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

Space Ends

  1. May 18, 2010 #1
    Does space go on forever,

    or does space end?

    There is a "big" difference, if any way you go space goes on forever or if any way you go space ends.

    What is a "big" difference between those two ideas?

    If space goes on forever any way you go, space does not have a shape.

    If space ends any way you go, then space can take a shape.

    Space can take a shape, if space ends.

    There is another "big" difference whether space ends or not. Can you think of what that is?

    You may tell people about this.

    Robert Lavelle
  2. jcsd
  3. May 18, 2010 #2


    User Avatar
    Science Advisor

    Bear in mind that because our universe is expanding, it has a horizon beyond which we cannot see and will never be able to see. So it appears that we will never know the answer to your question.
  4. May 18, 2010 #3


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Can you find the "end" of the surface of a balloon? Does a balloon have a shape?
  5. May 18, 2010 #4
    I was just thinking of Carl Sagan when I read this post.

    Space can indeed appear to go on forever from within, but still have a shape from the outside. Space can be curved into a 4th physical dimension but appear flat to us.
  6. May 18, 2010 #5
    Where do you come up with the idea that the is like a ball and space is on the outside of it, that way you only move in 2 dimentions not three
  7. May 18, 2010 #6
    And`if you wrap a 3d shape around a 4th, you can move in 3d. However anyone with three working braincells knows that that was an analogy. I detect you are either deliberately not getting it to be awkward. Or you are a troll.

    Enjoy not being around for long.
  8. May 18, 2010 #7


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    The balloon is an analogy, our universe can have higher dimensional shape that we, stuck in 3d cannot sense.
    Aren't you the one speculating about things which you have no practical basis for? I am attempting to show you that you may not have all the information necessary to make the claims you are making. Common sense means nothing in these matters, here on earth we simply do not have the experiences necessary to logically understand the larger universe. To even think about the shape of the universe we must correlate our observations with a mathematical model. Have you used either?

    It must be nice to imagine that you have full knowledge of the universe and that everything you observe from your kitchen table applies exactly.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook