Relativity paradox

Discussion in 'Physics & Math' started by renislaj, Apr 18, 2013.

  1. Tach Banned Banned

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    I challenge you to make the rod fall by cutting the suspending wires in zero gravity.
     
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  3. Pete It's not rocket surgery Registered Senior Member

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    There are no wires in the dumbed down scenario. Just a rod moving at constant speed toward the floor.
     
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  5. Tach Banned Banned

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    Then open your own thread on the dumbed down scenario. Stop polluting this thread.
     
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  7. Pete It's not rocket surgery Registered Senior Member

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    So you agree that the dumbed down scenario is not unphysical and is in the domain of SR?
     
  8. Tach Banned Banned

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    No, I don't . It is unphysical, so you can stop trolling. Please go open your own thread, stop polluting this one.
     
  9. Pete It's not rocket surgery Registered Senior Member

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    What is unphysical about a rod moving at constant speed in zero gravity?
    I really don't understand what the difficulty is with the scenario. There's no point in making a thread about a flawed scenario, so I'd like to nail this down first.
     
  10. Tach Banned Banned

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    Like I said, based on your above calculations, I am having a hard time taking you seriously.
     
  11. Pete It's not rocket surgery Registered Senior Member

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    Which line do you disagree with?
     
  12. Tach Banned Banned

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    You can't see? LOL.
     
  13. Pete It's not rocket surgery Registered Senior Member

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    If you see a mistake, I 'd be happy for you to point it out so it an be corrected.
     
  14. Tach Banned Banned

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    Do you want me to redline your mistakes?
     
  15. Undefined Banned Banned

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    But you agree that in either formalism the floor of the train, like the rod, will always appear crooked to the platform observer? If yes then the train floor and the platform surface can never appear level parallel to the platform observer unless you combine frames like I think you did there? I am still confused.


    Edit/ It is also my naive understanding that in SR problems any reasonably weak Gravitational Field can be sliced up into small distances and any "GR curvature" may be effectively ignored (even if initial motion of the rod is due to that field, it need not be a strong acceleration but a weak one)? Wouldn't the same "simplification" eliminating GR from consideration apply to each subsequent small slice of distances to each subsequent position traced along the path line to the floor (or platform or whatever)? I can't see why we can't do this problem like Pete wants and see what we get so I can improve my naive understandings from it.
     
  16. Pete It's not rocket surgery Registered Senior Member

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    Please, point out the mistakes you see, and I'll fix them.
     
  17. Tach Banned Banned

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    No, it wouldn't, please stop hacking at the problem. There are enough hacks in the thread already. See what Neddy Bate tried, see what Pete is trying.
     
  18. Tach Banned Banned

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    Move your post in another thread, dedicated to the dumbed down version and I will be more than happy to point out the mistakes in your math. Honestly, for someone so quick to point out other's mistakes, I am surprised that you have such a hard time seeing your own, they are quite obvious.
     
  19. Fednis48 Registered Senior Member

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    Ok, you disagree. You and Pete are working through the math, so I'll leave you to that. If you can show mathematically that parallel-ness is transitive in SR, I'll immediately concede that I'm wrong about everything.

    But in the mean time, you have yet to respond to post 151 at all. Sorry to harp on that so much, but I rather liked post 151, and it irks me a little to see you ignore it in reply after reply. Without invoking any equations from SR, post 151 shows that if the wires are cut at different times in the platform frame, the rod hits the floor at an angle in the platform frame. Could you please tell me what is wrong with that argument? Or at least acknowledge that I made it?
     
  20. Pete It's not rocket surgery Registered Senior Member

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    To be honest, I haven't double-checked yet. I mistakenly thought it would be quicker if you simply pointed out the mistake/s you found. There are also a few steps I did on paper that I didn't transcribe to tex.

    Now, before I make a new thread, you said earlier that the dumbed-down scenario is unphysical.
    There's no point in making a thread about a flawed scenario, so I'd like to nail that down first.
    What is unphysical about a rod moving at constant speed in zero gravity?
     
  21. Tach Banned Banned

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    It is trivial, the space (not spacetime) of SR is Euclidian. in Euclidian space, parallel-nes is a transitive property.

    I did, you just seem to refuse to accept the answer. As an aside, you and Pete should jointly open a separate thread dealing with the dumbed down scenario that you seem so intent on analyzing. I would like to keep this thread on the OP. Deal?
     
  22. Pete It's not rocket surgery Registered Senior Member

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    I believe I see where you think there's mistake now. I'll add the in-between lines (that change expressions in t' to expressions in t'') so you can see how it works.
     
  23. Tach Banned Banned

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    I think that is telling about your outlook, you are just blind to your own mistakes, I think it would be educational if you made the effort to find them, I narrowed down the post to the lines (not one) containing the mistakes (multiple).
     

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