Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

B Light-clock and time dilation [was: Hydrogen atom expressed mathematically]

  1. Nov 26, 2017 #26

    PeroK

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    I'm sorry if that is your attitude. You'll need to find someone else to waste their valuable time trying to teach you something you don't really want to learn.

    Your misapprehensions about this experiment are actually quite common. You shouldn't mistake beginner's errors for insights that a hundred years of professional physicists have missed.
     
    Last edited: Nov 26, 2017
  2. Nov 26, 2017 #27
    Which target will an individual photon hit? Target one or two?

    It is very clear to me now that you can't answer that. You all should not have been sarcastic and condescending towards me at my original question regarding the hydrogen atom, since you are now stumped by my question. Questioning my level of research, etc, in such a way is counter to the purpose of this forum.

    At the end of this, it is clear that you do understand time dilation and so do I. The true issue is, the light clock thought experiment is invalid, which was my original thesis when I asked about the hydrogen atom.

    I predict that you will not answer the question. You will either go silent or make another remark about my attitude, when it was you who started with the attitude at my original post.
     
  3. Nov 26, 2017 #28

    A. Neumaier

    User Avatar
    Science Advisor

    A photon can have a wave function concentrated on many rays simultaneously.
     
  4. Nov 26, 2017 #29
    Agreed. Can you tell me which target an individual photon would hit at T+15?
     
  5. Nov 26, 2017 #30
    IE, I am not questioning special relativity itself, rather, the validity of the light clock thought experiment.
     
  6. Nov 26, 2017 #31
    Key issue - I am talking about just a single photon and where it eventually hits. Target one or target two? Can't be both unless we are talking two photons, in which case we are measuring two different paths of different lengths.
     
  7. Nov 26, 2017 #32

    Ibix

    User Avatar
    Science Advisor

    You may wish to look up "relativistic aberration", which is the phenomenon you are denying occurs.
     
  8. Nov 26, 2017 #33


    Somebody missed something. Which target? 1 or 2?
     
  9. Nov 26, 2017 #34

    Ibix

    User Avatar
    Science Advisor

    Depends on your setup - I think you intend it to hit the blue target, but I'm not completely clear on your setup. Both frames will agree, whichever it is. Google relativistic aberration.
     
  10. Nov 26, 2017 #35
    I am not denying anything. I am asking which target? Can anyone answer?

    I know all these concepts and I know the concepts are correct.

    The only incorrect thing here is the light clock thought experiment, which I have proven invalid. Can anyone prove it valid?

    This experiment works, with matter, but not light.


    upload_2017-11-26_13-51-5.png
     
  11. Nov 26, 2017 #36

    Ibix

    User Avatar
    Science Advisor

    Your diagram seems to be denying it...
     
  12. Nov 26, 2017 #37
    If it hits target 2, then the path is different (and longer) as the photon went at another angle, unless we believe the photon hits both targets.

    I do know that the moving target also experiences time dilation so it would observe the photon hitting target one at a different time.
     
  13. Nov 26, 2017 #38
    Is the path to target two longer or shorter (or the same)
    than the path to target one?

    Does a photon aimed straight up (relative to target one) deflect to follow and strike target one?


    Actually, yes I am denying the validity of the light clock thought experiment.
     
  14. Nov 26, 2017 #39

    Ibix

    User Avatar
    Science Advisor

    Let's analyse this carefully. Don't worry about any movement for a minute. In a frame in which your setup is not moving, which target do you expect to be hit?
     
  15. Nov 26, 2017 #40
    Target 1.
     
  16. Nov 26, 2017 #41
    Actually, in a non-moving experiment, both targets.
     
  17. Nov 26, 2017 #42

    Ibix

    User Avatar
    Science Advisor

    OK. Now will it hit or miss that target when the setup is moving?

    Note that any other answer than "it hits the same target" implies that an observer inside the rig can detect whether or not the rig is moving without referring to anything outside it. That is, you imply the existence of absolute motion, and deny the principle of relativity.
     
    Last edited: Nov 26, 2017
  18. Nov 26, 2017 #43
    If you aim your emitter (laser pointer) at right angle in the emitter's frame, this light pulse will always have the same x - velocity as the emitter. In this case the target and the emitter are always at points of closest approach, or right opposite.
    If you wish to hit a target which was at point of closest approach at the moment of emission, you must aim your emitter (laser pointer) backward at relativistic aberration angle ##\sin \alpha = v/c##
    This video in the youtube shows path of light pulse in different frames.

     
  19. Nov 26, 2017 #44
    If target one moves perpendicular to the source beginning at T-0 at 0.87C, while target two remains stationary, and both targets are 15 light seconds from the emitter at T-0, what target does it hit at T+15 seconds?

    Any answer other than target two implies that we have violated the principle of matter occupying more than one place at the same time.

    I am going to write a paper on this and ask you all to peer review it if you don't mind. My point is, the light clock thought experiment is invalid. Relativity is valid.

    Thanks!
     
  20. Nov 26, 2017 #45

    PeterDonis

    Staff: Mentor

    Yes, it is. Look up relativistic aberration.
     
  21. Nov 26, 2017 #46
    Agreed. Now in this case, the light photon is actually traveling the hypotenuse and will hit the moving target. The observer traveling parallel to it will experience time dilation such that from his view, light remains constant velocity C and gives the appearance of 'straight up' movement within his reference frame.

    Therefore the light traveled at the angle and hits target one. Light projected 'straight up' from the vantage point of the emitter, and per this point of view, will deflect and hit target two. Thus the emission angle makes the difference.
     
  22. Nov 26, 2017 #47

    Ibix

    User Avatar
    Science Advisor

    We've answered this already. Actually, according to your green observer, the pulse hits nothing at T+15 - it's still in flight (towards target 1). According to an observer on the rig it hits target 1 at that time (they have different notions of what "fifteen seconds later" means).
    I've no idea why you think that. The light strikes target 1 and only target 1. I think you need to read up on relativistic aberration, since that explains why target 1 is hit from the perspective of your green observer.
    Since what you are describing is inconsistent with relativity, you may wish to review the rules on personal theories before doing so.
    Those two sentences contradict one another.
     
  23. Nov 26, 2017 #48

    PeterDonis

    Staff: Mentor

    We don't do peer review here. That's not what PF is for. You would need to submit your paper to an actual scientific journal that does peer review. I doubt any journal would accept it since you have a number of obvious misconceptions, but you could try.

    As far as I (or everyone else posting in this thread) can see, your understanding is what is invalid. We've done our best to try to help you, but you are not listening. Therefore, this thread is closed.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook