (at least assumed to be) conserved in all known physics. It
is
> >therefore beholden upon a critic -- who bases his critique on
> >non-conservation of energy -- to be less cavalier about it.
>
> I don't know. Who? You have claimed two competing effects cancel to
> provide an alternative to gr.
Sigh. Read the thread. We're talking about deliberate misrepresentation.
> Since you claim to base this on something
> having to do with noether's theorem, you should have no problem whipping
> out the conserved quantity.
Energy. Done.
> In fact, these two competing quantities
> themselves should have a symmetry and conservation law that exists
> independently of anything but the parameters used to describe the effects.
> Otherwise, they can't cancel.
False, irrelevant and unsupported.
>
> Now, go do what you constantly pester other people to do and in all
> likelyhood, they will pay more attention to you than you've ever paid
> to anyone that's ever done as you've asked. Here's your chance to prove
> that everyone else is more closed minded than you are. You even have it
> easier. All you need are derivations and an explanation of the tests
> suggested by those derivations along with any supporting argument needed
> to fill in gaps. Time to put up or shut up.
ROTFLMAO.
YOU (speaking for our hypothetical expert) claimed that
1) All LeSage theories are disproven because the Earth will spiral into the
sun. This is a lie. Because you believe that the Earth would actually
spiral out, due to aberration. But it's harder to find the reason.
2) After a plausible mechanism is raised to counter #1, you bring up
aberration and claim that all LeSage theories are disproven because the
Earth will spiral out. But this is a lie, because you are withholding the
information of the possibility of balance -- as exists in GR. It is a lie
because it is provided out of context.
3) But GR suffers the same "flaw" as #2. And when someone finally notices,
you haul out Noether to "save" GR. But GR is assumed to follow from Noether
(or vice versa).
4) Now -- backed fully up -- you claim that any alternative must "prove"
that Noether's theorem (conservation of energy) applies. This is also a
lie, because it is a double standard. Because you have to assume
conservation of energy for Noether's theorem. And you insist on proof that
energy is conserved for anything other than GR.
greywolf42
greywolf42
> On Fri, 6 Apr 2001, greywolf42 wrote:
>
> >
> > "Matthew Nobes" <man...@fraser.sfu.ca> wrote in message
> > news:Pine.GSO.4.30.010406...@fraser.sfu.ca...
> > > sci.physics added with followups there.
> > >
> > > My Thanks to Bilge for his post which highlighted these statements
> > >
> > > On Thu, 5 Apr 2001, greywolf42 wrote:
> > >
> > > > Of course GR has always suffered from the Lagrange argument. It is
not
> > > > "particle-based" so there is no obvious primal source for any "back
> > > > action."
> > >
> > > This makes no sense. Back action of what?
> >
> > Those "velocity-dependent" terms that cancel the "fling" in GR. "Back
> > action" is used instead of that evil word "force."
>
> That's because it's not a force.
A rose by any other name.......
> > > It's all included in the GR
> > > lagrangain, the action of the field on the particles, and the action
of
> > > the particles on the field is all there. Just like the
Maxwell--Lorentz
> > > lagrangian.
> >
> > Which is why so many GR-ists insisted that gravity has "no" speed. It
> > simply is.
>
> No. That is not how I understand it at all. There is a field, if it's
> static then it is just there. But changes in the field propagate at c.
> This is the same as E&M
I happen to agree that changes propagate. I question what the speed is.
But the point was not what you and I think. The point was the endless
repetitions of claims that gravity "does not propagate, gravitational waves
propagate" by GR-ists on this newsgroup.
I didn't mean forgot it name. I meant forgot it's uses -- specifically that
gravity has a speed of propagation.
>
> > Perhaps I was mistaking those who represent themselves as experts on
> > this usenet for real "modern physicists."
>
> Well I assure you that I know a lot about Noether's theorem, and I
> suppose I'd take the label "modern" physicist.
See what trouble labels can cause?
> > Point being that "modern physicists" (the ones you point to here)
understand
> > that Noether solved Einstein's GR aberration problem through
conservation of
> > {energy}. Yet those same experts will ignore Noether and apply
arguments
> > wildly contrary to Noether when dealing with an aether theory.
>
> You need a Lagrangain to apply Noether's theorem. Please post the
> Lagrangian of your theory, then we'll get to work.
You are incorrect. A Lagrangian states that the sum of "potential energy"
and "kinetic energy" is constant. This means energy is conserved.
Noether's theorem means total energy is conserved. One does not require the
other. They each require the assumption of energy conservation.
I didn't state that they'd forgotten it's name. My point (understandable in
context) is that they forget what Noether's theorem SAYS.
>
> AS for Dr. Carlip's paper. I thought he was refuting Tom van Flandren's
> arguements by summerizing some (little known but uncontroversial) facts
> about GR.
But those arguments apply to ANY theory that assumes energy is conserved.
>
> Again I assure you that people working in GR know all about Noether's
> theorem.
Apparently not.
>
> >> [...]
> >>> You are currently making the claim that it is "extraordinarily
> >>> improbable" that such a balance can obtain. (In your GR paper,
> >>> I recall the section "Is it a miracle?") But at it's core,
> >>> Noether's theorem is only a re-statement that energy in a system
> >>> is conserved -- a rephrasing of the Lagrangian. So such a balance
> >>> is not "improbable" at all. Nothing about orbital dynamics
> >>> is self-evident. But conservation of energy is tried and true.
> >>
> >> It certainly is not simply a restatement of energy conservation. First
> >> of all, noether's theorem is far more general. Noether's theorem is
> >> where the electromagnetic potential in qed come from, for example. So,
> >> is it also a simple restatement of charge conservation?
>
> > "Charge conservation" predates QED by 40 years. It predates Noether's
> > theorem by 15 years.
>
> So? That doesn't change the fact that oen can use Noether's theorem to
> derive conservaion of charge from the Maxwell Lagrangian. Hence Noether's
> theorem applies to much more then enegy conservation. That's the point.
>
> > And I can't think of much more general than energy conservation.
>
> Conservation of momentum?
I'd accept those two as 1-2, 2-1 or tied. :)
>
> > Of course, the point was the use of Noether's theorem in GR.
>
> Well you've shown that you don't really understand it so why should we
> take your comments very seriously?
Ah! If I disagree, then I must not understand. Perfect special plead.
> > And the ironic use of the "extraordinarily improbable" possibility of
> > balance -- for any theory but GR.
>
> ??? AS I understand Dr. Carlip's paper, and my notes on Jackson's text
> the arguements are similar for both Maxwell's theory and GR.
Okay we're 2 for 2. But any "other" theory is "extraordinarily improbable."
Do I detect a double standard?
>
> >> [...]
> >>>
> >>> Note the progression of backing and filling in the above thread.
> >>> Each step is plausible. Drag, aberration, "unlikely balance",
> >>> Noether.
> >>> One didn't state something that was not strictly true. But it is
> >>> disingenuous because you know each statement is not the whole truth.
> >>> And the clear purpose is to mislead the audience.
> >
> >> Let me phrase noether's theorem in the way that it applies to physics:
> >>
> >> "For each contiuous symmetry of the lagrangian, there exists
> >> a conserved current".
> >
> > That's what I said when I described Noether's theorem.
>
> No you said "Noether's theorem is only a re-statement that energy in a
> system is conserved -- a rephrasing of the Lagrangian"
>
> This is false on two counts.
>
> 1) Noether's theory applies to far more then energy conservation.
So does the Lagrangian -- if you want it to -- and place another "conserved"
quantity into it.
> 2) Given the symmetries one can construct an infinity of lagrangains which
> will obey them, hence Noether's theorem by itself cannot uniquly determine
> the Lagrangian (that's my best guess at what rephrase is supposed to mean
> in this context).
That's not what I meant, but it is true.
>
> > I just used less pretentious (and possibly less precise) language.
>
> That's an understatement
Thank you.
> > "Continuous symmetry of the lagrangian" translates to "where the flow
> > of energy is closed and continuous."
>
> Only in your fantasy land. The QCD lagranian is invairant under continous
> local SU(3) transformations. How does this "tranlate" to "the flow of
> energy"?
>
> > "Conserved current" means no energy is lost.
>
> Only in a special case.
The case where we are talking about energy. Which we are.
> > Taken together, that means energy is conserved.
> >
> > Of course, you can substitute other quantities into the mathematical
> > symbols. And the ink on the page (or phosphors on the screen) don't
> > care. But the underlying assumption is the same. If you assume energy
> > is conserved, then energy is conserved. If you assume "X" is
> > conserved, then "X" is conserved.
>
> Again this is not what Noether's theorem says
>
> You assume that the Lagrangian is invariant under time translations this
> *implies* that energy is conserved.
Yes. They are equivalent statements.
>
> > But Noether is far more precise and quantified than this simple
> > explanation.
> >
> >>
> >> Use it to derive the "balance" you insist upon.
> >>
> > ???? I'm not sure what you mean by this.
> >
> > Energy is (at least assumed to be) conserved in all known physics.
> > It is therefore beholden upon a critic -- who bases his critique on
> > non-conservation of energy -- to be less cavalier about it.
>
> It is beholden upon somebody who want's to use Noether's theorem in an
> arguement to acutuyally produce a Lagrangian to which said theorem can be
> applied. Wouldn't you agree?
No. Because both are particular restatements of {insert quality here}
conservation. You don't need one to "derive" the other. If you have
{quality} conservation, then you have both.
greywolf42
greywolf42
> greywolf42 <min...@sim-ss.com> wrote:
>
> [On balancing gravitational aberration and drag in LeSage models]
>
> > You are currently making the claim that it is "extraordinarily
improbable"
> > that such a balance can obtain. (In your GR paper, I recall the section
"Is
> > it a miracle?") But at it's core, Noether's theorem is only a
re-statement
> > that energy in a system is conserved -- a rephrasing of the Lagrangian.
So
> > such a balance is not "improbable" at all. Nothing about orbital
dynamics
> > is self-evident. But conservation of energy is tried and true.
>
> Noether's theorem, as applied to the particular case of time translation,
says
> that *total* energy is conserved.
That was my point.
> In GR, the orbital energy can be carried
> off only by gravitational waves---there's nothing else around to
participate
> in the interaction---
That is an assumption.
>and you can combine Noether's theorem with the very
> weak quadrupole coupling of gravitational waves to show that aberration
and
> velocity-dependent forces must nearly cancel.
Of course they must. Because that is what Noether's theorem says! If total
energy is conserved, then total energy is conserved. But you haven't
demonstrated what GR's "velocity-dependent forces" are. You have used NT to
say "it must be so."
> In a LeSage theory, total energy is perhaps also conserved. (I say
perhaps
> because you can draw this conclusion from Noether's theorem only if the
> full theory is derived from a time translation invariant Lagrangian.
Incorrect. A time-translation invariant Lagrangian is a fancy way of saying
"assume energy is conserved."
>Show
> me a Lagrangian and I'll make the statement stronger.) But now the system
> isn't just the orbiting bodies plus gravitational radiation;
But a LeSage theory has not "gravitational radiation" in the sense that GR
does.
> it also includes
> the LeSage ``ultra-mundame particles'' (or ether, or whatever), and you
> have to take into account any extra transfer of energy between the
orbiting
> bodies and these particles/this medium.
I presume you mean Feynman drag.
> The conservation argument that
> works for GR can be extended *only* if you can prove that this energy
> transfer is very small.
Incorrect. You have assumed a LeSagian will have all of GR's "outlets" --
specifically (as yet unobserved) gravitational radiation -- PLUS some
Feynman drag. But since energy is conserved, I, too can invoke "total
energy is conserved."
>
> The energy transfer certainly *isn't* small for a typical model. After
all,
> the whole point of drag is that energy is transferred from the moving body
> to the medium exterting the drag. For the balance you want, you would
have
> to show that the energy transferred to the medium by drag is exactly
balanced
> by energy transferred from the medium to the orbiting body by aberration.
> This is not a conservation argument; it requires a detailed analysis of
the
> dynamics.
But a similar level of proof is not required of GR. A "lagrangian" is
written that ASSUMES nothing except gravitational radiation. And
gravitational radiation is "ad hoc" method of extracting that "extra"
energy.
>
> > It is dishonest to claim that a theory (or type of theory) is disproven
by
> > Feynman's argument (drag). It is dishonest to claim that a (type of)
theory
> > is disproven by Lagrange's argument (aberration). Because you KNOW
> > that they are contrary tendencies, that balance in some situations.
>
> I don't know that they balance in some situations. Show me. Give me a
> concrete calculation.
The argument is dishonest. Period. You do know that they "balance" for GR.
>
> As I said before, the two ``contrary tendencies'' have a different
dependence
> on the masses and velocities of the orbiting objects. In particular, for
a planet
> orbiting the Sun, they have a *very* different dependence on the mass of
the
> Sun, and on the mass of the orbiting body. Work it out!
>
> If you can find any way to get the two effects to cancel, for more than
one orbit
> at one radius with one mass ratio, I'd like to see it. Once again, this
is not a
> question about belief, but about the numbers.
>
> [... later in the same post]
>
> > What I was pointing out was that so long as the speed of gravity
> > was on the close order of c, any of these theories could give the proper
> > perihelion advance. That was the point of my statement. Sorry if I
wasn't
> > clear. I thought I was paraphrasing your claims in your 1999 paper very
> > well. I guess the context threw you off.
>
> Not the context, the content. Your claim is in no way a paraphrase of my
paper;
> if you think it is, you haven't understood my paper.
I understood it quite well. You stated that GR could support a speed of
gravity from c to infinity. Because Noether's theorem assures the answer
will come out "right."
>
> >> Unless you have some other reason for expecting a particular value of
V_g,
> >> you are now simply stating that these theories make no prediction about
> >> the perihelion advance.
>
> > Almost precisely. Ther is no other OBSERVATIONAL reason for expecting
> > a particular value of Vg.
>
> > But please include GR in the list. Ther is no "other" reason for
expecting
> > Vg to be "c" in GR, either.
>
> You're simply wrong here. There is no freedom to adjust the speed of
gravity
> in GR; there is no free parameter to tune.
>
> Steve Carlip
>
You are incorrect. Mainly from long habit.
greywolf42
Matthew Nobes
script that Mr. Mingst likes to use whenever he's confronted with a
reference he doesn't want to see. But nontheless here we go.
My main reference will be Peskin and Schroeder "An Introduction to Quantum
Field Theory" refered to as P&S. I'll also quote from "Classical Dynamics
of Point Particles and Systems" by Marion and Thornton, refered to as M&T.
This thread has now illustrated my point that Mr. Mingst seems to be
incapbable of admitting that he might have something to learn about
physics.
On Tue, 10 Apr 2001, greywolf42 wrote:
> "Matthew Nobes" <man...@fraser.sfu.ca> wrote in message
> news:Pine.GSO.4.30.01040...@fraser.sfu.ca...
> > On Fri, 6 Apr 2001, greywolf42 wrote:
> >
> > >
> > > "Matthew Nobes" <man...@fraser.sfu.ca> wrote in message
> > > news:Pine.GSO.4.30.010406...@fraser.sfu.ca...
> > > > sci.physics added with followups there.
> > > >
> > > > My Thanks to Bilge for his post which highlighted these statements
> > > >
> > > > On Thu, 5 Apr 2001, greywolf42 wrote:
> > > >
> > > > > Of course GR has always suffered from the Lagrange argument.
> > > > > It is not "particle-based" so there is no obvious primal
> > > > > source for any "back action."
> > > >
> > > > This makes no sense. Back action of what?
> > >
> > > Those "velocity-dependent" terms that cancel the "fling" in GR.
> > > "Back action" is used instead of that evil word "force."
> >
> > That's because it's not a force.
>
> A rose by any other name.......
You should learn field theory.
> > > > It's all included in the GR
> > > > lagrangain, the action of the field on the particles, and the action
> > > > of the particles on the field is all there. Just like the
> > > > Maxwell--Lorentz lagrangian.
> > >
> > > Which is why so many GR-ists insisted that gravity has "no" speed. It
> > > simply is.
> >
> > No. That is not how I understand it at all. There is a field, if it's
> > static then it is just there. But changes in the field propagate at c.
> > This is the same as E&M
>
> I happen to agree that changes propagate. I question what the speed is.
And apparently maintain that it's an adjustable parameter. This is fals
within GR.
> But the point was not what you and I think. The point was the endless
> repetitions of claims that gravity "does not propagate, gravitational waves
> propagate" by GR-ists on this newsgroup.
Changes in the field propagate. Nobody who knows about GR would dispute
that.
What part of what I said didn't you understand. P&S detail several uses
of Noether's theorem. The use it to derive conservation of energy,
momentum, charge ...
> -- specifically that gravity has a speed of propagation.
Granted the refs. I gave don't address that point.
> > > Perhaps I was mistaking those who represent themselves as experts on
> > > this usenet for real "modern physicists."
> >
> > Well I assure you that I know a lot about Noether's theorem, and I
> > suppose I'd take the label "modern" physicist.
>
> See what trouble labels can cause?
Like what? AS I said, I assure you I know a hell of a lot about Noether's
theorem.
> > > Point being that "modern physicists" (the ones you point to here)
> > > understand that Noether solved Einstein's GR aberration problem
> > > through conservation of {energy}. Yet those same experts will
> > > ignore Noether and apply arguments wildly contrary to Noether when
> > > dealing with an aether theory.
> >
> > You need a Lagrangain to apply Noether's theorem. Please post the
> > Lagrangian of your theory, then we'll get to work.
>
> You are incorrect.
No I'm not. From see P&S page 17
> A Lagrangian states that the sum of "potential energy" and "kinetic
> energy" is constant.
I'm speechless.
1) The Lagraingian is the kinetic MINUS the potential energy. (see M&T
page 235 equation 7.2). Perhaps you're thinking of the Hamiltonian,
which is the total energy (sum of kinetic and potential)
2) The Lagrangain doesn't "state" anything. It's kinetic minus potential,
there is *no* a priori reason to suspect that this is constant
> This means energy is conserved. Noether's theorem means total energy
> is conserved. One does not require the other. They each require the
> assumption of energy conservation.
NO NO NO
Okay start with the Hamiltoian its kinetic plus potential, which we'll
write as
H = T - U
Now *if* this is constant in time then energy will be conserved. But
sometimes it's difficult to determine this, this is where Noether's
theorem comes in handy. It turns out that *if* L = T - U is invairant
under time translations (note I've I've made no assumptions about L, I'm
only saying that *if* it is invariant) then the hamiltonian will be
constant in time.
Notice that again a priori you do not assume energy conservation. You
check whether or not the Lagrangian is invariant. IF is is so THEN energy
is conserved.
And you are *wrong* Check *ANY* modern field theory textbook.
> > AS for Dr. Carlip's paper. I thought he was refuting Tom van Flandren's
> > arguements by summerizing some (little known but uncontroversial) facts
> > about GR.
>
> But those arguments apply to ANY theory that assumes energy is conserved.
Prove it. You don't just wave your hands and chant Noether's theorem.
You have to write down a Lagrangian and derive things.
> > Again I assure you that people working in GR know all about Noether's
> > theorem.
>
> Apparently not.
Are your refering to me?
> > >> [...]
> > >>> You are currently making the claim that it is "extraordinarily
> > >>> improbable" that such a balance can obtain. (In your GR paper,
> > >>> I recall the section "Is it a miracle?") But at it's core,
> > >>> Noether's theorem is only a re-statement that energy in a system
> > >>> is conserved -- a rephrasing of the Lagrangian. So such a balance
> > >>> is not "improbable" at all. Nothing about orbital dynamics
> > >>> is self-evident. But conservation of energy is tried and true.
> > >>
> > >> It certainly is not simply a restatement of energy conservation. First
> > >> of all, noether's theorem is far more general. Noether's theorem is
> > >> where the electromagnetic potential in qed come from, for example. So,
> > >> is it also a simple restatement of charge conservation?
> >
> > > "Charge conservation" predates QED by 40 years. It predates Noether's
> > > theorem by 15 years.
> >
> > So? That doesn't change the fact that oen can use Noether's theorem to
> > derive conservaion of charge from the Maxwell Lagrangian. Hence Noether's
> > theorem applies to much more then enegy conservation. That's the point.
> >
> > > And I can't think of much more general than energy conservation.
> >
> > Conservation of momentum?
>
> I'd accept those two as 1-2, 2-1 or tied. :)
What about sonservation of charge?
> > > Of course, the point was the use of Noether's theorem in GR.
> >
> > Well you've shown that you don't really understand it so why should we
> > take your comments very seriously?
>
> Ah! If I disagree, then I must not understand. Perfect special plead.
No you *don't* understand. Your comments above make it perfectly clear
that you totally misunderstand Lagrangian mechanics.
I want to convince you of that. So tell me, what exactly would you regard
as sufficent evidence that you don't understand this?
Let's start with a simple one. DO you agree that you're defintion of the
LAgrangain was incorrect?
> > > And the ironic use of the "extraordinarily improbable" possibility of
> > > balance -- for any theory but GR.
> >
> > ??? AS I understand Dr. Carlip's paper, and my notes on Jackson's text
> > the arguements are similar for both Maxwell's theory and GR.
>
> Okay we're 2 for 2. But any "other" theory is "extraordinarily improbable."
> Do I detect a double standard?
Dr. Carlip gave you precisely the reason why it's improbable in Le Sage
theory.
> > >> [...]
> > >>>
> > >>> Note the progression of backing and filling in the above thread.
> > >>> Each step is plausible. Drag, aberration, "unlikely balance",
> > >>> Noether.
> > >>> One didn't state something that was not strictly true. But it is
> > >>> disingenuous because you know each statement is not the whole truth.
> > >>> And the clear purpose is to mislead the audience.
> > >
> > >> Let me phrase noether's theorem in the way that it applies to physics:
> > >>
> > >> "For each contiuous symmetry of the lagrangian, there exists
> > >> a conserved current".
> > >
> > > That's what I said when I described Noether's theorem.
> >
> > No you said "Noether's theorem is only a re-statement that energy in a
> > system is conserved -- a rephrasing of the Lagrangian"
> >
> > This is false on two counts.
> >
> > 1) Noether's theory applies to far more then energy conservation.
>
> So does the Lagrangian -- if you want it to -- and place another "conserved"
> quantity into it.
You don't "place" conserved quanities in a Lagrangain.
> > 2) Given the symmetries one can construct an infinity of lagrangains which
> > will obey them, hence Noether's theorem by itself cannot uniquly determine
> > the Lagrangian (that's my best guess at what rephrase is supposed to mean
> > in this context).
>
> That's not what I meant, but it is true.
Then what did you mean by "rephrasing"
> > > I just used less pretentious (and possibly less precise) language.
> >
> > That's an understatement
>
> Thank you.
I was refering to the parenthetical comment.
> > > "Continuous symmetry of the lagrangian" translates to "where the flow
> > > of energy is closed and continuous."
> >
> > Only in your fantasy land. The QCD lagranian is invairant under continous
> > local SU(3) transformations. How does this "tranlate" to "the flow of
> > energy"?
??? Guess can't answer that one.
> > > "Conserved current" means no energy is lost.
> >
> > Only in a special case.
>
> The case where we are talking about energy. Which we are.
Then you should have made that clear. But you didn't. You used blanket
langauge, betraying your ignorance.
> > > Taken together, that means energy is conserved.
> > >
> > > Of course, you can substitute other quantities into the mathematical
> > > symbols. And the ink on the page (or phosphors on the screen) don't
> > > care. But the underlying assumption is the same. If you assume energy
> > > is conserved, then energy is conserved. If you assume "X" is
> > > conserved, then "X" is conserved.
> >
> > Again this is not what Noether's theorem says
> >
> > You assume that the Lagrangian is invariant under time translations this
> > *implies* that energy is conserved.
>
> Yes. They are equivalent statements.
Your statement and mine? If so that's false.
> > > But Noether is far more precise and quantified than this simple
> > > explanation.
> > >
> > >>
> > >> Use it to derive the "balance" you insist upon.
> > >>
> > > ???? I'm not sure what you mean by this.
> > >
> > > Energy is (at least assumed to be) conserved in all known physics.
> > > It is therefore beholden upon a critic -- who bases his critique on
> > > non-conservation of energy -- to be less cavalier about it.
> >
> > It is beholden upon somebody who want's to use Noether's theorem in an
> > arguement to acutuyally produce a Lagrangian to which said theorem can be
> > applied. Wouldn't you agree?
>
> No. Because both are particular restatements of {insert quality here}
> conservation. You don't need one to "derive" the other. If you have
> {quality} conservation, then you have both.
No you do not. You do not "have" the Lagrangian if you postualte energy
conservation. All you have is (by Noether's theorem) the statement that
whatever your lagrangian is it will be invariant under time translation
invaraince. This still leaves you with an infinite set of lagrangians to
pick from. Don't belive me? Check P&S pages 18-19.
How hard is it to admit you're wrong?
Bilge
>
>You are incorrect. A Lagrangian states that the sum of "potential energy"
>and "kinetic energy" is constant. This means energy is conserved.
>Noether's theorem means total energy is conserved. One does not require the
>other. They each require the assumption of energy conservation.
No he isn't. YOU are incorrect. The _Hamiltonian_ is _often_ the sum
T + U, but noether's theorm applies to the lagrangian, or more specifically,
a lagrangian density. There's an entire section devoted to noether's theorem
in goldstein. hint, hint.
As I said before, conservation of energy is not what noether's theorem is
useful for. In fact, if that were its sole or even primary utility, it would
have been forgotten the day it was published. Ever notice the form of the
standard model:
SU(3) x SU(2)_L x U(1)_Y
What do you suppose this particular notation reflects?
[...]
>
>I didn't state that they'd forgotten it's name. My point (understandable in
>context) is that they forget what Noether's theorem SAYS.
>
Not hardley. If what noether's theorem states had been forgotton,
there would be no standard model, no BCS theory of superconductors,
and in short, not much of the modern physics you love so much. Frankly,
if you realized what your argument entails, you wouldn't keep posting
what you post regarding physics. You weren't the first to realize
noether's theorem is useful, although you may very well be the first
to decide it isn't when you can't use it to promote an unphysical
argument. Most would consider eliminating unphysical arguments a plus,
however.
[...]
>No. Because both are particular restatements of {insert quality here}
>conservation. You don't need one to "derive" the other. If you have
>{quality} conservation, then you have both.
You have absolutely no idea why or for what, noether's theorem is
useful. Noether's theorem does not tell anything is conserved in advance.
Nother's theorem tell's you that you are guaranteed to find one, IF, you
have a symmetry and you employ the symmetry to construct it from the
lagrangian. So, your model, whatever that is, must have terms from
which you may construct a lagrangian. You should be able to obtain
an exact statement for a conservation law which includes your terms
for your "drag". Not only that, the conservation law you get should
provide some obvious relationships or indicate how to find one or
more relationships which would serve as a test.
Matthew Nobes
[snip]
> Okay start with the Hamiltoian its kinetic plus potential, which we'll
> write as
>
> H = T - U
CORRECTION, should be H = T + U
Chris Hillman
[Snip Barry Mingt's ["greywolf"'s] continued mangling of Noether's
theorem.]
On Tue, 10 Apr 2001, greywolf42 wrote:
> "Matthew Nobes" <man...@fraser.sfu.ca> wrote in message
> news:Pine.GSO.4.30.01040...@fraser.sfu.ca...
> > There is a field,
(In classical relativistic field theories)
> > if it's
> > static then it is just there. But changes in the field propagate at c.
> > This is the same as E&M
>
> I happen to agree that changes propagate. I question what the speed is.
Once again: part of the trouble here is that Barry M is not being very
careful to clarify what theory he is discussing, or whether he is talking
about "what Nature really does". It really should be perfectly obvious to
him by now that if he is discussing gtr or Maxwell's theory of EM, then
changes in the field do indeed propagate as radiation at the speed of
light (at the level of tangent planes, in gtr, since as we all know--
yes?-- "speed" without qualification makes no sense in curved spacetimes).
> But the point was not what you and I think. The point was the endless
> repetitions of claims that gravity "does not propagate, gravitational waves
> propagate" by GR-ists on this newsgroup.
Barry, if you are talking about gtr, then it is a mathematically
verifiable fact that gravitational radiation consists of dynamic
perturbations in the spacetime curvature (in fact, the Weyl tensor) and
propagates at the speed of light. Changes in gravitational -forces-
require some qualification to discuss in the context of gtr, but no matter
how you make the qualification, the same conclusion holds: "updating" of
the gravitational field in gtr, and of the EM field in Maxwell's theory of
EM, occurs in a vacuum via radiation propagating at the speed of light.
(In a fluid, for example, obviously a sound wave moves material around and
this changes the gravitational field, and this kind of wave propagates
slower than the speed of light, etc.--- this doesn't invalidate anything
Matthew or I or any other knowledgeable poster have said about what
propagates in gtr and how quickly it does so.)
[snip more stuff unread, but the following did catch my virtual eye:]
> You are incorrect. A Lagrangian states that the sum of "potential energy"
> and "kinetic energy" is constant.
<snicker>
Your ignorance is showing again, Barry. Suggest you read Wald, General
Relativity, paying particular attention to Lagrangian and Hamiltonian
formulations of gtr and to the nature of energy and conservation laws in
curved spacetimes.
[snip more stuff unread]
Chris Hillman
Home Page: http://www.math.washington.edu/~hillman/
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
NOTE TO WOULD-BE CORRESPONDENTS: I have installed a mail filter which
deletes incoming messages not from the "*.edu" or "*.gov" domains, but
also deletes messages from some bad actors whose emails happen to be in
the "*.edu" domain and "passes" messages from a few friends with email
addresses in other domains.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Bilge
>
>news:slrn9ctnm...@radioactivex.lebesque-al.net...
>> greywolf42 said some stuff about
>> .
>> >
>> >No one on this group mentioned that Noether's theorem "solved" GR's
>> >problems. They kept trying to state that gravity had "no" speed in GR
>> >(which violates Noether's theorem) -- to avoid Laplace's argument.
>Until
>> >Dr. Carlip published his 1999 paper, and reminded the crowd.
>>
>> And the main reason noether came up with those two theorems, was to
>> assist hilbert in obtaining einstein's field equations from an invariance
>> principle. The theorems basically originate with gr.
>
>And your point would be what?
[...]
>>
>> Explain how 40 years prior to QED, someone connected charge conservation
>> to a massless photon.
>
>Non sequiteur. Charge conservation was postulated by Millikan. I'm not
>"connecting" it to a massless photon.
Why would it be conserved?
>> Or else provide a compelling reason for it that
>> doesn't require lots of ad hoc-ery. I can get it from one symmetry.
>> Why is energy conservation "basic"?
>
>Because it is assumed in all of physics. One assumes energy conservation
>and one assumes momentum conservation.
Why? Can I simply invent a new conservation law anytime I can't
find a process that doesn't conserve something?
>> I see nothing that indicates a reason
>> energy is special without some general principle that gives it a less
>> ad hoc apperance.
>
>Energy conservation is an ad hoc assumption?
Apparently, you must think so, since you don't seem to know why it
should or shouldn't be. I guess you just buy into the status quo of
the 17th century and are afraid to rock the boat, huh?
>> You also don't have a good reason to believe otherwise
>> unless you can state a principle more general that,
>
>I have no need to state a "more general" principle that "energy is
>conserved."
Of course not. It would force you to include some physical principle to
go along with the "physics that would be really keen if...". If you could,
you would and had you actually read the posts, you could have simply
copied the answer.
>
>> "because". Friction
>> doesn't appear to be energy conserving, and based on nothing else, why
>> would you assume the heat from friction was identeical to the energy loss?
>
>Why would I bother with such a silly straw man?
Because you have a silly litle straw theory? No? When the going
gets tough, any excuse will due, for the "Lapdogs of LaSage Society",
huh?
>> >And the ironic use of the "extraordinarily improbable" possibility of
>> >balance -- for any theory but GR.
>>
>> You always have the option of showing otherwise. Since you don't do
>> so, I see no reason to assume you are correct. But, go for broke. Prove
>> me incorrect.
>
>But you are the one making the claim that anything other than GR is
>"extraordinarily improbable." I have no way of showing otherwise, since you
>have nothing to back up your claim. You made the claim, you back it up.
No. I'm making the claim that the likelyhood that you will manage
to come up with anything credible that gets withing 5+ orders of
magnitude of the precision of Gr is not only improbable, but unlikely
on the time scale of the age of the universe.
>> [...]
>> >That's what I said when I described Noether's theorem. I just used less
>> >pretentious (and possibly less precise) language. "Continuous symmetry
>of
>> >the lagrangian" translates to "where the flow of energy is closed and
>> >continuous." "Conserved current" means no energy is lost. Taken
>together,
>> >that means energy is conserved.
>>
>> Since it also gives you:
>>
>> 1) conservation of momentum from translational invariance
>
>That was also assumed.
>
>> 2) conservation of angular momentum from rotational invariance
>
>That was also assumed.
What was assumed? There are no assumptions apart from the symmetry
listed.
>
>> 3) E&M and conservation of charge through phase invariance
>> 4) The weak interaction and the W+/-, Z through weak isospin invariance
>> 5) The strong interaction and gluons through color charge invariance
>> 6) the low lying states in light to medium nuclei throught the
>> application of isospin invariance to analog nuclei.
>> 7) The prediction of the pi0, pi+ pi- as an isospin triplet.
>> 8) conservation of the stress-energy tensor in gr, which is the
>> generalization of conservation of energy (differing from your
>> definition).
>> 9)
>>
>> and a long list of others, including essentially the entire standard
>> model.
>
>And all of these are merely plugging different values into the equation that
>says:
>
>"If you assume a quantity is conserved, then it is conserved."
Boy, are you dense. You apparently quit reading anything regarding
noether's theorem as soon as you could spell "noether".
>> >Of course, you can substitute other quantities into the mathematical
>> >symbols. And the ink on the page (or phosphors on the screen) don't
>care.
>> >But the underlying assumption is the same. If you assume energy is
>> >conserved, then energy is conserved. If you assume "X" is conserved,
>then
>> >"X" is conserved.
>> >
>> >But Noether is far more precise and quantified than this simple
>explanation.
>>
>> Yeah. I know. That's why I expect (well maybe not quite "expect") you
>> to make use of that fact and derive results and suggest the tests that
>> will differentiate it from gr.
>
>Will differentiate Noether's theorem from GR????
No. Differentiate what you loosely refer to as a theory of
gravity from gr.
>> Noether's theorem gives you a prescription,
>> since your conservation law will have a symmetry assosciated with it.
>
>Symmetry is a restatement of assumed conservation.
In other words, you cannot even restate what it is you think
your conjecture of gravity conserves? But, you know for certain,
that it will be whatever you assume.
>> The
>> converse of noether's theorems are also true.
>
>Huh??? If energy is not conserved, then it is not conserved. Very deep.
Not as deep as your coma.
[...]
>>
>> Now, go do what you constantly pester other people to do and in all
>> likelyhood, they will pay more attention to you than you've ever paid
>> to anyone that's ever done as you've asked. Here's your chance to prove
>> that everyone else is more closed minded than you are. You even have it
>> easier. All you need are derivations and an explanation of the tests
>> suggested by those derivations along with any supporting argument needed
>> to fill in gaps. Time to put up or shut up.
>
>ROTFLMAO.
"Really Opaque Theory For Lusers, Mentally and Otherwise"?
Is that the title of your theory?
>
>YOU (speaking for our hypothetical expert) claimed that
I speak only for myself.
>
>1) All LeSage theories are disproven because the Earth will spiral into the
>sun. This is a lie. Because you believe that the Earth would actually
>spiral out, due to aberration. But it's harder to find the reason.
Of course, you had the opportunity to use noether's theorem to
prove this, but you seemed to forget what it was, other than how
to spell it.
>2) After a plausible mechanism is raised to counter #1, you bring up
>aberration and claim that all LeSage theories are disproven because the
>Earth will spiral out. But this is a lie, because you are withholding the
>information of the possibility of balance -- as exists in GR. It is a lie
>because it is provided out of context.
Of course, the wouldn't be an issue, if you knew as much about
noether's theorem as you do about tossing out phrases like
"straw man" and "appeal to authority" to avoid reading about it..
>3) But GR suffers the same "flaw" as #2. And when someone finally notices,
>you haul out Noether to "save" GR. But GR is assumed to follow from Noether
>(or vice versa).
That doesn't help you any. You didn't use noether's theorem for anything
(except the jargon value).
>
>4) Now -- backed fully up -- you claim that any alternative must "prove"
>that Noether's theorem (conservation of energy) applies. This is also a
>lie, because it is a double standard. Because you have to assume
>conservation of energy for Noether's theorem. And you insist on proof that
>energy is conserved for anything other than GR.
>
No, the only thing I assume is that you have absolutely
no theory of anything, and simply troll to abuse people.
You should have spent your time at berkeley standing somewhere
besides the cyclotron beam dump.
greywolf42
> greywolf42 said some stuff about
> Re: Reference for Non-newtonian Perihelion advance of Mercury to usenet:
> >
> >"Bilge" <ro...@radioactivex.lebesque-al.net> wrote in message
> >news:slrn9ctnm...@radioactivex.lebesque-al.net...
> >> greywolf42 said some stuff about
> >> .
> >> >
> >> >No one on this group mentioned that Noether's theorem "solved" GR's
> >> >problems. They kept trying to state that gravity had "no" speed in
GR
> >> >(which violates Noether's theorem) -- to avoid Laplace's argument.
> >Until
> >> >Dr. Carlip published his 1999 paper, and reminded the crowd.
> >>
> >> And the main reason noether came up with those two theorems, was to
> >> assist hilbert in obtaining einstein's field equations from an
invariance
> >> principle. The theorems basically originate with gr.
> >
> >And your point would be what?
>
> That obviously, gravity does not violate noether's theorem.
??? No one said it did.
> [...]
> >>
> >> Explain how 40 years prior to QED, someone connected charge
conservation
> >> to a massless photon.
> >
> >Non sequiteur. Charge conservation was postulated by Millikan. I'm not
> >"connecting" it to a massless photon.
>
> Why would it be conserved?
Ask Milliken. Answer" (like any good quantum physicist) "it just is, and
you can't ask why."
> >> Or else provide a compelling reason for it that
> >> doesn't require lots of ad hoc-ery. I can get it from one symmetry.
> >> Why is energy conservation "basic"?
> >
> >Because it is assumed in all of physics. One assumes energy
conservation
> >and one assumes momentum conservation.
>
> Why? Can I simply invent a new conservation law anytime I can't
> find a process that doesn't conserve something?
Huh? The question was "why is energy conservation basic?" What the heck
does you question have to do with this?
> >> I see nothing that indicates a reason
> >> energy is special without some general principle that gives it a less
> >> ad hoc apperance.
> >
> >Energy conservation is an ad hoc assumption?
>
> Apparently, you must think so, since you don't seem to know why it
> should or shouldn't be. I guess you just buy into the status quo of
> the 17th century and are afraid to rock the boat, huh?
No, I do not think energy conservation is an ad hoc assumption. Becuase it
is a postulate of all physics. (PRIOR to any other assumptions). Therefore
not ad hoc (after the fact).
> >> You also don't have a good reason to believe otherwise
> >> unless you can state a principle more general that,
> >
> >I have no need to state a "more general" principle that "energy is
> >conserved."
>
> Of course not. It would force you to include some physical principle to
> go along with the "physics that would be really keen if...". If you could,
> you would and had you actually read the posts, you could have simply
> copied the answer.
Bilge, you really need to stay off whatever you've been ingesting. I can't
make head or tails of your last three attempts at argument.
> >
> >> "because". Friction
> >> doesn't appear to be energy conserving, and based on nothing else, why
> >> would you assume the heat from friction was identeical to the energy
loss?
> >
> >Why would I bother with such a silly straw man?
>
> Because you have a silly litle straw theory? No? When the going
> gets tough, any excuse will due, for the "Lapdogs of LaSage Society",
> huh?
Huh? Will do fine. YOUR silly straw man was "friction doesn't appear to be
energy conserving." Laughable on it's face. It has nothing to do with
LeSagian theories. This is deep space argument #4.
> >> >And the ironic use of the "extraordinarily improbable" possibility
of
> >> >balance -- for any theory but GR.
> >>
> >> You always have the option of showing otherwise. Since you don't do
> >> so, I see no reason to assume you are correct. But, go for broke.
Prove
> >> me incorrect.
> >
> >But you are the one making the claim that anything other than GR is
> >"extraordinarily improbable." I have no way of showing otherwise, since
you
> >have nothing to back up your claim. You made the claim, you back it up.
>
> No. I'm making the claim that the likelyhood that you will manage
> to come up with anything credible that gets withing 5+ orders of
> magnitude of the precision of Gr is not only improbable, but unlikely
> on the time scale of the age of the universe.
GR is off by 50 orders of magnitude. Hardly precise.
> >> [...]
> >> >That's what I said when I described Noether's theorem. I just used
less
> >> >pretentious (and possibly less precise) language. "Continuous
symmetry
> >of
> >> >the lagrangian" translates to "where the flow of energy is closed
and
> >> >continuous." "Conserved current" means no energy is lost. Taken
> >together,
> >> >that means energy is conserved.
> >>
> >> Since it also gives you:
> >>
> >> 1) conservation of momentum from translational invariance
> >
> >That was also assumed.
> >
> >> 2) conservation of angular momentum from rotational invariance
> >
> >That was also assumed.
>
> What was assumed? There are no assumptions apart from the symmetry
> listed.
Clueless question: Symmetry of what? Answer: Energy.
> >
> >> 3) E&M and conservation of charge through phase invariance
> >> 4) The weak interaction and the W+/-, Z through weak isospin
invariance
> >> 5) The strong interaction and gluons through color charge invariance
> >> 6) the low lying states in light to medium nuclei throught the
> >> application of isospin invariance to analog nuclei.
> >> 7) The prediction of the pi0, pi+ pi- as an isospin triplet.
> >> 8) conservation of the stress-energy tensor in gr, which is the
> >> generalization of conservation of energy (differing from your
> >> definition).
> >> 9)
> >>
> >> and a long list of others, including essentially the entire standard
> >> model.
> >
> >And all of these are merely plugging different values into the equation
that
> >says:
> >
> >"If you assume a quantity is conserved, then it is conserved."
>
> Boy, are you dense. You apparently quit reading anything regarding
> noether's theorem as soon as you could spell "noether".
Devastating reply.
> >> >Of course, you can substitute other quantities into the mathematical
> >> >symbols. And the ink on the page (or phosphors on the screen) don't
> >care.
> >> >But the underlying assumption is the same. If you assume energy is
> >> >conserved, then energy is conserved. If you assume "X" is
conserved,
> >then
> >> >"X" is conserved.
> >> >
> >> >But Noether is far more precise and quantified than this simple
> >explanation.
> >>
> >> Yeah. I know. That's why I expect (well maybe not quite "expect") you
> >> to make use of that fact and derive results and suggest the tests that
> >> will differentiate it from gr.
> >
> >Will differentiate Noether's theorem from GR????
> No. Differentiate what you loosely refer to as a theory of
> gravity from gr.
How does this claim relate to "If you assume "X" is conserved, then "X" is
conserved."?
> >> Noether's theorem gives you a prescription,
> >> since your conservation law will have a symmetry assosciated with it.
> >
> >Symmetry is a restatement of assumed conservation.
>
> In other words, you cannot even restate what it is you think
> your conjecture of gravity conserves?
I just said you could.
> But, you know for certain,
> that it will be whatever you assume.
Precisely.
> >> The
> >> converse of noether's theorems are also true.
> >
> >Huh??? If energy is not conserved, then it is not conserved. Very
deep.
>
> Not as deep as your coma.
>
> [...]
> >
> >YOU (speaking for our hypothetical expert) claimed that
>
> I speak only for myself.
Then start your own thread.
{snip rewrite of thread topic by Matt}
greywolf42
greywolf42
>
> [Snip Barry Mingt's ["greywolf"'s] continued mangling of Noether's
> theorem.]
>
> On Tue, 10 Apr 2001, greywolf42 wrote:
>
> > "Matthew Nobes" <man...@fraser.sfu.ca> wrote in message
> > news:Pine.GSO.4.30.01040...@fraser.sfu.ca...
>
> > > There is a field,
>
> (In classical relativistic field theories)
>
> > > if it's
> > > static then it is just there. But changes in the field propagate at
c.
> > > This is the same as E&M
> >
> > I happen to agree that changes propagate. I question what the speed is.
>
> Once again: part of the trouble here is that Barry M is not being very
> careful to clarify what theory he is discussing, or whether he is talking
> about "what Nature really does". It really should be perfectly obvious to
> him by now that if he is discussing gtr or Maxwell's theory of EM, then
> changes in the field do indeed propagate as radiation at the speed of
> light (at the level of tangent planes, in gtr, since as we all know--
> yes?-- "speed" without qualification makes no sense in curved spacetimes).
I just got through saying changes propagate. Where is the "trouble?"
>
> > But the point was not what you and I think. The point was the endless
> > repetitions of claims that gravity "does not propagate, gravitational
waves
> > propagate" by GR-ists on this newsgroup.
>
> Barry, if you are talking about gtr, then it is a mathematically
> verifiable fact that gravitational radiation consists of dynamic
> perturbations in the spacetime curvature (in fact, the Weyl tensor) and
> propagates at the speed of light. Changes in gravitational -forces-
> require some qualification to discuss in the context of gtr, but no matter
> how you make the qualification, the same conclusion holds: "updating" of
> the gravitational field in gtr, and of the EM field in Maxwell's theory of
> EM, occurs in a vacuum via radiation propagating at the speed of light.
Again, why are you pretending to argue? Do you feel you have to try to
argue with every statement I make?
>
> (In a fluid, for example, obviously a sound wave moves material around and
> this changes the gravitational field, and this kind of wave propagates
> slower than the speed of light, etc.--- this doesn't invalidate anything
> Matthew or I or any other knowledgeable poster have said about what
> propagates in gtr and how quickly it does so.)
Again, why are you pretending to argue? Do you feel you have to try to
argue with every statement I make?
Where were you last year when a half dozen "GR-ists" insisted that gravity
does not propagate?
>
> [snip more stuff unread, but the following did catch my virtual eye:]
>
greywolf42
greywolf42
"greywolf42" <min...@sim-ss.com> wrote in message news:...
>
> "Bilge" <ro...@radioactivex.lebesque-al.net> wrote in message
> news:slrn9d9i0...@radioactivex.lebesque-al.net...
>
> {snip rewrite of thread topic by Matt}
My apologies -- rewrite by Bilge, not Matt....
>
> greywolf42
>
>
Bilge
>>
>> Why would it be conserved?
>
>Ask Milliken. Answer" (like any good quantum physicist) "it just is, and
>you can't ask why."
As usual, you can't even offer a highschool level answer.
I get charge conservation, a massless photon, and maxwell's
equations all from a single invariance principle. You take
your interpretation of milliken as religious gospel. In fact,
you deliberately retain this and the rest of the ad hoc classical
theories. I guess a simple principle that ties all of those things
together diminishes the opportunities to be a crackpot, huh?
Thank you for admitting your faith in charge conservation is based
upon religion.
>> Why? Can I simply invent a new conservation law anytime I can't
>> find a process that doesn't conserve something?
>
>Huh? The question was "why is energy conservation basic?" What the heck
>does you question have to do with this?
That's what I asked. Why is energy conservation basic? Thank you for
admitting your only basis for believing it is religion. To which long-
dead physicist should I attribute this? All of the ones with whom I'm
familiar, considered conservation laws something of a mystery and
one of the reasons that classical mechanics didn't start and end with
newton.
>>
>> Apparently, you must think so, since you don't seem to know why it
>> should or shouldn't be. I guess you just buy into the status quo of
>> the 17th century and are afraid to rock the boat, huh?
>
>No, I do not think energy conservation is an ad hoc assumption. Becuase it
>is a postulate of all physics. (PRIOR to any other assumptions). Therefore
>not ad hoc (after the fact).
Thank you for admitting that conservation of energy is your ad hoc
assumption. The reason people believed it prior to this century was
religion and a belief it could be shown to follow from a more general
principlee. It looks like you're the one that accepts mathematical
expressions as physics without questioning how it relates to nature.
Thanks for pointing that out as well.
>>
>> Of course not. It would force you to include some physical principle to
>> go along with the "physics that would be really keen if...". If you could,
>> you would and had you actually read the posts, you could have simply
>> copied the answer.
>
>Bilge, you really need to stay off whatever you've been ingesting. I can't
>make head or tails of your last three attempts at argument.
You can't answer a single question you've been asked. Why I
expect this to be different?
[...]
>Huh? Will do fine. YOUR silly straw man was "friction doesn't appear to be
>energy conserving." Laughable on it's face. It has nothing to do with
>LeSagian theories. This is deep space argument #4.
I didn't say it did. Thank you for admitting there was no reason to
believe that frictional forces conserved energy. In fact, if you apply
noether's theorem to the macroscopic process, frictional forces are not
energy conserving. They are not invariant time translations. Since you
have no idea why energy is conserved and no idea what noether's theorem
is about, you have no reason to bring it up.
[...]
>> No. I'm making the claim that the likelyhood that you will manage
>> to come up with anything credible that gets withing 5+ orders of
>> magnitude of the precision of Gr is not only improbable, but unlikely
>> on the time scale of the age of the universe.
>
>GR is off by 50 orders of magnitude. Hardly precise.
Please provide evidence for a 50 order of magnitude deviation
of gr from observations. First, answer my previous question.
[...]
>>
>> What was assumed? There are no assumptions apart from the symmetry
>> listed.
>
>Clueless question: Symmetry of what? Answer: Energy.
Thank you for admitting you've never read anything about the subject.
[...].
>
>How does this claim relate to "If you assume "X" is conserved, then "X" is
>conserved."?
