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In a major discovery, scientists say space-time churns like a choppy sea
- idlewords 3y agoThis article (about a super interesting and precise measurement of background gravitational waves) reads like it came from Parade Magazine: "The gravitational wave background, as described by the astrophysicists, does not put any torque on everyday human existence. There is not a weight-loss discovery in here somewhere. A burble of gravitational waves cannot explain why some days you feel out of sorts. But it does offer potential insight into the physical reality we all inhabit." This is just embarrassing for the Washington Post; the scientists who worked so long for this result deserve better science journalism.
- wernercd 3y agoYou expect good articles out of WashPo? Scientific journalism... from... WashPo? WashPo is many things... but good journalism and scientific journalism is not two.
- NotYourLawyer 3y agoScience journalism is 99% trash. WaPo is independently 99% trash. The odds of this being a good article were pretty low.
- throwaway290 3y agoIt's absolutely key to put these clarifications in a magazine read by laypeople to whom the actual paper would be complete gibberish. If you think there are no silly quacky pseudoscientific ideas spreading from people who misunderstand the phrasing, I have bad news for you. Kudos for journalists trying to combat that.
- snowwrestler 3y agoThose are jokes, a signature of the writing style of Joel Achenbach, who is a respected and experienced science writer.
- throwawaylinux 3y ago[flagged]
- astrange 3y agoHow greedy can Bezos be if he's both retired and lost half his wealth in a divorce? If I was greedy I would simply not have done that.
- throwawaylinux 3y ago"Greedy people wouldn't get divorced or retire." Swing and a miss.
- astrange 3y agoThis but unironically. Bezos's interests are in cheating on his wife with plastic surgery Latinas and not manipulating society through the press. You can tell because he spent half his wealth to do this.
- throwawaylinux 3y agoWrong.
- kleene_op 3y agoThe style of this article is quite something. At first I thought it was AI generated.
- mhandley 3y agoThis Ars Technica article did a good job of answering a lot of the questions I had: https://arstechnica.com/science/2023/06/nanograv-picks-up-signal-of-cosmic-choir-of-supermassive-black-holes/ https://arstechnica.com/science/2023/06/nanograv-picks-up-si...
- Mystery-Machine 3y agoThank you! This should be the actual link, not this WP disgrace.
- yieldcrv 3y ago> In this artist’s interpretation Why arent we using midjourney for obligatory space article pictures? World’s most replaceable job award goes to Astronomy editorial artists
- singleshot_ 3y agoMe personally? Because I don't know how. You? I have absolutely no idea why you did not do this and I wish you would! It'd be even better if you could make some kind of "Astronomy.com's RSS feed -> yieldcrv's midjourney prompt" but one step at a time.
- MattRix 3y agoThere are many reasons, but two of the biggest are that AI art can’t be copyrighted, and that using AI art is immoral. You may disagree with the second point but the fact is that it’s a very common viewpoint. To me it’s especially clear that using AI to make art is immoral when you use it for a purpose that you would have previously hired a human artist for. Harvesting work from artists without permission and then using that to replace them is pretty scummy.
- breput 3y ago"The collaboration stopped short of claiming outright detection, opting to describe their results instead as strong evidence of the expected gravitational wave background. That said, "In our statistical analyses, there's a less than 1-in-1,000 chance of nature giving our results without gravitational waves being present," NANOGrav chair Stephen Taylor of Vanderbilt University said during a press briefing." (from the Ars Technica article) That is far short of the usual 5-sigma (1-in-3,500,000) threshold. So I guess interesting results but not really a major discovery?
- ftxbro 3y ago> "In our statistical analyses, there's a less than 1-in-1,000 chance of nature giving our results without gravitational waves being present" I wonder how many science experiments were done on earth yesterday. It was probably more than a thousand. This is why if you are doing science, you should always do the sciences that will give amazing headlines if you are right. Maybe you will be one of that day's lucky one in a thousand!
- tobinfricke 3y agoThis is an unnecessarily cynical point of view. There has been 1 pulsar-timing experiment looking for gravitational waves and it produced this positive, 1-in-1000 result. Seems extremely promising.
