Arthur T Knackerbracket has found the following story:
The field of astronomy has been revolutionized, thanks to the first-ever detection of gravitational waves (GWs). Since the initial detection was made in February of 2016 by scientists at the Laser Interferometer Gravitational-wave Observatory (LIGO), multiple gravitational events have been detected. These have provided insight into a phenomenon that was predicted over a century ago by Albert Einstein.
As it turns out, the infrastructure that is used to detect GWs could also crack another astronomical mystery: dark matter. According to a new study by a team of Japanese researchers, laser interferometers could be used to look for weakly interacting massive particles (WIMPs), a major candidate particle in the hunt for dark matter.
To recap, WIMPS are a theoretical elementary particle that interacts with normal matter (baryonic) only through the "weak" force gravity. As with other elementary particles that are part of the Standard Model (of which WIMPS are not), they would have been created during the early universe when the cosmos was extremely hot.
WIMPs are essentially the microscopic candidate particle, which puts them at the opposite end of the spectrum from the other major candidate—the macroscopic massive compact halo objects (MACHOs). So far, multiple experiments have been conducted to find these particles, ranging from particle collisions and indirect detections to more direct methods, but the results have been largely inconclusive.
As Dr. Satoshi Tsuchida, a professor of physics at Osaka City University and the lead author of the study, told Universe Today via email:
"[Most] MACHOs are believed to consist of baryonic matter, but baryons account for only 5 percent of the universe. Thus, we cannot explain the structure of the present universe if all of dark matter consists of MACHOs. On the other hand, WIMPs are non-baryonic matter, and we have no reason to exclude [them] from dark matter… Therefore, WIMPs can be promising dark matter candidates."
(Score: 1, Interesting) by Anonymous Coward on Saturday September 14 2019, @11:02AM (1 child)
Hard to tell how exactly these detectors are supposed to actually detect the dark matter. I guess it's a matter of them excluding all the terrestrial noise sources, subtracting the signals that look like gravitational waves, and seeing if there's anything left over. If so, it might be dark matter.
Except these detectors aren't really optimized for volume, which seems like something you'd need. They're talking about a dark matter particle interacting with the actual mirror in the interferometer. That's not very much material at all. It just seems really unlikely to happen.
(Score: 2) by FatPhil on Saturday September 14 2019, @11:11AM
Great minds discuss ideas; average minds discuss events; small minds discuss people; the smallest discuss themselves
(Score: 5, Interesting) by FatPhil on Saturday September 14 2019, @11:08AM (5 children)
Or the ones that were postulated later, which were testable early-LHC, and failed to exist?
Or the ones that were postulated later, which were testable 8-14 TeV-LHC, and failed to exist?
Are you saying they've come up with even more that can be tested for and be shown not to exist - after all, they do have a reputation to uphold.
I remember seeing a vid of a lecture by Nima A-H, about an upcoming experiment (early-LHC era, I think) which he was so supremely confident (Nima, confident - say it ain't so!) would demonstrate the existence of some new particle that he said if it didn't he'd eat his hat. It didn't. He didn't. Why should I show him any respect after that? He seemed to think that the beauty of the maths obligated physics to follow it, which is complete nonsense/nonscience.
I'm not dissing this experiment, or any others, just the attitudes of some of the people who are involved with them. I'll be as happy as any of them if they can pull off a 5-sigma result, but the rider "it's about bloody time" might be attached to my praise.
Great minds discuss ideas; average minds discuss events; small minds discuss people; the smallest discuss themselves
(Score: 2) by HiThere on Saturday September 14 2019, @04:11PM (3 children)
Well, the "It's about bloody time" is really unjustified, even though you dislike their attitude. When you don't know what the answer is, you need to look at everything plausible. When looking for my glasses I often even look again at places I've already looked...sometimes it works.
OTOH, given the current uncertainty about the Hubble constant, one might wonder just how certain it's reasonable to be about "dark energy" and "dark matter". *Something* is clearly unexplained, but it's shape might not be what it's expected to be.
Javascript is what you use to allow unknown third parties to run software you have no idea about on your computer.
(Score: 3, Informative) by FatPhil on Sunday September 15 2019, @06:41PM (2 children)
Make claim 1
Say We're sure experiment 1 will justify claim 1
Perform experiment 1
Experiment 1 doesn't support claim 1
Make claim 2
Say We're sure experiment 2 will justify claim 2
Perform experiment 2
Experiment 3 doesn't support claim 2
Make claim 3
Say We're sure experiment 3 will justify claim 3
Perform experiment 3
Experiment 3 doesn't support claim 3
Make claim 4
Say We're sure experiment 4 will justify claim 4
Perform experiment 4
Experiment 4 doesn't support claim 4
Make claim 5
Say We're sure experiment 5 will justify claim 5
Perform experiment 5
Experiment 5 does support claim 5!
Congratulations, but it's about bloody time.
Perfectly justified. They shouldn't have gone into things with such arrogance. 1/5 is not a good hit rate for grand theories that seemingly must be true. You really sound like you've never seen a Nima A-H lecture.
Great minds discuss ideas; average minds discuss events; small minds discuss people; the smallest discuss themselves
(Score: 2) by HiThere on Sunday September 15 2019, @08:40PM (1 child)
Well, you've got me on that. I *have* never attended one of his lectures...or read any of his papers.
Javascript is what you use to allow unknown third parties to run software you have no idea about on your computer.
(Score: 2) by FatPhil on Monday September 16 2019, @05:41AM
Great minds discuss ideas; average minds discuss events; small minds discuss people; the smallest discuss themselves
(Score: 0) by Anonymous Coward on Sunday September 15 2019, @04:51AM
His prediction was that the particle collider in question would find the Higgs Boson. Turns out the LHC did find the Higgs Boson, once it was able to do sufficiently powerful proton beams with a good enough inverse femtobarn.
(Score: 2) by Rupert Pupnick on Saturday September 14 2019, @05:37PM (3 children)
"WIMPs are essentially the microscopic candidate particle, which puts them at the opposite end of the spectrum from the other major candidate—the macroscopic massive compact halo objects (MACHOs)."
If they're macroscopic and massive, why are they so hard to find? The word "macroscopic" carries with it the implication of not needing special equipment to detect it, right? Or is there some parallel definition of "macroscopic" in particle physics of which I'm ignorant? If so, could we call it something else besides "macroscopic"?
(Score: 1, Interesting) by Anonymous Coward on Sunday September 15 2019, @04:37AM
Because they are dark and isolated. Basically, it is any baryonic matter that does not emit radiation nor interact with local objects that do. An example of a MACHO would be a comet that has been thrown into interstellar space or a black hole. You can only really "see" them through their gravitational effects on things we can see. They definitely exist, the question is how much of it exists because they are so hard to see. Other indications, like the CMB, suggests its not more than a small percentage of the total mass/energy of the Universe, but the exact amount is an open question.
(Score: 1, Interesting) by Anonymous Coward on Sunday September 15 2019, @05:01AM
https://en.wikipedia.org/wiki/Massive_compact_halo_object [wikipedia.org]
MACHO = I guess there are so many black holes, brown dwarfs, rogue planets, interstellar rocks, etc. that we didn't account for, that dark matter isn't real after all! It was just "missing matter"!
The idea is that instead of 5% ordinary matter and 27% dark matter, it's 32% ordinary matter. It has been largely ruled out as an explanation.
(Score: 0) by Anonymous Coward on Sunday September 15 2019, @08:12PM
BZZT! Wrong. It's right in the the name! Obviously, you need a macroscope to see that stuff. Sheesh!
The problem is that there is no such thing as a macroscope, hence the problem in detection. Duh!
(Score: 2) by Gaaark on Saturday September 14 2019, @10:03PM (1 child)
"Gravitational Wave Detectors Might Be Able To Detect Dark Matter Particles Colliding"
Yawn.
You know where my bets are.
--- Please remind me if I haven't been civil to you: I'm channeling MDC. ---Gaaark 2.0 ---
(Score: -1, Redundant) by Anonymous Coward on Saturday September 14 2019, @10:20PM
Hood rat Gaaark is going to pop a cap in they dark asses.