Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Twin Paradox Theory

  1. Apr 1, 2007 #1
    I know there are a few threds already on this subject, but it seems to me that all of them require preknowlage on the subject busides a wikipedia search wich only seems to tell you that If one twin leave earth vie. space ship, and travels .99c to a Galaxy 2 light years away, turns around, and comes back to earth, around 4 years will have gone by for that person. But because he was moving at the speed of light, time affected him differently, and back on earth, 13 years have gone by.
    Time is relative to speed, the faster you are going, the slower time is, the slower you are going, the faster time affects you. Speed is times medium, just like mass and tempter is sound and light’s medium.
    It would not be possible thought to change your ‘internal clock’ by driving 90 mph down a highway, because compared to the speed of light 90 mph is really quite insignificant.
    Or atlest thats what i got out of it.

    basicly what i want to know, and dont get, is WHY this happens, like what specifically is Earths time speed compaird to the speed of light? -wich seems to me would solve the question, though im not totally sure.

    What happens to Distance at near the speed of light, because there is an object in space going the speed of light, wouldnt it creat a 'curve' space? this might not seems so relevent, but if your going at the speed of light, wouldnt distance become not so relevent, or somthing like that...I dont really know anymore, ive staired at the problem for so long :yuck:.

    And i would also like to understand the effects of traveling near c on mass.
    would it become extreamly dence, or impload? uhh.

    Well if someone would be willing to explain this to me as soon as posible, in the simplest turms posible, I'm only in 9th grade, so i dont have much - if any deep understading of physics.

  2. jcsd
  3. Apr 2, 2007 #2


    User Avatar
    Science Advisor
    Gold Member

    Since speed is relative, you can't make the comparison you are talking about.

    Distance along the direction you are going appears shorter in comparison to something not moving relative to the object you are looking at.

    To the outside observer mass would increase. The moving object does not sense any mass increase.
  4. Apr 2, 2007 #3
    If c is a universal constant for everybody and everywere, then two people travelling at different speeds would measure the speed of light to be c. But as one of them travels quicker than the other, time must be slower if he has to determine the same value for c.

    What it is not known is why c is constant. It is just a theory that has been proven in a number of experiments. One of them: two atomic clocks have been travelling in oposite directions aboard earth satellites. After some time, these clocks have shifted slightly as the relativity theory predicts, while total speed was high but far from c.

    A corollary: time on earth is different from time on faster or slower planets, as each planet is travelling at different speed through space.
  5. Apr 2, 2007 #4

    Claude Bile

    User Avatar
    Science Advisor

    The twins paradox is not really a paradox once you take the effect of acceleration into account.
    Note that from your frame of reference time would not appear to slow down. It would only appear to slow down to other observers' frames of reference.
    It wouldn't be possible because you will always be stationary in your reference frame, not because the speed you are traveling at is small compared to c.

Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: Twin Paradox Theory
  1. The twin paradox (Replies: 1)

  2. Twin paradox and time (Replies: 4)

  3. Twin Paradox and age (Replies: 18)