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Cosmic Inventory

  1. Dec 4, 2014 #1
    1. The problem statement, all variables and given/known data
    One of our homework problems asks us to state the density of Baryons, Cold Dark Matter, Radiation, Dark Energy, and the total density of the universe in terms of the critical density today. It also states to give the density of each quantity in dimensionless Omega units (the density parameter).
    It finishes by saying that there are multiple ways of determining some of these values, and we have to list two of them and identify the measurement that makes the tightest constraint.
    2. Relevant equations
    We weren't given any, but I'm guessing this is one:

    and 7215e34146072041c98e6a266ba1ee4e.png
    I would imagine values found on the internet (from trustworthy sources) would count as well.
    3. The attempt at a solution
    I honestly have no idea where to begin. If I at least had a starting point I might be able to do the actual problem.
  2. jcsd
  3. Dec 4, 2014 #2


    Staff: Mentor

    You could start by checking the terms on wikipedia and see what stats you can find and how they are determined.
  4. Dec 4, 2014 #3
    Unfortunately no matter where I go on the internet (wikipedia included), I can't seem to find any values or calculations for the values :/
  5. Dec 4, 2014 #4


    Staff: Mentor

    The article gives you percentages and you can find the size of the known universe somewhere and perhaps the total mass.
  6. Dec 5, 2014 #5


    User Avatar
    2016 Award

    Staff: Mentor

    The Cosmic Energy Inventory
    First google hit for me if I look for "Cosmic Inventory".
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