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How many baryons are there in the universe?

  1. Jul 17, 2009 #1
    Many articles and papers say that 4% of all energy in the universe is baryonic. How many baryons does that make? I do not seem to find any wikipedia article or paper that gives an absolute number. Can anybody help?

    Thank you!

    François
     
  2. jcsd
  3. Jul 17, 2009 #2

    George Jones

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    Then number of baryons in the observable universe is usually estimated to be about 1080. See, for example, the solution to problem 6.8,

    http://www.physics.ucsb.edu/~tt/PHYS133/hws5.pdf,

    from Barbara Ryden's excellent book Introduction to Cosmology.
     
  4. Jul 17, 2009 #3

    Nabeshin

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    Coors Cosmology, I like it.
     
  5. Jul 18, 2009 #4

    Chronos

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    Good answer, Nabeshin, whatever that meant. Fran asked for a number, George gave the best current estimate. Do you have a rebuttal or are you just sniping?
     
  6. Jul 18, 2009 #5

    George Jones

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    The document to which I linked calculates the number, and after the calculation writes:

    "*COORS COSMOLOGY*
    The number of baryons in the observable universe is roughly equal to the number of
    baryons in a bottle of beer, cubed."
     
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