No, the Universe is not expanding at an accelerated rate, say physicists
Back in 2011, three astronomers were awarded the Nobel Prize in Physics for their discovery that the Universe wasn’t just expanding - it was expanding at an accelerating rate.
The discovery led to the widespread acceptance of the idea that our Universe is dominated by a mysterious force called dark energy, and altered the standard model of cosmology forever. But now physicists say this discovery might have been false, and they have a much larger dataset to back them up.
Earlier this year, NASA and ESA scientists found that the Universe could be expanding around 8% faster than originally thought.
By all accounts, the discovery was a solid one (Nobel Prize solid) but it posed a very difficult question - if the collective gravity from all the matter expelled into the Universe by the Big Bang has been slowing everything down, how can it be accelerating?
Since scientists first proposed dark energy, no one's gotten any closer to figuring out what it could actually be.
But now an international team of physicists from institutions say don't worry about it, because it probably doesn't even exist, and they've got a much bigger database of Type 1a supernovae to back them up.
By applying a different analytical model to the 740 Type Ia supernovae that have been identified so far, the team says they've been able to account for the subtle differences between them like never before.
They say the statistical techniques used by the original team were too simplistic, and were based on a model devised in the 1930s, which can't reliability be applied to the growing supernova dataset. They also mention that the cosmic microwave background isn't directly affected by dark matter, so only serves as an "indirect" type of evidence.
Instead of finding evidence to support the accelerated expansion of the Universe, Sarkar and his team say it looks like the Universe is expanding at a constant rate. If that's truly the case, it means we don't need dark energy to explain it.
Source & further reading:
http://www.sciencealert.com/no-the-universe-is-not-expanding-at-an-accelerated-rate-say-physicists?perpetual=yes&limitstart=1
Paper:
http://www.nature.com/articles/srep35596
#physics #space #research #universe
Wow, that's quite something! A big theory destroyed and some egos shattered. The simpler the better.
ReplyDeleteMay the Force be with you!
Thanks for sharing.
This account of the news is more clear-cut than the one I'd read, according to which the evidence for an accelerated expansion that gave rise to the 2011 Nobel was weakened by a more extended data set that brings the possibility of no acceleration at all, back within the margin of error.
ReplyDeleteI do think it is important not to write off that dark matter and dark energy might still exist, there is still much we don't know and ideas need to be challenged, but not necessarily discounted.
ReplyDeletehttp://www.forbes.com/sites/startswithabang/2016/10/19/no-number-of-additional-galaxies-can-prevent-the-universe-from-needing-dark-matter/
themoth.org - The Moth
ReplyDeleteJust for giggles, listen to this...❤
It sounds like getting manned (or womaned) space exploration in and around the solar system and maybe next door to Alpha Centari to collect more data would help......only so much we can do sitting on this tiny third rock from the sun......
ReplyDeleteHas the basis of a Nobel prize ever been disproved? If this new finding pans out, it would be a very big deal... Whatever happened to extraordinary claims require extraordinary evidence? Folks will be even more distrustful of science - not good
ReplyDeleteAstonishing news! If it's verified it would imply that the Nobel Prize has been granted too fast...! If only new methods other than the Supernovae 1a could orientate the decision, until then some long debates are going to feed the controversy, for sure... Thank you for the sharing Corina Marinescu
ReplyDeleteWow. So what does this say about the Cosmological Constant in Einstein's equations?
ReplyDeleteJason Owlbright that it might be 0 instead of 10^−29 g/cm3 = 10^-122 in Planck units (not very much).
ReplyDeleteEdit: that's about 10 milligrams for the volume of the Earth... and for each equal volume of empty space.
Thanks for sharing Miss Corina....:-)....
ReplyDeleteOui!
ReplyDeleteThis would be huge news if validated. The accelerating expansion of the universe isn't just about the existence of dark matter/energy. It's also critical to the Big Bang Theory, one of who's fundamental principles explains the expansion of space-time.
ReplyDeleteBryce Etheridge Not really. The Big Bang Theory lived for decades without this accelerated expansion whose late 90es observation is now put into doubt.
ReplyDeleteThis is the nicest thing about science... There is no absolute true, just incremental knowledge.
ReplyDeleteD'oh !
ReplyDeleteBoris Borcic True. But dark energy provides an answer to some parts of the Big Bang that were not fully explained. It quite neatly provides a force that's responsible for the expansion of space rather that having expansion be a thing that space just does.
ReplyDeleteLacking that part of the explanation opens the big bang up to other theories. I'm specifically thinking of theories that would explain universal observable red-shift without the expansion of space, which would be counter to the Big Bang. Perhaps light waves just spread out naturally over long distances, for example.
Bryce Etheridge Didn't you hear that at the time Einstein devised the equations of General Relativity -- 1916 -- he missed predicting the Big Bang because
ReplyDelete(a) the assumption of a steady-state universe was dominant at the time
(b) the simplest form of his equation (with no cosmological constant, dark energy of acceleration of the expansion) forbade a steady-state universe (and in fine required a Big Bang), so that
(c) he plugged in, as the simplest way to "repair" his equation, a cosmological constant exactly like the cosmological constant used to explain the acceleration but with the opposite sign, that he then
(d) removed in 1929 while calling it "the biggest blunder of my life" when Hubble interpreted the redshifts of distant galaxies as universal expansion ?
From 1929 on, for seven decades Einstein's GR without a cosmological constant happily provided explanation of the redshifts as due to the expansion of space, to rule other explanations out. As noted, these equations would even have predicted the redshifts before they were observed if Einstein had put more faith into what the equations appeared to tell in their non-doctored form.
Boris Borcic That's pretty cool, I had not heard it
ReplyDeleteBoris Borcic The cosmological constant, 'the biggest error of my life' Einstein said. Your comment is a necessary good abstract of what is now the History of Physics.
ReplyDeleteThere's something common to Einstein's wrongheaded distrust of his GR equation and how he predicted in effect quantum entanglement but presenting it as a refutation of QM. It's a commentary on his profound and humble genius that even his mistakes opened way to major inroads.
ReplyDeleteThis new publication contradicts this contradictory post... and we go back to the initial hypothesis: the supernovae 1a are enough accurate to establish the pace of the expansion of the universe, therefore the theory of dark energy is still on the agenda....
ReplyDeleteSummary: New research by cosmologists confirms the accuracy of Type Ia supernovae in measuring the pace at which the universe expands. The findings support a widely held theory that the expansion of the universe is accelerating and such acceleration is attributable to dark energy. The findings counter recent headlines that Type Ia supernova cannot be relied upon to measure the expansion of the universe.
sciencedaily.com - Role of supernovae in clocking the universe
Interesting article
ReplyDelete