Proper Time v. Absolute Motion.
Daniel Weston
It appears that Twin A goes off on one of his classical relativistic
journeys. And he returns to shake hands with Twin B. Question, who
actually made the trip?
From the standpoint of relativity, A could have gone on the trip and
returned, or we could just as permissibly say that A was stationary, and
B together with the earth and the universe went on the trip. Our
conclusion is that motion between A and B is relative, and it cannot be
said with certitude who made the trip.
But not so fast. There is a way to find out who really made the trip.
Let there be a comparison of the twin's clocks upon being reunited.
Twin A's clock shows 20 years less elapsed time than B's, and A's
physiological age is 20 years less. It is therefor concluded that the
motion between A and B was not relative, but rather it can be said with
certainty that A made the trip, and not B.
How is this conundrum resolved?
xx...@bellsouth.net
that have a self-attenuated math.
You and I, and many, many others know something is not right with
Einstein's formally accepted conclusion. Even Einstein knew it for
cripes sake! He couldn't figure it out, but he let it ride for its
apparent functionality in lieu of THAT something more complete.
In his mid and later years, he split his focus between the math of
Relativity (SR-GR) and this doubt. In essence, even he didn't give
credulity to his own theory. But he knew that it described something
well. He apparently did not know how to separate subjectivity from
objectivity. In fact, just in his last years, he made his doubt known
in no uncertain terms. (But maybe by then, he was just talking crazy,
and when did that start?)
Yes, Virginia, there is a real space (Christmas, you know). You will
know it, not by what you measure (relativity), but by its perfunctory
logic. It is not the bogymen or trolls that you see - it is only for
you to realize that space is moving according to the laws imbibed in
it. Or, pray tell, given that nothing remains fixed, why should there
be a static space in this universe?
I see it, you see it. Why can't everybody else see it?
Dean
"Daniel Weston" <dani...@webtv.net> wrote in message
news:29069-41C...@storefull-3137.bay.webtv.net...
>
> It appears that Twin A goes off on one of his classical relativistic
> journeys. And he returns to shake hands with Twin B. Question, who
> actually made the trip?
The one that applied force and therefore acceration in order to turn
around, thereby not remaining in an inertial frame of reference and
changing their velocity. Time dialation under these circumstances has
been experimentally confirmed. In fact, time dialation is used with the
GPS sattelites in order to accurately ascertain ground position.
> From the standpoint of relativity, A could have gone on the trip and
> returned, or we could just as permissibly say that A was stationary,
and
> B together with the earth and the universe went on the trip. Our
> conclusion is that motion between A and B is relative, and it cannot
be
> said with certitude who made the trip.
That is incorrect. The one that turned around accelerated to leave their
orignial inertial frame of reference and end in a differenent frame of
reference. Simply, if B turned around, the B changed their direction and
hence their velocity from going away from A to going towards A while A
could remain in its original inertial frame of reference. One of them
had to turn around for them to meet up again.
>
> But not so fast. There is a way to find out who really made the trip.
> Let there be a comparison of the twin's clocks upon being reunited.
> Twin A's clock shows 20 years less elapsed time than B's, and A's
> physiological age is 20 years less. It is therefor concluded that the
> motion between A and B was not relative, but rather it can be said
with
> certainty that A made the trip, and not B.
>
> How is this conundrum resolved?
>
This web page does a good job at explaining and demonstrating the
resolution to the twin paradox.
http://www.phys.unsw.edu.au/~jw/twin.html
robert j. kolker
Daniel Weston wrote:
>
> How is this conundrum resolved?
Who's world-line was closer to the null light-line?
Integrate each twin's proper time along the world-line taken. See which
is less. The longest interval between to events is one with no space
traversed.
Bob Kolker
TomGee
evidence of time dilation, and this was only one way to show it. There
is no mystery to solve because in order for the astronaut twin to have
aged less, he had to have gone faster than the Earth during the trip.
The question of who made the trip is not relevant to the SR Twin
Paradox.
Daniel Weston
accelerated. As I understand it, neither twin when confined within
their lab, will be able to determine whether A is accelerating and
returns to B, or B is accelerating (along with the universe) and returns
to A.
jahn
"Daniel Weston" <dani...@webtv.net> wrote in message news:29069-41C...@storefull-3137.bay.webtv.net...
>
If both twins have a common view of a satellite,
say... one of Jupiter's moons and they count the
same number of orbits for the duration of the
experiment, then there is no conumdrum.
Clocks predictably affected by motion are a
hypothetical construction of Special Relativity
and are simulated by an ether wind blowing
a bouncing light on to a diagonal course.
Sue...
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
Androcles
"Daniel Weston" <dani...@webtv.net> wrote in message
news:29069-41C...@storefull-3137.bay.webtv.net...
>
By doing the math correctly.
For people that cannot do math, use a common clock,
for example, the moons of Jupiter.
Let A and B count the orbits.
If they are not the same, you've travelled in time. Well done,
H.G. Weston-Wells.
The Earth has completed fewer orbits of the sun
and fewer rotations on its own axis, because Io, Ganymede,
Callisto and Europa have a fixed ratio to each other and
Ganymede takes 7.154553 days to complete one orbit of Jupiter.
20 years for 52 weeks, so A and B both count 1040 orbits.
If B counts them is less time, then B concludes that Ganymede
is whizzing around Jupiter and violating Kepler's third law
(and just about every other law of physics).
Now, you ARE permitted to conclude that Ganymede *appears*
to move slowly on the outbound trip and *appears* to be moving
quickly on the inbound trip. This is called "Doppler shift".
What you are NOT permitted to conclude is a number different
from 1040 for the entire trip, which is what you are calling
a conundrum.
If the moving clock slows down on the outbound trip, then
it speeds up on the inbound trip.
You've been suckered by Einstein.
Androcles.
Androcles
"jahn" <susyse...@yahoo.com.au> wrote in message
news:32f8kvF...@individual.net...
You were writing that at a metric
sqrt(x^2 +y^2 +z^2 + i(ct)^2) from me.
I chose Ganymede, which one did you pick?
Androcles.
jahn
"Androcles" <du...@dummy.net> wrote in message news:t%uwd.52324$tg2...@fe1.news.blueyonder.co.uk...
I chose the one that doesn't use ASCII math.
Io or I/O I think.
http://www.astrosociety.org/pubs/mercury/31_03/jupiter.html
http://www.usgs.gov/features/lewisandclark/LC_USGS.html
Which one is that ? giggle
Sue...
>
>
Dean
The twin that applies the force required to accelerate to turn around
will know that they have changed direction, due to the force of
acceleration pushing them towards one end of their lab when they turn
around. One of them has to turn around for them to meet up again, which
requires applying a force. The web page explains it much better than I
can. It should be clear to you if you visit it:
http://www.phys.unsw.edu.au/~jw/twin.html
I mean by testing that atomic clocks have been accelerated and shown to
have acquired the predicted discrepancy in time.
jahn
"Dean" <anon...@yahoo.com> wrote in message news:Mpvwd.60553$QJ3....@newssvr21.news.prodigy.com...
I have won small prizes playing a lottery game but I
don't claim as a result of this "prediction",
special insight to the aerodynamic principles that
affect which numbered ball will pop out of the
lottery machine.
If accuracy of the prediction has any importance,
GPS clocks were predicted to APPEAR faster
as a result of a falling photon gaining energy.
You can still find some of Neil Ashby's old PS
and PDF papers on the web if you have doubts.
His HTML paper on LivingReviews was changed
in 2003. Causality ARE hard to support that is
what Einstein's gravitational redshift reduces to.
Sue...
>
>
jahn
OOps! That should read:
Causality [violations] ARE hard to support that is
what Einstein's gravitational redshift reduces to.
----------
I have won small prizes playing a lottery game but I
don't claim as a result of this "prediction",
special insight to the aerodynamic principles that
affect which numbered ball will pop out of the
lottery machine.
If accuracy of the prediction has any importance,
GPS clocks were predicted to APPEAR faster
as a result of a falling photon gaining energy.
You can still find some of Neil Ashby's old PS
and PDF papers on the web if you have doubts.
His HTML paper on LivingReviews was changed
in 2003. Causality [violations] ARE hard to support that is
Dean
Probability is a feature of quantum mechanics but not relativity as far
as I know, so I don't see how your parable applies.
>
> If accuracy of the prediction has any importance,
> GPS clocks were predicted to APPEAR faster
> as a result of a falling photon gaining energy.
>
Odd that they work then.
> You can still find some of Neil Ashby's old PS
> and PDF papers on the web if you have doubts.
>
I've done what you suggest and everything that I've seen suggests that
his contribution is towards and accurate accounting for the relativistic
effects including time dialation. Every authoritative source that I've
seen concurs with the predictions of relativistic effects.
For example, from
http://www.colorado.edu/physics/Web/directory/faculty/ashby_n.html
"The principal emphasis of Prof. Ashby's research is on theoretical
general relativity with practical applications. For example, studies of
relativistic effects within navigational satellite systems such as the
Global Positioning System (a set of 24 satellites carrying atomic
clocks) show that several relativistic effects must be accounted for in
order for the system work properly. "
> His HTML paper on LivingReviews was changed
> in 2003. Causality ARE hard to support that is
> what Einstein's gravitational redshift reduces to.
>
Causality is the foundation of science, from theory to application (e.g.
the premise that one must be able to repeat a cause to get the predicted
result to confer a scientific truth).
> Sue...
Harry
SNIP
> > If accuracy of the prediction has any importance,
> > GPS clocks were predicted to APPEAR faster
> > as a result of a falling photon gaining energy.
> >
> Odd that they work then.
No Dean, he didn't talk about that. The claimed cause must be *wrong*, or
more tactfully, "misleading" as was quite well exposed in the AJP: "the
photon energy is conserved in a static gravitational field" (Okun et al, AJP
68, Feb.2000, p.115).
Obviously you understood nothing of what Sue is talking about...
Cheers,
Harald
Harry
According to Einstein, each one of them is equally right, as you also
remark. But that's nowadays rejected by many, even by some who claim to
follow his metaphysics. I can send you Builder's IMO conclusive paper about
it which is nevertheless also rejected by many (PDF, 2Mb).
Harald
jahn
"Dean" <anon...@yahoo.com> wrote in message news:t_vwd.60560$QJ3....@newssvr21.news.prodigy.com...
Indeed!
<< When the gravitational field due to the earth is considered,
the picture is only a little more complicated. There still
exists a coordinate time that can be found by computing a correction
for gravitational redshift, given by the first correction term in Eq. (28).
>>http://relativity.livingreviews.org/Articles/lrr-2003-1/node4.html
Equation 28 clearly has the word "PATH" on the intgeral signs.
Math GIF files aren't so easy to update on a living web site.
Don't misunderstand, I have no beef with people altering their
POV as they learn, and altering published articles consistant
with new information. But claims that the alterations represent
a prediction are a bit far afield. An "inflight" redshift was predicted
and Pound-Rebka, Vessot and GPS was offered as the proof.
http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=AJPIAS000068000002000115000001&idtype=cvips&gifs=yes
Do we believe cesium clocks, pendumlum clocks or balance wheel
clocks. The position in the earth's magnetic field is far more likely
to affect a rubidium clock than gravity but AFAIK this possibily has
yet to be eliminated.
Sue...
>
> > Sue...
>
>
Paul B. Andersen
> Clocks predictably affected by motion are a
> hypothetical construction of Special Relativity
> and are simulated by an ether wind blowing
> a bouncing light on to a diagonal course.
>
> Sue...
Which brings us back to the "light clock" thought experiment.
Previously you said that Einstein's light clock
"slows as the ether wind blows the beam off course."
This is Einstein's light clock:
Light path viewed in the rest frame of the morrors:
------
|
|
|
------
In the rest frame of the mirrors, the speed
of light is according to the second postulate c,
and the light will use the time d/c between
the mirrors.
The light clock will thus run at the frequency
f = c/2d obsereved in the mirror frame.
The very same light path observed in the rest
frame of an arbitrary observer, where the light
clock is moving at v:
-----------------
/\ /\
/ \ / \
\/ \/ \/
-----------------
Since the speed of light in the observer's rest
frame according to the second postulate i c,
the light will use the time d/sqrt(c2-v2) between
the mirrors.
The moving light clock will thus run at the frequency
f' = (c/2d)*sqrt(1 - v2/c2) = f*sqrt(1 - v2/c2)
observed in the observer-frame.
The moving light clock runs slow.
So what did you mean by your statement:
"the ether wind blows the beam off course"?
Did you mean that any arbitrary observer will
pull the ether along with him, so if we at the same
time have a number of observers moving relative
to each other, the light beam will be pulled
off course in a number of different ways at the same time?
I think you better explain your words about the ether wind.
Yes, I have written this before, and you have fled
the discussion before.
Will you flee again?
Paul
Dean
"Harry" <harald.v...@epfl.ch> wrote in message
news:41c29ccd$1...@epflnews.epfl.ch...
"The classical phenomenon of the redshift of light in a static
gravitational potential, usually called the gravitational redshift, is
described in the literature essentially in two ways: On the one hand,
the phenomenon is explained through the behavior of clocks which run
faster the higher they are located in the potential, whereas the energy
and frequency of the propagating photon do not change with height. The
light thus appears to be redshifted relative to the frequency of the
clock. On the other hand, the phenomenon is alternatively discussed
(even in some authoritative texts) in terms of an energy loss of a
photon as it overcomes the gravitational attraction of the massive body.
This second approach operates with notions such as the "gravitational
mass" or the "potential energy" of a photon and we assert that it is
misleading."
The claimed cause, due to time dialation, is not contested. The
causality is easy to support.
> Cheers,
> Harald
>
>
Androcles
The one without the volcanoes ?
Androcles.
> Sue...
>
>>
>>
>
>
jahn
"Paul B. Andersen" <paul.b....@deletethishia.no> wrote in message news:cpu9u9$gea$1...@dolly.uninett.no...
No but I'll be brief.
If a 40 km/hr wind is blowing the
rain so it appears diagonal, then you have every
reason to calculate a different time of fall because
it indeed follows a longer path to the ground.
If the rain only APPEARS to fall diagonally because
you are moving 40 km/hr, then the diagonal path
is not valid for the rain and you will be in error if
you use it to calculate the time of fall.
If Einstein assumed an electrodynamic ether,
then the light-clock and ether wind is consistant
with *some* of his calculations. Since they are
not self consistant, by his own admission, and
several clock mechanisms are implied, no model
can be expected behave consistant with each
clock he uses.
Personally, I think a grandfather clock towed
behind a powerboat might "dilate" the just way
he envisioned. ;-)
Now, stop babbling about motion affecting clocks
until you can show a functional mechanism.
Sue...
>
> Paul
Harry
Yes the causality is perfectly supported by that paper.
What I emphasized to you I will now summarise in one phrase, maybe that will
work:
The idea that this "time dilation" is caused by "a falling photon gaining
energy" is contested.
The AJP paper contests it by concluding that "the photon energy is conserved
in a static gravitational field". In fact it was the purpose of that paper
to show that the (only) cause in this case is the faster running of clocks.
But it falls on deaf ears...
Harald
Not Martin Stone
I'm just gonna repeat this point in slightly different words, it may help.
If you sit in a car on totally smooth road and close your eyes, you can't
tell if you're moving. Open your eyes and look out the window and then you
know you are - there are objects moving past you. And of course you could
argue that the objects are moving and you're stationary - motion is relative
and the OP has grasped that.
Now close your eyes again, and I stamp on the accelerator. You'll know
about it, you don't need to look out the window (ie: you don't need a
reference point) to know you're accelerating, and neither will the twin.
Sum it up as: acceleration is absolute.
A much better relativity paradox than the twins is this: "the last place you
should ask a question about relativity is on sci.physics.relativity".
Mainly because you'll get a load of posts saying relativity is wrong, and
those who accept and understand relativity will get dragged into very old
arguments operating above your level (and mine) and a layman just doesn't
know who to listen to.
(Hint: listen to Dean - I think)
A Layman.
Androcles
Not really. Satellites drift due to perturbation by the Moon and Sun,
and where it is is as important as when it is. Ground stations upload
position and time constantly. If they didn't, then it would indeed fail.
Engineers know what they are doing, even if relativists do not.
Androcles.
Dirk Van de moortel
"Androcles" <du...@dummy.net> wrote in message news:qcuwd.50854$tg2....@fe1.news.blueyonder.co.uk...
>
> "Daniel Weston" <dani...@webtv.net> wrote in message
> news:29069-41C...@storefull-3137.bay.webtv.net...
