HOCUS POCUS
mlut...@wanadoo.fr
Two electrons E1 and E2 are ejected along a straight line with
opposite velocities v1 and v2 from a device stationary in S,
at t=0 according to S clock.
Assuming that v1 = -0.6 c and v2 = 0.8 c, what is the relative
velocity between E1 and E2 ?
After a time interval t measured on his clock, S will conclude
that the distance separating E1 from E2 is (0.6 + 0.8) ct = 1.4 ct,
hence that E2 is moving away from E1 at V = 1.4 c, or that E1 is
moving away from E2 at V = 1.4 c, meaning that the relative velocity
between E1 and E2 exceeds c.
Ein Zwei Ein Stein HOCUS POCUS
E1 = S',
V = (.8 c-(-0.6c))/(1+0.8*0.6) = 1.40/1.48 c = ~.9459 c
E2 moves at 1.4/1.48 c relative to S'
E2 moves at 1.4/1.48 c relative to E1
ABRACADABRA
420000 = ~283784
By assimilating E1 to a frame S' moving away at -0.6 c from a frame S,
Srists claim that the electron E2, which had a velocity V = 1.4 c
wrt E1 measured in S, has only a velocity V' = ~0.9459 c measured in
S'.
But the electrons don't bother about which name they are given, nor
does their relative velocity V depend on their velocity wrt the device
by which they have been emitted. Such device -the frame S according
to SRists- should be ignored after their emission, it belongs to
history.
For instance, E1 could have been emitted at -0.5 c, and E2 at 0.9c,
hence their relative velocity V remains 1.4 c.
But, according to SRists, V' is then
(0.9 c-(-0.5c))/(1+0.9*0.5) = 1.40/1.45 c, which is different from
1.40/1.48 c!
Marcel Luttgens
PD
mlut...@wanadoo.fr wrote:
> HOCUS POCUS
>
> Two electrons E1 and E2 are ejected along a straight line with
> opposite velocities v1 and v2 from a device stationary in S,
> at t=0 according to S clock.
>
> Assuming that v1 = -0.6 c and v2 = 0.8 c, what is the relative
> velocity between E1 and E2 ?
>
> After a time interval t measured on his clock, S will conclude
> that the distance separating E1 from E2 is (0.6 + 0.8) ct = 1.4 ct,
> hence that E2 is moving away from E1 at V = 1.4 c, or that E1 is
> moving away from E2 at V = 1.4 c, meaning that the relative velocity
> between E1 and E2 exceeds c.
Yes, and there is nothing wrong with that.
>
> Ein Zwei Ein Stein HOCUS POCUS
> E1 = S',
> V = (.8 c-(-0.6c))/(1+0.8*0.6) = 1.40/1.48 c = ~.9459 c
> E2 moves at 1.4/1.48 c relative to S'
> E2 moves at 1.4/1.48 c relative to E1
> ABRACADABRA
> 420000 = ~283784
>
> By assimilating E1 to a frame S' moving away at -0.6 c from a frame S,
> Srists claim that the electron E2, which had a velocity V = 1.4 c
> wrt E1 measured in S, has only a velocity V' = ~0.9459 c measured in
> S'.
Yes.
>
> But the electrons don't bother about which name they are given, nor
> does their relative velocity V depend on their velocity wrt the device
> by which they have been emitted. Such device -the frame S according
> to SRists- should be ignored after their emission, it belongs to
> history.
Not at all. You seem to think that relative velocity between two
objects should be a frame-independent quantity. It's not. I don't know
why you think it should be.
kenseto
<mlut...@wanadoo.fr> wrote in message
news:1158066750....@d34g2000cwd.googlegroups.com...
> HOCUS POCUS
>
> Two electrons E1 and E2 are ejected along a straight line with
> opposite velocities v1 and v2 from a device stationary in S,
> at t=0 according to S clock.
>
> Assuming that v1 = -0.6 c and v2 = 0.8 c, what is the relative
> velocity between E1 and E2 ?
>
> After a time interval t measured on his clock, S will conclude
> that the distance separating E1 from E2 is (0.6 + 0.8) ct = 1.4 ct,
> hence that E2 is moving away from E1 at V = 1.4 c, or that E1 is
> moving away from E2 at V = 1.4 c, meaning that the relative velocity
> between E1 and E2 exceeds c.
The closing velocity as observed by observer S is indeed 1.4c. However, as
measured in the frame of E1 or E2 the relative velocity between them is
~.9459c. Why? because the signal from E2 toward E1 is being transmitted by a
stationary ether at a max speed of c.
Ken Seto
Sorcerer
"PD" <TheDrap...@gmail.com> wrote in message
news:1158069037.2...@e3g2000cwe.googlegroups.com...
| Not at all. You seem to think that relative velocity between two
| objects should be a frame-independent quantity. It's not. I don't know
| why you think it should be.
You are good at saying what things are NOT, shithead.
You are NOT smart, you ARE a fuckwit.
http://www.androcles01.pwp.blueyonder.co.uk/Smart/Smart.htm
Androcles
Randy Poe
mlut...@wanadoo.fr wrote:
> HOCUS POCUS
>
> Two electrons E1 and E2 are ejected along a straight line with
> opposite velocities v1 and v2 from a device stationary in S,
> at t=0 according to S clock.
>
> Assuming that v1 = -0.6 c and v2 = 0.8 c, what is the relative
> velocity between E1 and E2 ?
As measured where?
> After a time interval t measured on his clock, S will conclude
> that the distance separating E1 from E2 is (0.6 + 0.8) ct = 1.4 ct,
> hence that E2 is moving away from E1 at V = 1.4 c, or that E1 is
> moving away from E2 at V = 1.4 c, meaning that the relative velocity
> between E1 and E2 exceeds c.
Well, the distance between them is growing greater than 3*10^8
m/sec, true.
However, this is not a relative velocity of any particular object
in the sense that any observer sees any object moving at
this speed. That's why applying the term "relative velocity" to
this quantity can lead to exactly the kind of confusion you
are experiencing here.
> Ein Zwei Ein Stein HOCUS POCUS
> E1 = S',
> V = (.8 c-(-0.6c))/(1+0.8*0.6) = 1.40/1.48 c = ~.9459 c
Correct. That really IS a relative velocity. It's the velocity of
E2 as seen by E1.
> E2 moves at 1.4/1.48 c relative to S'
> E2 moves at 1.4/1.48 c relative to E1
Right.
> ABRACADABRA
> 420000 = ~283784
Wrong. The separation rate between E1 and E2 AS MEASURED
BY S, is not the same as the velocity of E2 AS MEASURED
BY E1. Two different observers will disagree on things
like that.
Is that news to you that SR says observations of such
things as lengths and velocities are observer-dependent?
- Randy
harry
Well put! - thus nothing to add, except for a precision below:
>> For instance, E1 could have been emitted at -0.5 c, and E2 at 0.9c,
>> hence their relative velocity V remains 1.4 c.
>>
>> But, according to SRists, V' is then
>> (0.9 c-(-0.5c))/(1+0.9*0.5) = 1.40/1.45 c, which is different from
>> 1.40/1.48 c!
This new V' is relative to *another* inertial frame. You correctly point out
that the choice of inertial frame matters for all relative speeds - even the
speed between two objects is not invariant. This point is even unclear to
some "SRists", possibly because the speed between E1 and E2 is the same for
the rest frames of E1 and E2.
Harald
>> Marcel Luttgens
>
Dirk Van de moortel
Yes, and now assume that E1 is emitted at 0.9459 c in S'
and E2 at 0 c in S'. Then according to those same "SRists",
V' = (0.9459c - (-0))/(1+0.9459*0) = 0.9459 c,
which is different from 1.40/1.48 c and from 1.40/1.45 c.
Magic! Abracadabra!
Dirk Vdm
Dirk Van de moortel
"kenseto" <ken...@erinet.com> wrote in message news:c3zNg.5022$zt1...@tornado.ohiordc.rr.com...
>
> <mlut...@wanadoo.fr> wrote in message
> news:1158066750....@d34g2000cwd.googlegroups.com...
>> HOCUS POCUS
>>
>> Two electrons E1 and E2 are ejected along a straight line with
>> opposite velocities v1 and v2 from a device stationary in S,
>> at t=0 according to S clock.
>>
>> Assuming that v1 = -0.6 c and v2 = 0.8 c, what is the relative
>> velocity between E1 and E2 ?
>>
>> After a time interval t measured on his clock, S will conclude
>> that the distance separating E1 from E2 is (0.6 + 0.8) ct = 1.4 ct,
>> hence that E2 is moving away from E1 at V = 1.4 c, or that E1 is
>> moving away from E2 at V = 1.4 c, meaning that the relative velocity
>> between E1 and E2 exceeds c.
>
> The closing velocity as observed by observer S is indeed 1.4c. However, as
> measured in the frame of E1 or E2 the relative velocity between them is
> ~.9459c.
Well done (with a minor nitpick about speed and velocity).
> Why? because the signal from E2 toward E1 is being transmitted by a
> stationary ether at a max speed of c.
Shriek!
Dirk Vdm
Dirk Van de moortel
Yes, and now assume that E1 is emitted at 0.9459 c in S'
and E2 at 0 c in S'. Then according to those same "SRists",
V' = (0.9459c - (-0))/(1+0.9459*0) = 0.9459 c,
which is different from 1.40/1.45 c but not from 1.40/1.48 c.
Magic! Abracadabra! Hocus! Pocus!
Dirk Vdm
>
> Marcel Luttgens
>
Sorcerer
"Dirk Van de moortel" <dirkvand...@ThankS-NO-SperM.hotmail.com> wrote
in message news:6aCNg.72651$df3.1...@phobos.telenet-ops.be...
Nice one, Dork :-)
http://www.androcles01.pwp.blueyonder.co.uk/Dork/Magic.htm
Androcles.
Sorcerer
Nice one, Dork ;-)
http://www.androcles01.pwp.blueyonder.co.uk/Shriek.htm
YBM
"404 - not found". This time you retired it even before publishing it.
You'd better not try to comment on trivial issues you happen not to
understand (differentials, logic, arithmetic, physics, and so on).
Sue...
mlut...@wanadoo.fr wrote:
> HOCUS POCUS
>
<< Two electrons E1 and E2 are ejected along a straight line...>>
What causes the electrons to move in a straight line ?
http://teachers.web.cern.ch/teachers/archiv/HST2005/bubble_chambers/BCwebsite/gallery/gal2_281.gif
http://teachers.web.cern.ch/teachers/archiv/HST2005/bubble_chambers/BCwebsite/gallery/gal3_weigh.htm
Sue...
[...]
Randy Poe
Sue... wrote:
> mlut...@wanadoo.fr wrote:
> > HOCUS POCUS
> >
> << Two electrons E1 and E2 are ejected along a straight line...>>
>
> What causes the electrons to move in a straight line ?
Newton's First Law.
>
> http://teachers.web.cern.ch/teachers/archiv/HST2005/bubble_chambers/BCwebsite/gallery/gal2_281.gif
Those are particles under the influence of a magnetic field, i.e.,
an external force.
- Randy
Sue...
Rephrasing... How does one prevent the electrons being influenced
by magnetic fields?
...bearing in mind, superposition of the the Coulomb force at points
along the path, in itself creates a magnetic field.
Sue...
>
> - Randy
mlut...@wanadoo.fr
I am skeptical about the physical validity of a formula (the
relativistic addition of velocities), which gives an infinity of
solutions for a same velocity V between to objects, for instance
1.4 c, measured in one frame (S in my example).
Let's consider a planet inhabited by advanced ET's, situated at
x billions light-years from the Earth. Their physicists, from the
redshift of the Earth galaxy A and the Hubble constant, calculate that
the Earth is moving away from them at -0.7 c. Opposite the Earth,
they observe another galaxy B, whose velocity relative to them is
+0.7c.
They conclude, in accordance with the cosmic expansion, that such
galaxy has a velocity 1.4 c relative to the Earth.
As they have mastered FTL communication, they transmit those data to
the Earth SRists, who calculate that B is in fact moving away from
them at 0.7c + 0.7c / 1 + 0.7*0.7 =~ 0.94 c, forgetting that it is
impossible to observe a galaxy moving away at 1.4 c.
Marcel Luttgens
Randy Poe
Because you have divine knowledge that separation rate
is independent of reference frame?
Well, the rest of us without divine knowledge are stuck
with describing what we see in experiment, which
is that the Lorentz transform is valid.
There's nothing I can do about the fact that your
divine knowledge contradicts experiment, that there
is some unknowable "reality" different from my
observable universe and accessible only to you.
So I'll stick with the equations that describe life
in my universe.
> Let's consider a planet inhabited by advanced ET's, situated at
> x billions light-years from the Earth. Their physicists, from the
> redshift of the Earth galaxy A and the Hubble constant, calculate that
> the Earth is moving away from them at -0.7 c. Opposite the Earth,
> they observe another galaxy B, whose velocity relative to them is
> +0.7c.
> They conclude, in accordance with the cosmic expansion, that such
> galaxy has a velocity 1.4 c relative to the Earth.
No, they conclude that those two points are separating
IN THEIR REFERENCE FRAME at 1.4 c.
> As they have mastered FTL communication, they transmit those data to
> the Earth SRists, who calculate that B is in fact moving away from
> them at 0.7c + 0.7c / 1 + 0.7*0.7 =~ 0.94 c, forgetting that it is
> impossible to observe a galaxy moving away at 1.4 c.
On Earth, galaxy B is OBSERVED to be moving
away at 0.94c. Earth scientists easily calculate that
the two points are separating at 1.4c from the point
of view of Planet X. They also can see galaxy C
receding at 0.7c (i.e., separating from Planet X
at 1.4c IN THE EARTH FRAME). They can easily
calculate that IN PLANET X FRAME, the observers on
Planet X would see Galaxy C receding at 0.94 c.
Planet X sends a message confirming that the
redshift of Galaxy C is consistent with a relative
velocity of 0.94c.
- Randy
harry
"Randy Poe" <poespa...@yahoo.com> wrote in message
news:1158156888.8...@m73g2000cwd.googlegroups.com...
I happen to have "devine knowledge" that skeptism is not entirely the same
concept as divine knowledge ;-)
> Well, the rest of us without divine knowledge are stuck
> with describing what we see in experiment, which
> is that the Lorentz transform is valid.
And some of us can even do better and don't think that they're "stuck" at
all. :-)
> There's nothing I can do about the fact that your
> divine knowledge contradicts experiment, that there
> is some unknowable "reality" different from my
> observable universe and accessible only to you.
???
> So I'll stick with the equations that describe life
> in my universe.
Actually, as you just pointed out above, they describe *observations*.
>> Let's consider a planet inhabited by advanced ET's, situated at
>> x billions light-years from the Earth. Their physicists, from the
>> redshift of the Earth galaxy A and the Hubble constant, calculate that
>> the Earth is moving away from them at -0.7 c. Opposite the Earth,
>> they observe another galaxy B, whose velocity relative to them is
>> +0.7c.
>> They conclude, in accordance with the cosmic expansion, that such
>> galaxy has a velocity 1.4 c relative to the Earth.
>
> No, they conclude that those two points are separating
> IN THEIR REFERENCE FRAME at 1.4 c.
Perhaps he just doesn't use jargon?
>> As they have mastered FTL communication, they transmit those data to
>> the Earth SRists, who calculate that B is in fact moving away from
>> them at 0.7c + 0.7c / 1 + 0.7*0.7 =~ 0.94 c, forgetting that it is
>> impossible to observe a galaxy moving away at 1.4 c.
>
> On Earth, galaxy B is OBSERVED to be moving
> away at 0.94c. Earth scientists easily calculate that
> the two points are separating at 1.4c from the point
> of view of Planet X. They also can see galaxy C
> receding at 0.7c (i.e., separating from Planet X
> at 1.4c IN THE EARTH FRAME). They can easily
> calculate that IN PLANET X FRAME, the observers on
> Planet X would see Galaxy C receding at 0.94 c.
> Planet X sends a message confirming that the
> redshift of Galaxy C is consistent with a relative
> velocity of 0.94c.
Yup - it's absolutely erroneous to claim that "it is impossible to observe a
galaxy moving away at 1.4 c" applies to this situation. Such statements
always relate to the frame in which the observer is in rest.
Harald
> - Randy
>
kenseto
"Randy Poe" <poespa...@yahoo.com> wrote in message
news:1158156888.8...@m73g2000cwd.googlegroups.com...
>
This shows me that you don't understand relativity. In relativity those two
points are separating IN THEIR REFERENCE FRAME at less than c.....in this
case ~.94c.
Randy Poe
You're having trouble sorting out the reference frames, Ken.
In the reference frame of Planet X, Galaxy A is moving away
at 0.7c. Galaxy B is moving away in the opposite direction
at 0.7c. According to observers on Planet X, the distance
between Galaxies A and B is growing at 1.4c.
- Randy
kenseto
No I have no such trouble.
>
> In the reference frame of Planet X, Galaxy A is moving away
> at 0.7c. Galaxy B is moving away in the opposite direction
> at 0.7c. According to observers on Planet X, the distance
> between Galaxies A and B is growing at 1.4c.
Observer at Planet X is a third party observer and indeed he can see the two
galaxies moving away from each other at 1.4c. But you said that "those two
points are separating IN THEIR REFERENCE FRAME at 1.4 c."
Ken Seto
mlut...@wanadoo.fr
Yes, that's the result obtained from the relativistic addition
of velocities.
But at what velocity is, according to Earth SRists, Planet X moving
away from Earth?
Marcel Luttgens
Randy Poe
OK, then it's the English language you're having trouble with.
> > In the reference frame of Planet X, Galaxy A is moving away
> > at 0.7c. Galaxy B is moving away in the opposite direction
> > at 0.7c. According to observers on Planet X, the distance
> > between Galaxies A and B is growing at 1.4c.
>
> Observer at Planet X is a third party observer and indeed he can see the two
> galaxies moving away from each other at 1.4c. But you said that "those two
> points are separating IN THEIR REFERENCE FRAME at 1.4 c."
"They conclude... IN THEIR REFERENCE FRAME".
There are two sets of observers in this discussion. One set is
on Planet X. The other is on Earth. "They conclude" referred
to Planet X. ML's "advanced ETs". Notice the sentence I
was responding to.
"They conclude, in accordance with the cosmic expansion, that such
galaxy has a velocity 1.4 c relative to the Earth."
My response:
"No, they conclude that those two points are separating
IN THEIR REFERENCE FRAME at 1.4 c."
Still confused about what "they" means in this exchange?
- Randy
Randy Poe
At 0.7c.
- Randy
PD
Well, there is one way to resolve matters of skepticism and that's to
make *measurements* and see if one should be skeptical or not.
You seem, however, to object to it on general principles, thinking
perhaps that relative velocity between two objects OUGHT to be
something that is observer-independent. I'd like to know on what basis
you have decided which physically meausurable quantities OUGHT to be
observer-independent and which ought to be observer-dependent. Surely
you do not believe that all physically measurable quantities are
observer-independent; consider momentum and kinetic energy, which are
clearly observer-dependent. So then, what is your criterion? How do you
know, without consulting experiment, which parameters OUGHT to be
observer-independent?
>
> Let's consider a planet inhabited by advanced ET's, situated at
> x billions light-years from the Earth. Their physicists, from the
> redshift of the Earth galaxy A and the Hubble constant, calculate that
> the Earth is moving away from them at -0.7 c. Opposite the Earth,
> they observe another galaxy B, whose velocity relative to them is
> +0.7c.
> They conclude, in accordance with the cosmic expansion, that such
> galaxy has a velocity 1.4 c relative to the Earth.
OK.
> As they have mastered FTL communication,
Why would they need FTL communication to send a signal to Earth which
is receding from them at 0.7c?
>they transmit those data to
> the Earth SRists, who calculate that B is in fact moving away from
> them at 0.7c + 0.7c / 1 + 0.7*0.7 =~ 0.94 c, forgetting that it is
> impossible to observe a galaxy moving away at 1.4 c.
But you're assuming that the ET's would conclude that Earth observers
wouldn't be able to observe the other galaxy, simply because the ET's
measure the relative speed to be 1.4c. That would be idiotic of those
ETs, because they clearly are making the wrong conclusion.
Forget the ETs. Here on Earth, we can observe a galaxy G receding from
us in one direction at 0.6c and in the opposite direction another
galaxy H receding from us at 0.7c. However, it would be idiotic for us
to conclude that galaxy G cannot observe galaxy H. Of *course* galaxy G
can observe galaxy H. The relative velocity that G sees H receding is
not larger than c. The *idiotic* conclusion that G could not see H
would only come from an assumption that if we see the relative velocity
between G and H to be greater than c, then G and H will also see the
same relative velocity. That assumption, of course, is precisely what's
wrong and what makes the conclusion idiotic.
PD
mlut...@wanadoo.fr
Yes, but don't you see any physical contradiction?
The universe is expanding, according to the present paradigm.
Hence, Earth galaxy A, ET's planet X and galaxy B participate in
the expansion. According to the ET's, A moves away from them at
-0.7 c, whereas B moves away at +0.7 c, meaning that the distance
AX is identical to the the distance XB.
Of course, such equality of distances also exists for the Earth
SRists, who claim, using the relativistic addition of velocities,
that galaxy B is OBSERVED to be moving away at 0.94c.
As, also for them, AX = XB, and the expansion velocity is proportional
to distance, AX should be moving away from them at 0.94 c / 2 = 0.47 c.
But they also claim that AX is moving away at 0.7 c !
Such contradiction can only be explained by the falseness of the
formula they use for adding velocities. As such formula is derived
from the Lorentz transformations, these are necessarily wrong.
Marcel Luttgens
mlut...@wanadoo.fr
No, I don't claim that relative velocity is observer-independent, I
only
demonstrated (once more) that the Lorentz transformations lead to
contradictory results, see my today answer to Randy Poe.
Marcel Luttgens
kenseto
<mlut...@wanadoo.fr> wrote in message
news:1158236387.9...@k70g2000cwa.googlegroups.com...
The .94c between A and B is predicted by X observer using SR. Observer X
will predict that A and B will measure their relative velocity to be .94c. X
observer will measure the relative velocity of A to be 0.7c wrt himself.
Also X will measure the relative velocity of B to be 0.7c wrt himself.
Ken Seto
Mike
You cannot devise an experiment to validate the velocity addition
formula since that would require measuring the OWSL. The velocity
addition formula is a deduction from the postulate of c invariance in
inertial FoR. So talk about valid deduction, it is ok, b ut do not
bullshut people that this is experimentally verified.
Mike
PD
Though this may seem like a physical contradiction to you, it is just
another instance of an assumption about something being an invariant
that is simply not an invariant. In this case, it is simply the same
assumption as before, just cast in a slightly different way.
You said in a reply to me that you are not assuming that relative
velocity should be an observer-independent quantity. But here you are
assuming that because the observer X says that it is equidistant
between A and B, that all such frames will make the same conclusion.
This is simply not the case, nor is there a physical reason why it
should be. (In fact, with just a little bit of thinking and a few lines
of algebra, you can convince yourself that the observer-independence of
ratios of relative distances is mathematically equivalent to
observer-independence of relative velocities.
It is indeed true that B does *not* see X to be equidistant between A
and B, even though X sees itself to be equidistant between A and B. Nor
is this a physical problem. There is nothing in physical experiment
that is inconsistent with that.
Yes, there *are* some unusual and surprising behaviors of relative
distances and relative speeds in the real world, things we wouldn't
assume to be true intuitively. But again, when stuff like this bumps up
against intuition, the way to resolve it is with experiment. If it
agrees with experiment, then it's time to question your intuition. It
may be true that what you *think* is a contradiction is simply a poor
assumption on your part.
PD
PD
That's simply not true. Relativistic kinematics is confirmed all the
time in particle experiments, where those high speeds and also
observations from two different reference frames are common.
PD
PD
Well, you said, " I am skeptical about the physical validity of a
formula (the relativistic addition of velocities), which gives an
infinity of solutions for a same velocity V between to objects, for
instance 1.4 c, measured in one frame (S in my example)." The infinity
of solutions is precisely the observer dependence of relative speed
between two objects.
As I commented in your response to Randy, the assumption that the ratio
of spacing intervals should be observer-independent is equivalent to
the assumption that relative velocities should be observer-independent.
Same assumption, just in different form.
PD
Mike
Yes, nobody disputes relativistic kinematics. The problem is that SR is
a particular variation of relativistic kinematics that assumes c
invariance in all inertial FoR.
Since c invariance in all inertial FoR cannot be proven, neither
logically (no universally quantified propositions can be proven) nor
experimentally (since it requires measuring OWSL in a SR way) you then
sound too stupid to me spewing the same crap about particle experiments
verifying velocity addition in SR.
Mike
Randy Poe
No. Separation rate is observer dependent. What does that
contradict, other than your belief that it shouldn't be?
> The universe is expanding, according to the present paradigm.
Yes.
> Hence, Earth galaxy A, ET's planet X and galaxy B participate in
> the expansion. According to the ET's, A moves away from them at
> -0.7 c, whereas B moves away at +0.7 c, meaning that the distance
> AX is identical to the the distance XB.
>
Assuming equal starting distance, yes.
> Of course, such equality of distances also exists for the Earth
It does? I think you just introduced a new axiom, that if
AX = XB according to one observer, it should be equal for
all observers. Why "of course"? That's just your belief again.
> SRists, who claim, using the relativistic addition of velocities,
> that galaxy B is OBSERVED to be moving away at 0.94c.
> As, also for them, AX = XB,
This is where you're going wrong.
So as I said, the "contradiction" is not with the universe, but
with your belief of how the universe should behave.
- Randy
PD
Well, what I sound like to you is not of particular importance to me.
There are three facts that remain
- The correct formula for combining velocities (independent of what
assumptions are made to *derive* that formula) has been completely
verified in particle experiments. Call it an empirically confirmed
formula, if you like, and forget about deriving it from any
assumptions. It's nevertheless a confirmed relation.
- TWLS invariance has certainly been measured, and TWLS and OWLS
isotropy has certainly been measured. This is mathematically equivalent
to a direct OWLS invariance measurement and so the latter measurement
is not required except to make people like you feel better about the
whole thing.
- The invariance of c in *different reference frames* has certainly
been measured, using direct time-of-flight measurement of single
photons in a number of measurements. A pion decay experiment is the
most cited one, but it is also routinely measured at the Advanced Light
Source and Advanced Photon Source facilities.
PD
Mike
Obviously, because you continue bullshuting me.
> There are three facts that remain
> - The correct formula for combining velocities (independent of what
> assumptions are made to *derive* that formula) has been completely
> verified in particle experiments. Call it an empirically confirmed
> formula, if you like, and forget about deriving it from any
> assumptions. It's nevertheless a confirmed relation.
Since there is no way to establish an observer that would measure
anything from any fast moving particle in an accelerator, the only
measurement possible is from a frame at rest wrt to the accelerator.
There is no way to measure the relative speed betweeen two particles
directly, but only infer it.
Because the above is true and makes sense, everything else you have
said sounds again too stupid to me.
I will re-phrase the questions has anyone ever measured directly the
relative speed between to moving particles at speeds close to c so that
the velocity addition formula can be validated?
The answer is NO. All measurements can take place from the frame at
rest in the frame of the laboratory and relative speed only calculated
using the velocity addition formula.
Mike
Dirk Van de moortel
"Mike" <ele...@yahoo.gr> wrote in message news:1158306653.2...@k70g2000cwa.googlegroups.com...
>
> PD wrote:
>> Mike wrote:
[snip]
Has anyone ever precisely measured directly the relative velocity
between two moving objects at every-day-life velocities, and
found a difference between the result of the classic velocity
addition formula and the relativistic velocity composition formula?
To use your words: "The answer is NO".
No one has done an experiment where a velocity of 10 m/s was
combined with a velocity of 10 m/s, which gave exactly
20.00000000000000 m/s like predicted by the classic theory, as
opposed to the 19.99999999999998 m/s that is predicted by
relativity theory.
There is no experimental basis for preferring the classic over the
relativistic formula. The only basis one could have for doing so, is
purely philosophical, which is your case is obviously a euphemism
for psychopathological.
This is a killer argument and you know it. The fact that you never
give a decent reply to it, demonstrates your malicious agenda, or
at best, your autistic imbecility.
Dirk Vdm
mlut...@wanadoo.fr
If you can, taking into account the cosmic expansion, algebraically
deduce from the velocily 0.94 c of galaxy B observed from Earth,
that Planet X is moving away from Earth at 0.7 c, I'll recognize
the validity of the relativistic addition of velocities.
Marcel Luttgens
Randy Poe
mluttg...@wanadoo.fr wrote:
> If [X] I'll recognize the validity of the relativistic addition of velocities.
I snipped the statement you wrote in X as I believe this
sentence is incorrect no matter what X is.
There is nothing that would make you recognize the validity
of the relativistic addition of velocities, including doing
the experiment with your own two hands. Certainly not
a verbal argument from any person. You have already
decided what you believe, and that kind of blind faith is not
easily shaken.
- Randy
mlut...@wanadoo.fr
It was a hasty intuition, not a belief.
If you can, taking into account the cosmic expansion, algebraically
deduce from the velocily 0.94 c of galaxy B observed from Earth,
that Planet X is moving away from Earth at 0.7 c, I'll recognize
the validity of the relativistic addition of velocities.
Marcel Luttgens
Dirk Van de moortel
"Randy Poe" <poespa...@yahoo.com> wrote in message news:1158336401....@h48g2000cwc.googlegroups.com...
Right.
Fortunately he hasn't reached the stage where he offers a vast
amount of money to the first person who can "prove him wrong".
See Henry Haapalainen, Dwain Higginbotham, and this one
that I recently found elsewhere: R.F. Norgan:
http://www.aethertheory.co.uk/
Frightening
Dirk Vdm
Dirk Van de moortel
<mlut...@wanadoo.fr> wrote in message news:1158336076....@d34g2000cwd.googlegroups.com...
>
> PD wrote:
[snip]
>> Though this may seem like a physical contradiction to you, it is just
>> another instance of an assumption about something being an invariant
>> that is simply not an invariant. In this case, it is simply the same
>> assumption as before, just cast in a slightly different way.
>>
>> You said in a reply to me that you are not assuming that relative
>> velocity should be an observer-independent quantity. But here you are
>> assuming that because the observer X says that it is equidistant
>> between A and B, that all such frames will make the same conclusion.
>> This is simply not the case, nor is there a physical reason why it
>> should be. (In fact, with just a little bit of thinking and a few lines
>> of algebra, you can convince yourself that the observer-independence of
>> ratios of relative distances is mathematically equivalent to
>> observer-independence of relative velocities.
>>
>> It is indeed true that B does *not* see X to be equidistant between A
>> and B, even though X sees itself to be equidistant between A and B. Nor
>> is this a physical problem. There is nothing in physical experiment
>> that is inconsistent with that.
>
> If you can, taking into account the cosmic expansion, algebraically
> deduce from the velocily 0.94 c of galaxy B observed from Earth,
> that Planet X is moving away from Earth at 0.7 c, I'll recognize
> the validity of the relativistic addition of velocities.
No one can do that - and you should know it since it has
been explained to you hundreds of times.
The relativistic composition of velocities is valid in globally
intertial frames -which don't exist in nature-, and locally in
sufficiently restricted inertial frames, which are too small
when you have cosmic expansion in mind.
What a transparent strawman.
Dirk Vdm
Mike
I think you have severe problems comprehending whose making arguments
about what. You should get examined by a competent neuropsychologist
and seek treatment.
1. I was replying to an argument PD made that such experiments are done
in accelerators and confirm velocity addition.
2. Nobody spoke about non-relativistic velocities but you. The problem
posed involved relativistic velocities.
3. It is clear that the only malicious person hovering these ngs is
you, an individual with severe comprehension problems and libellous
behaviour.
The fact is that no experiment can confirm the relativistic velocities
addition formula and your ad hominen attack is intended to distract
readers from this important point of mine. Relativistic velocity
addition is an ad hoc formulation with no physical basis as it should
to qualify for part of a physical theory.
Mike
>
> Dirk Vdm
Dirk Van de moortel
"Mike" <ele...@yahoo.gr> wrote in message news:1158337590.9...@i42g2000cwa.googlegroups.com...
Perhaps they do, perhaps they don't. It doesn't even matter.
You "objected" by regurgitating your million dollar question:
| "I will re-phrase the questions has anyone ever measured directly the
| relative speed between to moving particles at speeds close to c so that
| the velocity addition formula can be validated?"
>
> 2. Nobody spoke about non-relativistic velocities but you. The problem
> posed involved relativistic velocities.
But you are too stupid and to pre-occupied with your obsession
to understand it. That's what I like about you :-)
>
> 3. It is clear that the only malicious person hovering these ngs is
> you, an individual with severe comprehension problems and libellous
> behaviour.
>
> The fact is that no experiment can confirm the relativistic velocities
> addition formula and your ad hominen attack is intended to distract
> readers from this important point of mine. Relativistic velocity
> addition is an ad hoc formulation with no physical basis as it should
> to qualify for part of a physical theory.
