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Last Week's Announcement About Gravitational Waves and Inflation May Be Wrong 194

Posted by samzenpus
from the not-so-fast dept.
KentuckyFC (1144503) writes "If you've been living under a stone, you might not have heard last week's announcement that astrophysicists from the BICEP2 experiment have found the first evidence of two extraordinary things. The first is primordial gravitational waves--ripples in spacetime from the very first moments after the Big Bang. The second is that these waves are evidence of inflation, the theory that the universe expanded rapidly, by twenty orders of magnitude in the blink of an eye after the Big Bang. But that can only be possible if the gravitational waves formed before inflation occurred. Now critics have begun to mutter that the waves might have formed later and so provide no evidence of inflation. The new thinking is that as the universe cooled down after inflation, various phase changes occurred in the Universe which generated the laws of physics we see today. These phase changes would have been violent events that generated their own ripples in space time, which would look very much like the primordial gravitational waves that the BICEP2 team claims to have found. So the BICEP2 team must rule out this possibility before they can claim evidence of inflation. But the critics say the data does not yet allow this to be done. That doesn't mean inflation didn't occur. Indeed, the critics say this is still the most likely explanation. But until the phase change possibility is ruled out, the result must be considered ambiguous. So put the champagne back in the fridge."
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Last Week's Announcement About Gravitational Waves and Inflation May Be Wrong

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  • No confirmation (Score:5, Insightful)

    by cciechad (602504) <chad.simmons@mem ... minus physicist> on Monday March 24, 2014 @09:30AM (#46563007)
    Um also this is one experiment with no confirmation yet. No one else has repeated the results as of yet so how about putting the champagne away until another group of experimenters confirms?
    • by JaredOfEuropa (526365) on Monday March 24, 2014 @09:35AM (#46563057) Journal
      Look at what that champagne (& other stuff) cost you last week compared to a few years ago; that's proof of inflation right there...
    • by bigpat (158134) on Monday March 24, 2014 @09:43AM (#46563133)
      We are just going to have to recreate another big bang and then see what happens and therefore settle this debate once and for all.
      • by hawkfish (8978)

        We are just going to have to recreate another big bang and then see what happens and therefore settle this debate once and for all.

        Sadly, if they were climatologists, this is exactly what would be demanded of them in some quarters...

    • Re:No confirmation (Score:5, Informative)

      by interkin3tic (1469267) on Monday March 24, 2014 @12:03PM (#46564407)
      It sounds like this is actually sort of the confirmation.

      Last year, another telescope in Antarctica — the South Pole Telescope (SPT) — became the first observatory to detect a B-mode polarization in the CMB (see Nature http://doi.org/rwt [doi.org]; 2013). That signal, however, was over angular scales of less than one degree (about twice the apparent size of the Moon in the sky), and was attributed to how galaxies in the foreground curve the space through which the CMB travels (D. Hanson et al. Phys. Rev. Lett. 111, 141301; 2013). But the signal from primordial gravitational waves is expected to peak at angular scales between one and five degrees...

      Furthermore, data taken with a newer, more sensitive polarization experiment, the Keck array, which the team finished installing at the South Pole in 2012 and will continue operating for two more years, showed the same characteristics. “To see this same signal emerge from two other, different telescopes was for us very convincing,” says Kovac.

      Nature [nature.com]

      So it's not just one experiment, there are multiple other readings that support it, though I guess a complete experiment duplication is not yet complete. That nature article mentions that the SPT is a competitor to BICEP2, which published the findings, and they were literally a few meters away at the south pole. So I'd assume that SPT and maybe some other competitor is most of the way to confirming the findings, enough that they were confident in publishing.

      That said, I'm totally not a physicist. It just sounds like this isn't a single experiment.

