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What is space

  1. May 6, 2005 #1
    Hi everyone.

    I was just wondering what is space. I know what it is but rather what my question should be is "Is our 4 Dimensional spacetime raped around anything?"

    I have heard that it is curved around a higher dimension, is it true?

    And also was wondering why there is no center to the universe? I asked this question to my teacher and he replied to my question with another question which was "If an ant is around a beachball and we tell it to go to the center of the ball will it be able to do so?" But what I don't get is that the ant is only able to move in 2 dimension (x,y) but in reality we are able to move in 3 dimension (x,y,z) and depending on our velocity through (t). so why cant there be a center to the universe?
  2. jcsd
  3. May 6, 2005 #2


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    At the moment, Einstein's theory of general relativity gives the best explanation and that, as you noted, only includes 3 dimensions of space and 1 of time with no other "higher" or "external" dimensions. That's it.

    If you check out String Theory/M-Theory, then you'll start seeing models which include additional dimensions of space, but so far there is no experimental evidence to verify that these dimensions exist.

    There's no center in ordinary 3D space. If space is infinite, then the no-center concept is fairly easy to accept. (As long as you can accept the idea of an expanding infinity!) If space is finite, then there is no center (there is observational evidence for this) through some mechanism of space curving back on itself. That, granted, is tough to imagine, particularly since Einstein's model does not include additional dimensions of space. Perhaps another member here would like to explain how the universe can do that? :smile:
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