VARIABLE SPEED OF LIGHT IN A GRAVITATIONAL FIELD
Pentcho Valev
radially with respect to a spherical mass varies with the
gravitational potential V:
(A) c' = c(1 + V/c^2)
(B) c' = c(1 + 2V/c^2)
(see http://www.mathpages.com/rr/s6-01/6-01.htm )
Equation A is consistent with the Pound-Rebka experiment and also
(through the application of Einstein's equivalence principle) with the
equation c'=c+v given by Newton's emission theory of light (v is the
speed of the light source relative to the observer). It is not clear
what equation B is consistent with.
Pentcho Valev
pva...@yahoo.com
Pentcho Valev
http://www.perimeterinstitute.ca/Outreach/Explore_Our_Universe/Why_Does_Gravity_Slow_Time?/1/
Perimeter Institute: "One may imagine the photon losing energy as it
climbs against the Earth’s gravitational field much like a rock thrown
upward loses kinetic energy as it slows down, the main difference
being that the photon does not slow down; it always moves at the speed
of light."
Pentcho Valev
pva...@yahoo.com
kduc
> Pentcho Valev
> pva...@yahoo.com
Pentcho Valev
http://fr.youtube.com/watch?v=4vuW6tQ0218
Pentcho Valev
pva...@yahoo.com
Pentcho Valev
http://streamer.perimeterinstitute.ca/mediasite/viewer/NoPopupRedirector.aspx?peid=5f32739a-624d-4ec8-9ecc-4d44d3d16fe9&shouldResize=False
Lee Smolin: "Newton's theory predicts that light goes in straight
lines and therefore if the star passes behind the sun, we can't see
it. Einstein's theory predicts that light is bent...."
Pentcho Valev
pva...@yahoo.com
Talebun
Ah, velocity relative to source. Could you explain to me how it is
possible to see double stars. I must say my profile was designed for
textural analysis rather than Relativity. It will serve though.
Androcles
"Talebun" <pmpa...@btinternet.com> wrote in message
news:270bce69-2fa5-4297...@d1g2000hsg.googlegroups.com...
| On 24 Jul, 08:31, Pentcho Valev <pva...@yahoo.com> wrote:
| > Einstein offered two equations showing how the speed of photons moving
| > radially with respect to a spherical mass varies with the
| > gravitational potential V:
| >
| > (A) c' = c(1 + V/c^2)
| >
| > (B) c' = c(1 + 2V/c^2)
| >
| > (seehttp://www.mathpages.com/rr/s6-01/6-01.htm)
| >
| > Equation A is consistent with the Pound-Rebka experiment and also
| > (through the application of Einstein's equivalence principle) with the
| > equation c'=c+v given by Newton's emission theory of light (v is the
| > speed of the light source relative to the observer). It is not clear
| > what equation B is consistent with.
| >
| > Pentcho Valev
| > pva...@yahoo.com
|
| Ah, velocity relative to source. Could you explain to me how it is
| possible to see double stars.
Yes. You are seeing double.
http://www.androcles01.pwp.blueyonder.co.uk/Algol/Algol.htm
http://www.androcles01.pwp.blueyonder.co.uk/Orbit/Orbit.htm
| I must say my profile was designed for
| textural analysis rather than Relativity. It will serve though.
I haven't read your profile so I have no idea why you must say that.
Was it important?
--- -. dotat
<Headm...@Hogwarts.physics> wrote:
>
>"Talebun" <pmpa...@btinternet.com> wrote in message
>news:270bce69-2fa5-4297...@d1g2000hsg.googlegroups.com...
>| On 24 Jul, 08:31, Pentcho Valev <pva...@yahoo.com> wrote:
>| > Einstein offered two equations showing how the speed of photons moving
>| > radially with respect to a spherical mass varies with the
>| > gravitational potential V:
>| >
>| > (A) c' = c(1 + V/c^2)
>| >
>| > (B) c' = c(1 + 2V/c^2)
>| >
>| > (seehttp://www.mathpages.com/rr/s6-01/6-01.htm)
>| >
>| > Equation A is consistent with the Pound-Rebka experiment and also
>| > (through the application of Einstein's equivalence principle) with the
>| > equation c'=c+v given by Newton's emission theory of light (v is the
>| > speed of the light source relative to the observer). It is not clear
>| > what equation B is consistent with.
>| >
>| > Pentcho Valev
>| > pva...@yahoo.com
>|
>| Ah, velocity relative to source. Could you explain to me how it is
>| possible to see double stars.
>
>Yes. You are seeing double.
>
> http://www.androcles01.pwp.blueyonder.co.uk/Algol/Algol.htm
> http://www.androcles01.pwp.blueyonder.co.uk/Orbit/Orbit.htm
>
>
Andro does not read my posts, so ask him what speed
(or velocity) his ballistic light balls will have when they
get reflected by a mirror.
And what happens when primary and reflected lightballs
interfere with each other...
+############ <---this was my cat
ahahahahahaaa..
w.
Pentcho Valev
I have already answered your question:
http://groups.google.com/group/sci.physics.relativity/msg/2059296fdadc420a
Pentcho Valev
pva...@yahoo.com
Pentcho Valev
> The Perimeter Institute sell Einstein's dead science:
>
> http://fr.youtube.com/watch?v=4vuW6tQ0218
Einstein's idiotic "science" is invincible because any normal
scientist trying to tackle it reaches, sooner or later, a state of
utter frustration:
http://www.davidpbrown.co.uk/jokes/monty-python-parrot.html
"I'm not prepared to pursue my line of inquiry any longer as I think
this is getting too silly!"
Pentcho Valev
pva...@yahoo.com
Pentcho Valev
> Einstein offered two equations showing how the speed of photons moving
> radially with respect to a spherical mass varies with the
> gravitational potential V:
>
> (A) c' = c(1 + V/c^2)
>
> (B) c' = c(1 + 2V/c^2)
>
>
> Equation A is consistent with the Pound-Rebka experiment and also
> (through the application of Einstein's equivalence principle) with the
> equation c'=c+v given by Newton's emission theory of light (v is the
> speed of the light source relative to the observer). It is not clear
> what equation B is consistent with.
Equation A has a simple derivation. The gravitational frequency shift
confirmed experimentally by Pound and Rebka is:
f' = f(1+V/c^2)
This should be combined with the textbook formula:
f' = c'/L' ; f = c/L
where L is the wavelength. So we obtain:
c' = c(1+V/c^2) ; L' = L (Einstein 1911)
or:
c' = c ; L' = L/(1+V/c^2) (anti-Einstein 1911)
Einstein 1911 is reasonable but fatal for Divine Albert's Divine
Theory. Anti-Einstein 1911 is absurd but it is the only salvation.
Pentcho Valev
pva...@yahoo.com
moky
> Einstein 1911 is reasonable but fatal for Divine Albert's Divine
> Theory. Anti-Einstein 1911 is absurd but it is the only salvation.
You already said it there:
http://groups.google.fr/group/fr.sci.physique/browse_thread/thread/dcb5ccb45525e0ac/3e8d684e9b8d7306?hl=fr&
I explaned why anti-Einstein has to be chosen.
Will you answer easier if I translate in English ?
Bonne nuit
Laurent
Pentcho Valev
> > Einstein 1911 is reasonable but fatal for Divine Albert's Divine
> > Theory. Anti-Einstein 1911 is absurd but it is the only salvation.
>
> You already said it there: http://groups.google.fr/group/fr.sci.physique/browse_thread/thread/dcb5ccb45525e0ac/3e8d684e9b8d7306?hl=fr&
>
> I explaned
YOU explained?! But you knew nothing about Einstein's 1911 equation
c'=c(1+V/c^2) 10 days ago.
> why anti-Einstein has to be chosen.
> Will you answer easier if I translate in English ?
OK give your "explanation" once more. English or French.
> Bonne nuit
> Laurent
Bonne nuit.
Pentcho Valev
pva...@yahoo.com
moky
> > I explaned
>
> YOU explained?! But you knew nothing about Einstein's 1911 equation
> c'=c(1+V/c^2) 10 days ago.
I still do not know anything about that equation :
On the one hand, I have a proof of anti-Einstein (this is what I
explaned) ... while, on the other hand, I have no proof af Einstien
1911.
In that case, I do not pretend to "know about" Enstein 1911 ;)
> OK give your "explanation" once more. English or French.
Just a translation. The original explanation is here
http://groups.google.fr/group/fr.sci.physique/browse_thread/thread/dcb5ccb45525e0ac/3e8d684e9b8d7306?hl=fr&
I'm following the reasoning of
http://homepages.ulb.ac.be/~cschomb/Relatgene.pdf
when she deduce the equation
> f1 = f2(1+gh/c^2) (2.5.35).
(We are looking at a light ray coming from the ground to a height of h
in an uniform gravitational field corresponding to the acceleration g)
Let K the the accelerated observer. At the instant t1, K coincides
with the inertial observer O1. At the instant t2, K coincides with the
observer O2 which has an uniform motion of velocity gh/c with respect
to O1.
We use the Doppler effect of special relativity between O1 and O2 in
order to get the well known formula
> f1 = f2(1+gh/c^2) (2.5.35).
Now, we have to find the wavelength using the definitions
> f1 = c1/L1 ; f2 = c2/L2
There are, of course, infinitely many solutions. Among others, the two
following ones :
>c1 = c2(1+gh/c^2) ; L1 = L2 (Einstein 1911)
and
> c1 = c2 ; L1 = L2/(1+gh/c^2) (anti-Einstein 1911)
How to chose ?
Let us do the same as what was done in order to deduce f1 = f2(1+gh/
c^2). We compare what happens in O1 and O2. These two are related by
an inertial motion of velocity gh/c. According to special relativity,
c1=c2 in that case.
Thus I choose anti-Einstein 1911.
If we agree with
> f1 = f2(1+gh/c^2) (2.5.35),
I do not see how not to agree with my proof of anti-Einstein.
Where is the problem ?
Have a good night
Laurent
PS : I feel free to add a summary of what happens here in our French
discussion, if you give up the French discussion (which seems to be
exactly on the same point as here)
moky
> (A) c' = c(1 + V/c^2)
> (B) c' = c(1 + 2V/c^2)
>Equation A has a simple derivation.
You did not gave the "simple derivation". Indeed, taking
f' = f(1+V/c^2) (1)
and
f' = c'/L' ; f = c/L (2)
you arrive 2 equations (2) for 3 unknowns (c',L and L'). Then you list
two solutions (out of an infinity)
> c' = c(1+V/c^2) ; L' = L (Einstein 1911)
> c' = c ; L' = L/(1+V/c^2) (anti-Einstein 1911)
From here, I have a certain number of questions ...
1. What is the relation between the $c$ in equation (1) and the one in
equation (2) ?
2. Should I consider (1) and (2) as a 3 equations system for the
unknowns c,c',f,f',L,L' ?
3. Whatever is the answer to my question 2, one obviously has
infinitely many solutions. Thus, in order to conclude one has to make
use of a new idea.
In light of my question 3, I think that you forgot one or two lines
because you stop your "simple derivation" by just listing two possible
solutions, without even explaining why these two are better than the
inifinitely many others.
Anyway, I guess that I would be able to answer the questions 1-3 by
myself if you just give your derivation of the formula
f' = f(1+V/c^2) (1),
on which we agree.
Pentcho Valev
> Laurent
>
> discussion, if you give up the French discussion (which seems to be
> exactly on the same point as here)
You must be writing a book or something (Einsteinians always fiercely
teach the world) and since the author of
http://homepages.ulb.ac.be/~cschomb/Relatgene.pdf
has not explained how gravitational time dilation relates to the
Doppler effect, you expect ME to fill the gap. I will not. I wish
Einsteinians would stop teaching the world so fiercely. Just for non-
relativists:
Derivations of this type in Einsteiniana are based on an implicit
(sometimes explicit) shift in meaning: the frequency and wavelength of
light are replaced by the frequency of emission of light pulses and
the distance between two adjacent travelling pulses respectively.
There can be nothing more idiotic than that but, on the other hand, in
Einstein zombie world nothing is idiotic by definition.
Pentcho Valev
pva...@yahoo.com
moky
> You must be writing a book or something (Einsteinians always fiercely
> teach the world) and since the author of
>
> http://homepages.ulb.ac.be/~cschomb/Relatgene.pdf
>
> has not explained how gravitational time dilation relates to the
> Doppler effect, you expect ME to fill the gap. I will not. I wish
> Einsteinians would stop teaching the world so fiercely. Just for non-
> relativists:
It happens often in university courses that a result studied two years
before is not recalled.
Equation (15.5.48) here
http://homepages.ulb.ac.be/~cschomb/CEDtout.pdf
(same author)
The Doppler effect is explained in terms of Lorentz. The link with the
gravitation is explained exactly in the reference I gave; and I
already re-wrote it twice on the forum.
What missing part are you speaking about ?
Anyway, the following questions are independent : you say that
Einstein-1911 has a simple derivation that you pretend to provide ...
but your simple derivation is incomplete.
f' = f(1+V/c^2) (1)
f' = c'/L' ; f = c/L (2)
you arrive 2 equations (2) for 3 unknowns (c',L and L'). Then you
list
two solutions (out of an infinity)
> c' = c(1+V/c^2) ; L' = L (Einstein 1911)
> c' = c ; L' = L/(1+V/c^2) (anti-Einstein 1911)
From here, I have a certain number of questions ...
1. What is the relation between the $c$ in equation (1) and the one
in
equation (2) ?
2. Should I consider (1) and (2) as a 3 equations system for the
unknowns c,c',f,f',L,L' ?
3. Whatever is the answer to my question 2, one obviously has
infinitely many solutions. Thus, in order to conclude one has to
make
use of a new idea. How do you conclude to Einstein instead of anti-
Einstein of any other solution ?
4. Are you ok that, without gravity, the Lorentz group is the correct
one ?
Good afternoon
Laurent
moky
I would like to add some precisions about my question.
> f' = f(1+V/c^2) (1)
> f' = c'/L' ; f = c/L (2)
> 1. What is the relation between the $c$ in equation (1) and the one in equation (2).
What trouble me is the following.
In equation (2), the symbol $c$ denotes the light speed for the first
observer, while $c'$ is the light speed for the second observer.
In equation (1), however, the symbol $c$ seems to be an "universal"
constant. At least in the way I derive equation (1), it is unclear if
$c$ is the light speed for the first or the second observer.
If the light speed depends on the observer, is it totally clear than
equation (1) should not be
> f' = f(1+V/c'^2) (1')
with a prime on the $c$ ?
In fact, if c is different of c', the derivation I give of equation
(1) is simply wrong because the light starts from the ground with
speed c and arrives at the top with speed c'. So the travel time
should be computed with something like an accelerated motion, while I
consider that travel time being h/c.
For me, it is unclear. How can one agree with equation (1) without
agreeing with an invariant speed of light ?
That's why I ask, Pentcho, YOUR derivation of (1). Because you simply
cannot agree with mine.
Hope my trouble is more clear like that
have a good afternoon
Laurent
Pentcho Valev
Laurent you are obviously a freshman in Einsteiniana and do not know
that the variability/constancy of the speed of light in a
gravitational field is one of the the cult's most important internal
problems that is solved in the following way: half of your superior
brothers teach that the speed of light is variable, the other half
teach it is constant. They believe and hope this type of teaching
would not allow Einstein zombie world to restore its lost rationality.
