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bill
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 Posted: Tue Jul 15, 2008 11:58 pm Post subject: The relativity of simultaneity |
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Regarding Einstein’s train gedanken depiction of the Relativity of
Simultaneity.
In ‘Relativity the Special and General Theory’ Einstein points out
that from the stationary observer’s point of view (M) flash B (toward
which the train is moving) will reach the passenger before flash A.
Will flash B arrive at the passenger’s location at the same point
relatively to the platform as seen by the stationary observer?
I.e. if there is a second stationary observer (S) located at the point
where, according to M, flash B arrives at the passenger’s location
will the passenger see flash B when he is at the same location as S? |
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Sue...
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| Posted: Wed Jul 16, 2008 12:35 am Post subject: Re: The relativity of simultaneity |
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On Jul 15, 7:58 pm, bill <cosmo...@optusnet.com.au> wrote:
| Quote: |
Regarding Einstein’s train gedanken depiction of the Relativity of
Simultaneity.
In ‘Relativity the Special and General Theory’ Einstein points out
that from the stationary observer’s point of view (M) flash B (toward
which the train is moving) will reach the passenger before flash A.
Will flash B arrive at the passenger’s location at the same point
relatively to the platform as seen by the stationary observer?
I.e. if there is a second stationary observer (S) located at the point
where, according to M, flash B arrives at the passenger’s location
will the passenger see flash B when he is at the same location as S?
|
The thought experiment doesn't use a model of light propagation
which we would use today.
http://en.wikipedia.org/wiki/Emitter_theory
Einstein’s theory of wavefronts versus
Einstein’s relativity of simultaneity
http://arxiv.org/abs/physics/0606233
So it has several ambiguous interpretations.
Your time will be better spent understanding
how formal space-time coordinate systems are
used. They don't need permission from the
philosophers of 1905 to use an imaginary
time axis. ;-)
Minkowski’s Four-Dimensional Space
http://www.bartleby.com/173/17.html
Space-time
http://farside.ph.utexas.edu/teaching/em/lectures/node113.html
Then you have some tools for real problems.
Relativistic particle dynamics
http://farside.ph.utexas.edu/teaching/em/lectures/node126.html
Sue... |
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paparios@gmail.com
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| Posted: Wed Jul 16, 2008 2:44 am Post subject: Re: The relativity of simultaneity |
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On 15 jul, 19:58, bill <cosmo...@optusnet.com.au> wrote:
| Quote: |
Regarding Einstein’s train gedanken depiction of the Relativity of
Simultaneity.
In ‘Relativity the Special and General Theory’ Einstein points out
that from the stationary observer’s point of view (M) flash B (toward
which the train is moving) will reach the passenger before flash A.
Will flash B arrive at the passenger’s location at the same point
relatively to the platform as seen by the stationary observer?
I.e. if there is a second stationary observer (S) located at the point
where, according to M, flash B arrives at the passenger’s location
will the passenger see flash B when he is at the same location as S?
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Yes, observer S being in the same frame as observer M will see light
signal coming from B arriving to the train observer M'.
Miguel Rios |
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bill
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| Posted: Wed Jul 16, 2008 4:06 am Post subject: Re: The relativity of simultaneity |
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On Jul 16, 12:44 pm, "papar...@gmail.com" <papar...@gmail.com> wrote:
| Quote: |
Yes, observer S being in the same frame as observer M will see light
signal coming from B arriving to the train observer M'.
Miguel Rios
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Thanks Miguel - but will the train passenger see the light signal
coming from B when he is at the same location as S? |
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bill
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| Posted: Wed Jul 16, 2008 4:42 am Post subject: Re: The relativity of simultaneity |
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On Jul 16, 10:35 am, "Sue..." <suzysewns...@yahoo.com.au> wrote:
| Quote: |
On Jul 15, 7:58 pm, bill <cosmo...@optusnet.com.au> wrote:
Regarding Einstein’s train gedanken depiction of the Relativity of
Simultaneity.
In ‘Relativity the Special and General Theory’ Einstein points out
that from the stationary observer’s point of view (M) flash B (toward
which the train is moving) will reach the passenger before flash A.
Will flash B arrive at the passenger’s location at the same point
relatively to the platform as seen by the stationary observer?
I.e. if there is a second stationary observer (S) located at the point
where, according to M, flash B arrives at the passenger’s location
will the passenger see flash B when he is at the same location as S?
The thought experiment doesn't use a model of light propagation
which we would use today.
|
Thanks Sue, but my question was specifically in relation to that
particular thought experiment. |
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Androcles
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| Posted: Wed Jul 16, 2008 11:03 am Post subject: Re: The relativity of simultaneity |
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"bill" <cosmosco@optusnet.com.au> wrote in message
news:0d32297c-48e7-4961-b5a1-6e680498282d@z66g2000hsc.googlegroups.com...
Regarding Einstein’s train gedanken depiction of the Relativity of
Simultaneity.
In ‘Relativity the Special and General Theory’ Einstein points out
that from the stationary observer’s point of view (M) flash B (toward
which the train is moving) will reach the passenger before flash A.
=============================================
Well, the idiot was wrong.
Why did Einstein say
the speed of light from A to B is c-v,
the speed of light from B to A is c+v,
the "time" each way is the same?
----------------------------------------------------------------------------------
Will flash B arrive at the passenger’s location at the same point
relatively to the platform as seen by the stationary observer?
I.e. if there is a second stationary observer (S) located at the point
where, according to M, flash B arrives at the passenger’s location
will the passenger see flash B when he is at the same location as S?
=============================================
Yes.
Now that we've established the idiot was a self-contradictory clown,
why keep prattling on about the moron? |
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Guest
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| Posted: Wed Jul 16, 2008 12:03 pm Post subject: Re: The relativity of simultaneity |
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bill ha escrito:
| Quote: |
Regarding Einstein�s train gedanken depiction of the Relativity of
Simultaneity.
In �Relativity the Special and General Theory� Einstein points out
that from the stationary observer�s point of view (M) flash B (toward
which the train is moving) will reach the passenger before flash A.
Will flash B arrive at the passenger�s location at the same point
relatively to the platform as seen by the stationary observer?
I.e. if there is a second stationary observer (S) located at the point
where, according to M, flash B arrives at the passenger�s location
will the passenger see flash B when he is at the same location as S?
Yes. |
RVHG (Rafael Valls Hidalgo-Gato) |
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Guest
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| Posted: Wed Jul 16, 2008 1:08 pm Post subject: Re: The relativity of simultaneity |
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Androcles ha escrito:
| Quote: |
"bill" <cosmosco@optusnet.com.au> wrote in message
news:0d32297c-48e7-4961-b5a1-6e680498282d@z66g2000hsc.googlegroups.com...
Regarding Einstein�s train gedanken depiction of the Relativity of
Simultaneity.
In �Relativity the Special and General Theory� Einstein points out
that from the stationary observer�s point of view (M) flash B (toward
which the train is moving) will reach the passenger before flash A.
============================================> Well, the idiot was wrong.
Einstein was right.
Why did Einstein say
the sped of light from A to B is c-v,
False. Einstein said {But the ray moves relatively to M', when |
measured in the stationary system (the embankment), with the velocity
c-v,...}. Relative velocity between two moving entities (the ray and
M') is NOT the speed of light c from A to B. YOU are the unique one
saying that "the sped of light from A to B is c-v,".
| Quote: |
the speed of light from B to A is c+v,
False. Einstein said {But the ray moves relatively to M', when |
measured in the stationary system (the embankment), with the velocity c
+v,...}. Relative velocity between two moving entities (the ray and
M') is NOT the speed of light c from B to A. YOU are the unique one
saying that "the speed of light from B to A is c+v,".
| Quote: |
the "time" each way is the same?
