• Gampa Dee
    46
    I had a discussion with Pierre Normand who showed me why I had a misunderstanding to a simple problem ... It involved a light clock on a moving frame (vertical); I had problems understanding that a horizontal light clock would have been in synch with the vertical light clock.

    The reason why I brought up this problem was due to it resembling the M&M experiment.
    It seemed at first, to be the same situation as Michelson and Morley, who expected to observe a shift difference, which involved a time difference.
    ...until it dawned on me, with the help of Pierre Normand, that we had a length contraction on the moving frame..

    However, this was exactly the explanation that Fitzgerald gave for the null result.
    Einstein claimed the light’s velocity is invariant without any specific reason why, while Fitzgerald
    pointed to the light’s velocity in the medium (ether) as being the cause. So in the case of the M&M experiment, Einstein would claim that there was no length contractions nor time dilations involved because there was no different inertial frames to measure....

    But, what if the light speed was c relative to the source (sort of particle theory) .The observer outside of the frame would measure the light speed in the direction of the motion as c+v (and would therefore observe a blueshift), as well as measure the light speed as being c-v in the opposite direction(and therefore observing a red shift)?

    It seems that, in this case, the M&M experiment would have been predictable.

    Grampa Dee
  • alan1000
    200
    On the other hand, the monoclastic neutrinal differentiation of the autosomatically-determined spin value inherent in all such equitational bivalent transmogrifications cannot be entirely ignored, wouldn't you agree? Particularly if we keep in mind the various M&M chromatic values which may be obtained at little expense in our own time.
  • noAxioms
    1.5k
    I actually never saw this post until it got bumped by alan1000's post. That post seems pretty much a word salad to me, but yay for the bump.

    The reason why I brought up this problem was due to it resembling the M&M experiment.Gampa Dee
    It very much does. Just like with a light clock, without length contraction, the M&M experiment would show it taking more time for light to make the circuit with and against the motion, and less time when it moves perpendicular to the motion. The difference should have been noticed and the Newtonian models were falsified when it wasn't.

    Einstein claimed the light’s velocity is invariant without any specific reason why
    It's a postulate, not something that can be known. Special relativity used a fairly strong version of the postulate, that light actually goes the same speed regardless of inertial frame choice. Some later papers took much of that metaphysical assertion away and used a weaker statement, that the laws of physics (including any measurement of light speed) are the same relative to any inertial frame.
    The latter wording allows for the existence of a preferred frame despite no local way to detect it.

    while Fitzgerald pointed to the light’s velocity in the medium (ether) as being the cause
    Nothing in any of relativity suggests an aether. Other theories do, but the additional postulate does not result in any empirical differences, so it's useless.

    So in the case of the M&M experiment, Einstein would claim that there was no length contractions nor time dilations involved because there was no different inertial frames to measure....
    I assure you that the M&M experiment was performed in many different inertial frames. The statement above is false and Einstein would certainly not have said anything to that effect.

    But, what if the light speed was c relative to the source (sort of particle theory)
    Immediately falsifiable by having two light sources moving at different speeds emit a flash when they pass each other. A distant observer would see one flash from the approaching source sooner than the one from the receding source, thus falsifying Einstein's postulate. Such a result is not observed. Light speed is empirically demonstrated to be independent of the speed of the light source.

    The observer outside of the frame
    An observer cannot be outside any frame. He's in all of them, just not stationary in them all.

    It seems that, in this case, the M&M experiment would have been predictable.
    M*M didn't have light sources moving at different velocities AFAIK.
  • jgill
    3.8k
    On the other hand, the monoclastic neutrinal differentiation . . .alan1000

    Sokol prize winner.
  • PhilosophyRunner
    302
    So in the case of the M&M experiment, Einstein would claim that there was no length contractions nor time dilations involved because there was no different inertial frames to measure....Gampa Dee

    The length contractions in Fitzgerald's theory is the same as that in Einstein's special relativity - they are both Lotentz transformations. The difference is that in Fitzgerald's theory the frame of reference of the ether was a privileged frame of reference in which light traveled, while Einstein showed that the ether was not needed in the theory and that the frame of reference can be any inertial frame of reference.

    To put is more simply:

    According to Fitzgerald: Light traveled in the ether frame of reference. This frame of reference was moving relative to an observer on Earth. Lorentz transformations can be used to explain length contractions due to the observer and ether being in different frames of references.

    According to Einstein: The ether is not needed in the theory. Length contractions due to Lorentz transformations are observed when the observer is in a different inertial frame of reference to the experiment, but this is not relevant to the M&M experiment as both the observer and experiment are in the same frame of reference.
  • noAxioms
    1.5k
    The difference is that in Fitzgerald's theory the frame of reference of the ether was a privileged frame of reference in which light traveled, while Einstein showed that the ether was not needed in the theory and that the frame of reference can be any inertial frame of reference.PhilosophyRunner
    Pretty much that. It asserts a preferred frame despite the fact that local detection of such a frame is not possible since empirical physics isn't any different in other inertial frames. Einstein saw no need for the additional premise when it served no predictive purpose.

