Re: SR time dilation on remote objects ?

From: Marcel Luttgens (mluttgens_at_wanadoo.fr)
Date: 09/24/04 

Date: 24 Sep 2004 04:25:07 -0700

Bjoern Feuerbacher <feuerbac@thphys.uni-heidelberg.de> wrote in message news:<ciug9a$ql7$1@news.urz.uni-heidelberg.de>...
> Marcel Luttgens wrote:
> > Bjoern Feuerbacher <feuerbac@thphys.uni-heidelberg.de> wrote in message news:<cis5cn$ai7$1@news.urz.uni-heidelberg.de>...
> >
> >>Marcel Luttgens wrote:
> >>
> >>>Bjoern Feuerbacher <feuerbac@thphys.uni-heidelberg.de> wrote in message news:<ciplnn$pbh$1@news.urz.uni-heidelberg.de>...
> >>>
> >
> >
> > <snip, because those points have already been discussed>
> >
> >
> >>>>>But you should realize that light is not sound, because
> >>>>>of the speed limit c.
> >>>>
> >>>>*sigh* Obviously. That's why one uses Nu(o) = Nu sqrt((1-v/c)/(1+v/c)),
> >>>>not Nu(o) = Nu / (1+v/c), if you didn't notice.
> >>>>
> >>>
> >>>
> >>>No, those who use Nu(o) = Nu sqrt((1-v/c)/(1+v/c)) because of time dilation,
> >>>forget that in an expanding universe,
> >>
> >>*sigh* For the 100th time: The Doppler shift formula of SR and LET,
> >>Nu(o) = Nu sqrt((1-v/c)/(1+v/c), is *not* used in cosmology.
> >>
> >
> >
> > GR is used, but is GR right?
>
> If you have evidence that it isn't, feel free to present it.
>
> I notice that you did not care to admit that your assertion above
> (the SR formula is used in cosmology) was wrong
>

I just said, GR is used, but is GR right?

>
>
> >>>>>No time dilation factor
> >>>>>is needed in an expanding universe, because the light source and the
> >>>>>observer are simultaneously receding wrt each other.
> >>>>
> >>>>Irrespective of a time dilation factor is needed or not, your
> >>>>formula above is simply wrong. If you think otherwise, present
> >>>>a derivation which is *not* based on "the distance changes, but let's
> >>>>consider that it it constant anyway".
> >>>>
> >>>
> >>>
> >>>IOW, you are saying that Nu(o) = Nu / (1+v/c) sould be used when
> >>>the light source is receding from the observer.
> >>
> >>NO.
> >>
> >>I say that for real movements, one should use Nu(o) = Nu
> >>sqrt((1-v/c)/(1+v/c)) (regardless if the source or the observer is
> >>moving, since motion is relative!), and in cosmology, one should use
> >>1+z = R(t0)/R(t) for the red shift (reminder: R is the curvature
> >>radius of the universe).
> >>
> >
> >
> > Yes, with many assumptions, like Omega M, flat universe, etc...
>
> Wrong. Omega_M and the flatness of the universe are *measured*,
> not assumed.
>

They were measured, after being assumed. Or the assumptions were made
a posteriori in order to justify the observations.

>
> > With some of those *needed* (should I say ad hoc?) assumptions,
> > GR gets about the same results as those obtained with a stable
> > universe and a "deceleration" cH.
>
> Which *still* makes no sense at all.
>
>
> > Use Ted Wright's calculator if you are not yet convinced.
>
> For the 10th time: I don't care about Wright's calculator.
> Compare the predictions of your formula against the actual data!!!!!
>

You don't care, because its results are the same as mine.
And your "actual" data are those of SNe, which are questionnable.
 
>
>
> > But I don't understand what you mean by "real" movements. Are
> > movements in cosmology not "real"?
>
> *sigh* I already explained that several times. That the distance
> of galaxies increases is, according to GR, not due to a movement
> of the galaxies, but due to the space between them expanding.
>

You are saying that the increase is not real, but simply the result
of GRT application. I wholly agree with you.