Yes, is the same. Distance from A to B equals distance from B to A |
(geometry is Euclidean), and the speed c is the same in both
directions (by postulate AND experience).
| Quote: |
----------------------------------------------------------------------------------
Will flash B arrive at the passenger�s location at the same point
relatively to the platform as seen by the stationary observer?
I.e. if there is a second stationary observer (S) located at the point
where, according to M, flash B arrives at the passenger�s location
will the passenger see flash B when he is at the same location as S?
============================================> Yes.
Now that we've established the idiot was a self-contradictory clown,
why keep prattling on about the moron?
|
RVHG (Rafael Valls Hidalgo-Gato) |
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harry
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| Posted: Wed Jul 16, 2008 4:05 pm Post subject: Re: The relativity of simultaneity |
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"bill" <cosmosco@optusnet.com.au> wrote in message
news:0d32297c-48e7-4961-b5a1-6e680498282d@z66g2000hsc.googlegroups.com...
: Regarding Einstein’s train gedanken depiction of the Relativity of
: Simultaneity.
: In ‘Relativity the Special and General Theory’ Einstein points out
: that from the stationary observer’s point of view (M) flash B (toward
: which the train is moving) will reach the passenger before flash A.
Ok, in the case of two simultaneous flashes (at each side of the train)
according to two observers M and M' near or in the middle of the train at
the time of the flashes (note that that will be so according to *any*
stationary observer; it's just that the two flashes will arrive at M at the
same time).
A-----------------B
-> train
: Will flash B arrive at the passenger’s location at the same point
: relatively to the platform as seen by the stationary observer?
Sure - that is called an event. Events cannot differ between views, as that
would lead to contradictions: everyone must agree on what locally happens
(the simulateneity problem is only about distant events).
: I.e. if there is a second stationary observer (S) located at the point
: where, according to M, flash B arrives at the passenger’s location
: will the passenger see flash B when he is at the same location as S?
Yes, that's even a way to verify that statement. Note that that "when"
refers to measurements in the stationary system (you could write it t1, to
distinguish it from the passenger's time t1'). And of course, all this will
only work if the passenger doesn't use the stationary system time keeping
but made a recalibration for the moving system.
Regards,
Harald |
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PD
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| Posted: Wed Jul 16, 2008 6:21 pm Post subject: Re: The relativity of simultaneity |
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On Jul 15, 6:58 pm, bill <cosmo...@optusnet.com.au> wrote:
| Quote: |
Regarding Einstein’s train gedanken depiction of the Relativity of
Simultaneity.
In ‘Relativity the Special and General Theory’ Einstein points out
that from the stationary observer’s point of view (M) flash B (toward
which the train is moving) will reach the passenger before flash A.
Will flash B arrive at the passenger’s location at the same point
relatively to the platform as seen by the stationary observer?
|
No, of course not. The train moves along the track, carrying the
passenger with it, while the light signal propagates.
Here, does this help?
http://www.youtube.com/watch?v=wteiuxyqtoM
| Quote: |
I.e. if there is a second stationary observer (S) located at the point
where, according to M, flash B arrives at the passenger’s location
will the passenger see flash B when he is at the same location as S? |
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Martin Hogbin
Guest
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| Posted: Wed Jul 16, 2008 11:29 pm Post subject: Re: The relativity of simultaneity |
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bill wrote:
| Quote: |
Regarding Einstein’s train gedanken depiction of the Relativity of
Simultaneity.
In ‘Relativity the Special and General Theory’ Einstein points out
that from the stationary observer’s point of view (M) flash B (toward
which the train is moving) will reach the passenger before flash A.
Will flash B arrive at the passenger’s location at the same point
relatively to the platform as seen by the stationary observer?
I.e. if there is a second stationary observer (S) located at the point
where, according to M, flash B arrives at the passenger’s location
will the passenger see flash B when he is at the same location as S?
|
Fistly, beware of the crackpots, there are many on this
group. Just ignore them.
Secondly, yes. What you are doing is setting up a
'stationary' reference frame in which events can be
assigned time and space ccordinates. This is the
conceptial mechanism by which M knows when the flash
reaches the passenger.
