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Twins paradox

  1. Apr 18, 2005 #1
    why is it a paradox? it makes sense to me.
  2. jcsd
  3. Apr 18, 2005 #2
    Yes, in my opinion it is not a paradox at all. I mean, what is so hard about believing that time could slow down for your twin? :rofl:
  4. Apr 18, 2005 #3


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    It's more of a pseudoparadox -- depending on the situation, it either reveals a mistake in the application of relativistic facts, or a flaw in the way one thinks about the problem.
  5. Apr 18, 2005 #4
    Someone502 - if you don't understand why someone might think it's a paradox, then there's a decent chance you probably don't understand the underlying issues as well as you might think you do. If one has never seen the twin paradox before, then resolving it is not necessarily obvious.
  6. Apr 18, 2005 #5


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    The Stages of Twin Paradox understanding:

    1. Wait, how can one twin be younger than the Other?
    2. Oh, I see, time runs slower for the twin that actually moves.
    3. Wait a minute, there is no absolute motion so the traveling twin can say that his brother was moving, so each Twin sees the other as younger. How is this possible?
    4. Oh, now I see, its the twin that accelerates that ages slower, so its acceleration that causes time to run slow.
    5. Hold on, experiments show that acceleration in of itself does not cause clocks to run slow.
    last stage. Actual understanding of the "paradox" and its resolution Through incorporating time dilation, length contraction, the Relativity of Simultaneity and changing frames.

    Unfortunately, many people get stuck at one of the stages before the last one.
  7. Apr 19, 2005 #6
    yeah well the paradox is mainly what Janus mentioned. How do you know which twin is actually in motion? Remembering motion is relative. Thus either twin will see the other twin as younger. Hence the twin paradox.

    ITS INSANE!!!! :rofl:
  8. Apr 19, 2005 #7
    Nice. And the last stage is by no means trivial to understand for a student of relativity.
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