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The ever expanding universe?

  1. Nov 16, 2006 #1
    I recently read in my "10th grade" physics textbook that the universes is constantly streaching making solarsystems farther apart, yet for some weird reason all objects still stay intact. This explination included ireverence for such fundimental concepts as the cartisian coordinate system. I was wondering, is there any reason why space has to streach, could it not be true, instead, that everything was getting smaller, everything constantly falling in on itself? This would make the explination make more sence, the only thing that my modle does not account for that I know of, is that my physics text book used the streaching model to explain the bending of light.

    Can someone with some knowledge of this tell me what an idiot I am and how I simply need to ignore the normal rules of reality in order to understand this level of physics?
  2. jcsd
  3. Nov 17, 2006 #2


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    No, your model wouldn't work. It isn't just that things are appearing smaller and we mistake that for moving away. The actual speed they are "moving away" is detectable with the Doppler Effect (google that), a shift of the light coming to us from the remote galaxies. Lots of people have tried to work out alternatives to the stretching, such as "tired light", but all these efforts have turned out to have wrong consequences, and the expanding universe, after 75 years of this, remains the last theory standing. Stretching is happening and is even acclerating! NASA just held a press conference yesterday to announce that work on the Hubble Space Telescope had now shown that the acceleration of the stretching has been going on since very early stages of the universe.
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