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Big Bang

  1. Mar 12, 2012 #1
    In school we are talking about the big bang, and it made me think. What if the cause of the bang was from a group of galaxies before us, very similar to us, and it was expanding just like our, but then we hit a "border", which caused a reverse action. Making that universe compact together and get so tight that it created a very large expansion, which we call the big bang theory.
  2. jcsd
  3. Mar 12, 2012 #2


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    Welcome to PF!

    No one really knows why the Big Bang happened or if there was a "before", but one possibility is that the universe oscillates between expansion and contraction and "before" its current incarnation was another universe that collapsedin on itself, starting the cycle again.

    However, at the moment it is believed that the universe is expanding too fast for that to be a likely model.
  4. Mar 13, 2012 #3
    My personal favorite theory on what happened before the big bang involves a truly infinite universe in which there are infinite big bangs that explode a certain points, and expand outward to eventually crash into each other. This allows for each big bang to accelerate as quickly as ours is right now, but also allows for a re-coallescense of matter at a certain point in the future to generate more big bangs.

    Just a fun thought.
  5. Mar 13, 2012 #4


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    Just a note, it's fine to hold your own opinions and beliefs about topics science hasn't (or cannot) shed light on, but don't delude yourself into thinking they have any predictive power. In the absence of very advanced and speculative physics and mathematics, it's just as justifiable to say that when two of these 'regions' collide they generate pink unicorns.
  6. Mar 13, 2012 #5
    I'm well aware :) Any speculation as to what happened before our big bang is only that. I apologize for my loose usage of the term "theory".
  7. Apr 29, 2012 #6
    is it possible that the big bang was caused from the first supernova which formed with every gas cloud there was creating an unimaginably large star
  8. Apr 29, 2012 #7


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    In short, no. Nothing about this agrees with our observations and models of the universe.
  9. Apr 30, 2012 #8
    Why doesn't it agree with the current observations, what are they?
    Last edited: Apr 30, 2012
  10. Apr 30, 2012 #9


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    Where to begin ....

    You really should read some actual cosmology. You might find it interesting.
  11. Apr 30, 2012 #10


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    Read the following threads: https://www.physicsforums.com/forumdisplay.php?f=206 [Broken]
    Last edited by a moderator: May 5, 2017
  12. Apr 30, 2012 #11


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    Usually, scientists assume the most simple explanation, until some evidence comes along that disproves it. At the moment, the most simple explanation (that is yet to be disproved) is the big bang theory. Which is why it is generally accepted.
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