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Lorentz Factor - Help!

  1. Apr 30, 2007 #1
    I looked up Twin Paradox, and I understand the concept of time in SR, and also understand the Einstein synchronization convention concept, but now there is just something I don't get here:
    I looked at twin paradoxes and apparently you must use the Lorentz factor (or it's inverse, anyway) to figure out the time a specific journey would take on the earth rest frame (or along the lines. Can't put it in words.)
    So, the only thing is, what does each letter stand for in :

    Which I believe is the inverse of the lorentz factor.

    Thanks in advance,
    Santural : Below the average layman.
    Last edited: Apr 30, 2007
  2. jcsd
  3. Apr 30, 2007 #2

    Doc Al

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    Staff: Mentor

    Are asking what v and c stand for? v = speed of the traveling twin (or moving frame); c = speed of light.
  4. Apr 30, 2007 #3
    Right! Thats part of what I need. However:
    Wikipedia says:
    (I added the bold).
    What is that epsilon? Where is 0.5 derived from?
  5. Apr 30, 2007 #4


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    Staff: Mentor

    By plugging numbers into that formula:

    [tex]\epsilon = \sqrt {1 - \frac{v^2}{c^2}} = \sqrt {1 - \frac{(0.866c)^2}{c^2}} = \sqrt {1 - 0.866^2} = 0.5[/tex]

    Or have I misunderstood your question?
  6. Apr 30, 2007 #5
    ......:uhh: hehe...um...:tongue: ....really, just um....hehe...my bad.....

    I guess I was being a LITTLE dumb there, sorry.
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