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

Why oh why?

  1. Jul 18, 2004 #1
    why the Universe was at a small point? Is this point like super small like.

    Plank length

    Or just any size smaller then Planck Length? To be undefinable.

    Why couldn't the universe just all of a sudden be created right where it is, in all the same motions as everything is in.
  2. jcsd
  3. Jul 18, 2004 #2
    Im sorry i dont understand want you point is.
  4. Jul 19, 2004 #3


    User Avatar
    Science Advisor

    The main reasoning behind the idea that the universe was once a small point is based on the redshift. The shifting of light toward the red end of the spectrum is taken by most coamologists to mean that the stars emitting this light are moving away from us. The more distant a star is, the more red-shifted its light; meaning that the more distant stars are moving away faster. This produces the image of a universe that is expanding. If the universe is exanding, then it is bigger today than it was yesterday. Therefore, it was smaller yesterday than it is today, and the day before yesterday it was smaller still.

    If this line of reasoning is taken back far enough, we get to a point when the universe was very very small.
  5. Jul 19, 2004 #4


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Till you get to a point where the universe ends up being so small that the physics we have is inadequate to explain it. Such a state is refered to as a singularity.

    To actually question the scale of size is meaningless unless you are a string theorist or particle astrophysicist.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook