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Quick Question about Gravity

  1. Jun 7, 2004 #1
    I'm sure that someone has already asked this question, but I can't find an answer for it, so here goes. If I sound like an idiot...well, whatever. :smile:

    If gravity is an acceleration (10 meters per second per second, etc.), then, if you "fell" far enough, would you eventually accelerate beyond c? If you can't, does that mean that the acceleration becomes nothing at c? And if so, doesn't that mean there is no gravity at c (because there is no acceleration), which wouldnt' work because then light wouldn't be affected by gravity, would it? If that was the case, is it possible that light itself isn't actually traveling at quite c?

    Sorry if this is a bit convoluted, and I'm sure its a simple answer, but it's driving me crazy. :yuck: Please help.
  2. jcsd
  3. Jun 7, 2004 #2


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    The acceleration relative to you, would always be the same. Relative to some fixed outside frame the acceleration would taper off as you got close to c.
  4. Jun 7, 2004 #3
    The question has an interesting facit - if you were accelerated by some constant external force other than a G field, as you approached the velocity of light your effective inertia would increase so that your acceleration would asympotically wane to zero. But in a G field, as your inertia increases, so does the attractive force due to the increased mass (according to Einstein). So things become undefined since at c,
    a = F/m = infinity/infinity
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