  • Phase changes (Score:5, Insightful)

    by P-niiice (1703362) on Monday March 24, 2014 @09:33AM (#46563031)
    I think phase changes on a universal scale is an amazing thing to ponder.
    • Re:Phase changes (Score:5, Insightful)

      Absolutely. Regardless of whether the results confirm or are consistent with the theory of Inflation, the every existence of coherant structure the scale of the universe itself is an amazing result. By default, there is no reason to expect any structure whatsoever at the highest cosmic sale. (I would argue that up to now this, there was essentially no struture to the CMB)

      Yet here we have "waves" of polarisation over a gigantic region of the night sky. The Universe has uniform strutures at the most enormous scales. It's a deep and awesome result that must be addressed, by inflation or whatever other theory we can propose for it.

    • by VortexCortex (1117377) <VortexCortex&project-retrograde,com> on Monday March 24, 2014 @10:40AM (#46563537) Homepage

      Now imagine phase changes on a multiversal scale. All those infinite chaotic dimensions then BLAM a few align such that their properties harmonize and propagate in a brilliant momentary flash before returning to chaos time and again like fireworks and then the energy density becomes low enough that the explosions stop among some dimensions and yet occur among others, and one of those final big bangs was this universe wherein at the smallest levels of reality we see the infinitely differentiable quantum uncertain foam from which chaotic energy crystallizes into matter momentarily and is destroyed in tiny little flashes, like fireworks, before returning to the chaos.

      Now imagine phase changes on a gigaversal scale... For this experiment beings aware of less than 12 dimensions will need a visual aid. You'll need to wrap your cognitive locus in tin-foil and have access to an old microwave oven. A turn table is optional -- it's the lamp and timer's "Ding" that's most important.

    • I think phase changes on a universal scale is an amazing thing to ponder.

      When we're talking about the moments after the Big Bang, a "universal scale" is actually quite tiny ;)

  • Creationisticism (Score:5, Insightful)

    by dingleberrie (545813) on Monday March 24, 2014 @09:39AM (#46563087)

    This aspect of the story is great as an example of science.
    It seems stubborn to hold onto a single interpretation of evidence during pursuit a theory, including the origin of the universe.
    Science is the willingness to relegate that evidence to be less significant than what some people want it to be.
    When you won't relegate the evidence, then you are practicing faith (in the evidence) instead of science.

    • by magsol (1406749)
      No, science is the willingness to relegate interpretations of evidence to be less significant than what some people want it to be. The evidence itself is pretty clear; what the scientists potentially got wrong is the interpretation. Suiting evidence to specific theories (as opposed to the other way around) is when you start practicing faith instead of science.
      • I'm not sure you're criticism is valid. He said, "Science is the willingness to relegate that evidence to be less significant than what some people want it to be."

        I don't think he was saying that valid evidence would be dismissed because it didn't fit the theory, but that it would be admitted to be less significant if it's found to insufficient to support the theory.

        • by geekoid (135745)

          ", but that it would be admitted to be less significant if it's found to insufficient to support the theory."
          and it might be depending on prior plausibility.
          When that happens, more data is need and more tests are run.

    • by Sockatume (732728)

      Ridiculous. The creationists, anti-vaccination advocates, anti-global warming people, bigfoot hunters and investigators of Atlantis all tell me that scientists totes agree with each other on everything and never succeed by competing and challenging each other's ideas. That many quacks can't possibly be wrong about everything.

    • by mmell (832646)
      Faith - the evidence of things unseen.

      Science - evidence and knowledge of the unseen supported by understanding what is seen.

      I notice that faith talks about things unseen, but doesn't mention how they know about these unseen things (heaven, hell, G*d, etc.). Science also talks about things unseen all the time - but only in the context of what we know. Faith quite handily skips that inconvenient reliance on facts.

  • by MiniMike (234881) on Monday March 24, 2014 @09:49AM (#46563179)

    the result must be considered ambiguous. So put the champagne back in the fridge.

    Already drank the champagne... Um, my fridge is, er, full, can we use yours?

  • ... in what caused or happened before the big bang. Even so someone interested in cosmology like myself, I can only take so much more "and at 1 second after the big bang this happened and 1 min after this". Yeah ok , thats all good fun for particle physics types, but its not actually that interesting compared to the Big Question of why is there something rather than nothing? Which frankly I get the impression not many cosmologists appear to be too interested in finding out, being more content to leaving it

    • At the moment, that question is not answerable, and in fact may never be answerable.

    • Imagine you set up a ridiculously-powerful computer to simulate a universe - literally a particle-by-particle perfect simulation. (You might need this to be a fairly small universe, of course)

      The simulation begins with everything in one tiny place and then it explodes outwards, cools down, matter starts to coagulate, etc. etc.

      Within the simulation, there was no time before that universe's Big Bang. You could pause and even rewind the simulation and this could never be noticed from inside. The simulation onl

    • ... in what caused or happened before the big bang.

      I still can't believe we haven't sent an expedition to see what's North of the North Pole!

      (This is the analogy Stephen Hawking uses when asked about "before the Big Bang")

    • There's a good YouTube video of Lawrence Krauss talking about getting "something from nothing" in which he explains that the current thinking is that nothing is very unstable (which is observed on the subatomic scale) and thus, in the time before time existed particles and energy popped in and out of existence so fast that they didn't violate any laws of physics. Until, the so rare as to possibly be unique event happened that what popped into existence exploded (big bang fashion) before it had a chance to
    • Well, take a deep look at Inflation teories. You'll be surprized.

      The kind of questions cosmologists are asking nowadays is simply amazing.

  • Having read the original paper to the best of my ability (which is not perhaps very good), as far as I can see, the "critics" are arguing that the gravitational ripples might not have been caused by inflation directly, but by another process which happens to be a by-product of inflation. So unless I'm missing something, even if the critics are right, BICEP2 has still provided proof of inflation.
    • by grub (11606)
      I think the skeptics are saying that the gravity waves have been confirmed, the question is were they created by the Big Bang or sometime later as things cooled down.
    • by mmell (832646)
      ...the gravitational ripples might not have been caused by inflation directly, but by another process which happens to be a by-product of inflation...

      I got the impression that it was a by product of expansion (which occurred after inflation) not inflation itself (which, while cosmoligists appear to have reached a concensus is still itself a theory, not a fact).

  • by wcrowe (94389) on Monday March 24, 2014 @10:11AM (#46563337)

    What really happened was that Wolowitz and Koothrappali rigged the electric can opener to create false postitive results for Sheldon's test equipment. He shouldn't have announced his findings so soon.

  • It's the only way to be sure. Don't forget those safety glasses!

  • ... regurgitated champagne?
  • If you laid all the economists in the world end to end, they wouldn't reach a consensus.

    • You do realise that this is an article about physics, right?

      Also, I don't think researchers in any area would reach a consensus if you get they all toguether.

      • Key words: "if they all get together." Probably most fields (of science) have consensus if you get like 75-90% of researchers together.
        • In the exact sciencies, you get consensus to nearly all questions that you craft well enough to exclude any kind oppinion, but you'll get plenty of "nobody knows". You won't get any kind of consesus on the likehood of a non-mainstream theory being right, and very little on how right (or wrong) are the mainstream theories, except if you use some completely objective measurement.

          In human sciences you won't have any "nobody knows" answer to those first questions. You'll have consensus on the known ones, and pl

  • Great assumed premise, guys, really.

    We've jumped way past the point of claiming that polarized background cosmic radiation = gravitational waves detected (right now, the polarization is just consistent with a theory that, IF there are gravitational waves, AND a particular inflation theory requiring gravitational waves to be possible is correct, THEN the observed polarization is consistent with fossil pre-inflation gravitational waves.

    We are now to the point of "alternate explanations for the gravitational w

  • ...as someone said once are human-centered idea, that there are laws obeyed by nature that we can grasp with our minds and that those laws must be unchanging. This is the unspoken assumption, that the models that would explain the physical processes never changed in the course of the evolution of the Universe. I'm beginning to think that such assumption is no different from Newton's "mind of God" that he wanted to know -- we just call it slightly differently.

    And how is this claim relevant? If those "laws" h

    • Are you proposing that the laws change randomly or something?

      If the laws of physics change with time, then what we thought were the laws aren't actually the laws, but rather the actual laws with parameterized time. It might make some experiments more difficult, but there is no philosophical conundrum. Actually, this idea is already implicit in lambda-CDM ("standard model" of cosmology), where there is a time-dependent "scale factor" in the Friedman equations.

  • ... with all of that skeptical insistence on the consideration of confounding explanations that might also be compatible with the data.

    Or is the term "skeptical" politically incorrect at this point, since everybody knows that no real scientist would disagree with the consensus view that he or she is told all of the other scientists have?

    To be honest, the really cool thing isn't (yet) the origin of the gravitational waves observed, it is the observation of gravitational waves at all. So far, that has eluded

  • "The universe expanded rapidly, by twenty orders of magnitude in the blink of an eye after the Big Bang." - what's the size of a singularity times itself 20 times? Still zero width. Great logic there. Then there's the fact that the universe expanding would actually flatten out waves. Then there's the fact that supernovas and black holes have been known to send out gravitational waves. There's actually no logic or science whatsoever behind the original headline-baiting bullshit.
    • The singularity isn't a real thing, it's because General Relativity breaks down as you get close to the Planck constants, and thus starts producing nonsensical answers.

    • by dfsmith (960400)
      Unless someone has plausably measured the curvature of the universe to be !=0 without telling me, the "singularity" can still be infinite in extent.
  • by Dcnjoe60 (682885) on Monday March 24, 2014 @02:41PM (#46566105)

    Only in theoretical physics is one allowed to say that the immutable laws of physics somehow changed as a way to blend the theories of the early universe after the big bang to the expanding universe we see today. The speed of light is a constant, oops, only from this point forward, same with the effects of gravity, motion and everything else.

    If all of that is true, that the laws of physics, of nature, itself, can mysteriously change with no rhyme or reason, it's almost as if some external force were directing the formation of the universe. Oh, wait, that sounds too much like a deity, so that can't be correct. No, instead, we have to accept that somehow, everything around was was created in an instantaneous blink of an eye. Well everything, that is except physics. That was created separately some time later.

    Or maybe, the physics didn't change, but math did. Maybe in the earliest universe it was permissible to divide by zero. I'm not sure who would have granted that permission, but if you are allowed to divide by zero, you can pretty much prove anything mathematically, so anything goes at the moment of the big bang! After all, dividing by zero just yields infinity and at the point of the big bang, the universe was an infinitesimally small place, so infinity was a lot smaller, too. So, like the speed of light, maybe infinity is relative, too, in which case it turtles all the way down (and up).

    • by iggymanz (596061)

      no, there are many models of the early universe with their own internal rules. Experiments and observations are being used to support those most likely to be useful. None of these models are built of things randomly chosen from a hat as you seem to imply.

      I'd guess you've never formally studied cosmology or field theories.

    • Actually, the immutable laws of physics are treated as, um, immutable. The speed of light is, and was, a constant, and Special Relativity was in effect. Special Relativity doesn't say nothing can ever move faster than light, although it does put some restrictions on such movement. In particular, the Universe can inflate faster than light, although I'm not going through the details here.

      Physics also doesn't answer the questions of how or why the Big Bang happened, or really what happened before inflati

  • by twenty orders of magnitude in the blink of an eye after the Big Bang

    A blink of an eye is in the order of 10^-3 seconds. The inflationary epoch lasted roughly in the order of 10^-33 seconds.

ASCII a stupid question, you get an EBCDIC answer.

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