The fact is that no experiment can refute the relativistic velocities
addition formula and your ad hominen attack is intended to distract
readers from this important point of mine. Galilean velocity
addition is an ad hoc formulation with no physical basis as it should
to qualify for part of a physical theory.
Did anyone ever say that you are a self-respecting clueless autistic
imbecile?
http://users.telenet.be/vdmoortel/dirk/Stuff/Self-respect.html
Dirk Vdm
Mike
Did I speak of Galilean physics clueless moron? Instead of focussing on
the problem discussed, as always you attack those that expose the
inefficiencies of your religion, the same way that that some clueless
muslims today attacked the Pope for exposing the fanatic elements of
their religion.
It is evident to everybody that when you are cornered you try to
intimidate the opponent. Your only defense is no defense and you keep
getting exposed day after day. You must be having a very miserable
life this way.
Mike
Sorcerer
"Dirk Van de moortel" <dirkvand...@ThankS-NO-SperM.hotmail.com> wrote
in message news:TTyOg.77717$Aj2.1...@phobos.telenet-ops.be...
| Has anyone ever precisely measured directly the relative velocity
| between two moving objects at every-day-life velocities, and
| found a difference between the result of the classic velocity
| addition formula and the relativistic velocity composition formula?
| To use your words: "The answer is NO".
Right for a change, local village dog tord.
But you can't integrate, because you are a moron.
dstupid/dm = V
Stupid = Vdm + Tusselad.
http://www.androcles01.pwp.blueyonder.co.uk/Fumble.htm
ROFL!
Androcles
Dirk Van de moortel
"Mike"
aka Bill Smith
aka Undeniable
aka Eleatis
<ele...@yahoo.gr> wrote in message news:1158340078.7...@i42g2000cwa.googlegroups.com...
[snip]
> Did I speak of Galilean physics clueless moron? Instead of focussing on
> the problem discussed, as always you attack those that expose the
> inefficiencies of your religion, the same way that that some clueless
> muslims today attacked the Pope for exposing the fanatic elements of
> their religion.
>
> It is evident to everybody that when you are cornered you try to
> intimidate the opponent. Your only defense is no defense and you keep
> getting exposed day after day. You must be having a very miserable
> life this way.
Cornered? Opponent? Defense?
Ha, so you think that this is some kind of fight or game :-)
Don't kid yourself, there is no reason or point for anyone to fight
or even play against a self-destructing entity like you:
http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/BrainHoles.html
Dirk Vdm
Mike
Dirk Van de moortel wrote:
You continue your defamation and libellous act while avoiding to talk
about the subject being discussed. YOu are obviously the one who
engages in these practices and exposes the compromising conditions
under which your local inertial clock is ticking.
Mike
>
> Dirk Vdm
Sorcerer
"Mike" <ele...@yahoo.gr> wrote in message
news:1158403327.9...@i3g2000cwc.googlegroups.com...
If he were a man I'd hit him, but I'm kind to animals.
Androcles
mlut...@wanadoo.fr
You "believe" that my statement
"If you can, taking into account the cosmic expansion, algebraically
deduce from the velocily 0.94 c of galaxy B observed from Earth,
that Planet X is moving away from Earth at 0.7 c, I'll recognize
the validity of the relativistic addition of velocities."
is incorrect.
You should have recognized that you didn't understand it, contrary to
the SR guru Dirk Van de moortel, who nevertheless tried to evade
the problem, claiming that
"The relativistic composition of velocities is valid in globally
intertial frames -which don't exist in nature-, and locally in
sufficiently restricted inertial frames, which are too small
when you have cosmic expansion in mind."
> There is nothing that would make you recognize the validity
> of the relativistic addition of velocities, including doing
> the experiment with your own two hands. Certainly not
> a verbal argument from any person. You have already
> decided what you believe, and that kind of blind faith is not
> easily shaken.
I was waiting for a scientific argument, not for a verbal one.
You should realize that Einstein's SR is similar to Picasso's
art, because he assumed that when x = ct, x' = ct'. This leads
to reality distorsion, and to unavoidable physical contradictions.
Otherwise, the transforms reduce to
(1) x' = sqrt(1 - u^2/c^2) * (x - ut) = (x - ut) / g
(2) t' = sqrt(1 - u^2/c^2) * t = t / g , where
u is the velocity of S' relative to S.
The relativistic addition of velocities can be obtained
as follows:
Let v be the velocity of an object relative to S, as measured by an
observer in S, and v' its velocity relative to S' when measured in S'.
Then v = dx/dt, v' = dx'/dt'.
>From (1), one gets dx' = (dx - udt) / g
>From (2), one gets dt' = dt / g
By substitution, one gets
v' = [(dx - udt) / g] / [dt / g]
= (dx / dt) - u
= v - u
Thus, Einstein's distorted formula
v' = (v - u) / (1 - uv/c^2) reduces to
v' = u - v
Hence, galaxy B is in moving away from the Earth at
0.7 c + 0.7 c = 1.4 c, and there is no contradiction any more.
But "you have already decided what you believe, and that kind of
blind faith is not easily shaken."
Marcel Luttgens
Randy Poe
mlut...@wanadoo.fr wrote:
> Randy Poe wrote:
> > mluttg...@wanadoo.fr wrote:
> > > If [X] I'll recognize the validity of the relativistic addition of velocities.
> >
> > I snipped the statement you wrote in X as I believe this
> > sentence is incorrect no matter what X is.
> >
> > There is nothing that would make you recognize the validity
> > of the relativistic addition of velocities, including doing
> > the experiment with your own two hands. Certainly not
> > a verbal argument from any person. You have already
> > decided what you believe, and that kind of blind faith is not
> > easily shaken.
> >
> > - Randy
>
> You "believe" that my statement
> "If you can, taking into account the cosmic expansion, algebraically
> deduce from the velocily 0.94 c of galaxy B observed from Earth,
> that Planet X is moving away from Earth at 0.7 c, I'll recognize
> the validity of the relativistic addition of velocities."
> is incorrect.
Yes, I believe that is incorrect.
But at any rate, cosmic expansion is not part of SR, so what
you're asking for is an SR explanation of a purely GR phenomenon.
If the velocitties of 0.7c you are talking about are supposed to
be the Hubble velocities, then 0.94c is NOT what Earth would
observe for Galaxy B. I think it's a more complex calculation.
It's not the same phenomenon that gives rise to the velocity
addition formula in SR. There's a different velocity composition
formula.
No doubt you'll claim this as a victory. But that's not a surprise.
As I said, there is no statement or argument which could make
you change your mind. That's why I believe any sentence containing
"... I'll recognize the validity of the relativistic..." is incorrect
when uttered by you.
- Randy
PD
Proton-proton collisions and electron-electron collisions (for example)
are routinely done in both collider and fixed-target environments. The
physics of these collisions is simple enough (at least for some
measurable distributions) that comparison of the nature of the
collisions in both environments is tantamount to measuring the same
process in two very different frames of reference. The relative speed
of the colliding particles is measured in both cases as a normal part
of beamline monitoring operations. The fact that the distributions are
identical if and only if the relative speeds in the two reference
frames are related exactly by the relativistic prescription, is
compelling evidence that the relativistic prescription is correct.
>
> Because the above is true and makes sense, everything else you have
> said sounds again too stupid to me.
>
> I will re-phrase the questions has anyone ever measured directly the
> relative speed between to moving particles at speeds close to c so that
> the velocity addition formula can be validated?
Yes.
>
> The answer is NO. All measurements can take place from the frame at
> rest in the frame of the laboratory and relative speed only calculated
> using the velocity addition formula.
No, that's not correct.
Mike
A self-proclaimed expert in these ng's (Dirt van dar Guppy] has a
different opinion, as he wrote:
"There is no experimental basis for preferring the classic over the
relativistic formula. The only basis one could have for doing so, is
purely philosophical, which is your case is obviously a euphemism
for psychopathological."
Mike
PD
I'll let him expand or clarify his own remarks, Mike. Mine is not an
opinion. It is an experimental fact, so well established that it is
considered a benchmark for basic operation, like looking to see if the
"on" light turns on when you flip the power switch.
PD
Sorcerer
"PD" <TheDrap...@gmail.com> wrote in message
news:1158419074.0...@d34g2000cwd.googlegroups.com...
How fast does this spinning magnet transfer energy to the
compass needle?
http://www.androcles01.pwp.blueyonder.co.uk/spin.gif
Dirk Van de moortel
"PD" <TheDrap...@gmail.com> wrote in message news:1158419770.4...@m7g2000cwm.googlegroups.com...
>
> Mike wrote:
>> PD wrote:
>> > Mike wrote:
[snip]
>> > > The answer is NO. All measurements can take place from the frame at
>> > > rest in the frame of the laboratory and relative speed only calculated
>> > > using the velocity addition formula.
>> >
>> > No, that's not correct.
>>
>>
>> A self-proclaimed expert in these ng's (Dirt van dar Guppy] has a
>> different opinion, as he wrote:
>>
>> "There is no experimental basis for preferring the classic over the
>> relativistic formula. The only basis one could have for doing so, is
>> purely philosophical, which is your case is obviously a euphemism
>> for psychopathological."
>>
>> Mike
>
> I'll let him expand or clarify his own remarks, Mike. Mine is not an
> opinion. It is an experimental fact, so well established that it is
> considered a benchmark for basic operation, like looking to see if the
> "on" light turns on when you flip the power switch.
I don't see why I would expand or clarify.
First, what I wrote is no opinion either.
Second, my remark is not even related to yours, so he has no
business opposing them and labelling them "different".
Third, his mind is blocked for expansions and clarifications anyway.
Slapping his face with a ping pong paddle seems to be the only
way one can communicate with him :-)
Dirk Vdm
PD
Dirk Van de moortel wrote:
Precisely.
mlut...@wanadoo.fr
I my scenario, I didn't leave you in uncertainty about the cause
of the velocity of the galaxies:
"Let's consider a planet inhabited by advanced ET's, situated at
x billions light-years from the Earth. Their physicists, from the
redshift of the Earth galaxy A and the Hubble constant, calculate that
the Earth is moving away from them at -0.7 c. Opposite the Earth,
they observe another galaxy B, whose velocity relative to them is
+0.7c.
They conclude, in accordance with the cosmic expansion, that such
galaxy has a velocity 1.4 c relative to the Earth.
[...] "
In your message of Sep 13 2006, you applied SR:
"On Earth, galaxy B is OBSERVED to be moving
away at 0.94c. Earth scientists easily calculate that
the two points are separating at 1.4c from the point
of view of Planet X. They also can see galaxy C
receding at 0.7c (i.e., separating from Planet X
at 1.4c IN THE EARTH FRAME). They can easily
calculate that IN PLANET X FRAME, the observers on
Planet X would see Galaxy C receding at 0.94 c.
Planet X sends a message confirming that the
redshift of Galaxy C is consistent with a relative
velocity of 0.94c."
Now, as you are cornered, you are contradicting yourself:
"If the velocitties of 0.7c you are talking about are supposed to
be the Hubble velocities, then 0.94c is NOT what Earth would
observe for Galaxy B. I think it's a more complex calculation."
I am sorry to notice once again, that SRists are not honest.
Be frank, recognize that SR in incompatible with the physical
reality.
Marcel Luttgens
kenseto
<mlut...@wanadoo.fr> wrote in message
news:1158485745....@e3g2000cwe.googlegroups.com...
That's why they invented the inflation hypothesis. In this hypothesis they
said that it is not the galaxies that are doing the expansion. It is the
space between them that is expansding. In real life no observer can see any
object has a relative velocity greater than c. The reason is that the signal
from the object is being transmitted by the ether at a max speed of c.
An observer can see two objects have a closing speed of under 2c but that's
not the speed they measure using thier own clock and rod.
Ken Seto
mlut...@wanadoo.fr
PD wrote:
> There are three facts that remain
> - The correct formula for combining velocities (independent of what
> assumptions are made to *derive* that formula) has been completely
> verified in particle experiments. Call it an empirically confirmed
> formula, if you like, and forget about deriving it from any
> assumptions. It's nevertheless a confirmed relation.
Exact references, please.
[...]
> Proton-proton collisions and electron-electron collisions (for example)
> are routinely done in both collider and fixed-target environments. The
> physics of these collisions is simple enough (at least for some
> measurable distributions) that comparison of the nature of the
> collisions in both environments is tantamount to measuring the same
> process in two very different frames of reference. The relative speed
> of the colliding particles is measured in both cases as a normal part
> of beamline monitoring operations. The fact that the distributions are
> identical if and only if the relative speeds in the two reference
> frames are related exactly by the relativistic prescription, is
> compelling evidence that the relativistic prescription is correct.
Exactly related, thus no error bars ?
Did the experimenters expressly claimed that their observed
distributions
are explained by the relativistic addition of velocities?
Where can their articles be found ? (Exact references, please).
Marcel Luttgens
PD
mlut...@wanadoo.fr wrote:
> PD wrote:
>
> > There are three facts that remain
>
> > - The correct formula for combining velocities (independent of what
> > assumptions are made to *derive* that formula) has been completely
> > verified in particle experiments. Call it an empirically confirmed
> > formula, if you like, and forget about deriving it from any
> > assumptions. It's nevertheless a confirmed relation.
>
> Exact references, please.
I've done this for you before Marcel, almost a year ago. Your memory is
short. That, or you learn nothing. That, or you didn't read what I
pointed you to. I pointed to the comparison of rapidity distributions
in proton-proton collisions at fixed target and collider experiments.
>
> [...]
>
> > Proton-proton collisions and electron-electron collisions (for example)
> > are routinely done in both collider and fixed-target environments. The
> > physics of these collisions is simple enough (at least for some
> > measurable distributions) that comparison of the nature of the
> > collisions in both environments is tantamount to measuring the same
> > process in two very different frames of reference. The relative speed
> > of the colliding particles is measured in both cases as a normal part
> > of beamline monitoring operations. The fact that the distributions are
> > identical if and only if the relative speeds in the two reference
> > frames are related exactly by the relativistic prescription, is
> > compelling evidence that the relativistic prescription is correct.
>
> Exactly related, thus no error bars ?
Don't be ridiculous. A measurement always involves error bars. You
should never use the presence of experimental error bars as an argument
that the evidence is not compelling enough. The measurement should be
sufficiently precise that it can clearly distinguish between a tested
model and a competing model. That is true in this case.
> Did the experimenters expressly claimed that their observed
> distributions
> are explained by the relativistic addition of velocities?
No, they did not. This has to be inferred from the background
information supplied in the references. If you're hoping that physics
articles are explicitly laid out to answer the specific question you
ask (as though the article is written in response to your question),
then your expectations about reading scientific articles probably needs
to be adjusted.
> Where can their articles be found ? (Exact references, please).
Given previously, Marcel. Do your own homework now.
>
> Marcel Luttgens
Randy Poe
> of the velocity of the galaxies:
>
> "Let's consider a planet inhabited by advanced ET's, situated at
> x billions light-years from the Earth. Their physicists, from the
> redshift of the Earth galaxy A and the Hubble constant, calculate that
> the Earth is moving away from them at -0.7 c. Opposite the Earth,
> they observe another galaxy B, whose velocity relative to them is
> +0.7c.
Ah well then, I was wrong. I thought you were asking a
question about SR and I answered it in that context.
- Randy
mlut...@wanadoo.fr
PD wrote:
> mlut...@wanadoo.fr wrote:
> > PD wrote:
> >
> > > There are three facts that remain
> >
> > > - The correct formula for combining velocities (independent of what
> > > assumptions are made to *derive* that formula) has been completely
> > > verified in particle experiments. Call it an empirically confirmed
> > > formula, if you like, and forget about deriving it from any
> > > assumptions. It's nevertheless a confirmed relation.
> >
> > Exact references, please.
>
> I've done this for you before Marcel, almost a year ago. Your memory is
> short. That, or you learn nothing. That, or you didn't read what I
> pointed you to. I pointed to the comparison of rapidity distributions
> in proton-proton collisions at fixed target and collider experiments.
>
Yes, I remember, but I didn't find any experiment whose data allowed
to confirm your claim.
> >
> > [...]
> >
> > > Proton-proton collisions and electron-electron collisions (for example)
> > > are routinely done in both collider and fixed-target environments. The
> > > physics of these collisions is simple enough (at least for some
> > > measurable distributions) that comparison of the nature of the
> > > collisions in both environments is tantamount to measuring the same
> > > process in two very different frames of reference. The relative speed
> > > of the colliding particles is measured in both cases as a normal part
> > > of beamline monitoring operations. The fact that the distributions are
> > > identical if and only if the relative speeds in the two reference
> > > frames are related exactly by the relativistic prescription, is
> > > compelling evidence that the relativistic prescription is correct.
> >
> > Exactly related, thus no error bars ?
>
> Don't be ridiculous. A measurement always involves error bars. You
> should never use the presence of experimental error bars as an argument
> that the evidence is not compelling enough. The measurement should be
> sufficiently precise that it can clearly distinguish between a tested
> model and a competing model. That is true in this case.
>
"Exactly" was a bit exaggerated. Anyhow, a statistical analysis is
needed to claim that such distinction exists. Where is it ?
> > Did the experimenters expressly claimed that their observed
> > distributions
> > are explained by the relativistic addition of velocities?
>
> No, they did not. This has to be inferred from the background
> information supplied in the references. If you're hoping that physics
> articles are explicitly laid out to answer the specific question you
> ask (as though the article is written in response to your question),
> then your expectations about reading scientific articles probably needs
> to be adjusted.
As the experimenters seemingly didn't mention your alleged relation
with the "relativistic prescription", I presume that you did the
analytical job
yourself. If this is the case, perhaps could you show us how you
reached your conclusion. Otherwise, the readers could remain skeptical.
Don't forget that the burden of the proof lies with the "claimant", not
with the reader.
Marcel Luttgens
mlut...@wanadoo.fr
A sin confessed is a sin half pardoned.
Marcel Luttgens
Dirk Van de moortel
<mlut...@wanadoo.fr> wrote in message news:1158610804....@d34g2000cwd.googlegroups.com...
Something we've never seen you do.
When we catch you with your pants down, you shut up,
you quietly go away, and 6 weeks later you come back
with exactly the same tripe.
Dirk Vdm
Randy Poe
What sin?
Let's recap: you made a claim that you could be convinced
of the validity of SR composition of velocities, by analysis
of a GR effect in which SR composition of velocities does
not apply.
Is that about right?
Will you confess your sin that the entire example was misleading
in a discussion purporting to be about SR composition of
velocities? Hmmm... maybe I should reexamine and comment
on your original post.
- Randy
Randy Poe
mlut...@wanadoo.fr wrote:
> Let's consider a planet inhabited by advanced ET's, situated at
> x billions light-years from the Earth. Their physicists, from the
> redshift of the Earth galaxy A and the Hubble constant, calculate that
> the Earth is moving away from them at -0.7 c. Opposite the Earth,
> they observe another galaxy B, whose velocity relative to them is
> +0.7c.
> galaxy has a velocity 1.4 c relative to the Earth.
> the Earth SRists, who calculate that B is in fact moving away from
> them at 0.7c + 0.7c / 1 + 0.7*0.7 =~ 0.94 c
No they don't, as SR is silent on cosmic expansion and the
composition of cosmic expansion velocities.
>, forgetting that it is
> impossible to observe a galaxy moving away at 1.4 c.
The relationship between observability and redshift is not
so simple at extreme distances, which you would require to
have cosmic expansion velocities of 0.7c (which would be
a redshift of about 0.7).
According to this website
http://haydenplanetarium.org/universe/duguide/app_redshift.php
the Hubble constant is 71 km/sec/Mpc, which means that
a relative velocity of 0.7 c (210000 km/sec) corresponds to a
distance of about 2960 Mpc, or about 10 billion light years.
That means that Galaxy B is 20 million ly from Galaxy A. At
those distances the linear Hubble's law no longer applies. The
relative velocity is not 1.4c, but it isn't given by the SR composition
formula.
- Randy
PD
mlut...@wanadoo.fr wrote:
> PD wrote:
> > mlut...@wanadoo.fr wrote:
> > > PD wrote:
> > >
> > > > There are three facts that remain
> > >
> > > > - The correct formula for combining velocities (independent of what
> > > > assumptions are made to *derive* that formula) has been completely
> > > > verified in particle experiments. Call it an empirically confirmed
> > > > formula, if you like, and forget about deriving it from any
> > > > assumptions. It's nevertheless a confirmed relation.
> > >
> > > Exact references, please.
> >
> > I've done this for you before Marcel, almost a year ago. Your memory is
> > short. That, or you learn nothing. That, or you didn't read what I
> > pointed you to. I pointed to the comparison of rapidity distributions
> > in proton-proton collisions at fixed target and collider experiments.
> >
>
> Yes, I remember, but I didn't find any experiment whose data allowed
> to confirm your claim.
I gave you references to the papers at the time. I don't know why you
wouldn't have been able to "find any experiment".
>
> > >
> > > [...]
> > >
> > > > Proton-proton collisions and electron-electron collisions (for example)
> > > > are routinely done in both collider and fixed-target environments. The
> > > > physics of these collisions is simple enough (at least for some
> > > > measurable distributions) that comparison of the nature of the
> > > > collisions in both environments is tantamount to measuring the same
> > > > process in two very different frames of reference. The relative speed
> > > > of the colliding particles is measured in both cases as a normal part
> > > > of beamline monitoring operations. The fact that the distributions are
> > > > identical if and only if the relative speeds in the two reference
> > > > frames are related exactly by the relativistic prescription, is
> > > > compelling evidence that the relativistic prescription is correct.
> > >
> > > Exactly related, thus no error bars ?
> >
> > Don't be ridiculous. A measurement always involves error bars. You
> > should never use the presence of experimental error bars as an argument
> > that the evidence is not compelling enough. The measurement should be
> > sufficiently precise that it can clearly distinguish between a tested
> > model and a competing model. That is true in this case.