- raattgift 3y agoWould it be a major discovery even with 5-sigma, given that it confirms what everyone thought anyway, namely that there are quite a lot of tens-to-hundreds-of-nanohertz gravitational waves, enough to support the idea of a stochastic background? That is, "General Relativity's right about gravitation yet again". Interesting, because it's yet another way of confirming the theory (at the linear level and a flavour of the equivalence principle), but not at all startling. What's intriguing is that pulsar timing arrays ("PTA") like NANOGrav, CPTA, EPTA, InPTA, PPTA etc may be seeing more gravitational waves than expected. Assuming the sources are all SMBH binaries in ~month-long mutual orbits, then maybe there are more SMBHs than expected, or they binarize more commonly than expected or earlier in the universe than expected, or through some unexpectedly popular channel other than galaxy mergers. Pulsar timing arrays appear likely to produce increasingly useful data about galaxy formation, mergers, and evolution. I think that having both LIGO (Hz-kHz, so ~stellar mass) and PTAs (~nHz, and much larger mass) giving views into different parts of the spectrum in gravtiational wave astronomy is pretty major. That LIGO appeared to work at all was awfully cool; and now we have these large international PTA collabs appearing to work too. I am tempted to compare high-end early 20th century optical telescopes at the dawn of radio telescopes: same electromagnetic spectrum, but sensitivity to different wavelengths, with different wavelengths associated with different phenomena and different objects. PS: I like InPTA's set of cartoons at https://twitter.com/InPTA_GW/status/1674208503395934208 https://twitter.com/InPTA_GW/status/1674208503395934208 (thread).
- yazaddaruvala 3y agoThis is so exciting!!! I get that on Earth we don't seem to have any crazy gravitational effects from the "churning" of spacetime. However, the universe is vast. There might be some parts of spacetime that churn more than it does on Earth. Can someone with more of a physics based background explain: Does this mean with the appropriate detection tools, we might actually start finding hyperspace lanes? i.e. Rather than creating spacetime bubbles with warp engines[0], we could instead "sail" / "surf" certain parts of spacetime for FTL? [0] https://en.wikipedia.org/wiki/Alcubierre_drive https://en.wikipedia.org/wiki/Alcubierre_drive
- raattgift 3y agoSorry to disappoint you. Watching some 68 stable millisecond pulsars for pulse-delays over a long time let the NANOGrav collaboration spot quite a lot of gravitational radiation from heavy bodies (heavy as in billions of solar masses each) in mutual orbits lasting months to years. LIGO, Virgo, and Kagra are sensitive to much quicker mutual orbits, where a single orbit is a fraction of a second. This also implies a much lower maximum mass for the bodies, somewhere between about 2 and 30 solar masses. A pair of bodies of lower mass can have a quicker orbit; heavier bodies will collide and merge instead. > sail or surf The sources of the type of gravitational radiation NANOGrav (and other pulsar timing array collaborations like CPTA, EPTA and PPTA) is sensitive to are scattered randomly across the sky at random distances and with orbits in random orientations. There is unlikely to be a directional bias in our part of the universe. The results are close to what everyone expected, although there may be support for a greater than expected count of supermassive black hole (SMBH) binaries. Binarization channels -- the ways in which a pair of initially-separated SMBHs go into ~months-long orbits with one another will get more study. This is of particular use in understanding the formation and merger of galaxies. Ultimately this is a mostly confirmation of 3-spacelike+1-timelike dimension General Relativity as a good theory for our universe at the largest scales. "Hyperspace lanes" have more dimensions right in the name, so I guess the NANOGrav 15-year study results seem to leave them in the land of fantasy. At best, one can imagine a variety of non-prosaic explanations for the unexpectedly high count of gravitational waves could mean sources other than SMBHs (some early universe phase transitions, that our spacetime has topological defects, unexpected action during cosmic inflation). None of that really invites realistic thinking about "sailing" or "surfing" any more than a random scattering of SMBH binaries. The prosaic explanation for the unexpectedly large number of SMBH-like signals is simply that black holes tended grow large in dustier regions than expected. Finally, for the most part (i.e., in not-very-dusty regions of space) light waves and gravitational waves move at the same speed, so at first glance it doesn't seem likely that gravitational waves would help one with FTL travel.
- deleted 3y ago[deleted]
- ajdude 3y agohttps://archive.is/Gd3wq https://archive.is/Gd3wq
- candiddevmike 3y agoCan you harvest energy from this somehow?
- lost_tourist 3y agoNo
- lll-o-lll 3y agoAww
- permo-w 3y agowhy? too weak?
- tetris11 3y agoYes. It would be like trying to harvest energy from vibrating sound waves, whilst using a sensitive microphone that requires orders of energy more to function. With sound waves you could use a really super thin piece of metal that vibrates to sound itself, in which you could harvest sound energy. But gravitational waves? I don't know how easy that would be. Maybe a super long and rigid cable, positioned thousands of kilometers apart that bends ever so slightly to changes in their anchors.... though I'm sure any energy harvested from that would have gravitational waves as their least contributing factor.
- dredmorbius 3y agoIf you were very close to the origins, perhaps. Though in that event, I suspect you might be having other priorities.
- tobinfricke 3y agoNot enough to be useful. In the case of these extremely low-frequency waves, also not enough to be measurable.
- senectus1 3y agoI read that headline and got Warhammer 40k vibes immediately.. sounds very much like the Warp.
- lordfrito 3y agoSo with all this background churning, is it possible to periodically get the waves to line up and interfere constructively to create "rogue waves" in spacetime? [1] I might be huge comparatively but still too small to measure it's effects maybe? [1] https://en.wikipedia.org/wiki/Rogue_wave https://en.wikipedia.org/wiki/Rogue_wave
- raattgift 3y agoThat's an unexpectedly neat question. Gravitational radiation can form caustics, so in one way, yes. This was an area of theory that Bondi and Pirani were interested in during the 60s to 80s. Caustics are meant in the sense of the bright spots in https://en.wikipedia.org/wiki/Caustic_(optics) https://en.wikipedia.org/wiki/Caustic_(optics) but rather than some "rogue wave" you might get a black hole. More recently mathematical-relativity studies of the stability of Kerr black holes included a 900+ page paper https://arxiv.org/abs/2205.14808 https://arxiv.org/abs/2205.14808 which among other things considers something like a rogue wave passing through a spinning black hole, and asking: does the black hole swallow up some of the wave? or does part of the wave get entrained into a sort of accretion disc? in that disc do caustics appear, and if so do they lead to black holes? if so, do those black holes fall in, fly away, or coalesce into long-term orbiting bodies around the original black hole? These questions were asked because "stability" means "if perturbed (e.g. by a powerful gravitational wave), does an initially Kerr-like black hole relax back into a Kerr-like black hole, or does it become something very much not like Kerr?". Caustics may also form by a powerful gravitational wave gravitationally-lensing around some massive object like a heavy galaxy cluster. And if that massive object has enough angular momentum, it's possible the caustic will evolve into a significant gravitational wave enhanced somewhat analogously to a slingshot manoeuvre by a spacecraft. Conversely, we can start with a rogue wave existing, and see what it does. Bondi and Pirani were also interested in spacetimes with enormous gravitational wave impulses. One family of those is the "sandwich wave", https://royalsocietypublishing.org/doi/10.1098/rspa.1959.0124 https://royalsocietypublishing.org/doi/10.1098/rspa.1959.012... (1959) (put "https://sci-hub.se/ https://sci-hub.se/ in front of that URL if you need to). Loosely, it's called "sandwich" because the spacetime is pretty bland (like white bread?) or even flat on either side of the wave, which divides the spacetime into three parts (including the wave itself). Thirty years later they showed that the sandwiches are pretty unhealthy as they tend to destroy everything in the universe they pass through (any set of finitely-but-widely-separated galaxy clusters in such a spacetime will end up colliding with each other in finite time). https://royalsocietypublishing.org/doi/10.1098/rspa.1989.0016 https://royalsocietypublishing.org/doi/10.1098/rspa.1989.001... (also on sci-hub, and with nice late-1980s diagrams). Fortunately, I don't think anyone has any idea how to generate a sandwich wave - it's just a feature of the spacetime put in by hand. Unfortunately, we could be in a sandwich spacetime and not know it yet. A sci-fi writer might speculate about a preferred orbital plane for a large number of (very-early-universe-born) supermassive black hole binaries building up an approximate sandwich wave over the course of billions of years. Or perhaps speculate that the apparent stochastic background that's the topic of the fine link at the top where I guess you get "churning" from is not caused principally by supermassive black hole binaries but by some tensor-mode reheating during cosmic inflation (or a false-vacuum-to-real-vacuum first-order (not as in recent Star Wars, or is it?) phase change), and that this effect happened to generate a sandwich wave which has already destroyed galaxies far far away. A hard-working hard science fiction writer might even be able to force a cosmologist to concede that such a picture might be consistent with observation, including the pulsar timing array results in today's news. A sandwich wave would zip through our galaxy at the speed of light, but the sandwich-wave-induced collapse of the galaxy into a caustic might take enough time that you could really what's-the-opposite-of-enjoy the experience. Pleasant dreams.
- deleted 3y ago[deleted]
- nashashmi 3y ago> What we measure is the Earth kind of moving in this sea. It’s bobbing around — and it’s not just bobbing up and down, its bobbing in all directions Of course the movement is so small and subtle that these movements are more like vibrations. Also known as the sound of the universe aka OM in Hindu scripture.
- armatav 3y agoMaybe you get rogue waves in it too
- amai 3y agoWhat’s the Frequency, Kenneth?