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Question about the Planck spaces and observable universe, please help.

  1. Jun 26, 2013 #1
    From Wikipedia:

    A Planck space has a volume of a Planck length cubed, which is the smallest measurable volume, at approximately 4.222×10^-105 cubic meters = 4.222×10^-99 cubic cm. Thus 2.5 cubic cm contain about a googol Planck spaces. There are only about 3×10^80 cubic metres in the observable universe, giving about 7.1×10^184 Planck spaces in the entire observable universe, so a googolplex is far larger than even the number of the smallest measurable spaces in the observable universe.

    If the entire volume of the observable universe (taken to be 3 × 10^80 cubic meters) were packed solid with fine dust particles about 1.5 micrometres in size, then the number of different ways of ordering these particles (that is, assigning the number 1 to one particle, then the number 2 to another particle, and so on until all particles are numbered) would be approximately one googolplex.

    So if the observable universe doesn't have enough space to contain a Googolplex of Planck spaces how come a Googolplex of 1.5 micrometres fine dust particles woud fit inside it?

    Thanks in advance and sorry if I've made any mistakes, this is my first post here :)
    Last edited: Jun 26, 2013
  2. jcsd
  3. Jun 26, 2013 #2


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    It doesn't say a googolplex dust particles fit in the universe, it says that if n is the number of dust particles, then a googolplex is approximately n factorial (the number of ways of ordering the dust particles)
  4. Jun 26, 2013 #3
    Awww, I feel like a noob :eek: I get it now! Thank you really!

    And BTW this is really a great forum, thanks for the quick answer! :P
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