So if you sincerely believe the speed of light is constant in a
gravitational field, then immediately start fighting those brothers of
yours that teach the opposite. The discussion with me is meaningless -
I am just nobody in your world. If you can reach the conclusion I have
reached, that is, that your brothers' ambiguous teaching is
deliberate, then leave the criminal cult, come on the other side of
the river and if I am still there, our discussion could continue.
Best regards,
Pentcho
moky
> that the variability/constancy of the speed of light in a
> gravitational field is one of the the cult's most important internal
> problems that is solved in the following way: half of your superior
> brothers teach that the speed of light is variable, the other half
> teach it is constant. They believe and hope this type of teaching
> would not allow Einstein zombie world to restore its lost rationality.
Ok. What about your "simple derivation" of Einstein-1911 ? You pretend
to prove it. I'm waiting. I'm honnest : I gave all the proves you
asked me.
I concluded to anti-Einstein-1911 with a complete set of proofs
relying on the Lorentz group between inertial obsevers, and the
correspondence principle.
What is you proof of anti-Einstein-1911 ? You announced a one,
isnt'it ?
For you, is the numerical value of $c$ in
> f' = f(1+V/c^2) (1)
the same as the one in
> f' = c'/L' ; f = c/L (2) ?
1. Show an error in what I say (I do not care what other say[1])
2. Prove your statement (which is different of mine)
If you do not do at least the second point, why do you post on the
forum ?
Do not try to deviate the debate from a scientific domain (proofs of
statements) to a personal one (me with respect to my colleages).
Have a good night
Laurent
[1] And, in particular, I do not care what Einstein said in 1905 or
1911. I'm working with data, knowledge and formalism of 2008.
Pentcho Valev
I am afraid you are too confused and should be more careful if you
want to make a career in Einsteiniana. ALL CLEVER Einsteinians know
that, in a gravitational field, the speed of light is variable. Of
course some of them teach it is constant, others try to undermine the
importance of Einstein's 1911 equation c'=c(1+V/c^2) etc. but this has
more to do with their honesty than with their intellect. That is the
reason why I am reluctant to discuss the problem with you - I simply
don't have the energy to analyse your silly idea of a variable
wavelength and a constant speed of light that even your cleverer
brothers would reject. Try to develop your physical (not mathematical)
intuition and you will understand why your idea is so silly.
Pentcho Valev
pva...@yahoo.com
kduc
> I am afraid you are too confused and should be more careful if you
> want to make a career in Einsteiniana. ALL CLEVER Einsteinians know
> that, in a gravitational field, the speed of light is variable. Of
> course some of them teach it is constant, others try to undermine the
> importance of Einstein's 1911 equation c'=c(1+V/c^2) etc. but this has
> more to do with their honesty than with their intellect. That is the
> reason why I am reluctant to discuss the problem with you - I simply
> don't have the energy to analyse your silly idea of a variable
> wavelength and a constant speed of light that even your cleverer
> brothers would reject. Try to develop your physical (not mathematical)
> intuition and you will understand why your idea is so silly.
J'aime bien ce genre de message où l'inculte à peine capable de citer,
sempiternellement, les trois ou quatre mêmes messages croit retourner
la situation en s'érigeant en donneur de leçons et en traitant de haut
celui dont il sait qu'il le dépasse, sur tous les plans de la
discussion, de mille longueurs.
Pencho, vous êtes un clown déplorable, vous ne trompez personne. Vos
manœuvres d'évitement sont tellement transparentes...
--
kd
moky
> want to make a career in Einsteiniana. ALL CLEVER Einsteinians know
> that, in a gravitational field, the speed of light is variable.
I already have a PhD in Einsteiniana:
http://edoc.bib.ucl.ac.be:81/ETD-db/collection/available/BelnUcetd-08282007-141821/
Do not worry for me.
