Bug-rivet paradox

Discussion in 'Physics & Math' started by DaleSpam, Mar 4, 2006.

?

According to SR, what is the final result of the bug-rivet scenario?

  1. Both frames agree, the bug doesn't get squished.

    10.0%
  2. Both frames agree, the bug gets squished.

    80.0%
  3. The two frames disagree.

    10.0%
  1. Dawoool Registered Member

    Messages:
    1
    I am the guy who dreamed up the paradox. I was in Dr. nave's modern physics, and he showed us the pole-barn paradox. I thought up the bug-rivet paradox as a more challenging version, then asked Dr. Nave and the rest of the class what happens. He couldn't answer at the time, but he put it on his website. I never anticipated the life my question would take on.
     
  2. Google AdSense Guest Advertisement



    to hide all adverts.
  3. origin Trump is the best argument against a democracy. Valued Senior Member

    Messages:
    9,993
    The question seems to have died, at least here, over 10 years ago.
     
  4. Google AdSense Guest Advertisement



    to hide all adverts.
  5. James R Just this guy, you know? Staff Member

    Messages:
    30,642
    What's your view on the problem, Dawoool?

    Thanks for the interesting scenario, by the way. And welcome to sciforums.
     
  6. Google AdSense Guest Advertisement



    to hide all adverts.
  7. Q-reeus Valued Senior Member

    Messages:
    2,605
    The paradox is ill-conceived imo. The faulty and unstated premise being the rivet is infinitely stiff, which contradicts relativity at the outset.
    Nevertheless no-one bothered to consider a frame in which bug-in-hole and rivet have equal and opposite velocities. In that frame, it's manifestly obvious the bug is safe - IF the fantasy of an infinitely stiff rivet (and hole) is assumed.
     
  8. DaveC426913 Valued Senior Member

    Messages:
    7,227
    That is the solution to the paradox.

    It is not obvious that rigidity is the crux of the issue. Not until you have the answer.
     
  9. Q-reeus Valued Senior Member

    Messages:
    2,605
    Ah good! I also learned as an aside that one or two current notable names in another forum signed up here many moons ago....
     
  10. paddoboy Valued Senior Member

    Messages:
    21,647
    http://math.ucr.edu/~jdp/Relativity/Bug_Rivet.html
    THE PARADOX: Is the bug touched by the rivet? Yes --- before the collision in one frame and after the collision in the other frame! In fact, special relativity requires that after collision, the rivet shank length increases beyond its at-rest length d. To require rigidity and to reject "rivet-stretching," is to accept the fact that the future affects the present.



    http://hyperphysics.phy-astr.gsu.edu/hbase/Relativ/bugrivet.html





    http://www.engr.mun.ca/~ggeorge/astron/BugRivet.pdf
     
  11. Q-reeus Valued Senior Member

    Messages:
    2,605
    Which then morphs into a 'real-world counterexample' to a so-called Tachyonic antitelephone: https://en.wikipedia.org/wiki/Tachyonic_antitelephone
     
  12. paddoboy Valued Senior Member

    Messages:
    21,647
  13. Elohist Registered Member

    Messages:
    24
  14. origin Trump is the best argument against a democracy. Valued Senior Member

    Messages:
    9,993
    ....
     
  15. James R Just this guy, you know? Staff Member

    Messages:
    30,642
    What's "..."?
     
  16. DaveC426913 Valued Senior Member

    Messages:
    7,227
    Passive aggression?

    Please Register or Log in to view the hidden image!

     
  17. James R Just this guy, you know? Staff Member

    Messages:
    30,642
    The only other poster who I have seen doing that regularly is dmoe.
     
    DaveC426913 likes this.

Share This Page