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Relationship between energy, information and dark energy

  1. Dec 31, 2015 #1
    Hi. I have no significant pure physics or math education or work experience (retired corporate analyst) but I was wondering what experts here might think about the relations between energy, dark energy and information.

    My understanding is that dark energy is the expansion of space, with space generally considered to be a "quantum foam" of teeming virtual particles popping in and out of existence. So the first question is, if the quantum foam is expanding, wouldn't that mean that new information is being continually created, with each virtual particle's appearance adding a little more information to the universe?

    Most cosmologists consider that the big bang is "still banging", that inflation never stopped. This leads to my second question: if the universe is still inflating then wouldn't that mean that the universe is an open system with an "environment" (quantum foam) from which it continues to draw additional energy and information via dark energy expansion?

    Where could this extra energy come from, seemingly in defiance of the first law? Could there be a feedback loop within the quantum foam itself between the energy and information that automatically and infinitely self regenerates? Is so, wouldn't that mean that energy is derived from information in a roughly analogously way to how mass is derived from energy? Instead of using the speed of light as a constant, might you use the speed of space? The speed of dark energy squared? ;)

    Thanks for your time. If the above is not reality, it would at least seem a decent sci fi premise ...
     
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  3. Dec 31, 2015 #2

    phinds

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    @Greta you have a fundamental misunderstanding about the expansion of the universe. I suggest that you google "metric expansion" and I also recommend the link in my signature.
     
  4. Dec 31, 2015 #3
    @ Phinds, I've seen the balloon analogy in many documentaries and web pages over the years.

    Are you saying that the quantum foam is thinning out in the expansion - that each cubic metre of space will ever have fewer virtual particles?

    I have operated under the assumption, as per string theory and cosmologists like Lawrence Krauss, that space consists of virtual particles popping in and out of existence.
     
  5. Dec 31, 2015 #4

    phinds

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    No, I'm not saying anything is thinning out. I'm saying that the expansion of the universe just means that things are getting farther apart. Did you read my article?

    Krauss is a wonderful popularizer and I find him very entertaining but he is not always taken seriously. You won't hear much on this forum about "quantum foam". Do a forum search.
     
  6. Dec 31, 2015 #5

    marcus

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    That strikes me as a delightful intellectual romp that takes off from verbal (not detailed or quantitative) notions widespread in media (science popularization)
    It's imaginative but not all that compatible, or so I think, with the kind of discourse that prevails here. Still, I think you can adapt and engage here. See if you can get something out of some papers by Thanu Padmanabhan---these are technical professional papers, on arXiv.org. But he is a bit more creative/wacky than most. Nevertheless he is a prominent respected theoretical relativist/cosmologist. He goes by the nickname "Paddy".

    If you can't get anything out of the non-math portions of Paddy's papers (the introduction and conclusions sections usually) there's no reason to be discouraged, there are other windows of access, other ways to connect . But give Paddy's paper "Gravity and/is Thermodynamics" a try.
    Here's a listing of his 9 most recent scholarly papers. See how many are invited papers---that is a sign of status, he is respected even though a bit out-of-ordinary imaginative.
    Don't worry if you don't understand many of the terms. Try to tune into the spirit. There are three of the nine papers that might be crazy enough to interest you
    The URL for this search is http://arxiv.org/find/grp_physics/1/au:+padmanabhan_t/0/1/0/all/0/1

    Showing results 1 through 25 (of 185 total) for au:padmanabhan_t
    1. arXiv:1512.06672 [pdf, ps, other]
    One hundred years of General Relativity: Summary, Status and Prospects
    T. Padmanabhan
    Comments: Extended version of: (a) Guest Editorial written for Current Science and (b) Plenary Talk at the 28th Texas Symposium on Relativistic Astrophysics (Geneva, 13-18 Dec); 13 pages; no figures
    Journal-ref: Current Science, 109, 1215-1219 (2015)
    Subjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Theory (hep-th)
    2. arXiv:1512.06546 [pdf, ps, other]
    Gravity and/is Thermodynamics
    T. Padmanabhan
    Comments: 17 pages; no figures
    Journal-ref: Current Science, vol 109, pp 2236-2242 (2015)
    Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th)
    3. arXiv:1508.06286 [pdf, ps, other]
    Distribution function of the Atoms of Spacetime and the Nature of Gravity
    T. Padmanabhan
    Comments: Invited review for the special issue on `Entropy in Quantum Gravity and Quantum Cosmology'; 35 pages; no figures
    Journal-ref: Entropy (2015), 17, 7420-7452
    Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th)
    4. arXiv:1508.04060 [pdf, ps, other]
    Thermodynamical interpretation of the geometrical variables associated with null surfaces
    Sumanta Chakraborty, T. Padmanabhan
    Comments: v2, Published version
    Journal-ref: Phys. Rev. D 92, 104011 (2015)
    Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th)
    5. arXiv:1507.06402 [pdf, ps, other]
    Extracting information about the initial state from the black hole radiation
    Kinjalk Lochan, T. Padmanabhan
    Comments: 12 pages
    Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th)
    6. arXiv:1507.05669 [pdf, ps, other]
    Renormalized spacetime is two-dimensional at the Planck scale
    T. Padmanabhan, Sumanta Chakraborty, Dawood Kothawala
    Comments: version 2; 8 Pages; references added
    Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th)
    7. arXiv:1506.03814 [pdf, ps, other]
    Momentum density of spacetime and the gravitational dynamics
    T. Padmanabhan
    Comments: six pages; no figures
    Subjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Theory (hep-th)
    8. arXiv:1505.05297 [pdf, ps, other]
    Gravitational field equations near an arbitrary null surface expressed as a thermodynamic identity
    Sumanta Chakraborty, Krishnamohan Parattu, T. Padmanabhan
    Comments: v2, 25 pages, no figures, to appear in JHEP
    Journal-ref: JHEP 10(2015)097
    Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th)
    9. arXiv:1503.01774 [pdf, other]
    A quantum peek inside the black hole event horizon
    Sumanta Chakraborty, Suprit Singh, T. Padmanabhan
    Comments: All it takes is 1+40 pages and 15 figures
    Journal-ref: JHEP06(2015)192
    Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th)
    10.
     
    Last edited: Dec 31, 2015
  7. Dec 31, 2015 #6
    @ Phinds. Thanks. I only scanned some of your material, but a search of your domain just returned this earlier forum post by you:
    So the first law is preserved because the energy driving the universe's expansion is actually already in the universe, just being converted into a different form?
     
  8. Dec 31, 2015 #7

    Nugatory

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    Space is not generally considered to be a "quantum foam" and it's not teeming with virtual particles popping into and out of existence.

    Both of those are just metaphors; not the real thing but they're useful when trying to describe modern physics to an audience that doesn't have the math needed for the real thing. As with all metaphors, there's only so far that they can be carried.
     
  9. Dec 31, 2015 #8

    Nugatory

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    Conservation of energy at a local scale is simple: Draw an imaginary box around a volume of space; measure the total energy in the box at a given time; wait for little while and measure again; the amount of energy in the box will be equal to what you started with plus or minus whatever passed through the walls of the box between measurements.

    At cosmological scales it gets much trickier - http://math.ucr.edu/home/baez/physics/Relativity/GR/energy_gr.html is a good overview.
     
  10. Dec 31, 2015 #9

    phinds

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    As Nugatory has pointed out, it is not at all that simple. Basically "conservation of energy" can't even be defined on cosmological scales so it makes no sense to ask whether it is conserved or not.
     
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