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“Odd Radio Circles” have astronomers excited
- edhelas 6y agoThat's the Ring from The Expanse, nothing more :p
- xwdv 6y agoWhat exactly is the throat of a wormhole?
- yodon 6y agoIt's extremely unlikely the phenomena "can't be explained" and far more likely that it "hasn't been explained." Science is like that. It's why discoveries are fun.
- stretchcat 6y agoWe should probably count ourselves fortunate that the title wasn't more directly contradicted by the first sentence of the article explaining it. I've noticed this a few times recently.
- rafaelvasco 6y agoYeah, everything can be explained. The only blocking factors are language to express it and/or knowledge to understand it.
- JackFr 6y agoTo believe that everything can be explained is an expression of faith not reason. Our brains are very good at tricking us into thinking they are universal understanders. They are not.
- TeMPOraL 6y agoPart of the job mathematics does in science is developing tools for describing patterns - any patterns. We've also learned to deal with uncertainty, so we can now describe approximate, probabilistic patterns as well. Thanks to this, if there's any pattern about a phenomenon to be found, we likely can describe it already; if not, there's no good reason to believe we won't be able to describe it in the future. That is the first step towards an explanation (second being tying the pattern to theories that fit other observable evidence, and that have predictive power). If there's absolutely no pattern to be found in a phenomenon, then it implies the phenomenon doesn't have any consequences on anything - which implies it isn't even observable in the first place. From that follows it isn't even worth thinking about.
- TheOtherHobbes 6y agoWhy would you assume that all patterns and relationships are comprehensible by humans - not just in terms of complexity, but in terms of root qualia? Cats can't count. They seem to understand quantity, but they have no concept of integers. It seems extremely rash and naive to assume that humans don't suffer from some related conceptual handicaps. And of course we're not aware of them, by definition.
- SargeZT 6y agoHumans were also unaware of numbers and counting until we discovered/invented them in antiquity. We may be unaware of limitations that we have now, but we seem to be in a unique position in the animal kingdom to be able to overcome those conceptual limitations once a need for those concepts is identified.
- matthewdgreen 6y agoThe article goes through a list of known cosmic phenomena trying to see if this observation can be explained by each, and concludes it’s unlikely. “Can’t be explained” clearly means “can’t be a explained by a known phenomenon”. Human language is a beautiful and powerful and (sometimes) ambiguous tool. We could write everything in terms that are completely unambiguous —- like some awful formally-verified programming language —- so people on HN couldn’t possibly adopt an absurdist interpretation and spend time knocking it down. Or alternatively, we can just use common sense and the world can be a slightly more interesting and mysterious place.
- yodon 6y agoOr we can attempt to preserve the meanings of simple words such as "can't" and "haven't" that exist for use in exactly these circumstances. They aren't hard words, and they have a role to play in even the most minimally intelligent conversation.
- esarbe 6y agoSometimes things "can't be explained" with the current theories. We need new theories before we can explain things. So, in this sense, I'd say it's correct to say that "things can't be explained". I wholeheartedly agree that discoveries like these are fun. They challenge us to develop new theories, try to make new predictions and then prove these wrong. :D
- peteradio 6y agoI don't understand, can't they bring them into focus to guess their distance? How can't they know if they are in or out of the galaxy?
- cecilpl2 6y agoLight rays are effectively parallel at these colossal distances. Everything is in focus. In fact, only 100 years ago this year was the "Great Debate" (https://en.wikipedia.org/wiki/Great_Debate_(astronomy) https://en.wikipedia.org/wiki/Great_Debate_(astronomy)) about whether Andromeda and other galaxies were outside the Milky Way, or whether they were small internal nebulae. To determine distances to things, we use the cosmic distance ladder (https://en.wikipedia.org/wiki/Cosmic_distance_ladder https://en.wikipedia.org/wiki/Cosmic_distance_ladder) which is rooted on very close stars whose parallax we can measure over the course of a year.
- peteradio 6y agoThanks for the reply! If we are moving through our galaxy at 220 km/s how long would we have to watch one of these things to determine its precise location (assuming its close) or alternatively set a limit on its distance?
- dnautics 6y agoit's angular motion that you care about, so it could still be a long time. We can put some hard lower bounds on how close it could be, though. For example, it's probably not a wormhole mouth within a few ly of our solar system.
- s_gourichon 6y agoThe picture feels especially surprising because of the fuzzy contours and transparency that do not fit the sharp stars. Keep in mind that the image is a superposition of an image in some radiowave frequency range (fuzzy either because of different sensor/tech/frequency range), superimposed to a normal image in visible spectrum with very different actual resolution. > The ghostly ORC1 (blue/green fuzz) on a backdrop of the galaxies at optical wavelengths.
- ncmncm 6y agoAstronomical radio images are naturally overwhelmingly sharper than optical images, because radio telescopes today can have much larger apertures than optical telescopes. The best-resolution optical images are made with two large telescopes and a temperature-controlled optical fiber from each one, arranged to interfere optically, yielding an image resolution equivalent to a mirror the size of the distance between the telescopes as the visual field is scanned on each simultaneously to sample pixels of the image, in sequence. The electromagnetic interference operation must be conducted purely optically because we are not equipped to sample and record time-registered electromagnetic signals at 1 trillion samples per second. (Yet. It is possible in principle, it just hasn't been achieved.) In contrast, output from radio telescopes can be sampled and recorded with careful time registration, and the samples interfered numerically, so signals from radio telescopes thousands of miles apart can be treated together, yielding images of overwhelmingly finer detail. Even when using just a single radio telescope, a reflector dish can be made much larger than any practical earthbound optical mirror. So, if a radio-telescope image is indistinct, it is likely that the object imaged is itself indistinct. The recent image of a black-hole accretion disc was composed from radio-telescope traces. No optical treatment could produce an image of such resolution.
- jcims 6y ago>Astronomical radio images are naturally overwhelmingly sharper than optical images, because radio telescopes today can have much larger apertures than optical telescopes. They can be higher resolution with very long baseline interferometry but I wouldn't say they are naturally higher. If I'm reading the article correctly these were collected by the ASKAP telescope array in Australia which has a resolution of 30 arcseconds at 1.4GHz [1], which is only about twice as good as the human eye. [1] https://www.atnf.csiro.au/projects/askap/config.html#:~:text=The%20initial%20ASKAP%20configuration%20is,30''%20at%201.4%20GHz https://www.atnf.csiro.au/projects/askap/config.html#:~:text.... To your point, though, when VLBI is used they can get ridiculous levels of resolution. M87 was imaged at tens of microarcseconds of resolution, which is 4-5 orders of magnitude better than any optical telescope in operation today.
- runxel 6y agoThis all sounds very much like there is some reaaally simple solution and nothing fancy going on. Expecially the "always circular" part threw me off. It looks like the blend effects you get when you make photos against the sun. There might be something similar with radio waves as well.
- chemeng 6y agoInteresting thought, though a very large number of things in astronomy are almost always circular or spheroid mostly due to gravity.
- rmelhem 6y agoKIC 11145123 is a good example.
- jrumbut 6y agoWhen it said circular I pictured a frisbee on the antenna.
- TeMPOraL 6y agoThere are plenty of funny optical artifacts that can happen, and I guess they may have their radio equivalents. Just today, when shooting our traditional New Year's Eve photo with my wife and kid - us with sparklers in hand - first few images were ruined by ghastly green circles appearing out of nowhere. After quick investigation with a flashlight, I realized that they're artifacts of a bright point light (like a sparkler) hitting the camera - I'm guessing an undesired reflection inside camera's optics. I wonder if something similar may be going on here?
- thisiszilff 6y agoThe article mentions they used other radio satellited to confirm it wasn't an artifact
- h2odragon 6y agopaper: https://arxiv.org/pdf/2006.14805.pdf https://arxiv.org/pdf/2006.14805.pdf > Frequency range: 800 – 1088 MHz > Total integration time: 100 hours but then > We observed ORC 1 and ORCs 2–3 (Project code C3350)with the Australia Telescope Compact Array (ATCA)on 9–10 April 2020, at 1.1–3.1 GHz (weighted centralfrequency after the removal of radio frequency inter-ference = 2121 MHz), over a period of 2×12 hours and > ORC-4 was found in archival 325 MHz GMRT data
- stretchcat 6y agoDo these spectral ranges represent the limits of the emission, or the limits of the instruments measuring it? Perhaps the emission is broad spectrum, and different instruments are picking up different parts of it?
- h2odragon 6y agoinstrument or at least measurement limits i think
- cygx 6y agoThe wormhole paper mentioned in the article: https://arxiv.org/abs/2006.15331 https://arxiv.org/abs/2006.15331
- DaiPlusPlus 6y agoAs a layperson I don’t want to be bamboozled by /woo/. Can any resident astrophysicists here on HN vouch for the quackery, or lack-of, in the linked paper?
- AnIdiotOnTheNet 6y agoI am by no means qualified to judge physics papers of any kind so take this with a grain of salt, but the invocation of Maxwell's Demon (a thought-experiment method of violating the 2nd law of thermodynamics) suggests it's presenting a pretty fringe idea I think. However, this supposedly happened prior to recombination and, if you can imagine it, I'm even less qualified to guess at the veracity of claims about that epoch.
- goodcanadian 6y agoWell, this is outside my area of expertise (more of an amateur astrophysicist), but I think it is a serious examination of a somewhat fringe idea. Basically, it is a theory paper asking the question of whether wormholes can explain the phenomenon, and if they were the cause, what would it look like? I wouldn't take the idea too seriously (and the paper's conclusion seems more like a "no" than a "yes" to me), but it does appear to be a sound examination of the question (though, I would appreciate comments from someone with more knowledge of relativity).
- RhodoYolo 6y agoIts radio emissions from another civilization obviously ;)
- foobar1962 6y agoIs this what the exhaust plume of an ion drive looks like?
- jefurii 6y agoThe article mentions thousands of these. Why would they all be moving away from us? Aside from the obvious of course.
- gremlinsinc 6y agoWE do not want to know what's headed our way for 2021. /s
- mrfusion 6y agoCan wormholes form naturally? What process makes that happen?
- ben_w 6y agoSo far as I can see, the general consensus is “if they’re possible they’d form naturally, but they’re probably not possible”. As for mechanism: quantum fluctuations might make Plank-scale wormholes pop into and out of existence all the time, the inflation period of the early universe might make those tiny ones into big ones, and if a cosmic string got into one that just might keep it from collapsing.
- elorant 6y agoWormholes in theory are tiny. Tiny as in subatomic scale. Nothing like a gigantic structure like what's described in the article.
- mrfusion 6y agoCould they be Dyson spheres?
- slowmovintarget 6y agoNot when there are whole galaxies in the center. That dot in the middle of the ORC in the picture is an entire galaxy. You also wouldn't be able to see through a Dyson sphere.
- btbuilder 6y agoFrom the article: “ We still have no idea how big or far away they are. They could be objects in our galaxy, perhaps a few light-years across, or they could be far away in the universe and maybe millions of light years across.”
- ben_w 6y agoIf it is on the far side of a galaxy it has to be bigger than that galaxy. Dyson swarms are about 6e9 times smaller radius than our galaxy.
- mellosouls 6y agoThis article was originally published a month ago here: https://theconversation.com/wtf-newly-discovered-ghostly-circles-in-the-sky-cant-be-explained-by-current-theories-and-astronomers-are-excited-142812 https://theconversation.com/wtf-newly-discovered-ghostly-cir...
- patcon 6y agofwiw The Conversation is an online magazine that pairs academics/researchers with journalist editors. The academics do the writing, and their assigned editors offer tons of hands-on support to help the academics to directly communicate their research with the general public in an approachable way. https://theconversation.com/ca/who-we-are https://theconversation.com/ca/who-we-are The author works for the science agency that built and operates the equipment that spotted the anomaly: https://theconversation.com/profiles/ray-norris-20 https://theconversation.com/profiles/ray-norris-20
- YeGoblynQueenne 6y agoYou guys, those are curvature propulsion trails, leaving behind dark zones of collapsed space-time. It's the Trisolaran fleet!
- dqv 6y agoI guess I need to finish this series. I only got about half way through the first book. New Years resolution here I come.
- deleted 6y ago[deleted]
- thelittleone 6y agoHave a name of said book? In need of some new sci-fi.
- coupdejarnac 6y agoI got about 80 pages into it before I couldn't take it any longer.
- esarbe 6y agoI actually managed to finish it. It was a chore. There's barely any interesting development to the main character. Strike that. To any of the characters. It's as if the novel follows an emotionless robots without any real social connections at all. The science story is ... okay-ish. There are some good ideas in TTBP, but all in all I'd rather slog through one of Greg Egan's more spaced-out maths novels. Greg Egan has good stuff, though. Diaspora is a masterpiece.
- ageofwant 6y agoI have a hard time understanding how radio emissions can be visualised like that. The sensors are ground based, the emissions are detected on earth from a point source which given the distances are effectively parallel. Or is it a visualization of a circular cloud of point sources, in which case the detector resolution must be fantastic.
- jlkasdfjkl 6y agoThey get that resolution by having a radio telescope array with many sensors spread over a wide area [0]. An incoming wavefront will hit the different sensors at slightly different times, depending on the direction the wave is coming from. By combining all the sensors' data, you can calculate the intensity of incoming radiation from every direction in the sky. The resolution increases as you increase the horizontal distance between the sensors, because that makes it easier to resolve the arrival time differences. [0] https://en.wikipedia.org/wiki/Australian_Square_Kilometre_Array_Pathfinder#/media/File:CSIRO_ScienceImage_2161_Close_up_of_a_radio_astronomy_telescope_with_several_more_in_the_background.jpg https://en.wikipedia.org/wiki/Australian_Square_Kilometre_Ar...
- beaner 6y agoCould it be hawking radiation from free-floating black holes?
- andrewflnr 6y agoThat would be a pointlike source.
- beaner 6y agoI am asking from the perspective of having no experience. But the article doesn't seem to say that it couldn't be from a point-like source. Can you elaborate?
- mkl 6y agoWe can detect them spread out over an area, as shown in the article, not just coming from a single point each. If they were point-like sources, we would see them as a dot in the radio frequency data, like a distant star visually.
- beaner 6y agoI'm not sure I understand. If something spreads out from a point, isn't it both "spread out over an area" and "from a single point"?
- mkl 6y agoYes, but the thing is we are viewing it at a single location (Earth), and it appears to come from an area, not a single point. The only way to get what we're seeing from a point source is for it to spread out in straight lines in all directions from the source point (as radio waves do, just like light), then somehow change direction towards us to converge back together here, appearing to come from multiple directions. That doesn't happen. (Gravitational lensing can change light's direction in some circumstances, but astronomers know all about that, so they'd give us that explanation if it made sense for this.) For example, imagine looking across a dark room at a single LED, a point source. You see a point. But the LED is sending light straight in all directions, not just at your eye. The light going in other directions doesn't reach us, so we don't see that "area". Imagine it's a white computer screen, an area source not a single point, and you can see the rectangular area. Every point on the screen is sending light spreading out straight in all directions, but for every point on the screen one of those directions reaches our eye, so we see the area. The light is coming to our eye from multiple directions, from the different parts of the screen, making the area.
- sandworm101 6y agoIf there is more than one, and they all appear to be circles from our perspective, wouldnt that make them spherical rather than circular?
- andi999 6y agoYes
- 867-5309 6y agocircular in two dimensions, spherical in more (re wormholes)
- studius 6y agoI tried my imagination, but I was disturbed... Are you saying that they'd be spherical in three dimensions, more than one set of three dimensions, or some other number? And, as Keller and Hughes once put it, "Don't change your number."
- 867-5309 6y agospherical in more (than two) dimensions
- qwantim1 6y agoHave terrestrial radio sources been ruled out?
- lolc 6y agoYes, they say that the finds were replicated.
- natch 6y agoObjects exploding outward into a vacuum can be spherical. Stellar explosions happen all the time in many corners of the universe. As material from a stellar explosion expands outward and impacts gases in the neighborhood, radio waves are emitted from the molecules energetically impacting each other. Naturally, the shape of the region from which such radio frequency emissions would originate would correspond to the spherical shape of the explosion. I don't know why this is being written up as something mysterious. OK, maybe I do know why. Clickbait. Any time you can make astronomy look like there may be a hint of aliens, it's tantalizing and leads to clicks. I don't blame the scientists for this… it's the news headline writers. Unfortunately working in favor of the clickbait is the fact that certainly scientists won't say that the above simple explanation is definitively what is happening, because it hasn't been tested yet. But you can bet they are looking into simple possibilities like this. And no aliens or Dyson spheres are required.
- 867-5309 6y ago>Could they be supernova remnants, the clouds of debris left behind when a star in our galaxy explodes? No. They are far from most of the stars in the Milky Way and there are too many of them.
- blackhaz 6y agoNote SNR explanation is ruled out exclusively because of ORCs' high galactic latitudes. Based on the appearance of these objects my bet is that they are high-latitude SNRs indeed.
- natch 6y agoThe article states (correctly or incorrectly, I don't know) that they don’t even know if these are in or near our galaxy.
- natch 6y agoThey state specifically that these might not be in the Milky Way.
- trevyn 6y agoThe article says that we’re not able to determine distance or put a size on whatever is radiating this, but doesn’t put a clear lower bound on that. What is the closest that this could be that is compatible with the data?
- tristram778 6y agoThis reminds me of the 'stellar rings' of Isserstedt and Schmidt-Kaler from the late 1960s and early 1970s: http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1973A%26A....29..277V&defaultprint=YES&filetype=.pdf http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_quer... http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1975A%26A....41..355L&defaultprint=YES&filetype=.pdf http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_quer...
- patagonia 6y agoCan radio astronomy apply “red shift” to statistically determine their relative movements from our position?
- phire 6y agoYou can only apply red shift calculations if you know what frequency it should be. We have no idea what they are so even less clues about what frequency it should be. It works for regular stars because each element emits light peaks at predictable wavelengths which we can measure and calibrate on earth.
- patagonia 6y agoSince they’re all expected to be emitting at roughly the same frequency (or at least we could assume for testing purposes) couldn’t we throw all their data into some maths to compare?