    According to Fitzgerald: Light traveled in the ether frame of reference.
    Well, light travels in all frames, but the speed of light is isotropic (same speed in all directions) only in the preferred frame. Remember, everything is in all frames of reference, but a thing is stationary only in one of them.

    this is not relevant to the M&M experiment as both the observer and experiment are in the same frame of reference.
    The experiment was the observer in M&M. In very few experiments are humans actually necessary while the experiment is running.
    M&M was testing for an older ether theory, one in which there were no Lorentz transformations or length contractions. That theory was falsified by the M&M, which is why it is of such historic importance.
    M&M of course cannot differentiate between SR and a modern aether theory since they make all the same predictions, differing only in complexity.

    OK, I lied; they make some different predictions, but the kind of test that requires that you don't report the results of your experiment to the rest of us, much like testing for an afterlife. Sure, you can demonstrate the afterlife to yourself, but not to those you left behind.
  • Gampa Dee
    46
    Thank you for responding, Alan:

    On the other hand, the monoclastic neutrinal differentiation of the autosomatically-determined spin value inherent in all such equitational bivalent transmogrifications cannot be entirely ignored, wouldn't you agree?alan1000

    I’m sorry, I don’t quite understand what you’ve written down. I haven’t read about spin values within any M&M experiment explanations.
    Are you speaking about the g factor? Could you expand?

    Particularly if we keep in mind the various M&M chromatic values which may be obtained at little expense in our own time.alan1000

    However, the null result of the M&M experiment can be explain by the particle theory of light, Why was this possibility not considered...or was it? I haven't read anything concerning this

    Thank you for your time.
    Grampa Dee
  • Gampa Dee
    46
    Thank you for responding, noAxiom

    The reason why I brought up this problem was due to it resembling the M&M experiment.
    — Gampa Dee
    It very much does. Just like with a light clock, without length contraction, the M&M experiment would show it taking more time for light to make the circuit with and against the motion, and less time when it moves perpendicular to the motion. The difference should have been noticed and the Newtonian models were falsified when it wasn't.
    noAxioms

    I agree with what you wrote, except, the Newtonian model would have predicted a null result as Newton believed that light was made up of particles.

    Einstein claimed the light’s velocity is invariant without any specific reason why

    It's a postulate, not something that can be known. Special relativity used a fairly strong version of the postulate, that light actually goes the same speed regardless of inertial frame choice. Some later papers took much of that metaphysical assertion away and used a weaker statement, that the laws of physics (including any measurement of light speed) are the same relative to any inertial frame.
    The latter wording allows for the existence of a preferred frame despite no local way to detect it.
    noAxioms

    it seems to me that Fitzgerald allowed a mechanism for the length contraction to exist, being the ether, whereas Einstein did not have any mechanism...for what I understand...and for me, it seems that the postulate of the invariant speed of light would fall into the "extraordinary claims require extraordinary evidence” category... I am not saying that Fitzgerald was correct and Einstein was not, only that Fitzgerald had a cause for the length contraction.
    My “personal” opinion would be that the particle theory, which would have predicted a null result, may have been disregarded prematurely. .

    So in the case of the M&M experiment, Einstein would claim that there was no length contractions nor time dilations involved because there was no different inertial frames to measure....

    I assure you that the M&M experiment was performed in many different inertial frames. The statement above is false and Einstein would certainly not have said anything to that effect.
    noAxioms

    I agree that my statement is false in the sense that Einstein did not write about the M&M experiment. But what I am saying is that Einstein “would have said” the M&M experiment did not contain any time dilation or length contraction because the light source and observer were on the same inertial frame, whereas Fitzgerald claimed the experiment did indeed experience a length contraction in the direction of motion.
    As for the M&M experiment performed on different frames, I think that the sun (being on a different inertial frame) was used as a source of light; however some have identified the light passing through the mirrors involved a “new source” for the light which brought the experiment back on the same frame as the observer.

    But, what if the light speed was c relative to the source (sort of particle theory)

    Immediately falsifiable by having two light sources moving at different speeds emit a flash when they pass each other. A distant observer would see one flash from the approaching source sooner than the one from the receding source, thus falsifying Einstein's postulate. Such a result is not observed. Light speed is empirically demonstrated to be independent of the speed of the light source.
    noAxioms

    Yes, but then again, it seems that there is still a possibility for the new source theory. Within a double star system, the light from a receding star and the one advancing might interact within a gas medium before leaving the system, which would cause the effect to disappear.

    The observer outside of the frame
    An observer cannot be outside any frame. He's in all of them, just not stationary in them all.
    noAxioms

    Yes; true...I am having problems in explaining scientific theories properly... :)

    Thank you for your time
    Grampa Dee
  • Gampa Dee
    46
    Thank you for replying PhilosophyRunner

    The length contractions in Fitzgerald's theory is the same as that in Einstein's special relativity - they are both Lotentz transformations. The difference is that in Fitzgerald's theory the frame of reference of the ether was a privileged frame of reference in which light traveled, while Einstein showed that the ether was not needed in the theory and that the frame of reference can be any inertial frame of reference.PhilosophyRunner

    However, by taking out the ether, it seems that Einstein was sort of claiming at the same time that light might not be a wave after all....I think he did so when he explained the photoelectric effect.

    To put is more simply:

    According to Fitzgerald: Light traveled in the ether frame of reference. This frame of reference was moving relative to an observer on Earth. Lorentz transformations can be used to explain length contractions due to the observer and ether being in different frames of references.

    According to Einstein: The ether is not needed in the theory. Length contractions due to Lorentz transformations are observed when the observer is in a different inertial frame of reference to the experiment, but this is not relevant to the M&M experiment as both the observer and experiment are in the same frame of reference.
    PhilosophyRunner

    I agree with most of what you wrote, except, If the ether was not needed, then, why was the length contraction and time dilation needed? what did it explain if it wasn't needed to explain the null result?

    Thank you for your time
    Grampa Dee
  • noAxioms
    1.5k
    I agree with what you wrote, except, the Newtonian model would have predicted a null result as Newton believed that light was made up of particles.Gampa Dee
    Yes and no. Particles would also have taken longer to go the greater distance with the grain than the shorter distance against it.
    But the interferometer used by M&M leverages the wave nature of light, something known back in Newton's time since particles don't explain rainbows. I don't know when interferometers were invented.

    Einstein claimed the light’s velocity is invariant without any specific reason why
    Empirical evidence? Einstein didn't originate the claim. He just ran with it without dragging in the baggage that everybody else tried to keep.

    It's a postulate, not something that can be known. Special relativity used a fairly strong version of the postulate, that light actually goes the same speed regardless of inertial frame choice. Some later papers took much of that metaphysical assertion away and used a weaker statement, that the laws of physics (including any measurement of light speed) are the same relative to any inertial frame.
    The latter wording allows for the existence of a preferred frame despite no local way to detect it.
    — noAxioms

    it seems to me that Fitzgerald allowed a mechanism for the length contraction to exist, being the ether, whereas Einstein did not have any mechanism
    The heck he didn't. It was explained via Minkowskian geometry. The contraction (and the underlying 4D geometry) derives directly from the frame-invariant speed of light, even if there was a preferred frame. The geometry and contraction were both a byproduct of the work of Minkowski and Lorentz, so that too wasn't something Einstein originated. Lorentz was first, but clung to the 3D ether model like Fitzgerald. That model added complications preventing the special version of the theory coming out before Einstein's, and preventing a general version from coming out until nearly a century after Einstein's.

    As I said, there are some empirical tests one can perform to see who is right, but not that one where results can be physically published in a journal.

    for what I understand...and for me, it seems that the postulate of the invariant speed of light would fall into the "extraordinary claims require extraordinary evidence” category.
    OK. For me it falls under Occam's razor: The simpler model is the more likely one, proposing the fewest additions and complications.

    My “personal” opinion would be that the particle theory, which would have predicted a null result
    It predicted no such thing since the particle would have longer to go this way than that way. The contraction (which both theories describe, but Newton does not) explains the null result of M&M.

    But what I am saying is that Einstein “would have said” the M&M experiment did not contain any time dilation or length contraction because the light source and observer were on the same inertial frame,
    He would not have said anything of the sort since the frame of the light source was trivially demonstrated not to matter.

    As for the M&M experiment performed on different frames, I think that the sun (being on a different inertial frame) was used as a source of light
    Doubt it. You need a laser to run an interferometer. I've never heard of anybody managing to run one with ambient light.

    But, what if the light speed was c relative to the source (sort of particle theory)
    Then an easy experiment would show it. As I said, this is easily falsified.
    The binary star thing doesn't work since there is no way to know when the light you're looking at was emitted. Both stars continuously emit light. You need two relatively moving sources that simultaneously, in each other's presence, emit a short pulse. The further away the emitter the better since it would give one pulse more time to outrun the other, showing up as two pulses at different times at the detector. No such thing is seen.

    Very fast objects (ejected by some explosion) have been observed. If they come right at us, they appear to approach faster than c due to Doppler effects. But if some explosion sent an object away from us, we would not be able to see that object at all since the light would take centuries longer to reach us. But we see them.
    Similarly, the approaching objects would be seen before the explosion that ejected them. This is not what is observed.

    Distant galaxies receding over c would not be visible due to the light approaching too slowly to stay inside our event horizon, but there they are, with Webb telescope finding ever more distant ones. The visible universe would be far smaller if light speed was dependent on emitter motion.
  • Gampa Dee
    46
    Thank you for responding noAxioms, I appreciate it.

    I agree with what you wrote, except, the Newtonian model would have predicted a null result as Newton believed that light was made up of particles.
    — Gampa Dee
    Yes and no. Particles would also have taken longer to go the greater distance with the grain than the shorter distance against it.
    But the interferometer used by M&M leverages the wave nature of light, something known back in Newton's time since particles don't explain rainbows. I don't know when interferometers were invented.
    noAxioms

    From what I understand, in the M&M experiment, the velocity of the light would be c through all paths within a particle theory of light.

    The Project Gutenberg EBook of The Theory of the Relativity of Motion, by
    Richard Chace Tolman

    Suggested Alternative to the Postulate of the Independence of the Velocity of Light and the Velocity of the Source.

    20. Because of the extraordinary conclusions derived by combining
    the principle of the relativity of motion with the postulate that the
    velocity of light is independent of the velocity of its source, a number
    of attempts have been made to develop so-called emission theories of
    relativity based on the principle of the relativity of motion and the
    further postulate that the velocity of light and the velocity of its source
    are additive...

    As a particular example of the simplicity of emission theories we may show, for instance, how easily they would account for the negative result of the Michelson-Morley experiment.

    Einstein claimed the light’s velocity is invariant without any specific reason why

    Empirical evidence? Einstein didn't originate the claim. He just ran with it without dragging in the baggage that everybody else tried to keep.
    noAxioms

    First, I hope that I’m not sounding as if I think little of the genius of any/all physicists who were at the same time developing QM.
    I was just wondering why Einstein, who did mention the particle characteristic of light for QM, did not think that this could also be the solution for the M&M experiment

    it seems to me that Fitzgerald allowed a mechanism for the length contraction to exist, being the ether, whereas Einstein did not have any mechanism

    The heck he didn't. It was explained via Minkowskian geometry. The contraction (and the underlying 4D geometry) derives directly from the frame-invariant speed of light, even if there was a preferred frame. The geometry and contraction were both a byproduct of the work of Minkowski and Lorentz, so that too wasn't something Einstein originated. Lorentz was first, but clung to the 3D ether model like Fitzgerald. That model added complications preventing the special version of the theory coming out before Einstein's, and preventing a general version from coming out until nearly a century after Einstein's.
    noAxioms

    I understand, but it was in consequence of the postulate in the first place; in other words, if the 2nd postulate is true, then certainly, there will be some modifications involved when dealing with space and time, since velocity is distance over time.

    As I said, there are some empirical tests one can perform to see who is right, but not that one where results can be physically published in a journal.noAxioms

    I have started reading a journal named “double star experiment”, which I will try to leave as a link.,if I
    cannot, I will write what I have read later on.

    for what I understand...and for me, it seems that the postulate of the invariant speed of light would fall into the "extraordinary claims require extraordinary evidence” category.
    OK. For me it falls under Occam's razor: The simpler model is the more likely one, proposing the fewest additions and complications.
    noAxioms

    I personally don’t see the 2nd postulate as being simple in essence.However, If it is indeed correct, well then yes, we don’t have any choice but to use it

    My “personal” opinion would be that the particle theory, which would have predicted a null result

    It predicted no such thing since the particle would have longer to go this way than that way. The contraction (which both theories describe, but Newton does not) explains the null result of M&M.
    noAxioms

    I don’t understand why you say one path would be longer than the other?


    But, what if the light speed was c relative to the source (sort of particle theory)

    Then an easy experiment would show it. As I said, this is easily falsified.
    The binary star thing doesn't work since there is no way to know when the light you're looking at was emitted. Both stars continuously emit light. You need two relatively moving sources that simultaneously, in each other's presence, emit a short pulse. The further away the emitter the better since it would give one pulse more time to outrun the other, showing up as two pulses at different times at the detector. No such thing is seen.
    noAxioms

    I need to ponder more on this one... I’m not sure what you’re saying.

    Distant galaxies receding over c would not be visible due to the light approaching too slowly to stay inside our event horizon, but there they are, with Webb telescope finding ever more distant ones. The visible universe would be far smaller if light speed was dependent on emitter motion.noAxioms

    Yes, but on the other hand, if the light speed is dependent on the emitter, there would simply be a different interpretation... that is, the receding galaxies with a velocity greater than c would not be interpreted as having those velocities....for example, could some of the red shifts be interpreted with distance, as well as velocities?

    Grampa Dee
  • noAxioms
    1.5k
    From what I understand, in the M&M experiment, the velocity of the light would be c through all paths within a particle theory of light.Gampa Dee
    Special relativity theory (early 20th century) posited the frame independent fixed speed (not velocity, which is frame dependent) of light. The M&M experiment (late 19th century) neither presumed nor demonstrated the fixed frame independent speed of light.
    The speed of light is not dependent on whether one uses a particle or wave model for it.

    "As a particular example of the simplicity of emission theories we may show, for instance, how easily they would account for the negative result of the Michelson-Morley experiment."
    There you go. That is an alternative explanation for M&M, since falsified, but not at the time.

