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Question about time

  1. Oct 2, 2011 #1
    hey everyone , so I have this question which has been in my head for a while and maybe someone can answer me.
    So I know that time flows at different rates in our universe, depending on how strong gravity is.So my question is could time have speed limit ..as in if there is a place in our universe which is absent of gravity(which is impossible) will time flow at an infinite rate, or is there a limit?
    If anyone could help It would be great as my physics teachers didnt offer much of an explanation.
     
    Last edited: Oct 2, 2011
  2. jcsd
  3. Oct 2, 2011 #2
    Infinite time is said to be at the singularity of black holes within or at the event horizon from the view point of the observer. As its infinite then there is no uppre limit. a point of notime would be just prior to BB when there is no matter/energy. Or a point in which there is no space as space and time are one and the same. Spacetime
     
  4. Oct 6, 2011 #3
    I would not at all say that space and time are one and the same.
     
  5. Oct 6, 2011 #4

    HallsofIvy

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    Saying that we live in a "four dimensional space- time continuum", as Einstein did, does NOT mean that "space and time are the same".
     
  6. Oct 6, 2011 #5
    With all due respect - this post is pretty much nonsensical.

    You have no authority to talk about the singularities of black holes - it is even postulated that singularities are entirely an artifact of GR and signify the breakdown of fundamental theory and are not a physical reality. If you can provide any sources for these assertations I would be interested to read them.

    You also talk about t=0 which is again without justification or validation. Physics can discuss t>0 and more specifically t>planck, so any assertations you make in relation to initial conditions prior to big bang are completely unfounded.
     
  7. Oct 6, 2011 #6
    It's an interesting question, but I would ask for more detail. By "infinite rate" - do you mean that all the time in the universe goes by in an instant? If this is so, then the question answers itself. Suppose you have found a place where all the time in the universe has gone by in an instant. Wouldn't that place no longer exist before you found it?
     
  8. Oct 6, 2011 #7
    One approach to grappling with the concept of space and time would be to first imagine the universe as a 4-dimensional space populated by 4-dimensional objects. The whole 4-dimensional universe is just there--all at once. This assures that you begin with a distinct separation of space and time into two separate concepts. This concept goes by the name of "Block Universe" and was suggested by Einstein's colleague, Kurt Godel (many physicists feel like Einstein embraced this concept--he just never liked to discuss it openly because of some of the bizarre implications).

    Now, put in consciousness moving along the 4th dimension at the speed of light. So, in some sense, the time comes in with the consciousness.

    I think Passion Flower has suggested in another post that you have consciousness present simultaneously, over the entire extent of an observer's 4-dimensional matter structure (bundles of neurons strung out along the 4th dimension), and the experience of time flowing is a psychological illusion.

    Special relativity seems more directly to imply the well known model in which all observers move along their respective 4th dimensions at the speed of light. This results in some difficult implications upon close scrutiny, so the ideas from Passion Flower's post would seem to work better.

    These ideas of space and time have been kicked around in several different special relativity topics.
     
    Last edited: Oct 6, 2011
  9. Oct 7, 2011 #8
    Hi Karl, welcome to physicsforums. :smile:

    I think that there should be a straightforward answer to your question.
    Your question can, I think, be reformulated as asking if the speed of light goes to infinite (as inferred from our reference system) in the absence of gravitational fields - just consider the operation of a light clock. Without relying on theory, my common sense intuition tells me that the speed of light will certainly not go to infinite.

    Now, the question to ask here if of course what GR predicts.
    Here is my 1 ct, based on my very limited knowledge of GR:

    The relevant equations are (approximately?) of the form (1 + a/r). That suggests that far from bodies, with r->∞, those terms do not go to 0 but to a "rest" value.

    I hope to incite with that a correction (or elaboration) by someone with a thorough knowledge of GR. :tongue2:
     
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