[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.
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(page generated 2023-07-11 23:00 UTC)