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Thread: Box speed of light paradox

  1. #1
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    Box speed of light paradox

    Setup:
    Observers A and B are in a box 1 m cubed, which has holes at its ends. A and B are at the holes.
    An Orange and Green clock enters the box through one hole and A takes a picture. The photo shows both clocks read 0 seconds. Apart from colour, both seem identical and move side-by-side at 1 atom apart.
    Light from the flash passes the clocks and reflects back from the other end towards them.
    Observer B records both clocks having the same time as they leave the box.
    The clocks move at one meter per second past A and B. And as far as the observers can tell the clocks move in a straight line.

    Task:
    The observers are tasked with preparing a report on the speed of light with respect to (wrt) them and the clocks.

    Report:
    They conclude that both clocks travel in a straight line at 1m/s.
    Both clocks read the same time.
    Special relativity theory says that the speed of the light flash is constant inside the box.
    Wrt A and B the speed at which the clocks move away from and towards the light flash is c-V and c+V respectively.
    Special relativity says that the speed of the light flash towards and away from the clocks is c (the clocks can be considered as moving observers).

    Paradox: I will add more information from outside the box that will create a paradox within the box. Before I do that, is there anything missing/wrong with their report?

  2. #2
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    well the first error is your following statement:

    Wrt A and B the speed at which the clocks move away from and towards the light flash is c-V and c+V respectively.
    with light speed, velocities do not add up like that.
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    Bi-weekly space physics research "blog" at tusenfem.blogspot.co.at

  3. #3
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    Quote Originally Posted by wisp View Post
    Wrt A and B the speed at which the clocks move away from and towards the light flash is c-V and c+V respectively.
    Special relativity says that the speed of the light flash towards and away from the clocks is c (the clocks can be considered as moving observers).
    What is "Wrt" supposed to stand for?
    How can you write two sentences which are in complete contradiction to each other?
    Special Relativity does not only state the the speed of light is constant (=c), but that nothing can move faster than the speed of light... c+V does not exist...

  4. #4
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    Quote Originally Posted by wisp View Post

    Report:
    1. They conclude that both clocks travel in a straight line at 1m/s.
    Both clocks read the same time.
    OK

    2. Special relativity theory says that the speed of the light flash is constant inside the box.
    Ok
    3. Wrt A and B the speed at which the clocks move away from and towards the light flash is c-V and c+V respectively.
    What gives you this idea?


    Paradox: I will add more information from outside the box that will create a paradox within the box. Before I do that, is there anything missing/wrong with their report?
    The "paradox" is created by your statement no.3. As already observed by two other posters, your statement is wrong. There is ample experimental disproof of your statement, so , if this is your ATM, it is DOA.
    Last edited by macaw; 2009-May-24 at 06:53 PM.

  5. #5
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    WRT = With Regard To.

    Fred
    "For shame, gentlemen, pack your evidence a little better against another time."
    -- John Dryden, "The Vindication of The Duke of Guise" 1684

  6. #6
    Quote Originally Posted by wisp View Post
    Report:
    They conclude that both clocks travel in a straight line at 1m/s.
    Both clocks read the same time.
    Correct.

    Special relativity theory says that the speed of the light flash is constant inside the box.
    Correct.

    Wrt A and B the speed at which the clocks move away from and towards the light flash is c-V and c+V respectively.
    Correct if you mean that according to A and B, the difference between the speed of the flash and that of the clocks is c-v and c+v, not the speed of the flash itself of course, which it looks like you do.

    Special relativity says that the speed of the light flash towards and away from the clocks is c (the clocks can be considered as moving observers).
    According to observers moving with the clocks themselves, yes, this is also correct.

    So everything seems fine so far, and all statements are correct, but there is no paradox because as other posters have mentioned, velocities do not add when changing perspectives as the speeds are measured between one frame of reference and another in special relativity and all observers will measure the speed of light itself as c.

  7. #7
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    Quote Originally Posted by tusenfem View Post
    well the first error is your following statement:



    with light speed, velocities do not add up like that.
    According the the rules of SR you are right. However, I kept the speed 1m/s low to make the maths in the argument simple.

    Thanks for pointing this out.

  8. #8
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    We have received a report from the other side of the universe that one of the clocks is on a continuous circular orbit almost infinite in diameter. However, inside the box they cannot distinguish between the clocks’ trajectories.

    One clock must record the speed of the light flash towards and away from it as c-1 and c+1 respectively. This is the sagnac effect, which has been experimentally verified many times to great accuracy. But, special relativity says that the clocks records the speed of the light flash towards and away from it as c.

    The box paradox is: Inside the box one clock reads lights speed as c+/-1 and the other as c. However, inside the box the clocks and their trajectories appear identical. It could be argued that outside the box there is no paradox, but something is wrong inside. Do the clocks in the box see the light’s speed as c+/-1 or c? Or both?

  9. #9
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    Quote Originally Posted by wisp View Post
    According the the rules of SR you are right. However, I kept the speed 1m/s low to make the maths in the argument simple.

    Thanks for pointing this out.
    You didn't answer the challenge that your theory is false for larger speeds. In order to be correct, a theory needs to work under all conditions.This means that your theory is DOA.
    Please answer the above challenge.

  10. #10
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    Quote Originally Posted by wisp View Post
    We have received a report from the other side of the universe that one of the clocks is on a continuous circular orbit almost infinite in diameter. However, inside the box they cannot distinguish between the clocks’ trajectories.

    One clock must record the speed of the light flash towards and away from it as c-1 and c+1 respectively.
    No, it doesn't. It records c. Exactly. You are trying to build one false thing on a false assumption.



    This is the sagnac effect, which has been experimentally verified many times to great accuracy.
    It isn't the Sagnac effect. You do not know what the Sagnac effect is. This is clear.



    The box paradox is: Inside the box one clock reads lights speed as c+/-1
    No, it isn't.

  11. #11
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    Quote Originally Posted by wisp View Post
    According the the rules of SR you are right. However, I kept the speed 1m/s low to make the maths in the argument simple.

    Thanks for pointing this out.
    You are trying to construct a false theory on a false assumption.
    The SR speed composition rule is :

    v2=(v1+w)/(1+v1*w/c^2)

    v1 is the speed wrt frame F1
    v2 is the speed wrt frame F2
    w is the speed between frames

    If you make v1=c you get v2=c.

    So, for light speed you never get your addition. End.

  12. #12
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    Quote Originally Posted by wisp View Post
    We have received a report from the other side of the universe that one of the clocks is on a continuous circular orbit almost infinite in diameter. However, inside the box they cannot distinguish between the clocks’ trajectories.

    One clock must record the speed of the light flash towards and away from it as c-1 and c+1 respectively. This is the sagnac effect, which has been experimentally verified many times to great accuracy. But, special relativity says that the clocks records the speed of the light flash towards and away from it as c.

    The box paradox is: Inside the box one clock reads lights speed as c+/-1 and the other as c. However, inside the box the clocks and their trajectories appear identical. It could be argued that outside the box there is no paradox, but something is wrong inside. Do the clocks in the box see the light’s speed as c+/-1 or c? Or both?
    As has already been pointed out, in SR, all inertial observers will measure the velocity of light in a vacuum to be c. Does your example require non-inertial observers?

  13. #13
    Quote Originally Posted by wisp View Post
    One clock must record the speed of the light flash towards and away from it as c-1 and c+1 respectively. This is the sagnac effect, which has been experimentally verified many times to great accuracy. But, special relativity says that the clocks records the speed of the light flash towards and away from it as c.
    In the same way as only the box observers measure the difference in the speed of light and that of the clocks as c-v and c+v, while observers moving with the clocks do not, but always at c, it also applies to the Sagnac effect. It will be measured by an inertial observer that light is travelling at c-v and c+v relative to a rotating apparatus, but to observers moving with the clocks or rotating with the apparatus, the speed of the light is still measured at c.

  14. #14
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    Suppose there is a photon travelling on a large sagnac ring on the other side of the universe, and there were several clocks travelling through the 1m box at speeds 1,2,3,4, m/s etc. In order for relativity to explain things, that photon would be seen to behave differently for each clock, otherwise the approach speeds would be c+1, c+2, c+3, c+4, etc.

    The photon can have no influence on the clocks on the other side of the universe, and so each clock must independently influence the path the photon takes. The maths of relativity does explain this, but this is illogical, and it can’t be real. It’s just maths.

    Interestingly relativity doesn’t allow oneway light speeds to be measured – light speed is postulated and then defined. In reality the real speed could simply be c+/-v.
    In the observers A,B frame, speeds c+v, c-v are possible. It makes no sense making rules that prevent this being this applying to the moving clocks' frame.

    To quote L. Essen. Wireless World 1978 - Relativity and time signals. "the continued acceptance and teaching of relativity hinders the development of electromagnetic theory".

    I agree.

  15. #15
    Quote Originally Posted by wisp View Post
    [Snip!]To quote L. Essen. Wireless World 1978 - Relativity and time signals. "the continued acceptance and teaching of relativity hinders the development of electromagnetic theory".

    I agree.
    wisp agrees while typing this old worn-out, discredited quote of Essen's into a computer powered by electricity, sending said message over the Internet via numerous phone cables and possibly several satellite jumps, despite the hindrance of "acceptance and teaching of relativity". My, my.

  16. #16
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    Quote Originally Posted by wisp View Post
    Suppose there is a photon travelling on a large sagnac ring on the other side of the universe, and there were several clocks travelling through the 1m box at speeds 1,2,3,4, m/s etc. In order for relativity to explain things, that photon would be seen to behave differently for each clock, otherwise the approach speeds would be c+1, c+2, c+3, c+4, etc.
    You continue to make the same error. In physics, speed of light does not add
    the way you think.

    The photon can have no influence on the clocks on the other side of the universe, and so each clock must independently influence the path the photon takes. The maths of relativity does explain this, but this is illogical, and it can’t be real.
    This is an empty statement. You are challenged to back it up.

    Interestingly relativity doesn’t allow oneway light speeds to be measured – light speed is postulated and then defined. In reality the real speed could simply be c+/-v.
    Prove it.

  17. #17
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    I'm confused: Special relativity is special: It can't be used when either source is traveling in an arc; it is only applicable to linear velocities in the absense of gravational effects...meaning it is only an approximation anywhere.

    Meanwhile, there is NO accepted marraige between quantum physics and relativistic physics, so any claim of a paradox is incredibly self evident: quantum mechanics can't reconciliated with general relativity.

    So while Wisp's argument is flawed, the results are irrelavent: There are known degenerative situations in mainstream theory, and this is one of them.

  18. #18
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    Quote Originally Posted by Jerry View Post
    I'm confused: Special relativity is special: It can't be used when either source is traveling in an arc; it is only applicable to linear velocities
    This is not correct, SR has a whole chapter dedicated to accelerating frames (called hyperbolic motion) and another chapter dedicated to rotating frames. There is a whole book dedicated to SR in rotating frames. I can recommend it to you.



    Meanwhile, there is NO accepted marraige between quantum physics and relativistic physics,

    This is incorrect as well, QFT is the application of SR to quantum mechanics.


    so any claim of a paradox is incredibly self evident: quantum mechanics can't reconciliated with general relativity.
    This is just half-correct, there is no quantum interpretation of GR at the present. This is what the string/brane theories are attempting to do.

    So while Wisp's argument is flawed, the results are irrelavent: There are known degenerative situations in mainstream theory, and this is one of them.
    Wisp has more basic misunderstandings, his have nothing to do with the reconciliation between GR and QM. Yours are different yet, see above.
    Now, do you have an ATM of your own? Because it looks like you are attempting to hijack the thread and this is a no-no.

  19. #19
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    Quote Originally Posted by Jerry View Post
    I'm confused: Special relativity is special: It can't be used when either source is traveling in an arc; it is only applicable to linear velocities in the absense of gravational effects...meaning it is only an approximation anywhere.

    Meanwhile, there is NO accepted marraige between quantum physics and relativistic physics, so any claim of a paradox is incredibly self evident: quantum mechanics can't reconciliated with general relativity.

    So while Wisp's argument is flawed, the results are irrelavent: There are known degenerative situations in mainstream theory, and this is one of them.
    Not true, SR can deal with acceleration. Do you think that they use GR when designing and operating synchrotron radiation sources?

  20. #20
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    Quote Originally Posted by wisp View Post
    ... almost infinite in diameter.

    O
    Nothing's "almost" infinite in diameter.

  21. #21
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    Quote Originally Posted by Fortis View Post
    Not true, SR can deal with acceleration. Do you think that they use GR when designing and operating synchrotron radiation sources?
    This was first year stuff at college, special relativity in an accelerating frame. Yes, you need to do a tiny bit more maths, but nothing unusual. We all sat there as eighteen year olds running through the proofs and the worked examples, and no contradictions emerged, nothing weird happened.

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