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B Conservation of energy across the universe

  1. Dec 27, 2016 #1
    Conservation of energy

    Is the law of conservation of energy absolute?

    If so, doesn't it follow that all the energy of the big bang came from somewhere? That the energy of our universe must predate the big bang?

    Isn't that circumstantial evidence of the validity of string theory which presupposes there was a 10 dimensional universe which broke down into a 6 and a 4.

    The implosion/ explosion of the inner 7 dimensions being the origin of our 4 and the event in question classically described as "Big Bang"?

    Just curious. I had jury duty 2 weeks ago and I learned about circumstantial evidence and how it is enough to establish guilt beyond a reasonable doubt.

    Isn't circumstantial evidence the reason scientists created dark energy? Since we can't see it or know anything about it directly?

  2. jcsd
  3. Dec 27, 2016 #2


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    Staff: Mentor

    There's no unambiguous way of defining all "the energy of our universe", which makes it hard to use conservation of energy for the universe as a whole. However, we can phrase the law more precisely, and then it works: Take a small volume of space. The total amount of energy contained in this volume will be what started out there, plus what flowed in, less what flowed out. This is the "differential form" of the law of conservation of energy described by Baez here: http://math.ucr.edu/home/baez/physics/Relativity/GR/energy_gr.html

    No. There's no relationship at all here.
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