Monday, August 13, 2012

Time Is But a Measure of Change


I saw another episode of the thought provoking TV-series Through the Wormhole, and here I go again: this time about time. I doubt that it exists as an entity of its own. It's just a convention we choose in order to note and measure change. That's all there is: change.


The essay has been moved to my personal website:

Time Is But a Measure of Change


kl. 2:18 PM
Etiketter: , ,

12 comments:

  1. michaelAugust 13, 2012 at 3:44 PM

    If you travel at the speed of light,
    time would stretch out infinitely for an outside spectator,
    not for the person traveling at the speed of light.

    Time is a line from the past to the future.

    Yes, but what if time has two or more dimensions?
    Then thoses virtual particles popping in and out of existence
    would not seem so strange?

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    Replies
    1. Stefan StenuddAugust 13, 2012 at 4:17 PM

      What would be the time experience of somebody traveling at the speed of light?

      In a multidimensional universe, surely time can have a couple of them. That would mean the possibility of shortcuts and traveling just about anywhere in time.

      Delete
    2. michaelAugust 13, 2012 at 5:10 PM

      Time slows down when you approach the speed of light.
      This is because atomic particles don't decay as quickly near the speed of light.

      But to reach the actual speed of light that requires an infinite amount of energy.
      Alcubierre drive might solve the problem,
      but for that to work we need negative energy, whatever that is?


      Delete
    3. Stefan StenuddAugust 13, 2012 at 6:38 PM

      Of course, according to present physics we can't travel at the speed of light. It wouldn't be a pretty sight if we tried.

      But how about light - does it age at all? If not, it reamins in an eternal present.

      Delete
    4. michaelAugust 13, 2012 at 7:18 PM

      A photon is massless, this is why it can travel at lightspeed.
      So the question is can something without mass age?

      Delete
    5. Stefan StenuddAugust 13, 2012 at 11:46 PM

      My impression is that light is massless because the law of relativity demands it of something with that speed. But it has mass in the sense that it's affected by gravity. I might misunderstand.

      Anyway, the question is if something without mass can change. If it can, this might be possible to describe as ageing. If it can't, then it can't age either.

      Delete
    6. Stefan StenuddAugust 15, 2012 at 9:34 PM

      I found the formula for time in relation to velocity, on the NASA website:

      "The standard equation for 'time dilation' is that the time passing on Earth will equal the time on the object * 1/sqrt(1-((v*v)/(c*c))), where v is the velocity of the object and c is the speed of light. At v=c this goes to infinity, or in other words, time would stop for an object moving at the speed of light. This is not a problem because objects can't go at the speed of light -- it would take an infinite amount of energy (and their mass would also become infinite).
      Dr. Eric Christian"

      So it seems that to photons it's an eternal now.
      Also, isn't the formula surprisingly simple and elegant?

      Delete
  2. michaelAugust 13, 2012 at 4:01 PM

    This comment has been removed by the author.

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    1. michaelAugust 13, 2012 at 4:13 PM

      The existence of an arrow of time does not rule out a flow of time.
      Logically, however, if time did flow, it need not be in the direction indicated by the arrow.
      Time could flow from future to past, and an observer would then
      see events "going backwards" relative to our own experience of the world.

      Or in Einsteins own words:

      "The distinction between past, present, and the future is
      only a stubbornly persistent illusion."

      Delete
    2. Stefan StenuddAugust 13, 2012 at 4:18 PM

      Maybe time is flowing backwards in our universe. How would we notice it?

      Delete
    3. michaelAugust 13, 2012 at 5:13 PM

      I guess we would not notice it, because we
      have nothing to compare with?

      Delete
    4. Stefan StenuddAugust 13, 2012 at 6:36 PM

      That's my guess, too. Time going this way or that makes no difference for those enclosed by it.

      Delete

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