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'Unbelievable': Astronomer Claims 'Direct Evidence' of Gravity Breaking Down
- mellosouls 3y agoMad clickbait, as expected. Gravity is not breaking down. The study author claims the results offer support for MOND which really ought to be interesting enough to reflect in the title.
- ecf 3y agoAfter the superconductor flop I imagine we will see a lot more stories like this where journalists hype up anything they possibly can.
- CatWChainsaw 3y agoThis is just every single news cycle. If it's not going to revolutionize everything then you're going to bore your audience to death. Hype is overhyped. Welcome to the 21st century.
- TheCoelacanth 3y agoIt doesn't seem like clickbait to me. "Breaking down" is a common way of expressing that a scientific theory isn't explaining experimental data in a certain set of circumstances, which is exactly what the person they're reporting on is claiming.
- Tagbert 3y agoThe theory may be “breaking down” but is gravity? That was the title’s confusing implication.
- A_D_E_P_T 3y agoThe fulltext of the study, which is free, is here: https://iopscience.iop.org/article/10.3847/1538-4357/ace101/pdf https://iopscience.iop.org/article/10.3847/1538-4357/ace101/... What's important to note is that while the work is suggestive, it's far from conclusive. The author notes, however, that "even stronger results than the present results are expected with later data releases of Gaia." So, presumably, we'll have more evidence very soon --- and, if not, the way to bet is that this finding will turn out to be due to the instrumentation's margins of uncertainty. The author also notes that "a recent study by Mistele (2023) showed that predictions of the AeST theory agree broadly with the results of this work." Which suggests that the AeST theory might be worth a look!
- bsaul 3y agohave any link explaining aest ?
- deleted 3y ago[deleted]
- A_D_E_P_T 3y agoThe Mistele paper referenced is pretty interesting: https://arxiv.org/pdf/2305.07742.pdf https://arxiv.org/pdf/2305.07742.pdf It's a MOND-derivative theory, so the Milgrom and Bekenstein MOND papers are foundational.
- T-A 3y agohttps://arxiv.org/abs/2007.00082 https://arxiv.org/abs/2007.00082
- bjornsing 3y agoWe're looking at a system of stars and talking about accelerations below one nanometer per second squared? Really...?
- ta8645 3y agoIt says "unbelievable", right in the title.
- taneq 3y agoOver millions of years and distances of light years it all adds up.
- Someone 3y agoThat is irrelevant for discussing how amazing it is that we (think we) can measure such quantities. They didn’t observe over millions of years.
- EspressoGPT 3y agoYou just end up with very small numbers (acceleration) when you divide trivial numbers (distance) by very large numbers (orbital period).
- mr_mitm 3y agoYou even divide it by a large number squared.
- Someone 3y agoThat makes me think “could easily be a numerical issue with precision or accuracy of the software used”. I couldn’t find the software, so I couldn’t check a bit deeper.
- topspin 3y agoBoth the data and the code (Python) is here: https://zenodo.org/record/8065875 https://zenodo.org/record/8065875 That link came from the paper. Zenodo.org is a open science site curated by NASA. The analysis is interesting. He is using Gaia space observatory data to identify "nearby" binary systems, filtering out those with a high likelihood of being compromised by additional bodies in the system, and those for which the bodies have poor mass estimates, then measuring the orbits of the remaining 26k systems that can be confidently projected to three dimensions and aren't too eccentric, etc. His results are that below some small level of gravitational acceleration (the stars are far apart with long orbital periods,) the orbits predictably deviate from Newtonian gravity, and that due to the small size of binary systems Dark Matter cannot be a factor. It's a Nobel prize winner if correct. Good old fashioned falsifiable Science: future data sets and peer review of the work will tell us. Too bad Gaia runs out of fuel in two years. The longer the data set the more confidence can be achieved in this sort of work. It's interesting that only the most recent of the so far three data sets from Gaia provides the data necessary (tangential and radial velocity,) to do this.
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- LinAGKar 3y agoClickbait title makes it sound like some doomsday scenario, when in reality it's just some evidence of gravity working slightly differently than believed.
- SomeoneFromCA 3y ago"Slightly different" is a breakdown in precise sciences like physics.
- mr_mitm 3y agoBreakdown of GR, maybe, not gravity. Which even though it would be groundbreaking is still a different thing.
- codethief 3y agoThis is splitting hairs. Our entire understanding of what gravity is and how it works rests on GR. If GR "broke down" in major ways, then the same would hold true for gravity, as we understand it.
- vbezhenar 3y agoJust call it dark gravity. Problem solved.
- jfengel 3y agoGeneral relativity is more fundamental than gravity. If general relativity breaks down, it completely redefines what we think gravity is. And much, much more -- practically everything beyond our solar system has to be reconsidered.
- LinAGKar 3y agoA breakdown of the theory maybe, but not of gravity itself. There is a difference between "Gravity Breaking Down" and "The Theory of Gravity Breaking Down".
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- sigmoid10 3y agoThis would be an incredible result and probably the biggest experimental physics discovery in decades (bigger than gravitational waves and the Higgs). But MOND has so many problems on so many levels and some of the people who promote it in the scientific community are borderline crackpots. So I'd treat this veeeeery carefully until confirmed by independent groups and measurements. For the moment, this is like the room-temp superconductor: Revolutionary if true, but I'd still bet on poorly executed measurements in combination with unknown errors as the real explanation.
- topspin 3y ago> But MOND has so many problems The fact that the results happen to fit some MOND model(s), while interesting, doesn't really mean much: these results could be 100% correct and all of MOND a pipe dream at the same time. The crucial question is, is the analysis correct?
- sigmoid10 3y agoIf the results are correct, it means that extreme weak field gravity laws are actually in need of modification. I'd be very surprised if any existing variant of MOND got it right, but it would still mean that the premise of MOND is correct, which would be a huge deal.
- V1ndaar 3y ago> premise of MOND is correct Well, typically the term MOND refers to very specific modifications of Newtonian gravity and doesn't even take into account GR. So I'm not sure I would agree with the statement in general terms (note, I haven't read the paper so far, so I don't know what they claim). There's _plenty_ of extensions of GR though that modify gravity. That in itself isn't really that surprising. Scalar-Tensor theory and the like. And there's a reason these are usually not called MOND. Some go by "MOG" for modified gravity.
- sigmoid10 3y ago
- sebzim4500 3y agoHere's a relevant thread by someone in the field: https://threadreaderapp.com/thread/1667141734055264256.html https://threadreaderapp.com/thread/1667141734055264256.html It's interesting that different teams are making statistically significant contradictory claims from the same dataset.
- mannykannot 3y ago...but different samples of the same dataset, surely? "Banik et al. only consider binaries with separations >2000 AU. Those are already quite close to the MOND regime, i.e. a0. You expect to find a change in behavior for different separations, i.e. once you approach the MOND regime, which they do not see. "Chae additionally considers tighter binaries than Banik, which must be in the Newtonian regime even in MOND (a>>a0). He uses these to calibrate his analysis, since he knows what Newton should do. He finds that MOND behaviors begins at 2000 AU! "Right where Banik's sample starts." He then goes on to mention a third sample which excludes triple systems.
- sebzim4500 3y agoYeah, that's what I mean. All the groups have downloaded the same dataset from Gaia, and yet have come to completely opposite conclusions based on the analysis techniques, filtering, etc.
- anentropic 3y ago> “When the results started to show up from my new and more reliable code, my initial reaction was that it was unbelievable,” Chae said in an email to Motherboard. “I was feeling like I was dreaming. It seemed so unreal. This is because my results did not match any previous results.” as a dev I'd be deeply skeptical of my own feelings here but, wow, amazing news if it turns out legit!
- digitcatphd 3y agoThis seems suspect coming from Vice.
- defrost 3y agoVice is reporting on the paper, the source of the paper is here: https://iopscience.iop.org/issue/0004-637X/952/2 https://iopscience.iop.org/issue/0004-637X/952/2 which of the companion pieces are you also dismissing without reading? Do you feel this way about every paper in The Astrophysical Journal or just these papers that appear in Volume 952 Number 2, 2023 August 1st ?
- fguerraz 3y agoYes, the problem is not the paper, but Vice's reporting. It is, as usual just clickbait.
- defrost 3y agoThe GP comment has been edited down .. originally it was along the lines of "appears in Vice == not worth reading further". The Vice reporting may well be subpar .. the paper, MOND, and general subject area is well worth reading more about especially given the level of conjecture and almost noise level data (well, for some of us at least).
- cal85 3y agoThis explains all those levitating rock videos I’ve been scrolling past recently
- sharikous 3y agoVery nice but the article could do without using the term "standard model". I get that she is talking about the standard cosmological model and she leaves it uncapitalized, but it really confuses readers familiar with "the" Standard Model as a QFT theory
- sigmoid10 3y agoIn the literature, LCDM is commonly referred to as the "standard model" (in cosmology of course). So there is nothing wrong with that. Though I wouldn't trust Vice to get their terminology right, so they probably got it from the authors.
- vidanay 3y ago"Extraordinary claims require extraordinary evidence” - Sagan
- hoseja 3y agoI've always been uncomfortable with the fudge-factor physicists call Dark Matter/Energy and confidently act like is real. Would be nice to see it destroyed.
- chadcmulligan 3y agoI went down the mond rabbit hole a while ago, The bullet cluster is one of the things that makes mond hard to support https://en.wikipedia.org/wiki/Bullet_Cluster https://en.wikipedia.org/wiki/Bullet_Cluster
- edgyquant 3y agoYour link seems to suggest that it being proof of dark matter and against MOND was based on bad data that has since been rectified.
- chadcmulligan 3y agoCould be, this is interesting https://pursuit.unimelb.edu.au/articles/digging-deep-for-dark-matter https://pursuit.unimelb.edu.au/articles/digging-deep-for-dar...
- chriswarbo 3y ago> the fudge-factor physicists call Dark Matter/Energy Those are two very different fudge factors (as in, those hypotheses are distinct; the observations they attempt to explain may turn out to have a single cause instead, but we don't yet know) > Would be nice to see it destroyed If you don't like fudge-factors, then you probably won't like MOND (the sort of hypothesis TFA is about). Edit: MOND theories put a fudge-factor "a₀" in their acceleration calculation; the value of a₀ is chosen such that (a) it is small enough to make no measurable difference from standard gravity in any existing observations; and (b) it can curve-fit observations of charged matter distribution to galactic rotation curves.
- uoaei 3y agoWhenever MOND comes up I feel obligated to refer interested readers to this expert astrophysicist's blog on the matter: https://tritonstation.com/new-blog-page/ https://tritonstation.com/new-blog-page/
- defrost 3y agohttps://en.wikipedia.org/wiki/Stacy_McGaugh https://en.wikipedia.org/wiki/Stacy_McGaugh Blast from the past, I hadn't realised he had a blog - thank you for that.
- piker 3y agoKnowing nothing about astrophysics, synthesizing: > binaries located within about 650 light years of Earth > developing a new code > below one nanometer per second squared we see a claim that an astronomer developed new code which produces a novel result relying on some very large numbers and a very small number. Red flags abound.
- uoaei 3y agoThese extremely low-acceleration regimes are precisely where the issue is, and why dark matter and MOND were both developed as competing frameworks for understanding discrepancies vs our current understanding. It's the only regime where these questions can be probed and investigated.
- Stevvo 3y agohttps://twitter.com/8minutesold/status/1667141734055264256 https://twitter.com/8minutesold/status/1667141734055264256 Thread with some more info.
- layer8 3y agohttps://threadreaderapp.com/thread/1667141734055264256.html https://threadreaderapp.com/thread/1667141734055264256.html
- m3kw9 3y agoKoreans hitting it out of the park lately with new theories/materials, although unproven
- mikewarot 3y agoI'm a follower of the "Quantized Gravity" flavor of modified gravity, as proposed by Mike McCulloch[1]. I fully realize it's a fringe theory, but there should be experimental evidence from an actual thruster flown in space, launching in less than 90 days..[2] I hope he's right... but the only way to know is to wait and see. Reactionless thrust would be a handy way to get around the cosmos. [1] https://physicsfromtheedge.blogspot.com/ https://physicsfromtheedge.blogspot.com/ [2] https://ivolimited.us/launch/ https://ivolimited.us/launch/
- qubex 3y agoYou mean “quantised inertia”.
- yencabulator 3y agoFrom the linked blog: > and there should be a property office for space to encourage space mining and a new gold rush Run by who? On the surface, that seems like a statement that all of space belongs to the author's favorite country.
- mikewarot 3y agoRun by whomever can provide rescue services if something goes wrong, and/or enforce a monopoly on violence.
- liftm 3y agoHope there's a stronger theory behind that than behind the https://en.wikipedia.org/wiki/EmDrive https://en.wikipedia.org/wiki/EmDrive …
- codethief 3y agoThis is the first time I'm hearing about Quantized Inertia. Are there any good, independent overviews over McCulloch's papers and the current state of affairs? Looks like the Wikipedia page (and references to it) have been deleted, and the QI subreddit has largely become inactive.
- workfromspace 3y agohttps://archive.is/Xdml7 https://archive.is/Xdml7
- hcks 3y ago[flagged]
- 10g1k 3y agoOnly geographically related, but Sejong Village Food Street is awesome. Note about mentions of the Higgs discovery: The Higgs boson was not observed. Never has been. Rather, an effect predicted to be caused by the Higgs boson was observed.
- phillias 3y agoPlease, this won't give us ufo technology. Quit sperging out and get into materials science stat!