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Thread: The Antimatter Mirror Universe Going Backwards in Time.... wut???

  1. #1
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    Question The Antimatter Mirror Universe Going Backwards in Time.... wut???

    This flew right over my head and kept on going. Say what?


    https://physicsworld.com/a/our-unive...ay-physicists/

    Cosmology Research update
    Our universe has antimatter partner on the other side of the Big Bang, say physicists
    03 Jan 2019

    Our universe could be the mirror image of an antimatter universe extending backwards in time before the Big Bang. So claim physicists in Canada, who have devised a new cosmological model positing the existence of an “antiuniverse” which, paired to our own, preserves a fundamental rule of physics called CPT symmetry. The researchers still need to work out many details of their theory, but they say it naturally explains the existence of dark matter. Standard cosmological models tell us that the universe – space, time and mass/energy – exploded into existence some 14 billion years ago and has since expanded and cooled, leading to the progressive formation of subatomic particles, atoms, stars and planets. However, Neil Turok of the Perimeter Institute for Theoretical Physics in Ontario reckons that these models’ reliance on ad-hoc parameters means they increasingly resemble Ptolemy’s description of the solar system. One such parameter, he says, is the brief period of rapid expansion known as inflation that can account for the universe’s large-scale uniformity. “There is this frame of mind that you explain a new phenomenon by inventing a new particle or field,” he says. “I think that may turn out to be misguided.”

    Instead, Turok and his Perimeter Institute colleague Latham Boyle set out to develop a model of the universe that can explain all observable phenomena based only on the known particles and fields. They asked themselves whether there is a natural way to extend the universe beyond the Big Bang – a singularity where general relativity breaks down – and then out the other side. “We found that there was,” he says. The answer was to assume that the universe as a whole obeys CPT symmetry.
    Do good work. —Virgil Ivan "Gus" Grissom

  2. #2
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    Also... "Turok says that the new model provides a natural candidate for dark matter. This candidate is an ultra-elusive, very massive particle called a “sterile” neutrino hypothesized to account for the finite (very small) mass of more common left-handed neutrinos."

    wat?
    Do good work. —Virgil Ivan "Gus" Grissom

  3. #3
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    Which bit of that is making you go "wat?"?

    Grant Hutchison

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    Quote Originally Posted by grant hutchison View Post
    Which bit of that is making you go "wat?"?
    Don't recall any previous discussion of the creation of a mirror-image antimatter reversed-time universe full of sterile neutrinos before the Big Bang. Maybe I missed it.
    Do good work. —Virgil Ivan "Gus" Grissom

  5. #5
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    I think Asimov wrote about an antimatter universe going backwards in time from the Big Bang in one of his F&SF columns back in the 70s. He was just having fun, though. (ETA: Actually, 1966, in an essay entitled "I'm Looking Over A Four-Leafed Clover", although I'm speaking from memory of its content.)

    It's not the reversed-time universe that's full of sterile neutrinos, BTW - it's ours. Turok derives an abundance of sterile neutrinos in this universe that makes them candidates for Dark Matter and high energy cosmic ray showers.

    Grant Hutchison
    Last edited by grant hutchison; 2019-Jan-08 at 05:42 PM.

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    Although sterile neutrinos have not been observed which rather breaks their claim about their model only relying on known particles and forces. Sterile neutrinos are also not a new idea or linked to their model in particular. The idea has been around for ages and they have been postulated as a DM candidate since neutrino mass oscillations were observed.

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    Ah, my bad on sterile neutrinos, got me there. Missed that.

    Everyone else must have heard about the antimatter mirror universe going backward in time. It was just a surprise to me. I'm good.
    Do good work. —Virgil Ivan "Gus" Grissom

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    Quote Originally Posted by Roger E. Moore View Post
    Everyone else must have heard about the antimatter mirror universe going backward in time. It was just a surprise to me. I'm good.
    It's been around for a while. See Carroll and Chen (2004) for instance.

    Grant Hutchison

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    Isn't it just a consequence (or interpretation) of CPT symmetry?

  10. #10
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    Quote Originally Posted by Roger E. Moore View Post
    Ah, my bad on sterile neutrinos, got me there. Missed that.

    Everyone else must have heard about the antimatter mirror universe going backward in time. It was just a surprise to me. I'm good.
    The idea of time reversed universes on either side of a low entropy state goes back to Boltzmann and Poincare from their studies in thermodynamics and statistical mechanics. It was an explanation for why we live in a universe with increasing entropy at a time when the prevailing model was the Steady State universe.

    Boltzmann speculated that the arrow of time points away from low entropy states and Poincare showed that such low entropy states will happen given sufficient time.

    Sent from my SM-G900F using Tapatalk

  11. #11
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    The original paper in PRL is open access and is available here:-
    https://journals.aps.org/prl/abstrac...ett.121.251301

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