> Of course some of them teach it is constant, others try to undermine the
> importance of Einstein's 1911 equation c'=c(1+V/c^2) etc. but this has
> more to do with their honesty than with their intellect. That is the
> reason why I am reluctant to discuss the problem with you - I simply
> don't have the energy to analyse your silly idea of a variable
> wavelength and a constant speed of light that even your cleverer
> brothers would reject. Try to develop your physical (not mathematical)
> intuition and you will understand why your idea is so silly.
This is exactly what I want.
Look at what I said :
«
3. Whatever is the answer to my question 2, one obviously has
infinitely many solutions. Thus, in order to conclude one has to
make use of a new idea. How do you conclude to Einstein instead of
anti-
Einstein of any other solution ?
»
I explicitly said that the pure mathematics are not enough for
conclude Einstein-1911 or anti-Einstein-1911. A new idea is needed. I
gave a one which allows me to conclude to anti-Einstein-1911.
you wrote :
>Equation A has a simple derivation. The gravitational frequency shift
> confirmed experimentally by Pound and Rebka is:
>f' = f(1+V/c^2)
>This should be combined with the textbook formula:
>f' = c'/L' ; f = c/L
>where L is the wavelength. So we obtain:
>c' = c(1+V/c^2) ; L' = L (Einstein 1911)
>or:
>c' = c ; L' = L/(1+V/c^2) (anti-Einstein 1911)
>Einstein 1911 is reasonable but fatal for Divine Albert's Divine
> Theory. Anti-Einstein 1911 is absurd but it is the only salvation.
Are the two last sentenses what you call "to develop your physical
(not mathematical) intuition" ?
Why should I believe in Einstein-1911 (without proof) while I have a
proof of anti-Einstein ?
Good afternoon
Laurent
Pentcho Valev
> Einstein offered two equations showing how the speed of photons moving
> radially with respect to a spherical mass varies with the
> gravitational potential V:
>
>
> (B) c' = c(1 + 2V/c^2)
>
>
> Equation A is consistent with the Pound-Rebka experiment and also
> (through the application of Einstein's equivalence principle) with the
> equation c'=c+v given by Newton's emission theory of light (v is the
> speed of the light source relative to the observer).
This is part of the answer to the "unresolved questions" formulated by
Eric Baird:
http://www.relativitybook.com/resources/c_speedoflight.html
"Towards the end of his life, Einstein wrote that he no longer
considered the decision to construct general relativity as a two-stage
model, with "curvature" arguments built on top of a flat-spacetime
"SR" foundation, as justifiable. It had been the best that could be
achieved at the time, but with the benefit of hindsight it didn't deem
to be defensible. [9] Quite what Einstein may have meant by this, what
the alternative might have been, and what the implications might be of
having a general theory that didn't have a forced reduction to special
relativity, still seem to be unresolved questions."
Pentcho Valev
pva...@yahoo.com
BURT
The speed of light is a constant but time for light isn't. Speed is
constant for light but time isn't.
Mitch Raemsch
moky
Pentcho Valev a écrit :
> On Jul 24, 9:31 am, Pentcho Valev <pva...@yahoo.com> wrote:
> > Einstein offered two equations showing how the speed of photons moving
> > radially with respect to a spherical mass varies with the
> > gravitational potential V:
> >
> > (A) c' = c(1 + V/c^2)
> > (B) c' = c(1 + 2V/c^2)
Up to here, okay. That's cool :)
> http://www.relativitybook.com/resources/c_speedoflight.html
> "Towards the end of his life, Einstein wrote that he no longer
> considered the decision to construct general relativity as a two-stage
> model, with "curvature" arguments built on top of a flat-spacetime
> "SR" foundation, as justifiable. It had been the best that could be
> achieved at the time, but with the benefit of hindsight it didn't deem
> to be defensible. [9] Quite what Einstein may have meant by this, what
> the alternative might have been, and what the implications might be of
> having a general theory that didn't have a forced reduction to special
> relativity, still seem to be unresolved questions."
But here ... I do not see the proof.
Ow.
By the way, we are ok that without gravitation, the Lorentz group is
the correct one ?
