[HN Gopher] Laniakea Supercluster ___________________________________________________________________ Laniakea Supercluster Author : corentin88 Score : 97 points Date : 2023-07-10 22:10 UTC (1 days ago) (HTM) web link (en.wikipedia.org) (TXT) w3m dump (en.wikipedia.org) | Steltek wrote: | For the neverending stream of talk about VR this, metaverse that, | and WebGPU there, there should really be a KISS 3D format for the | web so we can view things like this properly. Like Markdown | simple. No shaders or animation or anything like that. Default | lighting only. | | It feels sad to look at a 2D image of the most 3D of all things. | Tommstein wrote: | How about VRML or its successor X3D? They support fanciness, | but you don't have to use it any more than you have to use | every random feature in Markdown. | pmlnr wrote: | There's also a short video on this: | https://www.youtube.com/watch?v=rENyyRwxpHo | | Plus there's that scene from Stargate Universe: | | - Are those stars? | | - No, those are galaxies. | ktm5j wrote: | SGU was by far my favorite Stargate and I'm forever sad that it | only lasted two seasons | frinxor wrote: | Followed some links around, and this was interesting | https://en.wikipedia.org/wiki/Abell_3266 ! | | "The Department of Physics at the University of Maryland, | Baltimore County discovered that a large mass of gas is hurtling | through the cluster at a speed of 750 km/s (466 miles/second). | The mass is billions of solar masses, approximately 3 million | light-years in diameter and is the largest of its kind discovered | as of June 2006." | Koshkin wrote: | Came here to learn about some new HPC supercluster... Oh well. | aktuel wrote: | yeah this supercluster is pretty high performance it might even | do some compute but it is definitely not new | FrustratedMonky wrote: | anybody have super high res pic of this? | stronglikedan wrote: | It's available right on that page (after clicking the preview): | https://upload.wikimedia.org/wikipedia/commons/8/81/07-Lania... | haunter wrote: | This will sound stupid... but as we find out that the universe is | bigger and bigger and there are more clusters, galaxies, stars, | and planets then we have imagined before (Laniakea have | 100,000-150,000 galaxies and the Milky Way _alone_ have 100-400 | billion stars) | | so does that increase or lower the chance that there is _any_ | kind of life outside there? Maybe not carbon-based life but any | kind. Next question would be I guess that what is "life" | | Fascinating stuff nonetheless | Tommstein wrote: | How could that do anything but increase the chance? | brummm wrote: | There is other live with almost 100% certainty in the universe. | The number of galaxies, stars and planets across the whole | universe is just too large for this not to be true. | | The thought that humans might be the only life in the universe | to me seems like the 21st century equivalent of believing earth | is the center of the universe. | BitwiseFool wrote: | I wonder how many times the Earth appears on alien "List of | potentially habitable exoplanets" articles. | | https://en.wikipedia.org/wiki/List_of_potentially_habitable_. | .. | zokula wrote: | [dead] | htss2013 wrote: | >The thought that humans might be the only life in the | universe to me seems like the 21st century equivalent of | believing earth is the center of the universe. | | Or it's an acknowledgment of the posterior data that has | arisen over the past 30 years. | | Every human has a camera 24/7 now and no one has documented | visitors. Countless new missions and sensor arrays have found | no evidence of life anywhere. | | That doesn't prove no life, but it does make it more likely | that the Drake equation is based on assumptions that are | fundamentally flawed. Otherwise the Fermi paradox wouldn't | still be a paradox. | | Maybe it's all a simulation. Maybe it's something from a | completely different paradigm. Who knows. But insisting | they're out there as more decades pass with none found...that | may be the real insistence that the sun revolves around the | earth. | dougmwne wrote: | Space is much bigger than you are accounting for and the | speed of light much slower. If the nearest spacefaring | civilization is in the next galaxy over, we will never meet | them. It actually seems rather unlikely any spacecraft | could ever reach us unless they evolved right in our | backyard, within a few dozen light years. | polishdude20 wrote: | That's also IF the life is space faring. We haven't even | found life anywhere that is at least remotely simple let | alone one that has built spacecraft. | wolfram74 wrote: | That there is no complicated life in Sol system besides on | earth, or even within 50 light years of Sol system, and | that there is complicated life in other parts of the | universe are easily mutually compatible facts. Considering | our search exhaustive at this point is selling the size of | the universe short. We'll likely never interact with extra | terrestrials, but it's silly to assume they're not out | there. | revscat wrote: | > Every human has a camera 24/7 now and no one has | documented visitors. | | You are being willfully obtuse. There have been thousands | of documented sightings over the past 80 years. Audiovisual | recordings abound, not infrequently matched with radar or | other secondary corroborating evidence. | | The typical response to this is: | | 1. "They are faked." | | 2. "That doesn't mean it's aliens." | | 3. "It's a secret government program." | | Fine. Nevertheless some percentage of documented events | cannot be explained. There is a non-zero chance that they | are caused by things that were not made by humans. They | deserve to be scientifically investigated in good faith, | without the arrogant dismissiveness that is so frequently | encountered. | | Something mysterious is going on in our skies. | Simon_O_Rourke wrote: | > Every human has a camera 24/7 now and no one has | documented visitors. | | Take a few minutes to listen to Prof. Robin Hanson talk on | this very thing. | | https://youtu.be/cQq2pKNDgIs | | The jist of what he says, is that there's very much weird | stuff seen in the sky, like the McMinnville photos [1], but | there's nobody as yet landing a craft on the White House | lawn and posing for the cameras. | | He puts forward a model for this kind of scenario, it's | worth a listen, that any visitors would quite rightly be | far in advance of the societies we currently live in, and | may only show themselves fleetingly so we gain an | acceptance of their presence. | | [1] | https://en.m.wikipedia.org/wiki/McMinnville_UFO_photographs | GolfPopper wrote: | I don't buy it. | | The "weird stuff" is _always_ distant, blurry, shot under | terrible conditions, etc. Yet when a research team, or | random passer-by snaps a photo of some never-before-seen, | or thought-extinct creature, there 's no difficulty in | getting a quality image, either on the initial sighting | or shortly afterward. It's only the "aliens" that are so | problematic. | | As for the idea that "they" are doing it deliberately | (and perfectly)... it reminds me of the TIGHAR folks and | Amelia Earhart. TIGHAR _knows_ that Earhart crash-landed | on Nikumaroro (Gardner Island), so every piece of | information they see is interpreted through the lens of | how it fits with that interpretation. But they have no | root basis for the conclusion, just that they really want | to believe it. | | When faced with the question, "Why are pictures of | possibly alien UFOs blurry?" two (of many) possible | answers are "because if they're not low-quality we can | tell they're not aliens" and "because the aliens are | carefully arranging circumstances so that pictures of | them are always low-quality" I know which one I'm putting | my money on. | jimmcslim wrote: | Have a look at the Grabby Aliens model [1] when essentially | says: | | 1. We are likely amongst the earliest of advanced space- | faring civilisations that have ever exists, which is why we | haven't established evidence of other life, | | 2. There are 'quiet' civilisations and 'loud' | civilisations. We will never see evidence of 'quiet' | civilisations, and the other 'loud' civilisations haven't | expanded sufficiently to be observable at this point in | time. | | 3. Assuming we don't die out ourselves and are therefore a | 'quiet' civilisation, we should encounter the other 'loud' | civilisations sometime in the next hundred million years or | so :-) | | [1] https://grabbyaliens.com/ | sliken wrote: | Not sure I buy the "we are special/early" explanation. | | However I don't think it makes sense for any civilization | to be 'loud'. Just seems naive to blunder about and risk | your civilization. However monitoring new civilizations | for intelligence, fairness, open mindedness, lack of | religions that justify killing outside their religion or | species, treating the less fortunate of their/other | species well and the like. Then once they hit some | developmental milestones for compatible civilizations you | introduce yourselves. Possible milestones include | practical fusion, returning your ecosystem to baseline, | practical anti-matter production/use, making a blackhole, | traveling to the nearest star that you don't orbit, | quantum computing at scale, etc. | | Might well be something on the moon, well stealthed, a | few meters down, with receivers capable of decryption RF | traffic, and sensors to see how quickly we are poisoning | ourselves. | | If you think about it, if you were an alien watching | earth, would you want to meet us? Or terminate us, at | least the humans, and wait for something else intelligent | to appear. | IanCal wrote: | There being life somewhere in the universe and something | coming to visit here are wildly different things though. | TechBro8615 wrote: | The universe is unfathomably big. Some hazy but AFAIU | relatively accurate napkin math suggests that there are more | stars in the universe than there are grains of sand on all of | Earth's beaches. But at the same time, there are more molecules | in ten drops of water than there are stars in the universe. | | https://www.npr.org/sections/krulwich/2012/09/17/161096233/w... | russdill wrote: | The more galaxies we can see, the more lack of evidence we have | for any large scale changes to the universe by any | intelligence. Many people take this as an indication that there | is no other intelligent life or life of any kind in our | observable universe. Also see: grabby aliens. | dougmwne wrote: | It seems scientifically implausible that we are alone. I base | this on a few things: | | Life started on Earth almost as soon as the surface was cool | enough to support it. The surface seems to have been stable | enough for life by 3.8 billion years ago, and we have some | weaker evidence of life at 3.7 and stronger at 3.5. At any | rate, based on what we can observe, life began relatively early | and so it seems that as soon as the basic building blocks and | preconditions are present, life evolves. | | We now know that exoplanets are extremely common. Based on | observations we can estimate that about 40% of stars have | planets, but that's just what we've been able to observe. | | There are a lot of stars in our galaxy, 100-400 billion. | | And a lot of galaxies in the observable universe, 200 billion | to 2 trillion. | | And that's just the observable universe based on our local | light cone. For all we know, there could be an infinite number | of galaxies. | | So we have n=1 where life started right away, and perhaps 10^25 | planets in the observable universe. That's a lot of rolls of | the dice! | | Hence the need for a proposed great filter that explains why we | don't get a visitor ever other week. Complex multicellular life | seems like a possibility, that took quite awhile, a few billion | years before the Cambrian explosion. Complex intelligence also | took awhile, resulting in only us after 3.5 billion years of | life. And yeah, given that we haven't been around all that long | and seem well on our way to destroying ourselves, seems like | complex society could be a great filter too. But space is vast, | EM signals attenuate quickly and the speed of light is a harsh | mistress. They are probably out there, but we'll probably never | meet them. | elorant wrote: | All it takes is for a Magnetar to have a hiccup and it could | sterilize an entire galaxy. | | When we take numbers and probabilities in consideration it's | good to also note how many hostile to life events can occur | on a cosmic scale. You have supernovas, gamma ray bursts, | black holes, neutron stars, magnetars, solar flares and | coronal mass ejections, and a host of other shit we don't | even now about that could destroy life at any stage. | lazide wrote: | Uh, we don't necessarily need a great filter to not be | constantly visited - we just need a lack of 'cheat codes' | (like warp drives, wormholes, dirt cheap energy from magical | fusion or zero point or whatever), combined with relatively | short lived complex civilizations. | | If no one can afford the trip (due to what we currently know | of physics), or survive as a complex civilization long enough | (100k+ years), then... you see what you see right now. | dontupvoteme wrote: | If you're talking about sending live people, absolutely | | If you're talking about sending alien drones, the light | mass and lack of having to keep them alive makes energy | requirements a lot lower, but they'd probably just be | scouting us (if not trying to kill us) so we wouldn't be | able to detect them | dougmwne wrote: | And this is why I suspect AGI superintelligence is | impossible. A bio civilization will never reach us. An | AGI will reach us rapidly. | lazide wrote: | Considering no human object has yet to leave the solar | system (meaningfully), and we've nearly wiped ourselves | out several times just in recent memory - that's still in | the realm of pure fantasy. | | There is no evidence yet that anything we can construct | (or a near peer) could make it to another system intact | enough to know it had arrived, let alone DO anything | regardless of the form any intelligence takes or how it | is packaged. | | Hell, as a species we still struggle to land probes on | mars and Venus. And they don't have to do anything but | send data back. | | Getting a toehold on a random solar system, or even | arriving and taking pictures and sending them back is so | many orders of magnitudes harder to do based on what we | know now it's essentially impossible. Even if we had a | 'fast forward' button. | | Hopefully we'll find something out that we're currently | missing, but as of yet we have no reason to believe it | exists. | dougmwne wrote: | You just proposed a great filter, short lived | civilizations. | | If civilizations lasted for billions of years or their AGIs | did the same, we'd have a lot higher chance of them | expanding to fill the galaxy and converting the surface of | all 8 planets and major asteroids into AGI probes and | compute. | lazide wrote: | That's not what I'd consider a great filter in the usual | usage. We've only had ~10k years of recorded history. If | we can't make a meaningful dent somewhere outside the | solar system in another 10x that amount of time, I doubt | we (or anyone) ever would. | | A civilization doesn't have to survive a billion years | (do you know how long that actually is?) to not be 'short | lived'. | dougmwne wrote: | I would define short lived as the difference between | dying out in a local star cluster or continuing to expand | till the heat death of the universe. A long-lived and | expansionary civilization will eventually reach us, even | if it takes 1k years to hop from star to star. A short | lived civilization will never reach us. | lazide wrote: | None of the situations you're giving are based entirely | off longevity - they use longevity as a factor of another | equation. | | A billion year old civilization that isn't expansionary | will never reach us either. | | Or one that doesn't want to spend the energy ($$$) if | other cheap energy forms we've speculated aren't possible | or as inexpensive/portable as would be needed. | | They could just as easily be happy being billion year old | zen masters, and we'd never know - even if they had warp | drives. | | They'd still exist though, and if we ever wanted to find | them I guess we'd be able to do so. But we'd never know | about them proactively. | pfdietz wrote: | Realize that if the cosmological constant has the nonzero value | that appears to be the case (in the lambda-CDM model), then | only about 6% of the galaxies we see are still reachable. The | rest will be carried away by accelerating expansion so quickly | that a photon emitted from us right now (or any slower than | light spaceship) will never reach them. | | Of course more stars increases the chance of life out there, | but without a good handle on the chance of life arising around | a random star, we cannot set any lower bound on the probability | that life is out there on the stars we see. | kibwen wrote: | A good and accessible video on this topic: | https://www.youtube.com/watch?v=uzkD5SeuwzM | taneq wrote: | So it's a fancy skybox. ;) | dougmwne wrote: | One that functions as the greatest physics experiment we | could never run and has revealed countless laws of the | cosmos, yes! | johncessna wrote: | Wild, I've def heard of some reasons how the Fermi paradox | could be resolved, but I missed this explanation. A quick | headline scan of the wiki article also doesn't mention it. | [1] | | You'd think that 94% of the observable universe not being | reachable would get more of a mention. Granted, we can still | look for artifacts such as radio signals or something | similar, but it does seem to cut out why a type 3 civ hasn't | shown up at our door. | | [1] https://en.wikipedia.org/wiki/Fermi_paradox | its_ethan wrote: | This is basically the premise to the Fermi paradox: | https://en.wikipedia.org/wiki/Fermi_paradox | | And more specifically the Drake equation (a subsection of the | wikipedia article). | | I personally think anyone's "answer" to the paradox just | reveals their personal opinion/ what they want to believe, | rather than any meaningful result from data. | blfr wrote: | This question has been (very unsatisfyingly) answered, or at | least resolved: | | > When the model is recast to represent realistic | distributions of uncertainty, we find a substantial | probability of there being no other intelligent life in our | observable universe, and thus that there should be little | surprise when we fail to detect any signs of it. | | https://arxiv.org/abs/1806.02404 | | SSC has an article on the paper as well | | https://slatestarcodex.com/2018/07/03/ssc-journal-club- | disso... | JohnMakin wrote: | Unfortunately this conclusion leads to Boltzmann brains, | which isn't very fun. | [deleted] | Octoth0rpe wrote: | I don't think there's been a significant increase in the | estimated # of galaxies lately. Identifying clusters is really | about identifying areas of higher density that form some | cohesive unit, rather than an increase in the actual count of | galaxies. | graycat wrote: | The universe as it seems from current astronomy, ..., is one huge | and intricate construction. Sorry, but tough to believe that all | of this has no purpose. | | Ah, two possibilities: | | (1) We really are the _center_ of the universe and the only life. | | There is a lot less to the universe than what seems from current | astronomy. In particular, objects we can never reach due to the | speed of light limit are just fake, something like a painted | screen. | | (2) We have not found it yet, but there is a way to violate the | speed of light. The whole universe is ours for the taking once we | see how to exceed the speed of light. There is a _game_ : For the | laws of physics, how long will it take for life to develop to | understand these laws and, in particular, how to exceed the speed | of light. | | For either of (1) or (2), maybe we should start a new subject, | _super cosmology_ , that assumes that the universe has a purpose. | We look for that purpose and, for each discovery we make, e.g., | dark matter, quantum mechanics, black holes, quasars, | gravitational waves, ..., ask what its role is in the purpose of | the universe. | kibwen wrote: | The next time you address a package to someone, err on the side | of caution and append "Earth, Solar System, Local Interstellar | Cloud, Local Bubble, Gould Belt, Orion Arm, Milky Way, Milky Way | Subgroup, Local Group, Local Sheet, Virgo Supercluster, Laniakea | Supercluster, KBC Void, Observable Universe, Universe", to help | the package carrier disambiguate. | kunwon1 wrote: | We're going to run out of address space, time to migrate to zip | code v6 | atonse wrote: | Will the 128 bits be enough to address all atoms in all | universes? | stvltvs wrote: | Looks like we'll need to upgrade to 512-bit addresses to be | on the safe side. | | https://www.wolframalpha.com/input?i=log2%2810%5E80%29 | | https://www.thoughtco.com/number-of-atoms-in-the- | universe-60... | NoMoreNicksLeft wrote: | Yes, in all 2 universes. | m3kw9 wrote: | We just need (universe)UPS coordinates. | ckozlowski wrote: | The Lagunitas Brewing Company features this on their sign for | their Petaluma brewery in fact. Though, it stops at "Virgo | Supercluster". | [deleted] | choeger wrote: | Alot of "locals". This will get awkward when we talk to species | from a different Bubble, Group, or Sheet. | kibwen wrote: | It'll work fine as long as the babelfish understand not to | transliterate place names. Human history is chock full of | this: "Istanbul" just means "within the city", "Zhongguo" | (China) just means "the land in the middle", "Ohio" and | "Mississippi" are just two different ways of saying "the big | river". | NoMoreNicksLeft wrote: | Wait, you named your sheet the Local Sheet too? We should be | friends! | its_ethan wrote: | This reads like a hitchhikers guide bit lol I love it | jamesgreenleaf wrote: | You don't have to specify "Multiverse" on the end, because your | package will be automatically delivered to all of them. | choeger wrote: | Except the weird one. You know, the one with the glitch. | sydbarrett74 wrote: | Thanks for the suggestion, Dedalus. :D | [deleted] | cdelsolar wrote: | Why are there so many stars and galaxies? | kirykl wrote: | see Feynman on "why" | https://www.youtube.com/watch?v=36GT2zI8lVA | q845712 wrote: | if it helps, that's just the stars and galaxies we're capable | of observing. There's probably more :) | qup wrote: | It's fun that we can't say for sure. | | I wonder how long before we can | r2_pilot wrote: | The physical continuing expansion of the universe | eventually causes any photon to be so far redshifted as to | be unobservable, so it actually goes the opposite way. One | day long from now, an alien civilization might look out | into their night sky and only see their galaxy, and be | completely unable to tell the previous history of the | universe from observing the sky. | Sanzig wrote: | There's also a possibility that a sizeable fraction of | all stars exist in the intergalactic medium [1], having | been ejected from the galaxies where they formed due to | galactic collisions or encounters with their original | galaxy's supermassive black hole. A civilization evolving | around one of these stars in the far future would be | totally unaware of the universe outside their own solar | system due to cosmic expansion. | | [1] https://en.wikipedia.org/wiki/Intergalactic_star | asimovfan wrote: | I agree, things couldn't be fun if we actually knew what | they were | PartiallyTyped wrote: | The other side to this is that given enough time, some | civilisation will be oblivious to the rest of the universe. | Their visible universe will just be their own galaxy. | BitwiseFool wrote: | That means they would have no way of discovering that the | universe is expanding, right? | PartiallyTyped wrote: | NB: Armchair """""physicist""""" | | If their physics is correct, they will figure it out. We | did because we verified that expansion is accelerating | even though our physics are incomplete. Until the late | 90s, physicists accepted a cosmological constant of 0, | which meant no acceleration. Turns out that that was | wrong. | | It may be possible that they figure it out via Quantum | Mechanics because it seems that acceleration of the | universe is related to the energy density of a vacuum / | empty space. The problem is that they won't be able to | empirically verify that I think. | alx wrote: | and what could they deduce from the void they have in | front of them? | PartiallyTyped wrote: | Probably nothing. | | The problem is that at such timescales, the CMB will have | shifted sooooooooo much that there's nothing they will be | able to deduce, all light has redshifted to absurd | scales, and worst of all, everything will be so far away | that light will never reach the galaxy. | ceejayoz wrote: | There are probably hundreds of possible answers to that, | depending on which aspect you're interested in, ranging from | "God" to "gravity" to "42" to "because" to "I dunno". | TechBro8615 wrote: | Probably for the same reason there are not zero. | Koshkin wrote: | Probably because there may be an upper limit on the size of an | individual celestial object (and thus on how many particles it | can consist of) - for it to be anything other than a black | hole, anyway. In the future, the Universe will entirely consist | of black holes, whose number will be much smaller. | [deleted] | igleria wrote: | at risk of being too tautologic: Because for us this is "so | many". Because of that we try to compare the scale of the | universe with the amount of sand on earth etc etc. At least for | me, that type of information does not give me a "better" idea | of the problem at hand other than "duuuuuuuuude what". | NKosmatos wrote: | We need Faster Than Light (FTL) travel otherwise we're stuck here | on Earth. I believe that there are other beings out there, but | the vast distances prevent contact. If they haven't discovered | exotic means of travel like wormholes, hyperspace, warp drives, | or something else, then we're doomed to remain separated :-( | | https://en.wikipedia.org/wiki/Faster-than-light | xwdv wrote: | We're not doomed and we don't need to be separate. We just need | to be patient. We must be willing to send generations of humans | on thousand year journeys. ___________________________________________________________________ (page generated 2023-07-11 23:00 UTC)