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Is time slowing down?

  1. Jun 6, 2006 #1
    Since Andromeda is accelerating toward us and since gravity is the only force that acts at a distance, as well as dialates time, then is it possible that the closer Andromeda gets to us, the slower time goes? This may be very farfetched, but I by no means am not a physicist, and this is just a thought.
  2. jcsd
  3. Jun 6, 2006 #2


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    The way gravity affects time is somewhat subtler than that.

    The fact that Andromeda gets closer would modify our measurements of time with respect to an external observer (located outside Andromeda and outside our galaxy). For us, things will not have that much of a difference locally.

    Also, even when we are talking about an enormous mass, the distance is also extremely large, so you can expect a very, very tiny effect.
  4. Jun 12, 2006 #3
    That Andromedda is approaching would have far less effect than the fact that other galaxies are receding due to the expansion of the universe.
  5. Jun 12, 2006 #4
    Yes, it would be relative to the rest of the universe, of course, but I'm not sure that was the point of the question. If the effect would cause time changes to occur slower in relation to the rest of the universe, that would be a real factor, should a catastrophe occur inside or out, to anything that exists long enough that is. What I mean is that if, hypothetically with a capital H, little green men in the distant galaxy, whose civilization decided they'd rather not have humans to spread our dubious values to their planet, might be rather happy to find that we're progressing at a slower speed relative to them, or very unhappy if the other way around.
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