    Einstein claimed the light’s velocity is invariant without any specific reason why
    He postulated it. He said essentially, If it were true, then yatta yatta yatta...
    The list of yattas made a lot of unintuitive empirical predictions, all of which were later verified. But the frame invariant speed of light has never been verified. It remains an assumption.

    First, I hope that I’m not sounding as if I think little of the genius of any/all physicists who were at the same time developing QM.
    Your questions are valid, and I'm the first to admit the validity of alternate theories that do not hold to Einstein's postulate.

    I was just wondering why Einstein, who did mention the particle characteristic of light for QM, did not think that this could also be the solution for the M&M experiment
    Because it has since been shown that light speed is not a function of the velocity of the emitter. It might be different from one frame to the next, but it's not a function of emitter velocity.

    I don’t understand why you say one path would be longer than the other?
    Picture a light clock moving at 0.866c with mirrors separated by a distance of 1. Presume no length contraction. Move the clock with the mirrors to the sides. Light travels a distance of 1 to the left and 1.732 up to get to the other side, a total distance of 2. Another 2 to get back. So it runs at half speed since it has a distance of 4 to go instead of 2 when the clock is stationary.
    Now turn the clock vertical and do it again. Light starts at the bottom at t=0 and after 7.464 time units, light has moved 7.464 and the top mirror has moved 6.464 units. It then reflects and takes 0.536 time units to get back to the bottom for a total elapsed time of 8. Light has a longer path to go (round trip of 8 instead of 4) if it's chasing the mirror instead of going from side to side.

    that is, the receding galaxies with a velocity greater than c would not be interpreted as having those velocities.
    Technically, they're rapidities, not velocities. The former adds the normal way (a+b) as opposed to velocity with adds the relativistic way, in natural units: (a+b)/(1+ab)
    I suppose since the entire theory or relativity would collapse under such a postulate, none of the usual methods could be used, so indeed, distant galaxies would be measured a different way.

    The better empirical evidence would be something like seeing incoming ejecta before seeing the explosion that caused it, or seeing a star explode well before the neutrinos hit instead of the observed neutrinos coming just before the light.
  • Gampa Dee
    46
    Thank you for responding noAxioms

    From what I understand, in the M&M experiment, the velocity of the light would be c through all paths within a particle theory of light.
    — Gampa Dee
    Special relativity theory (early 20th century) posited the frame independent fixed speed (not velocity, which is frame dependent) of light. The M&M experiment (late 19th century) neither presumed nor demonstrated the fixed frame independent speed of light.
    The speed of light is not dependent on whether one uses a particle or wave model for it.
    noAxioms

    Yes, I do have a hard time with the “velocity” concept, but the reason I use the term is due to the fact that I need it in context with the light going in a specific direction.....I will try to go back to the old thread “The Newtonian gravitational equation seems a bit odd to me” sometimes because I’ve read some things concerning vector additions that I just don’t get, which maybe you could help me out with.

    I don’t understand why you say one path would be longer than the other?
    Picture a light clock moving at 0.866c with mirrors separated by a distance of 1. Presume no length contraction. Move the clock with the mirrors to the sides. Light travels a distance of 1 to the left and 1.732 up to get to the other side, a total distance of 2. Another 2 to get back. So it runs at half speed since it has a distance of 4 to go instead of 2 when the clock is stationary.
    noAxioms

    It seems that this would imply the light as having a speed of .5c relative to the mirror, whereas, if I’m not mistaken, the emission theory would claim the light as having a speed of c. If you’re speaking of an observer moving at .866c, relative to the frame of the clock, then, accordingly, the observer should measure the light as having a speed of 1.886c relative to himself and still c relative to the mirror. However, there might be indeed some “apparent” speeds due to the Doppler Effect, but those aren’t real.

    that is, the receding galaxies with a velocity greater than c would not be interpreted as having those velocities.
    Technically, they're rapidities, not velocities. The former adds the normal way (a+b) as opposed to velocity with adds the relativistic way, in natural units: (a+b)/(1+ab)
    noAxioms

    ... I would be interested in learning more about the scientific jargon...I will try to read up on this more.

    The better empirical evidence would be something like seeing incoming ejecta before seeing the explosion that caused it, or seeing a star explode well before the neutrinos hit instead of the observed neutrinos coming just before the light.noAxioms

    I think I see what you mean.... here's the link that I told you about concerning the "double star experiement"....I hope it works... just started to read it; still got lots to go through, and you might be interested in this.

    [url]http://research_papers_astrophysics_science_journal_5693.pdf [/url]
  • noAxioms
    1.5k
    I’ve read some things concerning vector additions that I just don’t get, which maybe you could help me out with.Gampa Dee
    Maybe. Don't know the problem.
    You mean the equation a = GM/r² ? I suppose that would need a unit vector to make it into a vector acceleration and not just a scalar. Nothing on the right side as I wrong it is a vector.


