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Time in a Vacuum

  1. Dec 9, 2008 #1
    Just to give everyone a background on my education in these topics (so that you know what level I'm on), I've completed up til physics 3 in college, which covers most basic concepts; In high school I made a hobby of studying various parts of special relativity and quantum mechanics via wikipedia (specifically the Lorentz factor and the paradoxes associated).

    So my question is: does time exist in a vacuum? As I understand it, the passage of time for a mass is a function of the velocity of that mass. Does this mean that no mass implies no time?
    Thank you.
  2. jcsd
  3. Dec 9, 2008 #2
    yes to the first, not necessarily to the second. A traditional vacuum is not "empty" space,if that's what you were thinking, but rather a region of space with at least quantum fluctuations and hence maybe even the abiltiy to spawn an entire new universe; but at least particle and antiparticle pairs...and vacuum energy is always present. If you mean, however, the brief period of time at the dawn of the universe, before mass,energy,space and time emerged from a "bang", maybe there was no time then.

    In relativity, travel at the speed of light implies no passage of proper time; a photon does not age and is massless. But in a region of space with just energy, for example, and no particles, time passes in the classical sense.

    The part of this that is NOT at all clear is whether time,space,mass,energy,etc are all fundamental or whether one is fundamental and the others emergent. In Penrose Twister theory, for example, which is not fully developed, Roger Penrose has fascinating mathematical constucts in which space is constucted from all the lightrays in space time...

    As far as is known, time must exist in order for our universe to evolve;it provides a framwork for change...Without time many of the elementary consitutuents of our universe could not have been produced in stars and supernovas...and the stars themselves would have never even formed....
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