> >
> > It appears that Twin A goes off on one of his classical relativistic
> > journeys. And he returns to shake hands with Twin B. Question, who
> > actually made the trip?
> > From the standpoint of relativity, A could have gone on the trip and
> > returned, or we could just as permissibly say that A was stationary,
> > and
> > B together with the earth and the universe went on the trip. Our
> > conclusion is that motion between A and B is relative, and it cannot
> > be
> > said with certitude who made the trip.
> >
> > But not so fast. There is a way to find out who really made the trip.
> > Let there be a comparison of the twin's clocks upon being reunited.
> > Twin A's clock shows 20 years less elapsed time than B's, and A's
> > physiological age is 20 years less. It is therefor concluded that the
> > motion between A and B was not relative, but rather it can be said
> > with
> > certainty that A made the trip, and not B.
> >
> > How is this conundrum resolved?
>
> By doing the math correctly.
> For people that cannot do math,
... there is only one teacher, right?
Androcles lectures on equations:
http://users.pandora.be/vdmoortel/dirk/Physics/Fumbles/SetSolve2.html
http://users.pandora.be/vdmoortel/dirk/Physics/Fumbles/Persuasive.html
http://users.pandora.be/vdmoortel/dirk/Physics/Fumbles/AndroDistri.html
http://users.pandora.be/vdmoortel/dirk/Physics/Fumbles/Pythagoras.html
http://users.pandora.be/vdmoortel/dirk/Physics/Fumbles/ToothlessBite.html
http://users.pandora.be/vdmoortel/dirk/Physics/Fumbles/Competent.html
http://users.pandora.be/vdmoortel/dirk/Physics/Fumbles/UseTrans.html
http://users.pandora.be/vdmoortel/dirk/Physics/Fumbles/Sheesh.html
http://users.pandora.be/vdmoortel/dirk/Physics/Fumbles/SetSolve.html
http://users.pandora.be/vdmoortel/dirk/Physics/Fumbles/DivZero.html
http://users.pandora.be/vdmoortel/dirk/Physics/Fumbles/Think.html
Androcles lectures on square roots:
http://users.pandora.be/vdmoortel/dirk/Physics/Fumbles/STILL.html
http://users.pandora.be/vdmoortel/dirk/Physics/Fumbles/CanSpecify.html
http://users.pandora.be/vdmoortel/dirk/Physics/Fumbles/Nearly.html
http://users.pandora.be/vdmoortel/dirk/Physics/Fumbles/Quadratic.html
http://users.pandora.be/vdmoortel/dirk/Physics/Fumbles/GrowUp.html
http://users.pandora.be/vdmoortel/dirk/Physics/Fumbles/Tautology.html
http://users.pandora.be/vdmoortel/dirk/Physics/Fumbles/Material.html
http://users.pandora.be/vdmoortel/dirk/Physics/Fumbles/GIVEN.html
http://users.pandora.be/vdmoortel/dirk/Physics/Fumbles/PythagoRescue.html
http://users.pandora.be/vdmoortel/dirk/Physics/Fumbles/SqrtRev.html
http://users.pandora.be/vdmoortel/dirk/Physics/Fumbles/NegSqrt.html
http://users.pandora.be/vdmoortel/dirk/Physics/Fumbles/SqrtAnswers.html
Androcles lectures on exclusive ors:
http://users.pandora.be/vdmoortel/dirk/Physics/Fumbles/Gibberish.html
Androcles lectures on partial differential equations:
http://users.pandora.be/vdmoortel/dirk/Physics/Fumbles/PartialDiff.html
http://users.pandora.be/vdmoortel/dirk/Physics/Fumbles/PartialDiff2.html
http://users.pandora.be/vdmoortel/dirk/Physics/Fumbles/PartialDiff3.html
Dirk Vdm
Dirk Van de moortel
"jahn" <susyse...@yahoo.com.au> wrote in message news:32fv2iF...@individual.net...
>
> "Paul B. Andersen" <paul.b....@deletethishia.no> wrote in message news:cpu9u9$gea$1...@dolly.uninett.no...
> > jahn wrote:
> > > Clocks predictably affected by motion are a
> > > hypothetical construction of Special Relativity
> > > and are simulated by an ether wind blowing
> > > a bouncing light on to a diagonal course.
> > >
> > > Sue...
> >
> > Which brings us back to the "light clock" thought experiment.
[snip]
With each post, your style gets closer to the original Dennis McCarthy.
Careful, Dennis, you are making a fool of yourself.
Dean
"Causality ARE hard to support that is
what Einstein's gravitational redshift reduces to."
I expect that GPS clocks were predicted to actually run faster (not
merely appear faster) due to general relativistic time dialation. And so
they do.
Also, the causality of Einstein's gravitational redshift due to time
dialation is easy to support. So his claim was mistaken.
According to the AJP reference which you supplied, the gravitational
redshift is due to time dialation and not falling photon energy. Not
that time dialation is not due to falling photon energy as you claim.
Harry
> what Einstein's gravitational redshift reduces to."
>
> I expect that GPS clocks were predicted to actually run faster (not
> merely appear faster) due to general relativistic time dialation. And so
> they do.
I didn't verify Sue's claims about Ashby's writings on this aspect. Anyway,
the reason for the AJP paper was the disagreements between the texts of GRT
specialists. Several people in this group who are good in GRT math continue
to claim (at least last time) that GPS clocks appear faster as a result of a
photon's energy gain - just check the archive!
> Also, the causality of Einstein's gravitational redshift due to time
> dialation is easy to support. So his claim was mistaken.
> According to the AJP reference which you supplied, the gravitational
> redshift is due to time dialation and not falling photon energy. Not
> that time dialation is not due to falling photon energy as you claim.
I tried to make myself clear, and I'm glad to see it worked this time!
According to that article the cause is a difference in clock rate. "time
dilation" usually refers to the "observed" difference in clock readings as
based on certain assumptions and is therewith neutral about cause.
If not "time dilation", what would you call in an accelerated frame the
disagreement between the measured frequencies? However, in that case it is
due to the Doppler effect, which is related to a change in photon energy.
Cheers,
Harald
kenseto
"Paul B. Andersen" <paul.b....@deletethishia.no> wrote in message
news:cpu9u9$gea$1...@dolly.uninett.no...
There is no such thing as the aether wind and there is no such thing as that
the light ray follows a slant path as you described in the diagram. All the
photons will move vertically as they are emitted. In the frame of the moving
light clock the first batch of photons will miss hitting that top mirror due
to the movement of the top mirror while the the photons are in transit.
From the outside observer's point of view he will see that each photon will
follow a vertical path on its way to the top mirror. The top mirror moved
while the photons are in transit and this causes the first batch of photons
to miss the top mirror. This means that the first photon that hits the top
mirror was not emitted until a later time and SR call this time dilation.
Ken Seto
Daniel Weston
Dean et al: The reason for the difference in the proper time of the
traveler, is NOT the occurrence of acceleration.
1) In the examples that are given where Twin A does not move, but Twin B
and the rest of the universe goes on the trip, it is said that Twin A
feels the same sense of acceleration as if he had done the acceleration.
I am most uncomfortable with this position.
2) Acceleration does not slow clocks nor speed them up. Therefore
acceleration cannot be a method for resolving the twin conundrum. Tom
Roberts and others have explained this on numerous occasions. I cannot
justify this position because I cannot take on a PHD in physics. My
math is suspect.
robert j. kolker
Daniel Weston wrote:
>
> 2) Acceleration does not slow clocks nor speed them up. Therefore
> acceleration cannot be a method for resolving the twin conundrum. Tom
> Roberts and others have explained this on numerous occasions. I cannot
> justify this position because I cannot take on a PHD in physics. My
> math is suspect.
Acceleration (speeding up) moves a body closer to a light-like world line.
Bob Kolker
Martin Hogbin
"Daniel Weston" <dani...@webtv.net> wrote in message news:24457-41...@storefull-3134.bay.webtv.net...
> Dean: I am uncertain what you mean by testing to see which twin
> accelerated. As I understand it, neither twin when confined within
> their lab, will be able to determine whether A is accelerating and
> returns to B, or B is accelerating (along with the universe) and returns
> to A.
You understand it wrongly. You know when you are accelerating.
Martin Hogbin
Daniel Weston
that acceleration would not be felt. I simply pointed out that it is
said that Twin A would get the sensation of acceleration if Twin A were
still and Twin B and the universe did the accelerating instead.
Martin Hogbin
"Daniel Weston" <dani...@webtv.net> wrote in message news:6097-41C...@storefull-3133.bay.webtv.net...
Keep going, you are nearly asking a sensible question.
Martin Hogbin
xx...@bellsouth.net
observer feels no acceleration?
xx...@bellsouth.net
and below 1.5R of Earth?
Androcles
Pigpen is a typical relativist, what can you expect?
They all try to sidetrack any logic that denies their religious beliefs.
Androcles.
TomGee
That probably has more to do with the influence of gravity dependent on
an object's particular location wrt the Earth. Since motion is
affected by gravity, that in turn influences an object's state of
motion.
TomGee
Paul B. Andersen
The point is that with no wind, the raindrops
ARE falling diagonally in _my rest frame_.
There is nothing apparent about that.
And exactly the same is the case with the light
clock. The light pulse IS moving diagonally in
the frame of reference in which the light clock
is moving. There is nothing apparent about that.
So where is the blowing ether you are talking about?
> If Einstein assumed an electrodynamic ether,
> then the light-clock and ether wind is consistant
> with *some* of his calculations. Since they are
> not self consistant, by his own admission, and
> several clock mechanisms are implied, no model
> can be expected behave consistant with each
> clock he uses.
But Einstein assumed no such thing.
The simple indisputable FACT you are disputing is:
The path of the one and only light pulse IS longer
in the moving observer's frame of reference than
it is in the light clock frame.
This is a thought experiment.
Einstein assumed that the speed of light is invariant.
The inescapable logic consequence of that
assumption is that the moving observer will
find that the light clock runs slower than his
own clock (which might be an equivalent light clock).
Note that the light clock doesn't "prove" SR.
Of bloody course it doesn't!
That never was the point.
The light clock PROVES only that the consequence
of the postulates of SR is that "moving clocks run slow".
And where the hell is the ether you are talking about?
> Personally, I think a grandfather clock towed
> behind a powerboat might "dilate" the just way
> he envisioned. ;-)
>
> Now, stop babbling about motion affecting clocks
> until you can show a functional mechanism.
This is so well experimentally confirmed that
it is plain stupidity to dispute it.
Paul
harald.v...@epfl.ch
effects of acceleration on the accelerated clock are not considered in
relativity - a "perfect"clock is immune to acceleration.
Coincidentally, experiments show that atomic clocks are indeed quite
insensitive to acceleration (it's less difficult than it seems to
distinguish between effects due to a different speed from effects due
to a change of speed!).
BTW, you didn't respond to my earlier posting, maybe you overlooked it,
once more here:
According to Einstein (1918), for the "traveller" (who according to
himself is not travelling), the gravitational field that is induced
during turnaround advances the other clock. And each one of them is
according to him equally right. That explanation is nowadays rejected
by many incl. myself, and even by some who claim to follow his
metaphysics.
I can send you Builder's IMO conclusive paper about it which is
nevertheless also rejected by many (Aus. J.Ph. 1958. PDF, 2Mb); Builder
was the guy who extended SRT to handle accelerating reference frames
(in his 1957 paper, I can send you that one as well!).
Cheers,
Harald
AllYou!
> Dean: I am uncertain what you mean by testing to see which twin
> accelerated. As I understand it, neither twin when confined within
> their lab, will be able to determine whether A is accelerating and
> returns to B, or B is accelerating (along with the universe) and returns
> to A.
LOL!
F = m * a. Duh............
Paul Cardinale
Daniel Weston wrote:
> It appears that Twin A goes off on one of his classical relativistic
> journeys. And he returns to shake hands with Twin B. Question, who
> actually made the trip?
> From the standpoint of relativity, A could have gone on the trip and
> returned, or we could just as permissibly say that A was stationary,
and
> B together with the earth and the universe went on the trip. Our
> conclusion is that motion between A and B is relative, and it cannot
be
> said with certitude who made the trip.
>
> But not so fast. There is a way to find out who really made the
trip.
> Let there be a comparison of the twin's clocks upon being reunited.
> Twin A's clock shows 20 years less elapsed time than B's, and A's
> physiological age is 20 years less. It is therefor concluded that
the
> motion between A and B was not relative, but rather it can be said
with
> certainty that A made the trip, and not B.
>
> How is this conundrum resolved?
The conumdrum is not in SR, but in your misconception of SR.
SR does not state that all motion is relative.
Paul Cardinale
Harry
> If a 40 km/hr wind is blowing the
> rain so it appears diagonal, then you have every
> reason to calculate a different time of fall because
> it indeed follows a longer path to the ground.
>
> If the rain only APPEARS to fall diagonally because
> you are moving 40 km/hr, then the diagonal path
> is not valid for the rain and you will be in error if
> you use it to calculate the time of fall.
>
> If Einstein assumed an electrodynamic ether,
> then the light-clock and ether wind is consistant
> with *some* of his calculations. Since they are
> not self consistant, by his own admission, and
> several clock mechanisms are implied, no model
> can be expected behave consistant with each
> clock he uses.
"Not self consistent by his own admission?
> Personally, I think a grandfather clock towed
> behind a powerboat might "dilate" the just way
> he envisioned. ;-)
>
> Now, stop babbling about motion affecting clocks
> until you can show a functional mechanism.
Doesn't the functional mechanism that Lorentz proposed do the job for you?
If not, what is wrong about it according to you? See also my new thread on
length contraction and time dilation.
Harald
xx...@bellsouth.net
astronaut twin to have
aged less, he had to have gone faster than the Earth during the trip."
>>xxein: Then why are timerates +/- different in orbital circuits above
and below 1.5R of Earth?
>TomGee: That probably has more to do with the influence of gravity
dependent on
an object's particular location wrt the Earth. Since motion is
affected by gravity, that in turn influences an object's state of
motion.
xxein: I must pick. How is the 'state of motion' of an object at a
circular orbit velocity at 1.5R equal to that of the (~non-rotating)
ECI frame?
This requires a 'state of motion' in a physical sense that supercedes
theories born by the mere conceptualizations one may beget from math
alone.
How does a gravitational time dilation impose itself on a 'state of
motion' and yet not require motion?
I think that you need to work by a new set of defnitions.
Paul B. Andersen
I see.
So the photons that hit the top mirror don't.
Dual realities, eh? :-)
Paul
Paul B. Andersen
> That's right, it's a basic point of relativity theory that eventual
> effects of acceleration on the accelerated clock are not considered in
> relativity - a "perfect"clock is immune to acceleration.
> Coincidentally, experiments show that atomic clocks are indeed quite
> insensitive to acceleration (it's less difficult than it seems to
> distinguish between effects due to a different speed from effects due
> to a change of speed!).
>
> BTW, you didn't respond to my earlier posting, maybe you overlooked it,
> once more here:
>
> According to Einstein (1918), for the "traveller" (who according to
> himself is not travelling), the gravitational field that is induced
> during turnaround advances the other clock.
Does it?
This statement is so ambiguous that it says nothing.
Of course an arbitrary remote observer's acceleration doesn't
physically affect the intrinsic properties of a clock in any way.
And don't tell me Einstein said it did, because the very idea is absurd.
However, the observer's acceleration will affect his result
when he compares the distant clock to his own, using Einstein's
definition of simultaneity in the comparison.
So he will _measure_ the distant clock to run fast.
> And each one of them is according to him equally right.
Indeed.
But about what are they equally right?
You don't seem to understand that when Einstein
said that each of them are equally right, it is _because_
neither of the clock's intrinsic properties are affected
in any way.
If one of the clocks - say the accelerated twin's clock -
were physically affected, then they would _not_ have
been equally right.
> That explanation is nowadays rejected
> by many incl. myself, and even by some who claim to follow his
> metaphysics.
What explanation is rejected?
> I can send you Builder's IMO conclusive paper about it which is
> nevertheless also rejected by many (Aus. J.Ph. 1958. PDF, 2Mb); Builder
> was the guy who extended SRT to handle accelerating reference frames
> (in his 1957 paper, I can send you that one as well!).
>
> Cheers,
> Harald
I think you should try to understand the modern
geometric interpretation of relativity.
Then you would see that this talk about "the rate of
the other clock" is simple geometry. It is - loosely -
the projection of the observed clock's world line onto
the observer's world line.
Start by learning to draw a space time diagram with
one spatial dimension. It is very illustrative.
And all the mysteries disappear.