> >
>
> "Exactly" was a bit exaggerated. Anyhow, a statistical analysis is
> needed to claim that such distinction exists. Where is it ?
In the papers. This is part and parcel of an experimental paper. Hint:
You may need to read some of the references to get a complete picture.
>
> > > Did the experimenters expressly claimed that their observed
> > > distributions
> > > are explained by the relativistic addition of velocities?
> >
> > No, they did not. This has to be inferred from the background
> > information supplied in the references. If you're hoping that physics
> > articles are explicitly laid out to answer the specific question you
> > ask (as though the article is written in response to your question),
> > then your expectations about reading scientific articles probably needs
> > to be adjusted.
>
> As the experimenters seemingly didn't mention your alleged relation
> with the "relativistic prescription", I presume that you did the
> analytical job
> yourself.
Actually, I didn't need to do that because I had already read and was
familiar with most of the papers referenced in the articles I referred
to you, or I was separately familiar with their results through contact
with the experimenters. Moreover, I'm familiar with the definition and
properties of rapidity. And so when I see rapidity distributions that
are identical at the same root-s, then I know what that means. People
that aren't as familiar with the field have to do a bit more background
reading to catch up, but it's not a huge issue.
> If this is the case, perhaps could you show us how you
> reached your conclusion. Otherwise, the readers could remain skeptical.
It's not my task to make you less skeptical. It's not my job to educate
you in a newsgroup. I am giving you enough information so that you can
correct your misconception and lack of familiarity with experimental
results on your own without too much difficulty. Now, do some homework.
> Don't forget that the burden of the proof lies with the "claimant", not
> with the reader.
This newsgroup is not the courtroom where such issues are decided. You
are owed no burden of proof here. The information you've been afforded
here in response to your error is a luxury. Anyone can *choose* to not
learn something if they're really not interested in learning it, and
that in no way places the burden on anyone to teach them anyway.
PD
Sorcerer
"Randy Poe" <poespa...@yahoo.com> wrote in message
news:1158611956.0...@b28g2000cwb.googlegroups.com...
Have you convinced yourself you are only person in this newsgroup?
Androcles
mlut...@wanadoo.fr
PD wrote:
> mlut...@wanadoo.fr wrote:
> > PD wrote:
> > > mlut...@wanadoo.fr wrote:
> > > > PD wrote:
> > > >
> > > > > There are three facts that remain
> > > >
> > > > > - The correct formula for combining velocities (independent of what
> > > > > assumptions are made to *derive* that formula) has been completely
> > > > > verified in particle experiments. Call it an empirically confirmed
> > > > > formula, if you like, and forget about deriving it from any
> > > > > assumptions. It's nevertheless a confirmed relation.
> > > >
> > > > Exact references, please.
> > >
> > > I've done this for you before Marcel, almost a year ago. Your memory is
> > > short. That, or you learn nothing. That, or you didn't read what I
> > > pointed you to. I pointed to the comparison of rapidity distributions
> > > in proton-proton collisions at fixed target and collider experiments.
> > >
> >
> > Yes, I remember, but I didn't find any experiment whose data allowed
> > to confirm your claim.
>
> I gave you references to the papers at the time. I don't know why you
> wouldn't have been able to "find any experiment".
Any experiment that confirmed your claim.
>
> >
> > > >
> > > > [...]
> > > >
> > > > > Proton-proton collisions and electron-electron collisions (for example)
> > > > > are routinely done in both collider and fixed-target environments. The
> > > > > physics of these collisions is simple enough (at least for some
> > > > > measurable distributions) that comparison of the nature of the
> > > > > collisions in both environments is tantamount to measuring the same
> > > > > process in two very different frames of reference. The relative speed
> > > > > of the colliding particles is measured in both cases as a normal part
> > > > > of beamline monitoring operations. The fact that the distributions are
> > > > > identical if and only if the relative speeds in the two reference
> > > > > frames are related exactly by the relativistic prescription, is
> > > > > compelling evidence that the relativistic prescription is correct.
> > > >
> > > > Exactly related, thus no error bars ?
> > >
> > > Don't be ridiculous. A measurement always involves error bars. You
> > > should never use the presence of experimental error bars as an argument
> > > that the evidence is not compelling enough. The measurement should be
> > > sufficiently precise that it can clearly distinguish between a tested
> > > model and a competing model. That is true in this case.
> > >
> >
> > "Exactly" was a bit exaggerated. Anyhow, a statistical analysis is
> > needed to claim that such distinction exists. Where is it ?
>
> In the papers. This is part and parcel of an experimental paper. Hint:
> You may need to read some of the references to get a complete picture.
>
Among those many papers, at least one of them should be unambiguously
pertinent. Which one?
> >
> > > > Did the experimenters expressly claimed that their observed
> > > > distributions
> > > > are explained by the relativistic addition of velocities?
> > >
> > > No, they did not. This has to be inferred from the background
> > > information supplied in the references. If you're hoping that physics
> > > articles are explicitly laid out to answer the specific question you
> > > ask (as though the article is written in response to your question),
> > > then your expectations about reading scientific articles probably needs
> > > to be adjusted.
> >
> > As the experimenters seemingly didn't mention your alleged relation
> > with the "relativistic prescription", I presume that you did the
> > analytical job
> > yourself.
>
> Actually, I didn't need to do that because I had already read and was
> familiar with most of the papers referenced in the articles I referred
> to you, or I was separately familiar with their results through contact
> with the experimenters. Moreover, I'm familiar with the definition and
> properties of rapidity. And so when I see rapidity distributions that
> are identical at the same root-s, then I know what that means. People
> that aren't as familiar with the field have to do a bit more background
> reading to catch up, but it's not a huge issue.
Iow, your experience of the subject matter justifies your personal
conclusion.
Scientifically, "seing" something is not enough. As you are so sure,
why
don't you publish a paper, that would bring you some fame?
>
> > If this is the case, perhaps could you show us how you
> > reached your conclusion. Otherwise, the readers could remain skeptical.
>
> It's not my task to make you less skeptical. It's not my job to educate
> you in a newsgroup. I am giving you enough information so that you can
> correct your misconception and lack of familiarity with experimental
> results on your own without too much difficulty. Now, do some homework.
Those are rather arrogant words, revealing a strong personality.
>
> > Don't forget that the burden of the proof lies with the "claimant", not
> > with the reader.
>
> This newsgroup is not the courtroom where such issues are decided. You
> are owed no burden of proof here. The information you've been afforded
> here in response to your error is a luxury. Anyone can *choose* to not
> learn something if they're really not interested in learning it, and
> that in no way places the burden on anyone to teach them anyway.
In a sense, it *is*a courtroom, where paranoia is condemned.
Marcel Luttgens
PD
mlut...@wanadoo.fr wrote:
> PD wrote:
> > mlut...@wanadoo.fr wrote:
> > > PD wrote:
> > > > mlut...@wanadoo.fr wrote:
> > > > > PD wrote:
> > > > >
> > > > > > There are three facts that remain
> > > > >
> > > > > > - The correct formula for combining velocities (independent of what
> > > > > > assumptions are made to *derive* that formula) has been completely
> > > > > > verified in particle experiments. Call it an empirically confirmed
> > > > > > formula, if you like, and forget about deriving it from any
> > > > > > assumptions. It's nevertheless a confirmed relation.
> > > > >
> > > > > Exact references, please.
> > > >
> > > > I've done this for you before Marcel, almost a year ago. Your memory is
> > > > short. That, or you learn nothing. That, or you didn't read what I
> > > > pointed you to. I pointed to the comparison of rapidity distributions
> > > > in proton-proton collisions at fixed target and collider experiments.
> > > >
> > >
> > > Yes, I remember, but I didn't find any experiment whose data allowed
> > > to confirm your claim.
> >
> > I gave you references to the papers at the time. I don't know why you
> > wouldn't have been able to "find any experiment".
>
> Any experiment that confirmed your claim.
The references I gave confirm this claim.
>
> >
> > >
> > > > >
> > > > > [...]
> > > > >
> > > > > > Proton-proton collisions and electron-electron collisions (for example)
> > > > > > are routinely done in both collider and fixed-target environments. The
> > > > > > physics of these collisions is simple enough (at least for some
> > > > > > measurable distributions) that comparison of the nature of the
> > > > > > collisions in both environments is tantamount to measuring the same
> > > > > > process in two very different frames of reference. The relative speed
> > > > > > of the colliding particles is measured in both cases as a normal part
> > > > > > of beamline monitoring operations. The fact that the distributions are
> > > > > > identical if and only if the relative speeds in the two reference
> > > > > > frames are related exactly by the relativistic prescription, is
> > > > > > compelling evidence that the relativistic prescription is correct.
> > > > >
> > > > > Exactly related, thus no error bars ?
> > > >
> > > > Don't be ridiculous. A measurement always involves error bars. You
> > > > should never use the presence of experimental error bars as an argument
> > > > that the evidence is not compelling enough. The measurement should be
> > > > sufficiently precise that it can clearly distinguish between a tested
> > > > model and a competing model. That is true in this case.
> > > >
> > >
> > > "Exactly" was a bit exaggerated. Anyhow, a statistical analysis is
> > > needed to claim that such distinction exists. Where is it ?
> >
> > In the papers. This is part and parcel of an experimental paper. Hint:
> > You may need to read some of the references to get a complete picture.
> >
>
> Among those many papers, at least one of them should be unambiguously
> pertinent. Which one?
The two primary papers I gave you are unambiguously pertinent. You want
to be spoon fed. I don't have a spoon that will fit your mouth.
I have my share of published papers, thanks, and I'm not in need of
fame, thanks. And yes, indeed, my experience of the experimental
evidence informs my personal conclusion. A personal conclusion that is
not based on experimental evidence, on the other hand, but is based on
intuition and incredulity, does not carry a whole lot of weight.
>
> >
> > > If this is the case, perhaps could you show us how you
> > > reached your conclusion. Otherwise, the readers could remain skeptical.
> >
> > It's not my task to make you less skeptical. It's not my job to educate
> > you in a newsgroup. I am giving you enough information so that you can
> > correct your misconception and lack of familiarity with experimental
> > results on your own without too much difficulty. Now, do some homework.
>
> Those are rather arrogant words, revealing a strong personality.
I don't care what you think about my personality, Marcel. Physics
doesn't have to be nice. You *are* expected to do some homework if you
want to do some physics.
>
> >
> > > Don't forget that the burden of the proof lies with the "claimant", not
> > > with the reader.
> >
> > This newsgroup is not the courtroom where such issues are decided. You
> > are owed no burden of proof here. The information you've been afforded
> > here in response to your error is a luxury. Anyone can *choose* to not
> > learn something if they're really not interested in learning it, and
> > that in no way places the burden on anyone to teach them anyway.
>
> In a sense, it *is*a courtroom, where paranoia is condemned.
Nonsense. Popularity contests and impassioned debates about what
*should* be so have no place in physics. Bucking the status quo for the
sake of doing just that serves no useful role in physics. This ain't no
coffee shop, this ain't no steenking philosophy club.
mlut...@wanadoo.fr
According to Google, there are about 52,200 papers about rapidity
distributions
in proton-proton collisions, so I would be grateful if you gave the
exact references
of those two primary papers. As you seem to be the only person claiming
that
the relativistic addition formula is validated by experiments, I am
convinced that
a lot of people would also be grateful to get those references.
