Simultaneity of Relativity
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From: Bruce Richmond on 1 Nov 2009 22:53 On Nov 1, 7:32 pm, mpc755 <mpc...(a)gmail.com> wrote: > On Oct 8, 11:49 am, mpc755 <mpc...(a)gmail.com> wrote: > > > If the aether is stationary relative to the embankment and stationary > > relative to the train, this is what will occur in Einstein's train > > thought experiment: > > >http://www.youtube.com/watch?v=jyWTaXMElUk > > Einstein says in order for the propagation of light to exist there > must be aether. Einstein also says the idea of motion may not be > applied to aether. And you have already stated that the aether can't be at rest WRT two relativly moving frames that share the same space. Seems you are running out of options. > I conclude this means aether must be at rest relative to the > embankment and at rest relative to the train which is physically > impossible if the embankment frame of reference and the train frame of > reference occupy the same three dimensional space. But they obviously can share the same space, and both measure the speed of light to be c using the coordinates of their own frame. If your theory can't explain how that happens your theory is wrong.
From: Bruce Richmond on 1 Nov 2009 22:57 On Nov 1, 10:13 pm, mpc755 <mpc...(a)gmail.com> wrote: > On Nov 1, 7:32 pm, mpc755 <mpc...(a)gmail.com> wrote: > > > > > > > On Oct 8, 11:49 am, mpc755 <mpc...(a)gmail.com> wrote: > > > > If the aether is stationary relative to the embankment and stationary > > > relative to the train, this is what will occur in Einstein's train > > > thought experiment: > > > >http://www.youtube.com/watch?v=jyWTaXMElUk > > > Einstein says in order for the propagation of light to exist there > > must be aether. Einstein also says the idea of motion may not be > > applied to aether. > > > I conclude this means aether must be at rest relative to the > > embankment and at rest relative to the train which is physically > > impossible if the embankment frame of reference and the train frame of > > reference occupy the same three dimensional space. > > mpc755 train thought experiment. > > The train is moving perpendicular to the line A and B exist on. > The train is wide enough that A' and B' exist on opposite sides of the > aisle. > > Here is an image of the train and the embankment and the corresponding > locations prior to the lightning strikes. The arrows represent the > train moving towards the embankment as viewed from the embankment > frame of reference: > > A-----M-----B > ^ ^ ^ > | | | > | | | > A'----M'----B' > > When the lightning strike occurs at A/A', A and A' exist at the same > point in three dimensional space. When the lightning strike occurs at > B/B', B and B' exist at the same point in three dimensional space. > > The train continues to move perpendicular to the line A and B exist on > after the lightning strikes. > > This is what the embankment and train look like after the lightning > strikes. The arrows indicate the train moving away from the embankment > as viewed from the embankment frame of reference: > > A'----M'----B' > ^ ^ ^ > | | | > | | | > A-----M-----B > > If the light from A and B reaches M simultaneously, the light from A' > and B' reaches M' simultaneously because A/A' was a single lightning > strike and B/B' was a single lightning strike and A and M, B and M, A' > and M', and B' and M' are equi-distant. But this requires the light to > travel from four locations to each Observer. It is either that or the > light travels from A and B to M and M', making the embankment the > preferred frame or the light travels from A' and B' to M and M', > making the train the preferred frame. > > I don't think this can be resolved in Relativity of Simultaneity.- Hide quoted text - > > - Show quoted text - This has nothing to do with Einstein's train experiment or relative simultaneity.
From: mpc755 on 1 Nov 2009 22:57 On Nov 1, 10:47 pm, Bruce Richmond <bsr3...(a)my-deja.com> wrote: > > > Since Einstein required the aether for the propagation of light, what > > you are referring to is an error of omission. > > Einstein did not require an aether for propagation of light. What part of the next sentence don't you understand? 'Ether and the Theory of Relativity by Albert Einstein' http://www-groups.dcs.st-and.ac.uk/~history/Extras/Einstein_ether.html "According to the general theory of relativity space without ether is unthinkable; for in such space there not only would be no propagation of light, but also no possibility of existence for standards of space and time (measuring-rods and clocks), nor therefore any space-time intervals in the physical sense."
From: mpc755 on 1 Nov 2009 23:20 On Nov 1, 10:57 pm, Bruce Richmond <bsr3...(a)my-deja.com> wrote: > On Nov 1, 10:13 pm, mpc755 <mpc...(a)gmail.com> wrote: > > > > > On Nov 1, 7:32 pm, mpc755 <mpc...(a)gmail.com> wrote: > > > > On Oct 8, 11:49 am, mpc755 <mpc...(a)gmail.com> wrote: > > > > > If the aether is stationary relative to the embankment and stationary > > > > relative to the train, this is what will occur in Einstein's train > > > > thought experiment: > > > > >http://www.youtube.com/watch?v=jyWTaXMElUk > > > > Einstein says in order for the propagation of light to exist there > > > must be aether. Einstein also says the idea of motion may not be > > > applied to aether. > > > > I conclude this means aether must be at rest relative to the > > > embankment and at rest relative to the train which is physically > > > impossible if the embankment frame of reference and the train frame of > > > reference occupy the same three dimensional space. > > > mpc755 train thought experiment. > > > The train is moving perpendicular to the line A and B exist on. > > The train is wide enough that A' and B' exist on opposite sides of the > > aisle. > > > Here is an image of the train and the embankment and the corresponding > > locations prior to the lightning strikes. The arrows represent the > > train moving towards the embankment as viewed from the embankment > > frame of reference: > > > A-----M-----B > > ^ ^ ^ > > | | | > > | | | > > A'----M'----B' > > > When the lightning strike occurs at A/A', A and A' exist at the same > > point in three dimensional space. When the lightning strike occurs at > > B/B', B and B' exist at the same point in three dimensional space. > > > The train continues to move perpendicular to the line A and B exist on > > after the lightning strikes. > > > This is what the embankment and train look like after the lightning > > strikes. The arrows indicate the train moving away from the embankment > > as viewed from the embankment frame of reference: > > > A'----M'----B' > > ^ ^ ^ > > | | | > > | | | > > A-----M-----B > > > If the light from A and B reaches M simultaneously, the light from A' > > and B' reaches M' simultaneously because A/A' was a single lightning > > strike and B/B' was a single lightning strike and A and M, B and M, A' > > and M', and B' and M' are equi-distant. But this requires the light to > > travel from four locations to each Observer. It is either that or the > > light travels from A and B to M and M', making the embankment the > > preferred frame or the light travels from A' and B' to M and M', > > making the train the preferred frame. > > > I don't think this can be resolved in Relativity of Simultaneity. > > This has nothing to do with Einstein's train experiment or relative > simultaneity. It has everything to do with Relativity of Simultaneity.
From: Peter Webb on 1 Nov 2009 23:35
"mpc755" <mpc755(a)gmail.com> wrote in message news:3cb3c494-a53a-4a33-8af9-d6679eda6c4c(a)s15g2000yqs.googlegroups.com... On Nov 1, 10:47 pm, Bruce Richmond <bsr3...(a)my-deja.com> wrote: > > > Since Einstein required the aether for the propagation of light, what > > you are referring to is an error of omission. > > Einstein did not require an aether for propagation of light. What part of the next sentence don't you understand? 'Ether and the Theory of Relativity by Albert Einstein' http://www-groups.dcs.st-and.ac.uk/~history/Extras/Einstein_ether.html "According to the general theory of relativity space without ether is unthinkable; for in such space there not only would be no propagation of light, but also no possibility of existence for standards of space and time (measuring-rods and clocks), nor therefore any space-time intervals in the physical sense." ______________________________________ Here is the full quote: Recapitulating, we may say that according to the general theory of relativity space is endowed with physical qualities; in this sense, therefore, there exists an ether. According to the general theory of relativity space without ether is unthinkable; for in such space there not only would be no propagation of light, but also no possibility of existence for standards of space and time (measuring-rods and clocks), nor therefore any space-time intervals in the physical sense. But this ether may not be thought of as endowed with the quality characteristic of ponderable media, as consisting of parts which may be tracked through time. The idea of motion may not be applied to it. You snipped the preceding sentence ... which heavily qualifies this as being "in a sense". You also snipped the last sentence, which says "The idea of motion may not be applied to it". I have no problem with you quoting Einstein, but quoting out of context - and in a manner which completely distorts what Einstein said - is clearly cheating. GR imposes a geometry on space. That geometry is sometimes nominally considered as applying to something, which in the above piece Einstein calls the "ether". It does not provide a unique inertial frame of reference, which is the claim made by people who believe in an ether (in the normal "sense" of the word ether, hence Einstein's explicit statement that he was using it another sense), and in fact the last sentence explicitly states that it cannot be used as baseline for measuring motion. If you believe in an ether (in the sense of a privileged stationary inertial reference frame) exists, you have to be able to describe an experiment which shows how it could be detected, and explain why the hundreds of experiments designed to detect the ether have all thus far failed. Lots of luck. |