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Physicists Simulate Critical 'Reheating' Period That Kickstarted the Big Bang (phys.org) 69

Posted by BeauHD from the blast-from-the-past dept.
An anonymous reader quotes a report from Phys.Org: Just before the Big Bang launched the universe onto its ever-expanding course, physicists believe, there was another, more explosive phase of the early universe at play: cosmic inflation, which lasted less than a trillionth of a second. During this period, matter -- a cold, homogeneous goop -- inflated exponentially quickly before processes of the Big Bang took over to more slowly expand and diversify the infant universe. Recent observations have independently supported theories for both the Big Bang and cosmic inflation. But the two processes are so radically different from each other that scientists have struggled to conceive of how one followed the other.

Now physicists at MIT, Kenyon College, and elsewhere have simulated in detail an intermediary phase of the early universe that may have bridged cosmic inflation with the Big Bang. This phase, known as "reheating," occurred at the end of cosmic inflation and involved processes that wrestled inflation's cold, uniform matter into the ultrahot, complex soup that was in place at the start of the Big Bang. David Kaiser, the Germeshausen Professor of the History of Science and professor of physics at MIT, and his colleagues simulated in detail how multiple forms of matter would have interacted during this chaotic period at the end of inflation. Their simulations show that the extreme energy that drove inflation could have been redistributed just as quickly, within an even smaller fraction of a second, and in a way that produced conditions that would have been required for the start of the Big Bang. The team found this extreme transformation would have been even faster and more efficient if quantum effects modified the way that matter responded to gravity at very high energies, deviating from the way Einstein's theory of general relativity predicts matter and gravity should interact. The findings have been published in the journal Physical Review Letters.
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Physicists Simulate Critical 'Reheating' Period That Kickstarted the Big Bang More

Physicists Simulate Critical 'Reheating' Period That Kickstarted the Big Bang

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  • Good grief (Score:5, Funny)

    by 93 Escort Wagon ( 326346 ) on Monday October 28, 2019 @10:40PM (#59357108)

    Not ANOTHER Kickstarter story!

  • But I'd prefer "this region within the Universe" unless they state up front that they're talking about one cyclic Universe. "Universes" these days are as cheap as "AIs", it seems.

    • Re: (Score:3)

      by rtb61 ( 674572 )

      Actually it feels more like the last vestiges of trying to probe the big bang as an other theory starts to take hold. You need, everything, everywhere, everywhen because you can not get something, somewhere, somewhen from nothing, nowhere, nowhen.

      • According to our best current understanding, nothing isn't even possible. Even completely empty space appears to have a froth of particles in it due to the uncertainty principle and quantum fields extend everywhere.

      • Re: (Score:2)

        by spun ( 1352 )

        Stephen Hawking says that matter and energy have positive energy, while space and time have negative energy. The two exactly balance out, leaving our universe with net zero energy. It's just a big quantum fluctuation, the net energy embodied in the universe is zero.

        But even if that theory is wrong, your logic is flawed. You are basing your theory on what you can observe inside the universe. Sure, inside the universe your postulates hold true on the macro scale. On the quantum scale, vacuum fluctuations viol

  • I used a microwave and some cookie dough. It worked out about the same.

  • What matter? Where did it come from?

  • Especially seeing as the 80% +/- of the universe that's said to consist of dark matter/dark energy isn't at all understood.

  • "My hand's gone, but who cares, I just earned the fucking Nobel, baby!"

  • If I understand it correctly, the universe expanded faster than the speed of light in those first moments.

    What happens when matter and energy accelerate at faster than the speed of light? What is produced? Or maybe, What's left in your wake after space-time accelerates past you faster than the speed of light?

    --
    She‘s our friend and she‘s crazy. – Dustin

    • Re:Can someboday please explain to me? (Score:5, Interesting)

      by beachmike ( 724754 ) on Tuesday October 29, 2019 @12:20AM (#59357268)
      MATTER did not expand faster than the speed of light. SPACE itself expanded faster than the speed of light, which it is still doing today outside of our light cone.

      • The theory is that spacetime itself expanded faster than the speed of light. This is fanciful math wankery based on nothing other than trying to wind back the clock and stuff the universe into the preconceived box that is the big bang.

        You claiming that this is still happening outside of our light cone is beyond preposterous. You may as well claim you have a super model girlfriend, but she's from outside our light cone so we wouldn't know her.

        • Re: (Score:2)

          by Agripa ( 139780 )

          The theory is that spacetime itself expanded faster than the speed of light. This is fanciful math wankery based on nothing other than trying to wind back the clock and stuff the universe into the preconceived box that is the big bang.

          You claiming that this is still happening outside of our light cone is beyond preposterous. You may as well claim you have a super model girlfriend, but she's from outside our light cone so we wouldn't know her.

          What do you think happens inside of an event horizon?

    • Re: (Score:1)

      by egilhh ( 689523 )

      Or maybe, What's left in your wake after space-time accelerates past you faster than the speed of light?

      Spaghetti. Or strings, as physicists like to call them... :p

    • https://en.wikipedia.org/wiki/... [wikipedia.org]

      Before you read that you need to understand that c is the speed of cause and affect. You can't have an affect on something in less than the time it takes light to reach the object*. In a way light isn't special in its speed it just moves at the speed of cause and affect. That doesn't mean that the distance between two points can't increase at faster than the speed of light. The distance can because this isn't violating the cause and affect.

      Now back to inflation - t

      • Should be Cause and Effect. Although Affect might be correct, everyone says Effect.

        When you start to talk special relativity, let alone quanum general relativity, all intuitions go out the window.

        Incidentally, Einstein used a very dubious train analogy to try to explain special relativity, and like most explanations he made a giant leap in one sentence without explanation.

      • Before you go any further, it might be a good idea to recognize that c.wave vs c.particle might be moving at different speeds not unlike cloud.thunder vs cloud.lightning and yeah.....

    • What happens when matter and energy MOVE faster than the speed of light? What is produced? Or maybe, What's left in your wake after space-time MOVES past you faster than the speed of light?

      1. Fixed that for you.
      2. Matter and energy cannot move faster than the speed of light (although energy in the form of light can move at the speed of light.)
      3. If you multiply a very large distance by a realistic expansion frequency you might get a "speed" that is faster than light. But anything at that distance is (a) outside of your light cone, (b) not observable, and (c) cannot go past you.
      4. Space cannot go past you faster than the speed of light. More to the point, you cannot go through space fast

    • Re:Can someboday please explain to me? (Score:5, Informative)

      by gtall ( 79522 ) on Tuesday October 29, 2019 @04:11AM (#59357544)

      As beachmike mentioned below before some trolls ate him, space expanded faster than the speed of light, not matter. Matter is in space and as such cannot travel faster than the speed of light.

      How many times does this have to be repeated?

      • How many times does this have to be repeated?

        That depends on how long the universe exists for, and if any of these alternate universes exist in some real sense. I'd just assume infinitely at this point.

    • What happens when matter and energy accelerate at faster than the speed of light?

      paraphrasing Futurama: The ship doesn't move faster than light (that's impossible). It moves the universe around it.

  • while some of the gui to console conversion api was written in Python the core simulation was written in Angry Birds 2.
  • Anyone can simulate anything but the reality is that the Universe has always existed;

    • Yes, but what does the last Turtle stand upon?

    • Re: (Score:1)

      by gtall ( 79522 )

      Wow! In one stroke you've fixed the Universe Problem for the physicists. I urge you tell them this quickly so they don't waste anymore time.

      • While you're at it, ask them how they measured the big bang. I'm curious to know what they put their ruler up against, after stepping out of their time machine, in a universe that has no matter in it. Maybe they can assign a numerical value to divide-by-zero while they're in the mood to enumerate the un-enumerable.
  • Comment removed based on user account deletion
    • Well, not really. Yeah ok for the random drilling of a hole but we have more than a snap second look (or at least we have really studied the snap shots in depth) and the further you look you are literally looking into the past. We can and do say from what we can tell the house was built in these ways from these materials but there is zero clue other than ideas what was before the big bang, your proverbial topology before the diggers rolled in.

      A theory isn't a fact it's just an idea that has support and ev

      • This whole universe could be a giant space babies poop for all we actually know but we didnt see any giant buttholes in any of our snap shots.

        Because telescopes point up, not toward Washington, D.C.

    • You worthless basement dwelling know-it-alls just kill me...

    • There's a big difference between having devout faith that the universe was created ex nihilo 6k years ago by a deity and holding the provisional view that the best models available currently indicate that the universe likely began 14 billion years ago in a process still being elucidated experimentally.

    • what I believe is that the Big Bang THEORY, (emphasis mine,)

      It's a shame that your understanding of sixth grade science is flawed so massively. Everything that came after that is just an interesting stroll into how misguided a world-view can be when one has such a massive deficit of basic scientific understanding.

    • It’s frankly absurd. I’ve been challenged on this before; “so what,” people ask, “do you believe in the Genesis creation story?” No... what I believe is that the Big Bang THEORY, (emphasis mine,) is just a retelling of the Genesis story with the names and dates changed. Same essential story, though.

      Some inscrutable and ineffable thing, for reasons of its own, a really super long time ago, for reasons we cannot fathom, of course, and of which we have no way of ever knowing, arbitrarily decided at some specific moment in nonhisotory, x amount of time ago, to MAKE the ... EVERYTHING WE SEE. Before that there was only nothingness, and then somethingness.

      It's neither inscrutable nor ineffable. It's a retelling of the Genesis myth that persists for a reason. That reason is called the Laws of Thermodynamics, and specifically the Second Law.

      In a natural thermodynamic process, the sum of the entropies of the interacting thermodynamic systems increases.

      The Universe is not at maximum entropy, which it should be if it were actually eternal, so therefore there must have been a beginning, so therefore... Big Bang.

      Thermodynamics rests on extremely solid ground. Basically all of modern society is built upon it. Steam turbines are designed and built and produce megawatts of

  • ...As I told my wife, this is exactly why I don't like to eat leftovers.

  • Physicists Simulate Critical 'Reheating' Period That Kickstarted the Big Bang

    Yes, we know. It is a tradition — every 13 billion years or so the physicists "simulate" the Big Bang...

    You can stop dieting now...

  • So this theory says that this huge explosion happened, causing tremendous heat, and eventually, all of the universe.

    What exploded, exactly? Wait, nothing exploded?

    Oh yeah, some fluctuation in space time. Wait, where did that fluctuation come from? What exactly fluctuated, and where did that come from?

    Keep tracing these explosions and fluctuations back further, and you eventually have to get back to absolute nothingness.

    And you're going to tell me that this nothingness suddenly produced a huge explosion?

    By c

    • Re: (Score:1)

      by Anonymous Coward

      > By comparison, GOD somehow seems less miraculous.

      It's tempting to put a name on it and say now you know the answer, but you haven't really learned anything about the origin of our universe. You've just hung a name on it.

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