>
You assume that. Not anyone else. It's not my fault that you are too
stupid to read.
>> >> Noether's theorem gives you a prescription,
>> >> since your conservation law will have a symmetry assosciated with it.
>> >
>> >Symmetry is a restatement of assumed conservation.
>>
>> In other words, you cannot even restate what it is you think
>> your conjecture of gravity conserves?
>
>I just said you could.
I didn't say I could prove your clueless notion of gravity conserves
energy. I could probably show the opposite. If you cannot show that energy
is conserved, there is no reason to believe otherwise. Demonstrate that
it does or put up with me stating that you cannot.
[...]
>>
>> I speak only for myself.
>
>Then start your own thread.
>
Don't worry, your posts are so full of holes, no one will
be deprived of any opportunity. And - if you can't actually answer
a question related to physics, I'll stick to what you can answer.
Simon Clark
> "Bilge" <ro...@radioactivex.lebesque-al.net> wrote in message
> news:slrn9d9i0...@radioactivex.lebesque-al.net...
>> greywolf42 said some stuff about
>> Re: Reference for Non-newtonian Perihelion advance of Mercury to usenet:
>> >
>> >"Bilge" <ro...@radioactivex.lebesque-al.net> wrote in message
>> >news:slrn9ctnm...@radioactivex.lebesque-al.net...
[snip]
>> >> 1) conservation of momentum from translational invariance
>> >
>> >That was also assumed.
>> >
>> >> 2) conservation of angular momentum from rotational invariance
>> >
>> >That was also assumed.
>>
>> What was assumed? There are no assumptions apart from the symmetry
>> listed.
>
> Clueless question: Symmetry of what? Answer: Energy.
Just out of curiosity: what's the difference between "symmetric energy" and
"asymmertic energy"?
--
Simon Clark
Steve Carlip
> In article <9alf0k$pmh$1...@woodrow.ucdavis.edu>,
> Steve Carlip <car...@dirac.ucdavis.edu> wrote:
>> In a LeSage theory, total energy is perhaps also conserved. [...]
>> But now the system isn't just the orbiting bodies plus gravitational
>> radiation; it also includes the LeSage ``ultra-mundame particles''
>> (or ether, or whatever), and you have to take into account any extra
>> transfer of energy between the orbiting bodies and these particles/this
>> medium. The conservation argument that works for GR can be
>> extended *only* if you can prove that this energy transfer is very small.
> Yes indeed, the aberration is a 'potential' and can act, if and only if,
> there is some means for it to 'grab' or act against something. In simpler
> terms, to gain the required energy to move these bodies apart, it MUST
> come from somewhere...
Right. But in a LeSage model, this is simple---the energy comes from
the ``ultra-mundane particles.''
For simplicity, consider two bodies of equal mass in circular orbits around
their center of mass. In a LeSage model, both bodies are being bombarded
from all sides by ``ultra-mundane particles,'' but each body provides a
``shadow'' that reduces the bombardment of the other. These particles
transfer momentum and energy to the orbiting bodies; because of the
shadow effect, there's a net transfer of momentum to each body in the
direction of the other, and thus a force.
If the ``ultra-mundane particles'' traveled at infinite speed, the shadow
of each body would fall on a line directly through the center of mass of
the system, and the momentum transfer would be toward the center of
mass. If the ``ultra-mundane particles'' travel at finite speed, though,
the direction of the shadow shifts---it curves slightly behind the motion
of each body. The net momentum transfer is thus not exactly toward the
center of mass of the system, but has a component tangential to the orbit.
It's this transfer of momentum (and energy) that's responsible for the
energy gain due to aberration.
>> As I said before, the two ``contrary tendencies'' [aberration and drag]
>> have a different dependence on the masses and velocities of the orbiting
>> objects. In particular, for a planet orbiting the Sun, they have a *very*
>> different dependence on the mass of the Sun, and on the mass of the
>> orbiting body. Work it out!
> Yes, I have. I now have the quantitative magnitude of the drag wrt orbital
> velocity AND the fling magnitude wrt to orbital radius, and can say that
> the fling potential exceeds the drag in the weak limit.
By a number of orders of magnitude, if I remember correctly. Doesn't
that pretty much preclude the possibility of cancellation?
Note also that the ratio of ``fling'' to ``drag'' depends on the mass of the
orbiting object. Consider, for example, the Earth and the Moon. Even if
you could somehow adjust your theory so that the two effects cancelled for
the Earth, you'd find that they drastically failed to cancel for the Moon.
But we have several decades of Lunar radar ranging data, and there's simply
no room allowed by observation for such an effect. (Again, I recommend
that you work this out; you'll find an enormous net force on the Moon.)
Steve Carlip
Chris Hillman
On Wed, 11 Apr 2001, greywolf42 (aka Barry Mingst) wrote:
> > > I happen to agree that changes propagate. I question what the speed is.
^^^^^^^ ^^^^^^^^^
[That's Barry.]
Changes in -what-? "Propagate" how? "Speed" in what sense?
> > Once again: part of the trouble here is that Barry M is not being very
> > careful to clarify what theory he is discussing, or whether he is talking
> > about "what Nature really does". It really should be perfectly obvious to
> > him by now that if he is discussing gtr or Maxwell's theory of EM, then
> > changes in the field do indeed propagate as radiation at the speed of
> > light (at the level of tangent planes, in gtr, since as we all know--
> > yes?-- "speed" without qualification makes no sense in curved spacetimes).
[That's me responding to the sentence quoted above.]
> I just got through saying changes propagate. Where is the "trouble?"
[That's Barry responding to my comment.]
<baffled stare>
Re-read what I wrote in the paragraph you quoted. What part don't you
understand?
</baffled stare>
> > > But the point was not what you and I think. The point was the endless
> > > repetitions of claims that gravity "does not propagate, gravitational
> > > waves
> > > propagate" by GR-ists on this newsgroup.
[That's Barry again.]
> > Barry, if you are talking about gtr, then it is a mathematically
> > verifiable fact that gravitational radiation consists of dynamic
> > perturbations in the spacetime curvature (in fact, the Weyl tensor) and
> > propagates at the speed of light. Changes in gravitational -forces-
> > require some qualification to discuss in the context of gtr, but no matter
> > how you make the qualification, the same conclusion holds: "updating" of
> > the gravitational field in gtr, and of the EM field in Maxwell's theory of
> > EM, occurs in a vacuum via radiation propagating at the speed of light.
[That's my comment on what he wrote.]
> Again, why are you pretending to argue? Do you feel you have to try to
> argue with every statement I make?
Re-read what I wrote. Why is it not clear to you that I was saying that
what you wrote was too imprecise to be meaninful, and that the facts of
the matter (regarding gtr) are more or less as I stated them. (Of course,
I could have gone into more detail and made more careful qualifications,
but there seems little point in trying to do that unless I feel that most
participants at least grasp the basics.)
> > (In a fluid, for example, obviously a sound wave moves material around and
> > this changes the gravitational field, and this kind of wave propagates
> > slower than the speed of light, etc.--- this doesn't invalidate anything
> > Matthew or I or any other knowledgeable poster have said about what
> > propagates in gtr and how quickly it does so.)
>
> Again, why are you pretending to argue? Do you feel you have to try to
> argue with every statement I make?
Same comment.
> Where were you last year when a half dozen "GR-ists"
^^^^^^^^^^^^^^^^^^^^
Who precisely to you have in mind? Since "GR-ist" is a phrase it seems
only you employ, you cannot expect me to guess whom you mean
> insisted that gravity does not propagate?
^^^^^^^^^^^^^^^^^^^
Sigh... you are not looking like a careful reader just now: you -still-
haven't realized that one of the major points in my responses has been
that "gravity propagates" DMS--- to make this into an umambiguous claim,
much less a -correct- one, you need to clarify what you mean by this
extremely vague phrase! (Which is ambiguous in at least three major
respects.)
To say the changes in the Weyl tensor propagate across vacuum regions as
gravitational radiation always makes sense (in gtr)--- to say that changes
in the amount of force experienced by some unambiguously defined class of
observers in a particular spacetime changes makes -some- sense but
-requires further careful qualification-. And the word "propagation"
applied to such changes is probably misleading at best; compare the
Bianchi differential identity and its role in coupling perturbations in
the Weyl and stress-momentum-energy tensors, where it is clear that this
identity lies at the very heart of the physical meaning of gtr and the
physical interpretation of the Weyl tensor and gravitational radiation.
There is nothing like that for "propagation of gravitostatic force" in gtr
(or "electrostatic force" in EM)--- this is one of the elementary points
about the two best known classical field theories which Tom Van Flandern
and some of this followers (including, it seems, Barry Mingst) seemingly
just cannot grasp.
See for example my collected posts on the Vaidya null dust.
greywolf42
Simon Clark <cla...@my-deja.com> wrote in message
news:1038747.3...@SRian-HQ.com...
It depends on whether you assume conservation of energy or not. Assume
conservation of energy, and energy is (equations are) symmetric.
greywolf42
Simon Clark
> Simon Clark <cla...@my-deja.com> wrote in message
> news:1038747.3...@SRian-HQ.com...
>> Just out of curiosity: what's the difference between "symmetric energy"
>> and "asymmertic energy"?
> It depends on whether you assume conservation of energy or not. Assume
> conservation of energy, and energy is (equations are) symmetric.
What I was trying to ask is: what is "symmetric/asymmetric" about the
energy? Given the energy of some sytem--e.g. a mass on a (possibly damped)
spring--how would I know if the energy was "symmetric" or not so that I can
apply Noether's theorem and deduce whether the energy is conserved or not?
--
Simon Clark
greywolf42
> greywolf42 said some stuff about
>
> >>
> >> Why would it be conserved?
> >
> >Ask Milliken. Answer" (like any good quantum physicist) "it just is,
and
> >you can't ask why."
>
> As usual, you can't even offer a highschool level answer.
> I get charge conservation, a massless photon, and maxwell's
> equations all from a single invariance principle.
Huh? Irony is lost on you Bilge. You asked me to justify why energy was
conserved (which is why you snipped the reference). Of course, you assume
the same thing. And you don't have a "single invariance principle" to get
all of the above. You have a THEOREM. Which depends on many prior
assumptions (postulates). That's why it's called a theorem, instead of a
postulate or principle.
> You take your interpretation of milliken as religious gospel.
In truth, I don't quite believe Milliken. But he was the first (or most
popular) presenter of the charge conservation principle.
> In fact,
> you deliberately retain this and the rest of the ad hoc classical
> theories.
You mean, like GR? The only way to not have an "ad hoc" theory, is to
include an explicit physical cause in the theory. The only "classical"
theory that does this is Maxwell for E&M. GM is ad hoc. QM is ad hoc. The
standard model is ad hoc.
What's your point?
> I guess a simple principle that ties all of those things
> together diminishes the opportunities to be a crackpot, huh?
> Thank you for admitting your faith in charge conservation is based
> upon religion.
Uh, I don't believe in "charge conservation" as it is normally taught
(charge structures are another matter). The point being discussed (which
you snipped) was whether charge conservation was first proposed by QED (as
you claimed) or Noether, or (as I noted) Milliken.
Milliken came first. I in no way implied I that he was a prophet.
> >> Why? Can I simply invent a new conservation law anytime I can't
> >> find a process that doesn't conserve something?
> >
> >Huh? The question was "why is energy conservation basic?" What the
heck
> >does you question have to do with this?
>
> That's what I asked. Why is energy conservation basic? Thank you for
> admitting your only basis for believing it is religion. To which long-
> dead physicist should I attribute this? All of the ones with whom I'm
> familiar, considered conservation laws something of a mystery and
> one of the reasons that classical mechanics didn't start and end with
> newton.
But Newton thought is was basic. It is basic to all physics (as I answered
and you snipped).
>
> >>
> >> Apparently, you must think so, since you don't seem to know why it
> >> should or shouldn't be. I guess you just buy into the status quo of
> >> the 17th century and are afraid to rock the boat, huh?
> >
> >No, I do not think energy conservation is an ad hoc assumption. Becuase
it
> >is a postulate of all physics. (PRIOR to any other assumptions).
Therefore
> >not ad hoc (after the fact).
>
> Thank you for admitting that conservation of energy is your ad hoc
> assumption.
Apparently you cannot read. Ad hoc means an explanation after the fact.
Postulate comes first.
> The reason people believed it prior to this century was
> religion
Your gross lack of knowledge of both history and physics is appalling.
>and a belief it could be shown to follow from a more general
> principlee. It looks like you're the one that accepts mathematical
> expressions as physics without questioning how it relates to nature.
> Thanks for pointing that out as well.
Bilge, you are amazingly tortuous and dishonest.
>
> >>
> >> Of course not. It would force you to include some physical principle
to
> >> go along with the "physics that would be really keen if...". If you
could,
> >> you would and had you actually read the posts, you could have simply
> >> copied the answer.
> >
> >Bilge, you really need to stay off whatever you've been ingesting. I
can't
> >make head or tails of your last three attempts at argument.
>
> You can't answer a single question you've been asked. Why I
> expect this to be different?
I've answered the ones that could be translated into English.
>
> [...]
> >Huh? Will do fine. YOUR silly straw man was "friction doesn't appear
to be
> >energy conserving." Laughable on it's face. It has nothing to do with
> >LeSagian theories. This is deep space argument #4.
>
> I didn't say it did. Thank you for admitting there was no reason to
> believe that frictional forces conserved energy.
Last one. This is ridiculous.
I said your silly strawman (that you snipped) that "friction doesn't appear
to be energy conserving" was laughable. How you managed to turn that into
an "admission" that there is no reason to believe they conserve energy
merely indicates the lengths of dishonesty you will stoop to.
Signing off.....
greywolf42
greywolf42
.
>
> On Wed, 11 Apr 2001, greywolf42 (aka Barry Mingst) wrote:
>
> > > > I happen to agree that changes propagate. I question what the speed
is.
> ^^^^^^^ ^^^^^^^^^
> [That's Barry.]
>
> Changes in -what-? "Propagate" how? "Speed" in what sense?
Changes in the statement that I was responding to -- that you snipped.
Apparently just to have something to argue about.
================
> On Tue, 10 Apr 2001, greywolf42 wrote:
>
> > "Matthew Nobes" <man...@fraser.sfu.ca> wrote in message
> > news:Pine.GSO.4.30.01040...@fraser.sfu.ca...
> > > There is a field,
>
> (In classical relativistic field theories)
>
> > > if it's
> > > static then it is just there. But changes in the field propagate at
c.
> > > This is the same as E&M
> >
> > I happen to agree that changes propagate. I question what the speed is.
>
> Once again: part of the trouble here is that Barry M is not being very
> careful to clarify what theory he is discussing, or whether he is talking
> about "what Nature really does". It really should be perfectly obvious to
> him by now that if he is discussing gtr or Maxwell's theory of EM, then
> changes in the field do indeed propagate as radiation at the speed of
> light (at the level of tangent planes, in gtr, since as we all know--
> yes?-- "speed" without qualification makes no sense in curved spacetimes).
I just got through saying changes propagate. Where is the "trouble?"
================
Changes in the gravitational field, or gravitational force, or in observed
accelerations of test particles.
Prop*a*gate: #5) Physics: To cause (a wave for example) to move through a
medium; transmit.
Speed: (sped) noun 1) Mathematics and Physics: The rate or measure of the
rate of motion; especially a) distance travelled divided by the time of
travel (also called the "average speed"). b) The limit of this quotient as
the time of travel becomes vanishingly small; the first derivative of
distance with respect to time: also called the "instantaneous speed." The
magnitude of a velocity.
[above quotes from the American Heritage Dictionary]
In other words, I mean as used in the English language or standard physics.
> > > Once again: part of the trouble here is that Barry M is not being very
> > > careful to clarify what theory he is discussing, or whether he is
talking
> > > about "what Nature really does". It really should be perfectly
obvious to
> > > him by now that if he is discussing gtr or Maxwell's theory of EM,
then
> > > changes in the field do indeed propagate as radiation at the speed of
> > > light (at the level of tangent planes, in gtr, since as we all know--
> > > yes?-- "speed" without qualification makes no sense in curved
spacetimes).
>
> [That's me responding to the sentence quoted above.]
Note to readers:
In this post, "you may call me doctor" Hillman has been randomly snipping
and reordering responses from different points and deleting his questions.
Then asking what I mean. This is known as misleading and a violation of the
posting guidelines on this newsgroup. But it hasn't stopped him before.
As such, I won't bother to waste my time responding to such trash.
Bilge
>
>conserved (which is why you snipped the reference). Of course, you assume
>the same thing. And you don't have a "single invariance principle" to get
>all of the above. You have a THEOREM. Which depends on many prior
>assumptions (postulates). That's why it's called a theorem, instead of a
>postulate or principle.
>> You take your interpretation of milliken as religious gospel.
>
>In truth, I don't quite believe Milliken. But he was the first (or most
>popular) presenter of the charge conservation principle.
I don't need to assume it in qed. It's a freebie.
>You mean, like GR? The only way to not have an "ad hoc" theory, is to
>include an explicit physical cause in the theory. The only "classical"
>theory that does this is Maxwell for E&M. GM is ad hoc. QM is ad hoc. The
>standard model is ad hoc.
>
>What's your point?
You've made it. Just as your foray into noether's theorm demonstrated
you knew zero about noether's theorem. I don't need to assume charge is
conserved in qed. It a freebie.
>
>Uh, I don't believe in "charge conservation" as it is normally taught
>(charge structures are another matter). The point being discussed (which
>you snipped) was whether charge conservation was first proposed by QED (as
>you claimed) or Noether, or (as I noted) Milliken.
I never claimed qed proposed it. It's derived.
>>
>> That's what I asked. Why is energy conservation basic? Thank you for
>> admitting your only basis for believing it is religion. To which long-
>> dead physicist should I attribute this? All of the ones with whom I'm
>> familiar, considered conservation laws something of a mystery and
>> one of the reasons that classical mechanics didn't start and end with
>> newton.
>
>But Newton thought is was basic. It is basic to all physics (as I answered
>and you snipped).
Thank you confirming once again that you cannot answer this question
either. Or rather, especially, since you kept harping on it only to
punt when it came time to ante up.
[...]
>> Thank you for admitting that conservation of energy is your ad hoc
>> assumption.
>
>Apparently you cannot read. Ad hoc means an explanation after the fact.
>Postulate comes first.
Yes and I thanked for admitting you can't answer the question.
>> The reason people believed it prior to this century was
>> religion
>
>Your gross lack of knowledge of both history and physics is appalling.
Since you don't seem to give examples, I assume this means you cannot.
>
>>and a belief it could be shown to follow from a more general
>> principlee. It looks like you're the one that accepts mathematical
>> expressions as physics without questioning how it relates to nature.
>> Thanks for pointing that out as well.
>
>Bilge, you are amazingly tortuous and dishonest.
I thought you'd appreciate your native language.
[whining rerun snipped]
greywolf42
> greywolf42 said some stuff about
>
> >
> >You are incorrect. A Lagrangian states that the sum of "potential
energy"
> >and "kinetic energy" is constant. This means energy is conserved.
> >Noether's theorem means total energy is conserved. One does not require
the
> >other. They each require the assumption of energy conservation.
>
> No he isn't. YOU are incorrect. The _Hamiltonian_ is _often_ the sum
> T + U, but noether's theorm applies to the lagrangian, or more
specifically,
> a lagrangian density. There's an entire section devoted to noether's
theorem
> in goldstein. hint, hint.
Notice that I was not so silly as to discuss the Lagrangian "operator", or
the Hamiltonian "operator." This may be difficult for a mathemetician to
understand. The fact the the Lagrangian operator is "T - U" is not
relevant. Energy conservation is still conserved.
I'll take a hit for the poor choice of word "states that." I should have
used "requires that" or "is based on."
Now to address the ridiculous quibbling, let's go to a reference for what
the Lagrangian assumes, and what it does not. After blowing some dust off
the top of Marion: 'Classiscal Dynamics of Particles and Systems' (Second
Edition), I find on page 210 the section titled "The Equivalence of
Lagrange's and Newton's Equations." Rather than simply imply that the
answer is available in some reference, I'll provide a quote (using ascii as
best as can be):
The section begins:
=========================================
"As we have emphasized from the outset, the Lagrangian and Newtonian
formulations of mechanics are equivalent: the viewpoint is different but the
content is the same. We now explicitly demonstrate this equivalence by
showing that the two sets of equations of motion are in fact the same."
par L d par L
-------- - --- ------.--- = 0 i = 1, 2, 3
par x_i dt par x_i
par (T - U) d par t (T - U)
------------- - -- --------.------ = 0
par x_i dt par x_i
But, in rectangular coordinates, and for a conservative system, we have
.
T = T(x_i) and U = U(x_i), so that
par T par U
-------- = 0 and -----.-- = 0
par x_i par x_i
Therefore, Lagrange's equations become
par U d par T
- -------- = --- -----.-- (Eq. 7.15)
par x_i dt par x_i
We also have (for a conservative system)
par U
- -------- = F_i
par x_i
and
d par T d par 3 1 . d
. .
--- --------- = --- -----.--- ( sum - m x^2_j ) = --- (m x_i) = p_i
dt par x_i dt par x_i j=1 2 dt
so that Eq. 7.15 yields the Newtonian equations, as required:
.
F_i = p_i
Thus, the Lagrangian and Newtonian equations are identical in the event that
the generalized coordinates are the rectangular coordinates.
===============================
You may note two items that I mentioned previosly were required for the
Lagrangian. One, that a "conservative system" is needed. This was
mentioned twice in this short section. Second, the Lagrangian is based on
conservation of energy (and momentum). For these two principles are the
foundation of Newtonian mechanics.
You may also note that the derivation was done only in cartesian
coordinates. But the equations hold regardless of coordinate system.
So -- since Noether's theorem applies to the Lagrangian, then Noether's
theorem requires conservation of .... (energy in this case). It is true the
above was done for energy and momentum. But it could -- in general -- be
applied to any conservative quantity. (i.e. any quantity that is assumed to
conserved).
So long as I have the book out, it is well worth looking at the beginning of
Marion's next section (emphasis in original):
===================
"The Essence of Lagrangian Dynamics"
In the preceding sections several general and important statements were made
concerning the Lagrangian formulation of mechanics. Before proceding
further, it seems worthwhile to summarize these points in order to emphasize
the difference between the Lagrangian and Newtonan viewpoints.
Historically the Lagrange equations of motion expressed in generalized
coordinates were derived prior to the statement of Hamiltion's Principle
(Lagrange's equations, 1788; Hamilton's Principle, 1834). We have elected
to deduce Lagrange's equations by postulating Hamilton's Principle because
this is the most straightforward approach and is also the formal method by
which the unification of classical dynamics is possible.
First and foremeost, it must be reiterated that lagrangian dynamics does not
constitute a NEW theory in any sense of the word. The results of a
Lagrangian analysis or a Newtonain analysis must be the same for any given
mechanical system; it is only the method used to obtain these results that
is different.
Whereas the Newtonian approach places the emphasis on an outside agency
acting ON a body (the force), the Lagrangian method deals only with
quantities which are associated WITH the body (the kinetic and potential
ENERGIES). In fact, nowhere in the Lagrangian formulation does the concept
of FORCE enter. This is a particularly important property of the method for
a variety of reasons. First, since energy is a scalar quantity, the
Lagrangian function for a system is invariant to coordinate transformations.
Indeed, such transformations are not restricted to be between various
orthogonal coordinate systems in ordinary space; they may also be
transformations between ORDINARY coordinates and GENERALIZED coordinates.
Thus, it is possible to pass from ordinary space (in which the equations of
motion may be quite complicated) to a configuration space which can be
chosen to yield maximum simplification for a particular problem. We are
accustomed to thinking of mechanical system in terms of VECTOR quantities
such as force, velocity, angular momentum, torque, etc., but in the
Lagrangnian formulation, the equations of motion are obeained entirely in
terms of SCALAR operations in configuration space.
======================================
>
> As I said before, conservation of energy is not what noether's theorem is
> useful for.
And I never claimed that conservation of energy was all that Noether's
theorem was useful for. The point at issue was using Noether's theorem to
demonstrate that general relatvity COULD NOT violate energy conservation
because of Noether's theorem. Regardless of the speed of propagation of
gravity.
> In fact, if that were its sole or even primary utility, it would
> have been forgotten the day it was published. Ever notice the form of the
> standard model:
>
> SU(3) x SU(2)_L x U(1)_Y
>
> What do you suppose this particular notation reflects?
Mathematician's rosary.
>
> [...]
> >
> >I didn't state that they'd forgotten it's name. My point/
(understandable in
> >context) is that they forget what Noether's theorem SAYS.
> >
> Not hardley. If what noether's theorem states had been forgotton,
> there would be no standard model, no BCS theory of superconductors,
> and in short, not much of the modern physics you love so much. Frankly,
> if you realized what your argument entails, you wouldn't keep posting
> what you post regarding physics. You weren't the first to realize
> noether's theorem is useful, although you may very well be the first
> to decide it isn't when you can't use it to promote an unphysical
> argument. Most would consider eliminating unphysical arguments a plus,
> however.
You've got at least two too many negatives in that last runon sentence. And
the part of Noether's theorem that was apparently forgotten by the GR-ists
on this site, is that gravity can propagate without aberration causing a
violation of energy conservation. Regardless of the uses put by
mathematicians prior to 1980.
>
> [...]
>
> >No. Because both are particular restatements of {insert quality here}
> >conservation. You don't need one to "derive" the other. If you have
> >{quality} conservation, then you have both.
>
>
> You have absolutely no idea why or for what, noether's theorem is
> useful.
The issue at hand is why it was useful to Dr. Carlip in "proving" that GR
had no aberration problem. In this thread, any other "uses" are irrelevant,
and I made no claims about it in any other arena.
> Noether's theorem does not tell anything is conserved in advance.
Correct. You assume that before you apply the theorem. Thus, the theorem
cannot tell you anything about what you have or have not assumed (that's why
it's a "theorem.")
> Nother's theorem tell's you that you are guaranteed to find one, IF, you
> have a symmetry and you employ the symmetry to construct it from the
> lagrangian.
Since the Lagrangian requires a conservative system (see derivation above),
you have to assume conservation to construct the Lagrangian. Thus,
Noether's theorem merely restates what you assume. It does tell you where
to find various pieces, but it's "guarantee" rests on the input assumption
(GIGO).
> So, your model, whatever that is, must have terms from
> which you may construct a lagrangian. You should be able to obtain
> an exact statement for a conservation law which includes your terms
> for your "drag".
Yup. Energy is conserved. And if I use Steve's approach, I simply say "I
have a Lagrangian. Therefore the velocity-dependent terms (drag or
back-action) must exactly cancel the aberration. Noether says so."
> Not only that, the conservation law you get should
> provide some obvious relationships or indicate how to find one or
> more relationships which would serve as a test.
>
The same tests apply to GR as to any other theory of gravity.
greywolf42
You "know" whether energy is conserved or not, because you assume it as your
(Newtonian) starting point.
The Lagrangian is a restatement of Newtonian "ordinary space" mechanics in
configuration space. If you have one, you have the other. If you have
Newtonian mechanics, then you have assumed that energy is conserved. If you
have the Lagrangian, then you have Noether's theorem.
Thus, (as I have repeatedly stated) one cannot use Noether's theorem to
"deduce" whether energy was conserved or not. Because you had to assume it
long before you started Noether's theorem.
"Symmetric energy" means energy is conserved. If energy is not conserved,
then Newton's equations fail. If Newton fails, then the Lagrangian fails.
If the Lagrangian fails, then Noether's theorem fails.
greywolf42
Unbelievable.....
What else can I say?
greywolf42
Chris Hillman
On Sat, 14 Apr 2001, Barry Mingst, alias "greywolf42", who badly needs to
learn to trim quoted text in the interests of readibility, wrote:
> Chris Hillman <hil...@math.washington.edu> wrote in message
> news:Pine.OSF.4.33.010413...@goedel1.math.washington.edu..
>
> > Changes in -what-? "Propagate" how? "Speed" in what sense?
>
> Changes in the statement that I was responding to -- that you snipped.
Changes in your -statement- propagate?!!!
Did you really mean to say that?
Didn't think so :-/
> Changes in the gravitational field, or gravitational force, or in
> observed accelerations of test particles.
I ask again--- what theory are you discussing? Gtr? If so, what do you
mean by "gravitational field"? What do you mean by "gravitational force"?
Do you understand the distinctions between the notions of "gravitational
field, gravitational force, and tidal accelerations" in gtr? Do you claim
that the "gravitational force" satisfies a wave equation? If so, can you
prove this? If not, what do you mean by saying that it "propagates"?
Alternatively, since you imply that you think my questions are
unreasonable, can you explain -why- you think they are unreasonable?
Bear in mind that this newsgroup is called sci.physics.relativity.
^^^^^^^
> Prop*a*gate: #5) Physics: To cause (a wave for example) to move through a
> medium; transmit.
[...]
> [above quotes from the American Heritage Dictionary]
In physics, of course, waves such as EM waves or gravitational waves are
not considered to move through a medium!
Quoting from the American Heritage Dictionary :-) might be appropriate in
a newsgroup called "alt.talk.popular_physics", it is pretty darn silly
here!
> In other words, I mean as used in the English language or standard physics.
Well, which is it? If you want to discuss the English language, this is
the wrong newsgroup, is it not?
If OTH you mean that you believe you are discussing -standard physics-
(can you be more specific?--- are you discussing gtr?), and that you are
employing physical terminology, then, as I have already explained to you
several times, you must begin by specifying what theory you are talking
about. If that theory is gtr, you have a lot of explaining to do when you
say (to paraphrase what I understand you to be saying) that "gravitational
forces propagate as waves"! As a matter of fact, you have some serious
explaining to do there even if the theory you are discussing is Newtonian
gravitation!
> In this post, "you may call me doctor" Hillman has been randomly snipping
> and reordering responses from different points and deleting his questions.
> Then asking what I mean. This is known as misleading and a violation of the
> posting guidelines on this newsgroup. But it hasn't stopped him before.
No, I'm trying to trim excess text in the interests of readibility and to
help you focus your attention on some of the points I keep raising and
which you keep trying to duck. You aren't fooling anyone, Barry.
> As such, I won't bother to waste my time responding to such trash.
Because you can't answer my questions, methinks :-/ If your statements are
to be believed, you don't even understand them! That says nothing good
about your understanding of what physics is about.
Chris Hillman
[Newsgroups corrected]
On Sun, 15 Apr 2001, Barry Mingst, aka "greywolf42", who is (of course!)
an -engineer- by training, wrote, revealingly:
> The Lagrangian is a restatement of Newtonian "ordinary space" mechanics in
> configuration space. If you have one, you have the other.
(ROFL!)
> "Symmetric energy" means energy is conserved. If energy is not
> conserved, then Newton's equations fail.
(ROFL!!)
> If Newton fails, then the Lagrangian fails. If the Lagrangian fails,
> then Noether's theorem fails.
(ROFL!!!)
I trust everyone else understands why this is so darn funny! :-)
Paul Stowe
"greywolf42" <min...@sim-ss.com> wrote:
>
>Simon Clark <cla...@my-deja.com> wrote in message
>news:1478829.x...@SRian-HQ.com...
>> greywolf42 <min...@sim-ss.com> wrote:
>>
>> > Simon Clark <cla...@my-deja.com> wrote in message
>> > news:1038747.3...@SRian-HQ.com...
>>
>> >> Just out of curiosity: what's the difference between "symmetric energy"
>> >> and "asymmertic energy"?
>>
>> > It depends on whether you assume conservation of energy or not. Assume
>> > conservation of energy, and energy is (equations are) symmetric.
>>
>> What I was trying to ask is: what is "symmetric/asymmetric" about the
>> energy? Given the energy of some sytem--e.g. a mass on a (possibly damped)
>> spring--how would I know if the energy was "symmetric" or not so that I
>can
>> apply Noether's theorem and deduce whether the energy is conserved or not?
>>
>> --
>> Simon Clark
>
> You "know" whether energy is conserved or not, because you assume it
> as your (Newtonian) starting point.
>
> The Lagrangian is a restatement of Newtonian "ordinary space" mechanics
> in configuration space. If you have one, you have the other. If you
> have Newtonian mechanics, then you have assumed that energy is conserved.
> If you have the Lagrangian, then you have Noether's theorem.
>
> Thus, (as I have repeatedly stated) one cannot use Noether's theorem to
> "deduce" whether energy was conserved or not. Because you had to assume
> it long before you started Noether's theorem.
>
> "Symmetric energy" means energy is conserved. If energy is not conserved,
> then Newton's equations fail. If Newton fails, then the Lagrangian fails.
> If the Lagrangian fails, then Noether's theorem fails.
>
> greywolf42
For readers of this thread NOT familiar with Noether's theorem, reference:
http://www.emmynoether.com/noeth.htm
http://theory1.physics.wisc.edu/~ldurand/711html/courseinfo/NoethersThm.html
http://peter.ingebretson.net/math_paper/node13.html
Paul Stowe
Simon Clark
> Simon Clark <cla...@my-deja.com> wrote in message
> news:1478829.x...@SRian-HQ.com...
>> What I was trying to ask is: what is "symmetric/asymmetric" about the
>> energy? Given the energy of some sytem--e.g. a mass on a (possibly
>> damped) spring--how would I know if the energy was "symmetric" or not so
>> that I can apply Noether's theorem and deduce whether the energy is
>> conserved or not?
> You "know" whether energy is conserved or not, because you assume it as
> your (Newtonian) starting point.
Then what is the point of using Noether's theorem? I want to -show- that
the energy is conserved (using Noether's theorem) not -assume- that it is
conserved.
> The Lagrangian is a restatement of Newtonian "ordinary space" mechanics in
> configuration space. If you have one, you have the other.
Yes, yes...
> If you have Newtonian mechanics, then you have assumed that energy is
> conserved.
and no. A mass on a damped spring is not a conservative system but obeys
Newtonian mechanics.
> If you have the Lagrangian, then you have Noether's theorem.
Yes, and since I have Noether's theorem I want to -use- it! Show me how to.
> Thus, (as I have repeatedly
and incorrectly
> stated) one cannot use Noether's theorem to "deduce" whether energy was
> conserved or not.
Gee, Noether must be really pissed of that someone named a useless theorem
after him.
> Because you had to assume it long before you started Noether's theorem.
Apparently you need to take Classical Mechanics 101 again.
Write down the Lagrangian for a damped spring. Apply Noether's theorem. The
energy of the spring is not conserved. Alternatively: use Newtonian
mechanics to calculate the energy of the spring. It is still not conserved.
> "Symmetric energy" means energy is conserved. If energy is not conserved,
> then Newton's equations fail. If Newton fails, then the Lagrangian fails.
> If the Lagrangian fails, then Noether's theorem fails.
You need to take look at those links that Paul Stowe just posted...
--
Simon Clark
Simon Clark
> In article <CUjC6.1271$05.13...@nntp1.onemain.com>,
> "greywolf42" <min...@sim-ss.com> wrote:
[snip]
> For readers of this thread NOT familiar with Noether's theorem, reference:
>
> http://www.emmynoether.com/noeth.htm
>
>
>http://theory1.physics.wisc.edu/~ldurand/711html/courseinfo/NoethersThm.html
>
> http://peter.ingebretson.net/math_paper/node13.html
Yes, I agree that Greywolf should probably read those links before trying
to discuss Noether's theorem!
--
Simon Clark
Simon Clark
[snip]
> Gee, Noether must be really pissed of that someone named a useless theorem
> after him.
[snip]
> You need to take look at those links that Paul Stowe just posted...
I guess I do to. My apologies to Ms Noether!
--
Simon Clark
Chris Hillman
On Sun, 15 Apr 2001, aka the Ides of April, which ought to be warning to
us all [just remember what happened this time -last- month, modulo a
millenium or two!] Simon Clark wrote:
> > The Lagrangian is a restatement of Newtonian "ordinary space" mechanics in
> > configuration space. If you have one, you have the other.
>
> Yes, yes...
?!!!
The notion of a Lagrangian is the marvelous concept which applies to and
to some degree unifies the formalism of classical mechanics, statistical
mechanics, quantum mechanics, electromagnetism, gtr, and other field
theories, -nicht wahr-? Or did I miss something earlier in the
conversation?
Cf. Lawrie, A Unified Grand Tour of Theoretical Physics.
> Gee, Noether must be really pissed of that someone named a useless theorem
> after him.
^^^
Not sure if Simon is joking or not, but the Noether in question is the
mathematician Emmy Noether, the daughter of her famous (but much less
famous!) father, the mathematician Max Noether :-/
Emmy Noether's many contributions to the mathematics of the twentieth
century include the development of module theory (see any modern textbook
on "modern algebra") and algebra in general--- as with Gauss and Euler,
"Noether's theorem" means different results in standard terminology in
math/sci, depending on context, because she proved so many fundamental
results. In addition, her students included several of the most
illustrious names in mathematics and mathematical physics, and EM is
frequently credited with doing as much or more than any other person to
further the development of modern algebra as we know it in the first half
of the twentieth century through her influence on her students.
Other people frequently credited with furthering the development of
modern algebra include B. L. van der Waerden and Andre Weil, as well as
Emil Artin and the pioneering Bourbakists in addition to Weil, to mention
just the leaders in the first part of the twentieth century--- by 1950 or
so, modern algebra was impossible to ignore, and the older generation of
mathematicians and physicists, which had attempted to some extent to
ignore in particular the rapid development of group theory and
representation theory, had died, either literatally or figuratively [as
in, their research tanked].
Hmm... speaking of mathematical dynasties, Michael Artin, son of Emil
Artin, is one of the leading algebraists of our own time, Garrett
Birkhoff, son of George D. Birkhoff (who proved the tremendously
influential "Birkhoff's pointwise ergodic theorem" as well as numerous
other results, including what gtr textbooks call "Birkhoff's theorem" :-/
was the coinventor (with Mac Lane) of lattice theory, a topic in modern
algebra with many applications [think "quantum logic"; see also my
expository paper "What is a Concept?"], and Henri Cartan, son of Elie
Cartan, was one of the leading Bourbakists. By the way, Birkhoff and Mac
Lane coauthored the first classic textbook in English on modern algebra,
which remains even today one of the very best available, and Mac Lane is
one of the inventors of category theory (see my expository paper "A
Categorical Primer").
Simon Clark
> On Sun, 15 Apr 2001, aka the Ides of April, which ought to be warning to
> us all [just remember what happened this time -last- month, modulo a
> millenium or two!] Simon Clark wrote:
>
>> > The Lagrangian is a restatement of Newtonian "ordinary space" mechanics
>> > in
>> > configuration space. If you have one, you have the other.
>>
>> Yes, yes...
>
> ?!!!
>
> The notion of a Lagrangian is the marvelous concept which applies to and
> to some degree unifies the formalism of classical mechanics, statistical
> mechanics, quantum mechanics, electromagnetism, gtr, and other field
> theories, -nicht wahr-? Or did I miss something earlier in the
> conversation?
I was agreeing with Graywolf's loose statement because I thought I knew
what he meant--i.e. that classical mechanics can be represented by the
equations of motion or the Lagrangian. (And because it wasn't as wrong as
the one that followed.)
> Cf. Lawrie, A Unified Grand Tour of Theoretical Physics.
>
>> Gee, Noether must be really pissed of that someone named a useless
>> theorem after him.
> ^^^
>
> Not sure if Simon is joking or not, but the Noether in question is the
> mathematician Emmy Noether, the daughter of her famous (but much less
> famous!) father, the mathematician Max Noether :-/
I forgot She was a she until after I sent the message. I guess that makes
me sexist...
--
Simon Clark
greywolf42
.
>
> [Newsgroups corrected]
>
> On Sun, 15 Apr 2001, Barry Mingst, aka "greywolf42", who is (of course!)
> an -engineer- by training, wrote, revealingly:
>
> > The Lagrangian is a restatement of Newtonian "ordinary space" mechanics
in
> > configuration space. If you have one, you have the other.
>
> (ROFL!)
>
> > "Symmetric energy" means energy is conserved. If energy is not
> > conserved, then Newton's equations fail.
>
> (ROFL!!)
>
> > If Newton fails, then the Lagrangian fails. If the Lagrangian fails,
> > then Noether's theorem fails.
>
> (ROFL!!!)
>
> I trust everyone else understands why this is so darn funny! :-)
>
> Chris Hillman
>
Devastating scientific rejoinder.
Too bad you snipped all the references and context. It would make the joke
so much better.
greywolf42.
greywolf42
This from the guy who knows so familiar with the subject that he thinks Emmy
Noether was a man.
greywolf42
greywolf42
> greywolf42 <min...@sim-ss.com> wrote:
>
> > Simon Clark <cla...@my-deja.com> wrote in message
> > news:1478829.x...@SRian-HQ.com...
>
> >> What I was trying to ask is: what is "symmetric/asymmetric" about the
> >> energy? Given the energy of some sytem--e.g. a mass on a (possibly
> >> damped) spring--how would I know if the energy was "symmetric" or not
so
> >> that I can apply Noether's theorem and deduce whether the energy is
> >> conserved or not?
>
> > You "know" whether energy is conserved or not, because you assume it as
> > your (Newtonian) starting point.
>
> Then what is the point of using Noether's theorem? I want to -show- that
> the energy is conserved (using Noether's theorem) not -assume- that it is
> conserved.
Too bad. What you "want" is irrelvant. Try creating your own theorem.
>
> > The Lagrangian is a restatement of Newtonian "ordinary space" mechanics
in
> > configuration space. If you have one, you have the other.
>
> Yes, yes...
>
> > If you have Newtonian mechanics, then you have assumed that energy is
> > conserved.
>
> and no. A mass on a damped spring is not a conservative system but obeys
> Newtonian mechanics.
No it doesn't. Newtonian mechanics explicitly assumes energy is conserved.
You have assumed non-Newtonian mechanics -- by simply not taking into
account
the heating the the damping system. And that heating is simply Newtonian
mechanics in the fluid doing the damping.
Although this is "easy" to calculate, it is not Newtonian dynamics.
>
> > If you have the Lagrangian, then you have Noether's theorem.
>
> Yes, and since I have Noether's theorem I want to -use- it! Show me how
to.
Sorry. I can't show you how to do the impossible (show that energy is
conserved without assuming it).
>
> > Thus, (as I have repeatedly
>
> and incorrectly
Proof by assertion.
> > stated) one cannot use Noether's theorem to "deduce" whether energy was
> > conserved or not.
>
> Gee, Noether must be really pissed of that someone named a useless theorem
> after him.
as;ldkfjalskdjfa;lskfj
Unless Noether has a posthumous sex-change operation, Emmy Noether was a
woman. (I know an advanced mathemetician like yourself is fully aware of
the history of your field.)
The fact that Noether's theorem cannot be used for impossible purposes by
ignorant and pompous foos does not detract from the usefulness of HER
theorem.
>
> > Because you had to assume it long before you started Noether's theorem.
>
> Apparently you need to take Classical Mechanics 101 again.
Now why is that? Specifically, why did you snip out the very clear and
concise quotes from "Classical Mechanics" text that I posted?
>
> Write down the Lagrangian for a damped spring. Apply Noether's theorem.
The
> energy of the spring is not conserved. Alternatively: use Newtonian
> mechanics to calculate the energy of the spring. It is still not
conserved.
First, you assumed that energy was not conserved -- by requiring a "damped"
spring. Of course Noether's theorem tells you the energy is not conserved.
That's what you assumed.
>
> > "Symmetric energy" means energy is conserved. If energy is not
conserved,
> > then Newton's equations fail. If Newton fails, then the Lagrangian
fails.
> > If the Lagrangian fails, then Noether's theorem fails.
>
> You need to take look at those links that Paul Stowe just posted...
>
> --
> Simon Clark
Why should I look at them again?
greywolf42
Chris Hillman
On Sun, 15 Apr 2001, Barry Mingst, whose totem is evidently Canis lupus,
wrote:
> > I trust everyone else understands why this is so darn funny! :-)
>
> Devastating scientific rejoinder.
>
> Too bad you snipped all the references and context. It would make the
> joke so much better.
To get the joke, which is on Barry, one need only look at a book such as
Ian Lawrie, A Unified Grand Tour of Theoretical Physics. See the FAQ for
the full bibliographic citation. (For the Lagrangian formulation of gtr,
see any modern gtr textbook!)
Chris Hillman (still chortling)
Chris Hillman
On Sun, 15 Apr 2001, greywolf42 wrote:
> > Then what is the point of using Noether's theorem? I want to -show- that
> > the energy is conserved (using Noether's theorem) not -assume- that it is
> > conserved.
>
> Too bad. What you "want" is irrelvant. Try creating your own theorem.
(ROFL)
This stuff is -priceless-!!
> > and incorrectly
>
> Proof by assertion.
Several people have pointed you at numerous references discussing
Noether's theorem from a variety of viewpoints. Here is yet another:
Frankel, Geometry of Physics. See the FAQ for the full citation.
> as;ldkfjalskdjfa;lskfj
Uh oh, I think Barry is regressing further into infancy :-/
> The fact that Noether's theorem cannot be used for impossible purposes by
> ignorant and pompous foos does not detract from the usefulness of HER
> theorem.
Barry, can you say "foozy woozy pompy foo"? :-)
> > You need to take look at those links that Paul Stowe just posted...
>
> Why should I look at them again?
Because you are so incredibly clueless concerning the subject of this
thread!
Chris Hillman
Simon Clark
>
> Simon Clark <cla...@my-deja.com> wrote in message
> news:1880125.5...@SRian-HQ.com...
>> Then what is the point of using Noether's theorem? I want to -show- that
>> the energy is conserved (using Noether's theorem) not -assume- that it is
>> conserved.
>
> Too bad. What you "want" is irrelvant. Try creating your own theorem.
Gee, why so hostile? I was only asking for your help. I hope you don't
treat your students like that when they ask you for help.
>> and no. A mass on a damped spring is not a conservative system but obeys
>> Newtonian mechanics.
>
> No it doesn't.
Yes it does. Write down the equations of motion. If F = ma then it obeys
Newtonian mechanics.
> Newtonian mechanics explicitly assumes energy is conserved.
I think you may be using non-standard terminology. What exactly do -you-
mean by "Newtonian mechanics"?
> You have assumed non-Newtonian mechanics -- by simply not
> taking into account
> the heating the the damping system. And that heating is simply Newtonian
> mechanics in the fluid doing the damping.
> Although this is "easy" to calculate, it is not Newtonian dynamics.
The spring heats up, and it slows down--but it still obeys Newton's laws of
motion.
>> > If you have the Lagrangian, then you have Noether's theorem.
>>
>> Yes, and since I have Noether's theorem I want to -use- it! Show me how
> to.
>
> Sorry. I can't show you how to do the impossible (show that energy is
> conserved without assuming it).
It isn't difficult.
>> > Thus, (as I have repeatedly
>>
>> and incorrectly
>
> Proof by assertion.
Says the King of Assertia.
>> Gee, Noether must be really pissed of that someone named a useless
>> theorem after him.
>
> as;ldkfjalskdjfa;lskfj
>
> Unless Noether has a posthumous sex-change operation, Emmy Noether was a
> woman. (I know an advanced mathemetician like yourself is fully aware of
> the history of your field.)
I have a bad cold at the moment and my thinking is rather fuzzy. I typed
"him" instead of "her" without thinking, and only realised what I'd done
when I reread my post when it appeared in the newsgroup. If you look you
will find that I placed a post a couple of minutes later correcting my
mistake.
> The fact that Noether's theorem cannot be used for impossible purposes by
> ignorant and pompous foos
Ad hominem!
> does not detract from the usefulness of HER theorem.
What is so useful about it if according to you it is a tautology? Give me
one use for it.
>> Apparently you need to take Classical Mechanics 101 again.
>
> Now why is that? Specifically, why did you snip out the very clear and
> concise quotes from "Classical Mechanics" text that I posted?
I didn't snip any quotes AFAIK. But even if I did, all that proves is that
you can read and type.
>> Write down the Lagrangian for a damped spring. Apply Noether's theorem.
> The
>> energy of the spring is not conserved. Alternatively: use Newtonian
>> mechanics to calculate the energy of the spring. It is still not
> conserved.
>
> First, you assumed that energy was not conserved -- by requiring a
> "damped" spring. Of course Noether's theorem tells you the energy is not
> conserved. That's what you assumed.
In the case of a damped spring I know that energy isn't conserved--that was
just a simple example. But what if I had a more complex system and -didn't-
know whether or not it was conservative? Given the Lagrangian for the
system how would you tell if the energy of the system was conserved or not?
>> You need to take look at those links that Paul Stowe just posted...
> Why should I look at them again?
So that you wont make incorrect claims about freshman physics?
--
Simon Clark
Simon Clark
> This from the guy who knows so familiar with the subject that he thinks
> Emmy Noether was a man.
I guess you didn't see the correction that I posted a couple of minutes
after I realised what I had written.
--
Simon Clark
Chris Hillman
On Sun, 15 Apr 2001, greywolf42 wrote:
> Simon Clark <cla...@my-deja.com> wrote in message
> news:1019864.U...@SRian-HQ.com...
> >
> > Yes, I agree that Greywolf should probably read those links before trying
> > to discuss Noether's theorem!
>
> This from the guy who knows so familiar with the subject that he
> thinks Emmy Noether was a man.
Yeah, the fact she was a woman -profoundly changes- the implications of
her theorem!!! In fact, it is -absolutely essential- to know this before
you can even -mention- Noether's Theorem!!!! Calling Noether a guy
consitutes -insulting behavior- and -flagrantly violates- the rules of
this newsgroup!
Further violations will be prosecuted (by "Nemesis"!). Maximum sentence
is life imprisonment in solitary confinement in a cell with a TV which
only shows reruns of "The Brady Bunch"--- and which you can't turn off!
Chris "Snicker Snicker" Hillman