Paul
kenseto
The speed of a photon is much higher than the motion of the top mirror.
Therefore the photons generated at a later time will have a chance to catch
up to it before the top mirror is moved out of position. This is the reason
why the amount of photons missing the top mirror is dependent on the speed
(absolute motion) of the light clock. If the top mirror is moving at speed
of light no photon will hit the top mirror. SR interprets this as time
standing still. This interpretation is bogus. Why? Because the first photon
is still moving in the ether at c and the passage of absolute time is
continually ticking at the same rate.
> Dual realities, eh? :-)
Only if you interpreted it from an SR religion point of view. :-)
Ken Seto
>
> Paul
kenseto
> harald.v...@epfl.ch wrote:
> > That's right, it's a basic point of relativity theory that eventual
> > effects of acceleration on the accelerated clock are not considered in
> > relativity - a "perfect"clock is immune to acceleration.
> > Coincidentally, experiments show that atomic clocks are indeed quite
> > insensitive to acceleration (it's less difficult than it seems to
> > distinguish between effects due to a different speed from effects due
> > to a change of speed!).
> >
> > BTW, you didn't respond to my earlier posting, maybe you overlooked it,
> > once more here:
> >
> > According to Einstein (1918), for the "traveller" (who according to
> > himself is not travelling), the gravitational field that is induced
> > during turnaround advances the other clock.
>
> Does it?
> This statement is so ambiguous that it says nothing.
>
> Of course an arbitrary remote observer's acceleration doesn't
> physically affect the intrinsic properties of a clock in any way.
> And don't tell me Einstein said it did, because the very idea is absurd.
>
> However, the observer's acceleration will affect his result
> when he compares the distant clock to his own, using Einstein's
> definition of simultaneity in the comparison.
> So he will _measure_ the distant clock to run fast.
Right the accelerated observer increased his state of absolute motion and
thus his clock is runng slower than before the acceleration and thus he
measures the distant clock to run fast.
Ken Seto
Henri Wilson
>"Dean" <anon...@yahoo.com> wrote in message
>news:Mpvwd.60553$QJ3....@newssvr21.news.prodigy.com...
>> The twin that applies the force required to accelerate to turn around
>> will know that they have changed direction, due to the force of
>> acceleration pushing them towards one end of their lab when they turn
>> around. One of them has to turn around for them to meet up again, which
>> requires applying a force. The web page explains it much better than I
>> can. It should be clear to you if you visit it:
>> http://www.phys.unsw.edu.au/~jw/twin.html
>>
>> I mean by testing that atomic clocks have been accelerated and shown to
>> have acquired the predicted discrepancy in time.
>>
>
>I'm just gonna repeat this point in slightly different words, it may help.
>
>If you sit in a car on totally smooth road and close your eyes, you can't
>tell if you're moving. Open your eyes and look out the window and then you
>know you are - there are objects moving past you. And of course you could
>argue that the objects are moving and you're stationary - motion is relative
>and the OP has grasped that.
>
>Now close your eyes again, and I stamp on the accelerator. You'll know
>about it, you don't need to look out the window (ie: you don't need a
>reference point) to know you're accelerating, and neither will the twin.
>Sum it up as: acceleration is absolute.
>
>A much better relativity paradox than the twins is this: "the last place you
>should ask a question about relativity is on sci.physics.relativity".
>Mainly because you'll get a load of posts saying relativity is wrong, and
>those who accept and understand relativity will get dragged into very old
>arguments operating above your level (and mine) and a layman just doesn't
>know who to listen to.
It depends whether aceleration is defined as F/m or dv/dt.
A person in free fall towards Earth cannot feel his absolute acceleration..but
an observer on Earth can measure his 'dv/dt'.
This is one reason the equivalence principle and GR are bullshit.
>
>(Hint: listen to Dean - I think)
>
>A Layman.
>
HW.
TomGee
Picking is fine with me. The answer to your first question depends on
a number of other factors which influence an object's state of motion.
I explained in my model of the universe my use of the phrase:
" It is necessary, I'm sure, to clarify my meaning of the phrase,
"state of motion," as I use it herein so often: When we speak of an
object's state of motion, we usually refer to the ve-locity or
momentum of bodies traveling in space. Yet, there is always motion
within all real objects, including molecular kinetic energy activity in
gases, molecular and atomic vibrations in matter, the motion of
particles through space and matter, and there may also be the "outward"
motion of matter resulting from the continuing expansion of the
universe. Any and all motions of discrete matter are included in the
phrase referred to above. In fact, we may say that everything visible
in our universe is in motion, which means that as far as we can tell,
there is nothing in our universe that is totally motionless, except
perhaps, space. Yet, it is gen-erally accepted today that space is
still expanding, and that action of expansion may be considered a type
of motion when viewed from a certain perspective."
Gravitation influences an object's state of motion by the accelerating
effects it imposes on it. As an object enters a gravity field its
velocity changes and if the speed factor of the velocity decreases, the
time rate of that object increases, or if it increased, its time rate
is slowed. Thus, gravitation does not directly influence time rates,
but indirectly, by way of affecting velocity which causes a change in
speed which in turn causes a time dilation.
You may be correct in saying I need a new set of definitions, if you
think that would allow me to provide better explanations. Any
suggestions?
TomGee
harry
geometrical interpretation, and here
we have a good example from Paul, it's pretty clear:
Paul wrote:
> What explanation is rejected?
Einstein's explanation that the point of view that the traveller was
slowed is correct but evenso that the stay-at -home has sped up. I'm
the only one in this newsgroup who even cites him. Note that the term
"intrinsic" was not used by Einstein, nor the claim that nothing
happened to the clock rates. A recent paper in the AJP returns to that
kind of interpretation about the reality of relativistic observations,
calling them physical inherent properties of the objects.
Paul continued:
> I think you should try to understand the modern
geometric interpretation of relativity.
Then you would see that this talk about "the rate of
the other clock" is simple geometry. It is - loosely -
the projection of the observed clock's world line onto
the observer's world line.
Start by learning to draw a space time diagram with
one spatial dimension. It is very illustrative.
And all the mysteries disappear.
The popular geometric view is that despite the physical effect nothing
happened to affect the rate of any clock.
BTW he thinks that I don't know how to draw a space-time diagram. ;-)
Until recently I thought that such math constructions obscure more than
enlighten reality, but now I changed my mind, it's also good to
illustrate the way I look at it: IMO, every angle corresponds to a view
of reality, and of those angles exactly one unknown angle must
correspond to reality.
Cheers,
Harald
Henri Wilson
wrote:
Are you saying that SR claims some motion is absolute?
Please tell us about this 'motion' that is NOT relative to another object.
Don't tell me..... Seto has converted you. He called you a runt once too ften
and you couldn't take it any more!
>
>Paul Cardinale
HW.
Paul B. Andersen
> PS as I already expected, I did not need to explain the popular
> geometrical interpretation, and here
> we have a good example from Paul, it's pretty clear:
>
> Paul wrote:
>
>>What explanation is rejected?
>
>
> Einstein's explanation that the point of view that the traveller was
> slowed is correct but evenso that the stay-at -home has sped up. I'm
> the only one in this newsgroup who even cites him. Note that the term
> "intrinsic" was not used by Einstein, nor the claim that nothing
> happened to the clock rates. A recent paper in the AJP returns to that
> kind of interpretation about the reality of relativistic observations,
> calling them physical inherent properties of the objects.
This is so imprecisely put that it can mean anything.
Einstein's explanation IS "the geometric interpretation."
Einstein defined that geometry.
> Paul continued:
>
>
>>I think you should try to understand the modern
>
> geometric interpretation of relativity.
> Then you would see that this talk about "the rate of
> the other clock" is simple geometry. It is - loosely -
> the projection of the observed clock's world line onto
> the observer's world line.
> Start by learning to draw a space time diagram with
> one spatial dimension. It is very illustrative.
> And all the mysteries disappear.
> <End quote>
And there is no other possible interpretation unless you
invoke a Lorentz type of ether ( or "preferred frame"),
which Einstein certainly did not.
The idea that the action of an arbitrary remote observer
in any way can affect the intrinsic physical properties
of the observed object is absurd!
> The popular geometric view is that despite the physical effect nothing
> happened to affect the rate of any clock.
A very ambiguous statement.
"despite the physical effect"?
Despite which "physical effect"?
> BTW he thinks that I don't know how to draw a space-time diagram. ;-)
> Until recently I thought that such math constructions obscure more than
> enlighten reality, but now I changed my mind, it's also good to
> illustrate the way I look at it: IMO, every angle corresponds to a view
> of reality, and of those angles exactly one unknown angle must
> correspond to reality.
>
> Cheers,
> Harald
I will iterpret this to mean that according to you,
there is an unknown preferred frame "corresponding to reality",
and only the view from this frame is "correct".
To claim that this was Einstein's view is absurd!
Paul
kenseto
> > geometric interpretation of relativity.
> > Then you would see that this talk about "the rate of
> > the other clock" is simple geometry. It is - loosely -
> > the projection of the observed clock's world line onto
> > the observer's world line.
> > Start by learning to draw a space time diagram with
> > one spatial dimension. It is very illustrative.
> > And all the mysteries disappear.
> > <End quote>
>
> And there is no other possible interpretation unless you
> invoke a Lorentz type of ether ( or "preferred frame"),
> which Einstein certainly did not.
> The idea that the action of an arbitrary remote observer
> in any way can affect the intrinsic physical properties
> of the observed object is absurd!
It is not as absurd as you think. Two observers A and B in relative motion A
predicts that B's clock is running fast or slow compared to his clock. After
A accelerated he will predict that B's clock rate has changed. SR claims
that these are geometric effects. This SR claim is bogus. Why? Because these
effect are accumulative whereas geometric effects are not accumulative. What
really happen is that the rate of A's clcok has changed due to a change of
his state of absolute motion after acceleration. A interprets the change of
his clock rate is due to B's clock rate has changed.
Ken Seto
Harry
"Paul B. Andersen" <paul.b....@deletethishia.no> wrote in message
news:cqe7tb$h45$1...@dolly.uninett.no...
SNIP
> > The popular geometric view is that despite the physical effect nothing
> > happened to affect the rate of any clock.
>
> A very ambiguous statement.
> "despite the physical effect"?
> Despite which "physical effect"?
Keep a bunch of clocks together and they keep on ticking the same.
Move one around and you find that as a result it lags behind on the others.
That's a physical effect by definition.
> > BTW he thinks that I don't know how to draw a space-time diagram. ;-)
> > Until recently I thought that such math constructions obscure more than
> > enlighten reality, but now I changed my mind, it's also good to
> > illustrate the way I look at it: IMO, every angle corresponds to a view
> > of reality, and of those angles exactly one unknown angle must
> > correspond to reality.
> >
> > Cheers,
> > Harald
>
> I will iterpret this to mean that according to you,
> there is an unknown preferred frame "corresponding to reality",
> and only the view from this frame is "correct".
Exactly - if with "correct" you mean "describing the underlying reality".
> To claim that this was Einstein's view is absurd!
I agree. I never claimed that that was Einstein's view, to the contrary.
Happy holidays.
Harald