And you think that your experience of the experimental evidence alone
does carry much weight ?
Marcel Luttgens
mlut...@wanadoo.fr
My example has misled a lot of people, including myself, because
I referred to galaxies subject to cosmic expansion, instead of
objects moving at a velocity Kx, where K is some constant.
Marcel Luttgens
PD
As I told you Marcel, I did the work and gave you explicit references
nearly a year ago. You can surely do some Google work to at least find
out where I did that, especially since you say you remember it. I'm not
about to make things lapdog-easy for you, Marcel. I wouldn't do it for
a serious physicis student, either, because knowing how to dig this
stuff up is as basic a skill as using a timing light is to a car
mechanic.
Now, you have three choices at this point:
a) You can say you don't want to work that hard at figuring this stuff
out, in which I'd invite you to steer clear of the business entirely
because there are plenty who are willing and eager to do that.
b) You can say that you don't know how to look stuff up, and you need
more basic training in how to do library research and how to find out
what work has been done on a topic that you're unfamiliar with. In this
case, I can recommend some options for getting that training other than
dawdling in newsgroups.
c) You can say that you are willing to work hard at figuring this stuff
out, and that you do know how to do library research, and then you go
do it.
In science, Marcel, experimental evidence carries enormous weight. It
trumps intuition, it trumps common sense, it trumps what looks to be
really good ideas. If it ain't confirmed by experimental evidence, then
it ain't worth squat.
Now, you may be of the opinion that for every bit of experimental
evidence that supports one idea, then there is other experimental
evidence that supports a completely different idea. This is tantamount
to rejecting the value of experimental evidence in science. If this is
what you think, then you either do not know what role experiment plays
in science, or you shouldn't be trying to do science, or both.
PD
mlut...@wanadoo.fr
About one year ago, you claimed that papers about rapidity
verified length contraction. Now, they allegedly verify the
relativistic
addition of velocities. You are acting like a snake oil seller !
The snake oil is of course SR.
> Now, you have three choices at this point:
> a) You can say you don't want to work that hard at figuring this stuff
> out, in which I'd invite you to steer clear of the business entirely
> because there are plenty who are willing and eager to do that.
> b) You can say that you don't know how to look stuff up, and you need
> more basic training in how to do library research and how to find out
> what work has been done on a topic that you're unfamiliar with. In this
> case, I can recommend some options for getting that training other than
> dawdling in newsgroups.
> c) You can say that you are willing to work hard at figuring this stuff
> out, and that you do know how to do library research, and then you go
> do it.
I will not repeat the "job" I did last year, as nowhere did I find a
confirmation
of your claims.
Shaky or alledged experimental evidences demonstrate nothing.
PD
Yes, indeed. Both are confirmed in the same pair of experiments.
>You are acting like a snake oil seller !
> The snake oil is of course SR.
Well, once again, if experiment says the oil works, it works. You can
call it snake oil all you want, but it works.
>
> > Now, you have three choices at this point:
> > a) You can say you don't want to work that hard at figuring this stuff
> > out, in which I'd invite you to steer clear of the business entirely
> > because there are plenty who are willing and eager to do that.
> > b) You can say that you don't know how to look stuff up, and you need
> > more basic training in how to do library research and how to find out
> > what work has been done on a topic that you're unfamiliar with. In this
> > case, I can recommend some options for getting that training other than
> > dawdling in newsgroups.
> > c) You can say that you are willing to work hard at figuring this stuff
> > out, and that you do know how to do library research, and then you go
> > do it.
>
> I will not repeat the "job" I did last year, as nowhere did I find a
> confirmation
> of your claims.
Really? Then apparently you don't know how to read scientific papers.
In that case, I recommend option (b). Would you like some suggestions?
Shaky? And on what basis do you say the evidence is shaky?
You are beginning to sound like Henri Wilson who says that any
experiment that provides support for SR obviously has something wrong
with it, without even looking at it.
As I said, if you're the kind of person that rejects the value of
experimental evidence, or decides whether experimental evidence is
shaky based on whether it agrees with your expectations, then you've
got no business attempting to do science.
PD
mlut...@wanadoo.fr
Another of your proofs by assertion !
See messages n° 369 sq. at
http://groups.google.fr/group/sci.physics.relativity/browse_frm/thread/151c620970e5b236/621b142dbc78068f?lnk=st&q=luttgens+rapidity&rnum=1&hl=en#621b142dbc78068f
Marcel Luttgens
PD
There are no proofs in science. Only experimental evidence in support
of models. The experimental evidence is where I indicated.
Yes, I remember your note. And where is the shakiness?
Randy Poe
I have now done so. Here is your post that posed this
question, and my response (edited slightly from the
version I already posted which you apparently missed):
mluttg...@wanadoo.fr wrote:
> Let's consider a planet inhabited by advanced ET's, situated at
> x billions light-years from the Earth. Their physicists, from the
> redshift of the Earth galaxy A and the Hubble constant, calculate that
> the Earth is moving away from them at -0.7 c. Opposite the Earth,
> they observe another galaxy B, whose velocity relative to them is
> +0.7c.
> They conclude, in accordance with the cosmic expansion, that such
> galaxy has a velocity 1.4 c relative to the Earth.
> As they have mastered FTL communication, they transmit those data to
> the Earth SRists, who calculate that B is in fact moving away from
> them at 0.7c + 0.7c / 1 + 0.7*0.7 =~ 0.94 c
No they don't, as SR is silent on cosmic expansion and the
composition of cosmic expansion velocities.
>, forgetting that it is
> impossible to observe a galaxy moving away at 1.4 c.
The relationship between velocity and redshift is not
so simple at extreme distances, which you would require to
have cosmic expansion velocities of 0.7c (which would be
a redshift of about 0.7).
According to this website
http://haydenplanetarium.org/universe/duguide/app_redshift.php
the Hubble constant is 71 km/sec/Mpc, which means that
a relative velocity of 0.7 c (210000 km/sec) corresponds to a
distance of about 2960 Mpc, or about 10 billion light years.
That means that Galaxy B is 20 million ly from Galaxy A. At
those distances the linear Hubble's law no longer applies. The
relative velocity is not 1.4c, but it isn't given by the SR composition
formula.
In addition, I'm not sure that earth's "GRists" would have
a problem with a cosmic expansion velocity > c. I don't
think the speed limit applies in that case, but as I
said I'm not really conversant on this topic.
- Randy
mlut...@wanadoo.fr
In my last message, I wrote:
"My example has misled a lot of people, including myself, because
I referred to galaxies subject to cosmic expansion, instead of
objects moving at a velocity Kx, where K is some constant."
Perhaps does SR then apply, as it does to accelerating frames.
Yes, as a velocity c is expected at a distance of ~13.7 billion ly.
Thus, to 0.7 c corresponds a distance of about 13.7 * 0.7 = 9.6 billion
ly.
Roughly, B is indeed at about 20 billion ly from A according to
Planet X, but also, Imo, according to an observer on A
(this contradicts SR, but, as you say, SR doesn't apply at such
enormous distances).
>
> That means that Galaxy B is 20 million ly from Galaxy A. At
> those distances the linear Hubble's law no longer applies. The
> relative velocity is not 1.4c, but it isn't given by the SR composition
> formula.
>
> In addition, I'm not sure that earth's "GRists" would have
> a problem with a cosmic expansion velocity > c. I don't
> think the speed limit applies in that case, but as I
> said I'm not really conversant on this topic.
Light emitted by objects whose velocity is much than c is so redshifted
that those objects cannot be observed. GRists could perhaps confirm
this opinion.
Thank you,
Marcel Luttgens
>
> - Randy
Randy Poe
I'm almost certain that's not true.
> GRists could perhaps confirm this opinion.
I was reading some websites on extreme redshifts, but unfortunately
did not bookmark any of them so I can't provide a cite without
some work. However, I remember statements to the effect that:
(a) redshifts larger than 1 are observer (the record now is
about 9, I believe).
(b) by the definition of redshift (delta-f/f - 1), it corresponds
to v/c at low velocities. Interpreting it that way, a redshift of 5
corresponds to v = 5c.
(c) The relationship between v and f is not that simple for large
redshifts, but this does correspond to a v > c.
(d) The Hubble law is not linear at large distances,
(e) The relationship between age of light and distance is also
not so simple at extreme distances/redshifts, so these objects
could be 20 billion ly away, but their light only 13 billion ly old.
This is all by memory, is all according to GR and has nothing
whatsoever to do with SR. Not even SR in accelerated frames.
I hope someone knowledgeable can comment. Meanwhile, I'll
try to find those links again.
- Randy
Sorcerer
|
| mlut...@wanadoo.fr wrote:
| > Randy Poe wrote:
| > > In addition, I'm not sure that earth's "GRists" would have
| > > a problem with a cosmic expansion velocity > c. I don't
| > > think the speed limit applies in that case, but as I
| > > said I'm not really conversant on this topic.
| >
| > Light emitted by objects whose velocity is much than c is so redshifted
| > that those objects cannot be observed.
|
| I'm almost certain that's not true.
HAHAHA!
I am absolutely positive you are wrong and a fuckin' idiot.
What he's describing is the edge of the observable universe which
even by relativists standards is where galaxies outpace light.
We are all blind to that, Blind Brandy Poe, fuckheaded troll.
Androcles
mlut...@wanadoo.fr
Ned Wright's calculator gives following results for z = 50.
Does they mean that a corresponding galaxy would be visible
(The light travel time was 13.618 Gyr.) ?
http://www.astro.ucla.edu/~wright/CosmoCalc.html
"For Ho = 71, OmegaM = 0.270, Omegavac = 0.730, z = 50.000
It is now 13.666 Gyr since the Big Bang.
The age at redshift z was 47.554 Myr.
The light travel time was 13.618 Gyr.
The comoving radial distance, which goes into Hubble's law, is 12274.2
Mpc or 40.033 Gly.
The comoving volume within redshift z is 7744.783 Gpc3.
The angular size distance DA is 240.6 Mpc or 0.7849 Gly.
This gives a scale of 1.167 kpc/".
The luminosity distance DL is 625912.2 Mpc or 2041.469 Gly.
1 Gly = 1,000,000,000 light years or 9.461*1026 cm.
1 Gyr = 1,000,000,000 years.
1 Mpc = 1,000,000 parsecs = 3.08568*1024 cm, or 3,261,566 light years."
Marcel Luttgens
Sue...
Randy Poe wrote:
> mlut...@wanadoo.fr wrote:
> > Randy Poe wrote:
> > > In addition, I'm not sure that earth's "GRists" would have
> > > a problem with a cosmic expansion velocity > c. I don't
> > > think the speed limit applies in that case, but as I
> > > said I'm not really conversant on this topic.
> >
> > Light emitted by objects whose velocity is much than c is so redshifted
> > that those objects cannot be observed.
>
> I'm almost certain that's not true.
I agree. It can't be true.
It would be quite a storm for a large emiiter moving
at signifiant speed through interstellar hydrogen.
After some extinction distance the light is moving
at c wrt the gas on the path.