Good night
Laurent
Dr. Henri Wilson
An interesting question, the answer to which is not currently known.
It could be c+v or c wrt the mirror..... or maybe something in between.
>And what happens when primary and reflected lightballs
>interfere with each other...
Also unknown..... because it has never been attempted.
>+############ <---this was my cat
>ahahahahahaaa..
>
>w.
Henri Wilson. ASTC,BSc,DSc(T)
www.users.bigpond.com/hewn/index.htm
All religion involves selling a nonexistant product to gullible fools. Einstein cleverly exploited this principle with his second postulate.
Matthew Johnson
[snip]
>An interesting question, the answer to which is not currently known.
"Not currently known"? Maybe not by you. But those of us who actually passed
upper-division E&M know the answer: in vacuum, light always propagates with the
same speed in any interial reference frame: that speed is c.
Spaceman
Matthew,
Two objects (A and B) are following each other and moving at
0.5c in direction N, the object in the back (B) is following object
A from 1 light second behind it, and the relative speed between the two is
0.
Object A turns on a lightsource.
Do you truly think it will take 1 wholesecond for object B to see the light
from A even though B is traveling at 0.5c towards the first emission point
of light?
Or would you say it takes only 1/2 second?
Matthew Johnson
[snip]
>> "Not currently known"? Maybe not by you. But those of us who actually
>> passed upper-division E&M know the answer: in vacuum, light always
>> propagates with the same speed in any interial reference frame: that
>> speed is c.
>Matthew,
>Two objects (A and B) are following each other and moving at
>0.5c in direction N, the object in the back (B) is following object
>A from 1 light second behind it, and the relative speed between the two is
>0.
>Object A turns on a lightsource.
>Do you truly think it will take 1 wholesecond for object B to see the light
>from A even though B is traveling at 0.5c towards the first emission point
>of light?
>Or would you say it takes only 1/2 second?
Obviously, the answer depends on which reference frame you measure th time in.
If you measure in the reference frame of objects A and B, then it takes 1
second.
But if you measure in the unnamed reference frame you alluded to when you said
"movint at speed 0.5c", then the answer is different. I'm sure you can compute
sqrt(1-(0.5)^2) as well as I can,
1/2 second is wrong in both reference frames.
Spaceman
> In article <tvqdnbY3YfLZeAnV...@comcast.com>, Spaceman
> says...
>>
>> Matthew Johnson wrote:
>>> In article <sun994hkfejivg629...@4ax.com>, Dr. Henri
>
> [snip]
>
>>> "Not currently known"? Maybe not by you. But those of us who
>>> actually passed upper-division E&M know the answer: in vacuum,
>>> light always propagates with the same speed in any interial
>>> reference frame: that speed is c.
>
>> Matthew,
>> Two objects (A and B) are following each other and moving at
>> 0.5c in direction N, the object in the back (B) is following object
>> A from 1 light second behind it, and the relative speed between the
>> two is 0.
>> Object A turns on a lightsource.
>> Do you truly think it will take 1 wholesecond for object B to see
>> the light from A even though B is traveling at 0.5c towards the
>> first emission point of light?
>> Or would you say it takes only 1/2 second?
>
> Obviously, the answer depends on which reference frame you measure th
> time in. If you measure in the reference frame of objects A and B,
> then it takes 1 second.
B says you are wrong.
These are inertial and no time dilation is occuring.
B comes up with 1/2 second timed.
If it did not, it was not moving at 0.5c to begin with.
It's basic math Matthew.
Why don't you understand basic math anymore?
> But if you measure in the unnamed reference frame you alluded to when
> you said "movint at speed 0.5c", then the answer is different. I'm
> sure you can compute sqrt(1-(0.5)^2) as well as I can,
>
> 1/2 second is wrong in both reference frames.
Nope.
I knew you would not understand there is no "time dilation"
in the above and any transform will give the wrong time
and of course you will ignore the closing speed of object B
to the lightwave front at the 1.5c occuring.
Figures.
:)