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

Information Transfer and the speed of light

  1. May 27, 2010 #1
    Hi, I have a question about the transfer of information at speeds faster than c. I have devised a thought experiment in order to express the logical problem I am having.

    Suppose you have a string of beads in a tube from here to alpha centauri where each bead in the tube touches the next sequential bead in the tube and so on. Now suppose you place a bead into the earth side of the tube forcing the bead on the end of the alpha centauri side out of the tube. Would one have effectively transfered information faster than light?
     
  2. jcsd
  3. May 27, 2010 #2

    mgb_phys

    User Avatar
    Science Advisor
    Homework Helper

    The push from one side of a bead to the other travels at the speed of sound through the bead.
    It's the same as the old push a lightyear long rod proposal.
     
  4. May 28, 2010 #3

    HallsofIvy

    User Avatar
    Science Advisor

    What your thought experiment proves is that, in relativity, there cannot be "perfectly rigid" objects. As each bead presses against the other, it compresses slightly. That is the "push" mqb phys is talking about.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook