Slashdot is powered by your submissions, so send in your scoop

 



Forgot your password?
typodupeerror
DEAL: For $25 - Add A Second Phone Number To Your Smartphone for life! Use promo code SLASHDOT25. Also, Slashdot's Facebook page has a chat bot now. Message it for stories and more. Check out the new SourceForge HTML5 internet speed test! ×
Science

Quantum Equation Suggests Universe Had No Beginning 288

cyberspittle writes: The universe may have existed forever, according to a new model that applies quantum correction terms to complement Einstein's theory of general relativity. The model may also account for dark matter and dark energy, resolving multiple problems at once. "In addition to not predicting a Big Bang singularity, the new model does not predict a "big crunch" singularity, either. In general relativity, one possible fate of the universe is that it starts to shrink until it collapses in on itself in a big crunch and becomes an infinitely dense point once again. ... In cosmological terms, the scientists explain that the quantum corrections can be thought of as a cosmological constant term (without the need for dark energy) and a radiation term. These terms keep the universe at a finite size, and therefore give it an infinite age. The terms also make predictions that agree closely with current observations of the cosmological constant and density of the universe."
This discussion has been archived. No new comments can be posted.

Quantum Equation Suggests Universe Had No Beginning

Comments Filter:
  • by Todd Knarr ( 15451 ) on Tuesday February 10, 2015 @03:23AM (#49023789) Homepage

    Equations and theories that not only explain current observations but bundle up and deal with things our other theories say we should observe that we don't are attractive from a neatness standpoint. I'm skeptical when they make exotic and complex predictions which we haven't seen any evidence of yet, but when they tie up all the loose ends without creating more I usually take that as a sign there's something fundamentally right about that path. Only time and accumulated evidence will add certainty to it, but I like the ideas in this one.

    And as far as a universe with no beginning or end is concerned, what's the problem? I was dealing with infinite open shapes (lines, planes) in grade school, unending closed shapes are trivial (a circle, a sphere), and if you assume our universe is a 4-dimensional "slice" of an n-dimensional space it's not that hard to construct an arrangement where you can travel forever in any "direction" (since the time axis counts as a direction here) inside our universe without either encountering an edge or returning to your starting point. The math's brain-bending when you start, but it's like differential equations: migraine-inducing and you hate it with the burning fire of a thousand suns right up until they describe the General Method, at which point you blink and go "Oh. That's easy. Why didn't you mention this in the FIRST PLACE?!

    • by steelfood ( 895457 ) on Tuesday February 10, 2015 @03:58AM (#49023897)

      And as far as a universe with no beginning or end is concerned, what's the problem?

      In a word: entropy.

      • And as far as a universe with no beginning or end is concerned, what's the problem?

        In a word: entropy.

        I'm sure there's a quantum correction for that.

      • by f3rret ( 1776822 )

        And as far as a universe with no beginning or end is concerned, what's the problem?

        In a word: entropy.

        As I understand it, this new equitation only deals with the nature of the universe, not any of the stuff in the universe. So, yeah entropy will always increase inside the universe and the universe will eventually become uniform and the same temperature and density in all directions.
        But, the universe itself is infinite and will stay so.

      • But entropy could go asymptotically to zero as time goes to minus infinity.
        So I still do not see the problem.

    • by imAck ( 102644 )

      And as far as a universe with no beginning or end is concerned, what's the problem? I was dealing with infinite open shapes (lines, planes) in grade school, unending closed shapes are trivial (a circle, a sphere), and if you assume our universe is a 4-dimensional "slice" of an n-dimensional space it's not that hard to construct an arrangement where you can travel forever in any "direction"

      Sort of like a world in Minecraft, well, at least in the XZ coordinates.

  • But... (Score:5, Interesting)

    by maugle ( 1369813 ) on Tuesday February 10, 2015 @03:23AM (#49023793)
    OK, these guys are probably far smarter than I'll ever be, but... the universe clearly isn't staying at a finite size, and playing the universe's expansion in reverse would imply that it started at a single point. How do they account for this? I even went as far as to read the article, but it wasn't mentioned.

    Are they saying that the universe fluctuates between a not-quite-a-singularity tiny point of density and a not-quite-eternally-infinite empty void, or that it simply was a not-quite-a-singularity tiny point of density for an infinite time before it expanded?
    • by ihtoit ( 3393327 )

      not sure but the bigger question would be how stoned would I have to be to even consider the ramifications of what you're suggesting?

    • They've also found ways to measure the ages of stars, etc, and you would expect some excessively old objects out there if the universe were infinitely old. Maybe. This is why we have ideas, hypotheses, theories, and natural laws. Things need to be thought up, tested, and proven. Over and over. It's annoying when people think of hypothesis as scientific fact. That's just not how science works.
      • I was under the impression that we're living amid a second generation of stars. Early-universe stars were very large, very bright, and have all died already, giving birth to the current generation of cooler, longer living stars we see in our night sky. Granted, I'm basing that off of reading the Xeelee sequence, so who knows.

    • Re: (Score:2, Interesting)

      by Anonymous Coward

      Things moving in a space don't describe the size of the space they're contained in unless they interact with a boundary. You can't make the claim that the universe is growing or shrinking. All you can say is that some objects are moving away from each other. This could either be space expanding (the popular theory involving dark energy which is just the pet name they gave the missing force they can't explain), or space is not expanding and another force acting on the mass that hasn't been accounted for.

    • OK, these guys are probably far smarter than I'll ever be, but... the universe clearly isn't staying at a finite size, and playing the universe's expansion in reverse would imply that it started at a single point. How do they account for this?

      Various Quantum Gravity theories predict different things here. Some, like Loop Quantum Gravity (LQG), predict that over extremely short distances gravity is repulsive. Applied to cosmology (Loop Quantum Cosmology, LQC) this leads to a prediction of a "bounce", where a contracting phase flips into an expansion phase.

      http://en.wikipedia.org/wiki/L... [wikipedia.org]
      http://en.wikipedia.org/wiki/B... [wikipedia.org]

    • by PhilHibbs ( 4537 )

      ...and playing the universe's expansion in reverse would imply that it started at a single point. How do they account for this?

      They're saying that under this theory, playing it backwards does not imply that it starts at a single point. I could point to someone blowing up a balloon, and say "it must have started from an infinitely dense singularity". I'd be completely wrong.

  • by DigitAl56K ( 805623 ) on Tuesday February 10, 2015 @03:24AM (#49023795)

    It's interesting, but I'm curious as to whether the model shows a universe developing with the features we observe. The density of the universe is one thing, the general structure of it is another. There seems to have been a lot of thinking around how the universe was shaped by the big bang including all sorts of models and simulations. It'll be interesting to understand if this new model also fits.

  • by ihtoit ( 3393327 ) on Tuesday February 10, 2015 @03:26AM (#49023809)

    and that involves a certain plant, a yard of gummed-edge pressed wood pulp and a bucket of munchies.

  • Toldja! (Score:5, Funny)

    by Tablizer ( 95088 ) on Tuesday February 10, 2015 @03:33AM (#49023825) Journal

    ...it's turtles, all the way down.

  • by jandersen ( 462034 ) on Tuesday February 10, 2015 @03:42AM (#49023855)

    One of the many, big, unanswered questions concerning the origin of the universe is - where did the energy come from? Conservation of energy - the assumption that energy cannot be either destroyed or created - is a fundamental axiom in physics, which goes against the idea that there was a point in time before which the universe didn't exist, but after, it did. Unless, of course, one can conceive of a negative energy of equal size having been created at that same moment.

    A naive consideration would say that if a mass, M, is created, then there must have an 'anti-mass', -M, as well; using Newton's equations, we would expect M and -M to repulse each other, while M would attract M and -M would attract -M (yes, doesn't make sense at stated, but follow my thought here, OK?) And, if one were to ramble on along those lines anyway, it seems tempting to look at the equations for how electric charges interact and think of electric charge as a kind of imaginary (as in complex numbers) mass. No doubt better people than I have already spotted this and worked out why it doesn't make sense, but I haven't seen their work yet.

    • Naively, doesn't conservation of energy also suggest that particles can't pop into existence out of nothing? But they do [wikipedia.org].

      TL:DR; physics is bonkers.

      • by PhilHibbs ( 4537 )

        Naively, doesn't conservation of energy also suggest that particles can't pop into existence out of nothing? But they do [wikipedia.org].

        Do they? Hawking Radiation has never been observed or proven. It's a theory. And in any case, the black hole would lose the same amount of energy as was in the radiation.

      • What happens to the photons that get their wavelengths lengthened by dark energy space expansion under the Big Bang model?

        A photon with gamma ray wavelength and the power to ionize atoms gets stretched by all possible observation points into a microwave that can do no such thing.

        Where did that energy go?

        It is different than red-shift (a directional observation bias) in that the energy simply is gone.
        • A photon with gamma ray wavelength and the power to ionize atoms gets stretched by all possible observation points into a microwave that can do no such thing.

          If by "observation points" you mean "reference frames," then won't there always be a reference frame where it has gamma ray (or any other) wavelength?

          Where did that energy go?

          Nowhere, I think. It's like running fast enough to snatch a bullet out of the air without hurting yourself. Relative to you, the bullet has very little kinetic energy.

    • [...] the idea that there was a point in time before which the universe didn't exist [...]

      Time is part of the universe, so there wasn't and there will never be a point in time when the universe doesn't exist. On the other hand, there could be other universes, possibly with their own times.

    • by MightyDrunken ( 1171335 ) on Tuesday February 10, 2015 @09:14AM (#49024961)
      While others have stated that though conversation of energy is one of the main axioms of physics it does not necessarily apply to the creation of the Universe, only what is within it. However many physicist believe that the net energy of the Universe is zero [wikipedia.org] as the potential energy of gravity is negative, balancing out the positive energy in the Universe.
    • by oreaq ( 817314 )

      Conservation of energy - the assumption that energy cannot be either destroyed or created - is a fundamental axiom in physics, which goes against the idea that there was a point in time before which the universe didn't exist, but after, it did

      Emi Noether showed in the first half of the last century that conservation of energy is equivalent to time invariance ("shift symmetry of time"). At the beginning of time, i. e. the beginning of the universe, there was no time invariance; time was just being "created". Hence no conservation of energy.

  • by ad454 ( 325846 ) on Tuesday February 10, 2015 @03:55AM (#49023891) Journal

    All of these type of models about the universe have elegant math behind them.

    But until they can any observable predictions which can be measured and possibly falsifiable, then we are really dealing with pure math and philosophy and not physics.

    One can construct countless mathematical models which fit known observations, but very few make new falsifiable observable predictions.

    This is my gripe with something like String/M-Theory, which has not made any legitimate predictions, and fails at stuff like monopoles which not been observed.

    • by Rashdot ( 845549 )

      If they're talking about a pulsating universe, there may be a way to verify some of it. I'm looking at this from a layman's perspective. If a big crunch happened before our current universe's big bang, could it be possible that this big bang happened before all of the material from the previous universe had been drawn into the singularity? Because simply put, why would the singularity wait for everything to fall into it? What if 'our' big bang annihilated that still inward falling matter while rapidly expan

  • by Anonymous Coward on Tuesday February 10, 2015 @04:00AM (#49023905)

    Suppose the Universe is filled by a Bose-Einstein condensate of gravitons with mass, and that the amplitude of the condensate's wavefunction spans the entire universe.

    Turns out that when you derive the FRW equations from this, doing so inserts a cosmological-constant lookalike into the equation for a''

    So plug the size of the Universe into the Yukawa equation and a graviton mass of 10^-32eV pops out. Plug this into the assumption that the wavefunction is a Gaussian the size of the universe (which makes d'Alembertian proportional to the wavefunction and gives you that nice constant) and you get a cosmological constant that's plausibly near to what we observe.

    Inserting the universe-condensate also creates a second correction term which prevents the FRW scale factor from blowing up or collapsing either in the past or the future, which makes that nasty big bang singularity go away.

    ----------

    It's worth noting that they invoke Bohmian quantum mechanics, which will immediately sketch out a lot of quantum folks...

    What bugs me is that the massive graviton blows up the mass hierarchy problem. It's hard enough to come up with a non-contrived way to have particles whose measured mass ranges from 1eV to 170GeV, but to extend it by 30 orders of magnitude on the light side is just mean.

    • Re: (Score:2, Interesting)

      by Anonymous Coward

      If gravitons have non-zero rest energy, then gravity can't have infinite range...if it's 10^-32 eV, then gravity doesn't extend farther than about 10^48 meters...ok...possible... LOL

      Bohmian mechanics is probably what prevents a singularity, as particle trajectories can't cross (quantum potential becomes infinite as trajectories converge)...

    • "d'Alembertian" gave it away.
  • by geogob ( 569250 ) on Tuesday February 10, 2015 @04:08AM (#49023923)

    too bad we can't verify them. Especially since the thrown most of the assumed ones out of their model. It's nevertheless an interesting approach in describing the universe if you take the time to read about it. Who knows, maybe the existing models were over-constrained and it might not be bad to give them a fresh look.

    The truth probably lays somewhere in between.

  • This has to be the first time any kind of science involving the word quantum has made more sense than an alternative.

  • Equation (Score:5, Funny)

    by geantvert ( 996616 ) on Tuesday February 10, 2015 @04:35AM (#49023987)

    A few years ago, a colleague proposed the idea that North-European population are tall because of an adaptation to the colder climate.
    He could prove his theory but only for a perfectly spherical viking.

  • by bug1 ( 96678 )

    Time is how we measure change, its a property of an object, not an object itself.

    For time to have a begining would mean a situation when nothing changed. Which suggests zero energy. So for time to have a beggining is to suggest energy can be created created.

    orsomethinglikethat

  • If the unisverse is not expanding (which it is presently) in general then that allows not to conclude that the age of the universe is infinite. It only shows that you cannot determine the age of the universe on the basis of inflation. However, you still could determine the age by entropy. The higher the entropy the older the universe. And if I look at my work desk, the universe is pretty damn old.

  • by YoungManKlaus ( 2773165 ) on Tuesday February 10, 2015 @06:06AM (#49024267)

    Obvious question, if the universe is infinitely old why do we still have hydrogen left for fusion?

  • Shepard tone (Score:4, Interesting)

    by Snard ( 61584 ) <mike.shawaluk@g[ ]l.com ['mai' in gap]> on Tuesday February 10, 2015 @07:00AM (#49024461) Homepage

    In music, there is something called a Shepard tone [wikipedia.org], which is a series of skillfully combined harmonics that, when listened to as a loop, appears to be constantly ascending.

    Perhaps the "expanding universe" is something like that.

  • "The universe may have existed forever,",

    Forever, yes, but how for is that ? I thought the time started ar big bang.

  • One of the basic tenets of Hiunduism is that the universe has no beginning and it has no end. Lots of Indian/Bengali names being mentioned in the research. The fine article has no math and it talks philosophically. And this concept is not all that new. I remember reading a book (may be about the neutrino) by Asimov that talks about "cyclic" universe that oscillates between expansion and contraction, or something that goes from big-bang to big-crunch, or big-bang to death due to infinite expansion etc. He ta
  • If all universe was smaller than, well, very small, how come it didn't form a black hole in the first seconds?

    And then if nothing exits the black hole, how did universe manage to do it?

  • Half Life (Score:4, Insightful)

    by Jim Sadler ( 3430529 ) on Tuesday February 10, 2015 @07:58AM (#49024619)
    I suppose that radioactive materials were put here by Satan to trick us. After all, with a perpetual universe we would have reached the half life of nuclear materials over and over again and we would have no radioactive materials at all. Oops!
  • When time is not a constant and may not have always existed?
  • Isn't this just a rehashing of the steady state theory of the universe?

  • Or so all other evidence indicates. That said, is there any reason why what we call the "big bang" represents nothing more than an unmeasurable atemporal interval between otherwise quite mundane spatio-temporal domains? That would satisfy the condition of "eternal existence" and leave room for the big bang.

    In other words, big bang, followed by big crunch some xx billion years later. Rinse, lather and repeat.

  • by phrackthat ( 2602661 ) on Wednesday February 11, 2015 @06:48AM (#49027695)
    Einstein - Only two things are infinite, the universe and human stupidity, and I'm not sure about the former.

NOWPRINT. NOWPRINT. Clemclone, back to the shadows again. - The Firesign Theater

Working...