An expanding dielectric doesn't inhibit the path
it simply stretches its length..
Sue...
- Randy
Randy Poe
That's how I interpret it.
>
> http://www.astro.ucla.edu/~wright/CosmoCalc.html
>
> "For Ho = 71, OmegaM = 0.270, Omegavac = 0.730, z = 50.000
>
> It is now 13.666 Gyr since the Big Bang.
> The age at redshift z was 47.554 Myr.
> The light travel time was 13.618 Gyr.
> The comoving radial distance, which goes into Hubble's law, is 12274.2
> Mpc or 40.033 Gly.
> The comoving volume within redshift z is 7744.783 Gpc3.
> The angular size distance DA is 240.6 Mpc or 0.7849 Gly.
> This gives a scale of 1.167 kpc/".
> The luminosity distance DL is 625912.2 Mpc or 2041.469 Gly.
> 1 Gly = 1,000,000,000 light years or 9.461*1026 cm.
> 1 Gyr = 1,000,000,000 years.
> 1 Mpc = 1,000,000 parsecs = 3.08568*1024 cm, or 3,261,566 light years."
Excellent page. Thanks for the link. I think I'll find a lot of the
theory I was alluding to in the tutorials, but I haven't yet read
them.
- Randy
Randy Poe
Poor ignorant Androcles doesn't realize that redshifts (roughly
corresponding to v/c) greater than 1 are routinely observed,
and that there is at least one report of a redshift of 6.96.
http://www.astro.ucla.edu/~wright/cosmolog.htm
Here are some numbers on redshift and velocity:
http://www.astro.ucla.edu/~wright/doppler.htm
"Thus for the largest known redshift of z=6.3, the recession
velocity is not 6.3*c = 1,890,000 km/sec... The actual recession
velocity for this object depends on the cosmological parameters,
but for an OmegaM=0.3 vacuum-dominated flat model the velocity
is 585,611 km/sec. This is faster than light."
Note that Ned Wright is telling us (well, all of us except poor
close-minded Androcles) that there is an observed object with
a relative velocity of close to 2c. Not, in fact, past the
observable edge of the universe.
Randy
Sorcerer
"Sue..." <suzyse...@yahoo.com.au> wrote in message
news:1158851393.2...@i3g2000cwc.googlegroups.com...
|
| Randy Poe wrote:
| > mlut...@wanadoo.fr wrote:
| > > Randy Poe wrote:
| > > > In addition, I'm not sure that earth's "GRists" would have
| > > > a problem with a cosmic expansion velocity > c. I don't
| > > > think the speed limit applies in that case, but as I
| > > > said I'm not really conversant on this topic.
| > >
| > > Light emitted by objects whose velocity is much than c is so
redshifted
| > > that those objects cannot be observed.
| >
| > I'm almost certain that's not true.
|
| I agree. It can't be true.
| It would be quite a storm for a large emiiter moving
| at signifiant speed through interstellar hydrogen.
| After some extinction distance the light is moving
| at c wrt the gas on the path.
Big Bang.
Expanding Universe.
Red shift.
The further away, the greater the shift.
The chickens have come home to roost.
Androcles
Sorcerer
|
| Sorcerer wrote:
| > "Randy Poe" <poespa...@yahoo.com> wrote in message
| > news:1158848414.3...@b28g2000cwb.googlegroups.com...
| > |
| > | mlut...@wanadoo.fr wrote:
| > | > Randy Poe wrote:
| > | > > In addition, I'm not sure that earth's "GRists" would have
| > | > > a problem with a cosmic expansion velocity > c. I don't
| > | > > think the speed limit applies in that case, but as I
| > | > > said I'm not really conversant on this topic.
| > | >
| > | > Light emitted by objects whose velocity is much than c is so
redshifted
| > | > that those objects cannot be observed.
| > |
| > | I'm almost certain that's not true.
| >
| > HAHAHA!
| > I am absolutely positive you are wrong and a fuckin' idiot.
| > What he's describing is the edge of the observable universe which
| > even by relativists standards is where galaxies outpace light.
|
| Poor ignorant Androcles doesn't realize that redshifts (roughly
| corresponding to v/c) greater than 1 are routinely observed,
| and that there is at least one report of a redshift of 6.96.
| http://www.astro.ucla.edu/~wright/cosmolog.htm
Poor fuckwit Blind Brandy Poe has never heard of Doppler
or Einstein's version of doppler shift.
http://www.androcles01.pwp.blueyonder.co.uk/Doppler/Doppler.htm
What the fuck is v/c, shithead?
HAHAHAHA! What an imbecile you are, Blind Brandy Poe.
Randy Poe
> | Poor ignorant Androcles doesn't realize that redshifts (roughly
> | corresponding to v/c) greater than 1 are routinely observed,
> | and that there is at least one report of a redshift of 6.96.
> | http://www.astro.ucla.edu/~wright/cosmolog.htm
>
> What the fuck is v/c, shithead?
Ratio of recession velocity to speed of light.
> HAHAHAHA! What an imbecile you are, Blind Brandy Poe.
Poor attention-deficit Androcles didn't get to the next
paragraph in my post, or read the link. Here again is
that link and some more relevant text:
http://www.astro.ucla.edu/~wright/doppler.htm
"When z is larger than 1 then cz is faster than the speed of light and,
while recession velocities faster than light are allowed, this
approximation using cz as the recession velocity of an object is no
longer valid. Thus for the largest known redshift of z=6.3, the
recession velocity is not 6.3*c = 1,890,000 km/sec. It is also not the
285,254 km/sec given by the special relativistic Doppler formula 1+z =
sqrt((1+v/c)/(1-v/c)). The actual recession velocity for this object
depends on the cosmological parameters, but for an OmegaM=0.3
vacuum-dominated flat model the velocity is 585,611 km/sec. This is
faster than light."
See in particular above comments about the Doppler formula
and its applicability here.
- Randy
Sorcerer
|
| Sorcerer wrote:
| > "Randy Poe" <poespa...@yahoo.com> wrote in message
| > news:1158853188.6...@m7g2000cwm.googlegroups.com...
| > | Poor ignorant Androcles doesn't realize that redshifts (roughly
| > | corresponding to v/c) greater than 1 are routinely observed,
| > | and that there is at least one report of a redshift of 6.96.
| > | http://www.astro.ucla.edu/~wright/cosmolog.htm
| >
| > http://www.androcles01.pwp.blueyonder.co.uk/Doppler/Doppler.htm
| > What the fuck is v/c, shithead?
|
| Ratio of recession velocity to speed of light.
"I'm trolling you" fuckhead?
Androcles
mlut...@wanadoo.fr
Randy Poe wrote:
> mlut...@wanadoo.fr wrote:
> > Randy Poe wrote:
> > > In addition, I'm not sure that earth's "GRists" would have
> > > a problem with a cosmic expansion velocity > c. I don't
> > > think the speed limit applies in that case, but as I
> > > said I'm not really conversant on this topic.
> >
> > Light emitted by objects whose velocity is much than c is so redshifted
> > that those objects cannot be observed.
>
> I'm almost certain that's not true.
In http://www.astro.ucla.edu/~wright/cosmology_faq.html#FTL ,
Ned Wright wrote
"For the critical density Universe, this velocity is given by
v = 2c[1-(1+z)-0.5] which is larger than c for z > 3 ."
The formula also means that v(max) = 2c. Iow, it is impossible
to observe a galaxy situated at distance >= 2c, because z is
then infinite.
In a flat Universe whose expansion is accelerating, the visibility
limit would depend on the chosen value for OmegaM.
Marcel Luttgens
Randy Poe
Sorcerer wrote:
> "Randy Poe" <poespa...@yahoo.com> wrote in message
> news:1158856438.7...@b28g2000cwb.googlegroups.com...
> |
> | Sorcerer wrote:
> | > "Randy Poe" <poespa...@yahoo.com> wrote in message
> | > news:1158853188.6...@m7g2000cwm.googlegroups.com...
> | > | Poor ignorant Androcles doesn't realize that redshifts (roughly
> | > | corresponding to v/c) greater than 1 are routinely observed,
> | > | and that there is at least one report of a redshift of 6.96.
> | > | http://www.astro.ucla.edu/~wright/cosmolog.htm
> | >
> | > http://www.androcles01.pwp.blueyonder.co.uk/Doppler/Doppler.htm
> | > What the fuck is v/c, shithead?
> |
> | Ratio of recession velocity to speed of light.
> And what the fuck is its significance to redshift, shit-for-brains
> "I'm trolling you" fuckhead?
Poor Tourette's-afflicted Androcles. The equations
on your own "Doppler" link give that answer, for SR.
The quantity called "redshift" by astronomers is
equal to (nu/nu')-1. It's the amount by which frequency
is decreased.
The general relation of v/c to redshift is that
they increase together. Large redshift means large
velocity. Large velocity means large redshift.
Marcel has actually provided a link to the relationship
for cosmic expansion recession velocities,
namely: v/c = 2[1-1/sqrt(1+z)] where z is the redshift
(under a "critical density universe" assumption).
You will see that this equation relates z (redshift)
to v/c. At least I hope you can look at that
equation and see that.
For the above relation, v/c > 1 if and only if
the redshift is greater than 3.
Again, I'll remind poor forgetful Androcles that
we have many examples of observed objects
with z>3, and the record is close to z=7.
- Randy
Sorcerer
|
| Sorcerer wrote:
| > "Randy Poe" <poespa...@yahoo.com> wrote in message
| > news:1158856438.7...@b28g2000cwb.googlegroups.com...
| > |
| > | Sorcerer wrote:
| > | > "Randy Poe" <poespa...@yahoo.com> wrote in message
| > | > news:1158853188.6...@m7g2000cwm.googlegroups.com...
| > | > | Poor ignorant Androcles doesn't realize that redshifts (roughly
| > | > | corresponding to v/c) greater than 1 are routinely observed,
| > | > | and that there is at least one report of a redshift of 6.96.
| > | > | http://www.astro.ucla.edu/~wright/cosmolog.htm
| > | >
| > | > http://www.androcles01.pwp.blueyonder.co.uk/Doppler/Doppler.htm
| > | > What the fuck is v/c, shithead?
| > |
| > | Ratio of recession velocity to speed of light.
| > And what the fuck is its significance to redshift, shit-for-brains
| > "I'm trolling you" fuckhead?
|
| Poor Tourette's-afflicted Androcles.
People with Tourette's Syndrome have a brain, fuckhead, so
you'll never suffer from it. In my case it is not Tourette's,
I'm impolite to all but reserve profanity for arsehole trolls
like you.
The equations
| on your own "Doppler" link give that answer, for SR.
| The quantity called "redshift" by astronomers is
| equal to (nu/nu')-1.
Oh, very good. Not the question I asked, though.
| It's the amount by which frequency
| is decreased.
The amount your income decreases is (old income)/(new income) - 1, is it?
| The general relation of v/c to redshift is that
| they increase together. Large redshift means large
| velocity. Large velocity means large redshift.
Ok... so c/c -1 = 1-1 = 0, a decrease of ... 0
and there is at least one report of a redshift of 6.96.
RIGHT, You fucking STOOOPID troll?