<snip>

> >
> > I show hereafter that the SR formula Nu(o) = Nu sqrt((1-v/c)/(1+v/c))
> > cannot be right.
>
> Unfortunately for you, it had been *tested* and *found* to be right.
>
>
> [snip]
>
>
>
> >>>Thus, 1+z = = lambda(o)/lambda = (c+v)/(c-v), and
> >>>z = 2v/(c-v) = 2 v/c / (1-v/c),
> >>>
> >>>which is the same formula as the one obtained with no time dilation!
> >>
> >>Nice for you.
> >>
> >>And now explain how this situation, where light is *reflected*, is
> >>relevant for cosmology.
> >
> >
> > Because those two identical results show that something must
> > be wrong in the derivation of the SR formula
>
> No, not at all. Why on earth do you think so?
>
>
> > Nu(o) = Nu sqrt((1-v/c)/(1+v/c))
> >
> > Let's apply the sound Doppler to light:
> >
> > 1) The light source is receding at v from light the receiver
> >
> > Then Nu(o)/Nu = c/(c+v), which leads to z = v/c.
> >
> > Such formula is nonsensical for light, because with it, z can never be
> > greater than 1.
>
> That formula is not nonsensical for light because z can never be
> greater than 1, but because it was derived using assumptions which
> are not valid for light.
>

Anyhow, it gives wrong results for light.

>
> > Or galactic light can have much bigger redshifts than 1.
>
> Huh?
>

Never heard of galaxies with redhifts 3 or more?

>
> > Let fS = c/(c+v)
> >
> > 2) The receiver is receding at v from the emitter
> >
> > Then Nu(o)/Nu = (c-v)/c, which leads to z = (v/c)/(1-v/c)
> >
> > This formula gives sensible results.
>
> The ultimate test if a formula gives sensible results is by
> comparing it with experiment. For light, the formula fails then.
>

No, look at Wright results.

>
> > The same formula can be obtained when the source is moving
> > by hypothetising a stable universe where light is subject at
> > every point of its trajectory to a negative acceleration cH.
>
> And how would that work?
>

I already explained this more than once.
 
>
>
> And how, exactly, do you plan to derive this formula in that
> case? I don't remember that you ever presented that calculation.
>

You easily forget things that are not in GR textbooks.

>
> > Notice that the reddening is then absolute, in the sense that
> > it is independent from observers.
> >
> > Let fR = (c-v)/c
> >
> > Now, the SR formula Nu(o) = Nu sqrt((1-v/c)/(1+v/c)), can be written
> >
> > Nu(o) = Nu sqrt((c-v)/c) * c/(c+v)), or
> > Nu(o)/Nu = sqrt(fR * fS)
>
> Nice.
>
>
> > The SR frequency ratio is simply the geometric mean of the frequency
> > ratio fR obtained when the receiver is receding and the frequency ratio
> > fS corresponding to the receding source!
>
> Of the corresponding ratios obtained for *sound*.
>
>
> > Since fS is wrong for light, the SR formula must be wrong.
>
> That's a *total* non sequitur.
>

Your reaction reveals once more that you are impervious to logic.

The SR formula Nu(o) = Nu sqrt((1-v/c)/(1+v/c)) can be written
Nu(o)/Nu = sqrt(fR * fS), where fR = (c-v)/c and fS = c/(c+v)

It can also be written
Nu(o) = sqrt(Nu(o)R * Nu(o)S), where

Nu(o) is the frequency observed by the receiver according to SR,
whether the source of light emitted at frequency Nu is moving or at rest
relatively to the receiver,

Nu(o)R is the frequency observed by the receiver when receding from the source
(according to the sound formula)
Nu(o)S is the frequency observed by the receiver when the source is receding
(also according to the sound formula, which gives in this case wrong results
for light)

As at least Nu(o)S is wrong for light, Nu(o) is logically wrong, IOW,
the *SR formula is wrong*.

If you disagree, you should explain why the form Nu(o) = sqrt(Nu(o)R * Nu(o)S)
is mathematically wrong, instead of simply maintaining that the SR formula
is right.

>
> > Notice also that no trace of a time dilation factor is to be found in
> > Nu(o)/Nu = sqrt(fR * fS).
>
> Err, when you write it in a way which does not show the time dilation
> factor directly, it's no wonder that the time dilation factor is
> not found in the formula, don't you think?
>

I can write the SR formula in different ways. As one of those ways clearly
demonstrates that the formula is wrong, and ignores time dilation,
those who claim that it is nevertheless right, and that time dilation
is nevertheless present, are acting as crackpots or ignorants.

>
> > If a single SR formula is wrong,
>
> *sigh* And you *still* ignore that this formula was *tested* and found
> to be *right*.
>

The results of those tests are not necessarily incompatible, taking
into account the statistical errors, with the SR formula under the form
Nu(o) = sqrt(Nu(o)R * Nu(o)S). This doesn't mean that it is right.

>
>
> [snip]
>
> > The problem with SR/GRists is that most of them swallow all
> > what they find in textbooks, and consider their findings as
> > gospel truth.
>
> The problem with you is that you don't care about experimental
> data and can't think logically.
>

Quite the contrary.

>
>
> Bye,
> Bjoern

Marcel Luttgens

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