    It seems that this would imply the light as having a speed of .5c relative to the mirror
    Well, no. In the scenario I outlined, when moving up it has a speed of .134c relative to the mirror, and in the reverse direction the relative speed would be 1.866. That still presumes light is independent of emitter speed.
    With emission theory, you'd have to specify the speed of emission, not obvious with a light clock which just reflects the pulse back and forth and has no obvious emission event. I am also unsure what emission theory says about how the speed gets altered when hitting a moving mirror.

    If you’re speaking of an observer moving at .866c, relative to the frame of the clock
    I wasn't. I was speaking of the clock moving at .866c relative to the ether. Neither the observer nor the frame plays any role in the predictions. That's the general model that the M&M experiment was trying to measure.

    then, accordingly, the observer should measure the light as having a speed of 1.886c relative to himself and still c relative to the mirror. However, there might be indeed some “apparent” speeds due to the Doppler Effect, but those aren’t real.

    I would be interested in learning more about the scientific jargon...I will try to read up on this more.
    If you accelerate at 10 m/sec² for 100 million seconds, you achieve a rapidity (or proper velocity) of a billion m/sec. You just add 10 a hundred million times.
    But to compute velocity relative to the frame in which you were initially stationary, you add 10 using relativistic addition, all those times. The former adds up to about 3.3c, meaning at that rapidity you move 3.3 light years for every year of your travel. But the velocity is .997c relative to Earth. That sort of illustrates the difference. So if your ship is fast enough, you can cross the 100,000 LY galaxy before you die because there's no upper limit to rapidity.

    here's the link that I told you about concerning the "double star experiement"....I hope it works.
    Doesn't work. It's just a pdf file name without a website in front of it. I tried searching the web for any site containing that file name and got nothing.
    I am interested. Tried googling it, but the name is too generic to get to what you're talking about.
    Sure, 2 orbiting stars will alternate approaching and receding, but that just results in redshift and blueshift. I don't know how they'd decide that the images being looked at departed at the same time, so to speak.
  • Gampa Dee
    46
    Thank you for replying,noAxioms

    I’ve read some things concerning vector additions that I just don’t get, which maybe you could help me out with.
    — Gampa Dee
    Maybe. Don't know the problem.
    You mean the equation a = GM/r² ? I suppose that would need a unit vector to make it into a vector acceleration and not just a scalar. Nothing on the right side as I wrong it is a vector.
    noAxioms

    .... I sent a post concerning this in the “The Newtonian gravitational equation seems a bit odd to me" thread.

    It seems that this would imply the light as having a speed of .5c relative to the mirror
    Well, no. In the scenario I outlined, when moving up it has a speed of .134c relative to the mirror, and in the reverse direction the relative speed would be 1.866. That still presumes light is independent of emitter speed.
    noAxioms

    Ok, I see.

    With emission theory, you'd have to specify the speed of emission, not obvious with a light clock which just reflects the pulse back and forth and has no obvious emission event. I am also unsure what emission theory says about how the speed gets altered when hitting a moving mirror.noAxioms

    I believe that one view is the reflected light (back towards the source from the mirror) having a speed of c relative to the mirror ( new source theory), and therefore a speed of (c+v) relative to the source while going back. However, The other option, I believe, hypnotizes that the light would have a reflected speed of (c+v) relative to the mirror, since it was also the speed of light going towards the mirror. This would make it a speed of (c+2v) relative to the source while going back towards the same.I’m not sure which would be correct through observation.
    Since my thought experiment was the mirror remaining stationary relative to the source, being the same in the M&M experiment, both option would agree, I think.

    If you’re speaking of an observer moving at .866c, relative to the frame of the clock
    I wasn't. I was speaking of the clock moving at .866c relative to the ether. Neither the observer nor the frame plays any role in the predictions. That's the general model that the M&M experiment was trying to measure.
    noAxioms

    Yes; I understand better now.
    I know that the M&M experiment was to try to measure the movement of the earth through the ether, but the particle theory does not have an ether or some other light medium model. Therefore, it would have predicted the nul result because of this....the light was going to be c relative to the whole experiment

    I would be interested in learning more about the scientific jargon...I will try to read up on this more.
    If you accelerate at 10 m/sec² for 100 million seconds, you achieve a rapidity (or proper velocity) of a billion m/sec. You just add 10 a hundred million times.
    But to compute velocity relative to the frame in which you were initially stationary, you add 10 using relativistic addition, all those times. The former adds up to about 3.3c, meaning at that rapidity you move 3.3 light years for every year of your travel. But the velocity is .997c relative to Earth. That sort of illustrates the difference. So if your ship is fast enough, you can cross the 100,000 LY galaxy before you die because there's no upper limit to rapidity.
    noAxioms

    Ok; thank you; I think I see.now.


    here's the link that I told you about concerning the "double star experiement"....I hope it works.
    Doesn't work. It's just a pdf file name without a website in front of it. I tried searching the web for any site containing that file name and got nothing.
    I am interested. Tried googling it, but the name is too generic to get to what you're talking about.
    Sure, 2 orbiting stars will alternate approaching and receding, but that just results in redshift and blueshift. I don't know how they'd decide that the images being looked at departed at the same time, so to speak.
    noAxioms

    I'm going to try the post the whole thing on a separate post and see what happens.
  • Gampa Dee
    46
    ok, that didn't work....for now, I will just copy some extract until we can figure out what can be done.


    The general science journal
    The Double-Star Experiment:
    A Comprehensive Review of de Sitter's 1913 Demonstration

    A. A. Faraj


    Abstract:
    In this review, the key points of the debate between W. de Sitter and M. la Rosa are discussed; and the
    main conclusions of de Sitter's 1913 demonstration are re-examined and compared to the theoretical
    predictions computed on the ballistic assumption, with regard to the velocity of starlight and the orbital
    velocity of binary stars, in accordance with the kinematic rules of the elastic-impact emission theory.

    Introduction:

    The Double-Star Experiment was the primary subject of a long series of exchange between W. de Sitter
    and M. la Rosa, which started in 1913 and ended, based on the published literature, more than a decade later in 1924.

    In spite of the poorly done translations that tend to make the arguments of both sides, and those of la
    Rosa in particular, appear weaker than they actually are, and contrary to the widely held view that de
    Sitter won it, the de Sitter-la-Rosa debate ended up in a tie, in which the supposed winner was forced to move from his initial simple position that the prediction of the Ritz theory violates the laws of Kepler
    [Ref. 1.a], and to take the complicated and less clear position that the Ritz theory, according to its
    Doppler equations, predicts fundamental changes in the spectra of binary stars [Ref. 1.e].

    Throughout the whole debate, W. de Sitter and, to some extent, M. la Rosa as well, had taken it for
    granted that starlight retains, based upon the formal Ritz theory, its original velocity resultant for the
    entire duration of its journey from binary stars to distant observers.

    However, recent and more thorough investigations of this subject indicate quite clearly that the formal
    Ritz theory, based on the published works of W. Ritz himself, is, in fact, a new-source theory, according
    to which starlight loses its initial velocities upon refraction and reflection by intervening materials.
    The distinguishing criterion, here, between a ballistic theory, in which starlight retains its original
    velocities, and a ballistic theory, in which it does not, is very simple:

    Is light, from a stationary source, reflected, according to the ballistic theory in question, from a directly
    approaching mirror, at the combined velocity of (c + v), or at the combined velocity of (c + 2v)?
    If the combined velocity of reflected light, in the reference frame of the laboratory, is (c + v), then the
    ballistic theory, in question, is a new-source theory, in which starlight loses its initial velocities.
    By contrast, if the combined velocity of reflected light, in the reference frame of the laboratory, is (c +
    2v) instead, then the ballistic theory, in question, is an elastic-impact theory, in which starlight does
    not lose its initial velocities.

    Since the combined velocity of reflected light from an approaching mirror, according to W. Ritz, is (c
    + v) relative to the reference frame of the laboratory, the predictions of his formal theory are very
    similar to the predictions of the classical wave theory and those of the Lorentz theory and Einstein's
    theory, with regard to light from binary stars. And so, the entire lengthy debate between de Sitter and
    la Rosa is irrelevant as far as the theory of W. Ritz is concerned.
    Nonetheless, the de Sitter-la Rosa debate is, in itself, interesting and still quite relevant within the
    framework of the elastic-impact emission theory.


    I'm going to stop here, and I could either continue to give you bits and pieces until we can figure out how I can send the whole thing.

    Grampa Dee
  • noAxioms
    1.5k
    I sent a post concerning this in the “The Newtonian gravitational equation seems a bit odd to me" thread.Gampa Dee
    Which I did not immediately see because you didn't reference me (reply to something of mine say) anywhere in it.

    Therefore, it would have predicted the nul result because of this....the light was going to be c relative to the whole experimentGampa Dee
    OK, so the M&M setup isn't the optimal experiment to falsify this particle theory.

    Throughout the whole debate, W. de Sitter and, to some extent, M. la Rosa as well, had taken it for granted that starlight retains, based upon the formal Ritz theory, its original velocity resultant for the entire duration of its journey from binary stars to distant observers. — Faraj
    Given that relativity theory was in its infancy at this time, this is a bold assumption. It's reasonable for inertial frames, but no inertial frame describes the real spacetime between stars. In the accelerating expanding frame that describes the universe at large scales, light speed (the rate at which the proper distance from Earth to an incoming light pulse) is not fixed, is not c. For instance, the light from some of the furthest objects seen by the Webb telescope was emitted from only a bit more than a billion LY away (proper distance), which is a lot closer than the emission distance of the light we see from galaxies closer by. Point is, the assumption they're making up there is not to be made lightly (pun intended).

    If the combined velocity of reflected light, in the reference frame of the laboratory, is (c + v), then the ballistic theory, in question, is a new-source theory, in which starlight loses its initial velocities. By contrast, if the combined velocity of reflected light, in the reference frame of the laboratory, is (c + 2v) instead, then the ballistic theory, in question, is an elastic-impact theory, in which starlight does not lose its initial velocities. — Foraj
    OK, I got that. I know the difference between the two now. They're both wrong, but they didn't know it at the time. Not sure if the spectra of binaries can falsify both since apparently the new-source theory produces spectra very similar to relativity theory (reflected light speed is neither c+v nor c+2v, but just c.

    I could either continue to give you bits and pieces until we can figure out how I can send the whole thing.Gampa Dee
    Check the copyright. Is it legal to paste the whole thing here? You already pasted an email address, which is against the rules for some forums.
    What question do you need answered?
  • Gampa Dee
    46
    Thank you for responding noAxioms

    I sent a post concerning this in the “The Newtonian gravitational equation seems a bit odd to me" thread.
    — Gampa Dee
    Which I did not immediately see because you didn't reference me (reply to something of mine say) anywhere in it.
    noAxioms

    Oops; sorry...my mistake;

    Therefore, it would have predicted the nul result because of this....the light was going to be c relative to the whole experiment
    — Gampa Dee
    OK, so the M&M setup isn't the optimal experiment to falsify this particle theory.
    noAxioms

    Well, if they would have observed some fringe interference, the ether would have been validated, and the particle theory disregarded.
    But, since no interferences were observed, this was to be explained; and so we had Fitzgerald who claimed the ether contracted the measuring rods, or there was the speed of light as being invariant, but the particle theory of light would have also explained the null result.

    If the combined velocity of reflected light, in the reference frame of the laboratory, is (c + v), then the ballistic theory, in question, is a new-source theory, in which starlight loses its initial velocities. By contrast, if the combined velocity of reflected light, in the reference frame of the laboratory, is (c + 2v) instead, then the ballistic theory, in question, is an elastic-impact theory, in which starlight does not lose its initial velocities. — Foraj

    OK, I got that. I know the difference between the two now. They're both wrong, but they didn't know it at the time. Not sure if the spectra of binaries can falsify both since apparently the new-source theory produces spectra very similar to relativity theory (reflected light speed is neither c+v nor c+2v, but just c.noAxioms

    Could you show me the experiments which proves this (reflected light has a speed of c)? I'd be interested..

    Check the copyright. Is it legal to paste the whole thing here? You already pasted an email address, which is against the rules for some forums.
    What question do you need answered?
    noAxioms

    There is no copyright on the copy I have...but I understand that copy and paste might involve some errors...so I won’t copy and paste the whole document.... I’ll continue to read the document and get back at you if I have any questions....thanks..

    Grampa Dee
  • noAxioms
    1.5k
    Could you show me the experiments which proves this (reflected light has a speed of c)? I'd be interested..Gampa Dee
    Experiments rarely prove anything. We cannot, for instance, prove that light speed is c in all directions, independent of frame. Hence it needing to be a postulate instead of something measured.

    Nevertheless, the mirror thing can be falsified. You just have two mirrors in a vacuum in the same place moving relative to each other. Shine a light pulse at it and detect the reflected light from each. If they arrive at the same time (but different wavelength/frequency), then light speed is not a function of the motion of the mirrors. If light from the approaching mirror gets there first, then we need to rewrite the last 130 years of physics.
  • Gampa Dee
    46
    Thank you for responding noAxioms

    Nevertheless, the mirror thing can be falsified. You just have two mirrors in a vacuum in the same place moving relative to each other. Shine a light pulse at it and detect the reflected light from each. If they arrive at the same time (but different wavelength/frequency), then light speed is not a function of the motion of the mirrors. If light from the approaching mirror gets there first, then we need to rewrite the last 130 years of physics.noAxioms

    Did they ever do this experiment? What is it called? It seems that a very simple version would be a cylindrical mirror rotating , where two laser light beams reflecting the rotating mirror, one on each side (mirror moving away on one side and forward the other side).
    My concern would be whether we would have the technology accurate enough to be able to observe
    whether the two light beams would have the same speed or not.

    Grampa Dee
  • noAxioms
    1.5k
    My concern would be whether we would have the technology accurate enough to be able to observe whether the two light beams would have the same speed or not.Gampa Dee
    I have no idea what actually has been done. Yes, the technology is there. What you describe doesn't even change the frequency of the light, so some kind of interferometer would easily measure a speed change involving half a wavelength.
    M&M had that technology 140 years ago, measuring the speed difference over one path vs another, with paths of under 10 meters in length.
bold
italic
underline
strike
code
quote
ulist
image
url
mention
reveal
youtube
tweet
Add a Comment

Welcome to The Philosophy Forum!

Get involved in philosophical discussions about knowledge, truth, language, consciousness, science, politics, religion, logic and mathematics, art, history, and lots more. No ads, no clutter, and very little agreement — just fascinating conversations.