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A computer teacher on a physics roll here?

  1. May 1, 2004 #1
    A certain teacher at my school who teaches compters always says "Magnetism is the future". He says that by utilizing the magnetic fields of planets as "energy boosts or a trampoline" for travel at c+. I explained this is impossible, according to SR a while back, but I backed off (because he was very determined in his idea). But now, I need a really compelling arguement. So, anyone here want to help?
  2. jcsd
  3. May 1, 2004 #2
    Sure. Try this: Alright, suppose you somehow manage to extract energy from a magnetic field by allowing it to accelerate a charged particle. Even better, a stream of charged particles carrying a message in binary. Suppose it travels at 1.2c and arrives in the radios of some friendly aliens at Proxima Centauri, about 4 light years distant. They, then, observe an effect (the signal) preceeding a cause (the use of the magnetic field to send the signal), which is of course impossible.

    In a good SR text book, there are more elaborate examples of why superluminal travel is impossible.
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