Flash B reaching the passenger is one event in all
frames. All that is different is the time and space
coordinates that differnt frames assign to that event.
Martin Hogbin |
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Martin Hogbin
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| Posted: Wed Jul 16, 2008 11:52 pm Post subject: Re: The relativity of simultaneity |
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PD wrote:
| Quote: |
On Jul 15, 6:58 pm, bill <cosmo...@optusnet.com.au> wrote:
Regarding Einstein’s train gedanken depiction of the Relativity of
Simultaneity.
In ‘Relativity the Special and General Theory’ Einstein points out
that from the stationary observer’s point of view (M) flash B (toward
which the train is moving) will reach the passenger before flash A.
Will flash B arrive at the passenger’s location at the same point
relatively to the platform as seen by the stationary observer?
No, of course not. The train moves along the track, carrying the
passenger with it, while the light signal propagates.
Here, does this help?
http://www.youtube.com/watch?v=wteiuxyqtoM
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I think one of us may have misunderstood the question.
Martin Hogbin |
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bill
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| Posted: Thu Jul 17, 2008 4:04 am Post subject: Re: The relativity of simultaneity |
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On Jul 17, 4:52 am, Martin Hogbin <goatNOSP...@hogbin.org> wrote:
| Quote: |
I think one of us may have misunderstood the question.
Martin Hogbin
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On the basis that your response agrees with my line of thinking
it is obvious that you were not the one that misunderstood
the question  |
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PD
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| Posted: Thu Jul 17, 2008 4:23 am Post subject: Re: The relativity of simultaneity |
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On Jul 16, 1:52 pm, Martin Hogbin <goatNOSP...@hogbin.org> wrote:
| Quote: |
PD wrote:
On Jul 15, 6:58 pm, bill <cosmo...@optusnet.com.au> wrote:
Regarding Einstein’s train gedanken depiction of the Relativity of
Simultaneity.
In ‘Relativity the Special and General Theory’ Einstein points out
that from the stationary observer’s point of view (M) flash B (toward
which the train is moving) will reach the passenger before flash A.
Will flash B arrive at the passenger’s location at the same point
relatively to the platform as seen by the stationary observer?
No, of course not. The train moves along the track, carrying the
passenger with it, while the light signal propagates.
Here, does this help?
http://www.youtube.com/watch?v=wteiuxyqtoM
I think one of us may have misunderstood the question.
|
Apparently, and I have no doubt who. Hopefully the link to the
animation will answer the question for the OP anyway. |
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Sue...
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| Posted: Thu Jul 17, 2008 5:04 am Post subject: Re: The relativity of simultaneity |
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On Jul 17, 12:23 am, PD <TheDraperFam...@gmail.com> wrote:
| Quote: |
On Jul 16, 1:52 pm, Martin Hogbin <goatNOSP...@hogbin.org> wrote:
PD wrote:
On Jul 15, 6:58 pm, bill <cosmo...@optusnet.com.au> wrote:
Regarding Einstein’s train gedanken depiction of the Relativity of
Simultaneity.
In ‘Relativity the Special and General Theory’ Einstein points out
that from the stationary observer’s point of view (M) flash B (toward
which the train is moving) will reach the passenger before flash A.
Will flash B arrive at the passenger’s location at the same point
relatively to the platform as seen by the stationary observer?
No, of course not. The train moves along the track, carrying the
passenger with it, while the light signal propagates.
Here, does this help?
http://www.youtube.com/watch?v=wteiuxyqtoM
I think one of us may have misunderstood the question.
Apparently, and I have no doubt who. Hopefully the link to the
animation will answer the question for the OP anyway.
|
I have a video that shows the Wicked Witch of the West
melting so I have never doubted that witches can do that.
If you have a video that shows light moving as a massive
particle, then it must be true.
http://en.wikipedia.org/wiki/Emitter_theory
http://nobelprize.org/physics/articles/ekspong/index.html
http://www.quackwatch.org/01QuackeryRelatedTopics/pseudo.html
Sue... |
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