[HN Gopher] A 1.3B-light-year-across ring of galaxies has confou...
       ___________________________________________________________________
        
       A 1.3B-light-year-across ring of galaxies has confounded
       astronomers
        
       Author : geox
       Score  : 231 points
       Date   : 2024-05-27 06:32 UTC (16 hours ago)
        
 (HTM) web link (cosmosmagazine.com)
 (TXT) w3m dump (cosmosmagazine.com)
        
       | sshb wrote:
       | Reminded me of the circles in the sky method that might help
       | studying the topological structure of the universe.
       | 
       | https://mphitchman.com/geometry/section8-3.html
       | 
       | (I think I read about it first in "The shape of space" book)
        
       | boxed wrote:
       | I mean.. you would expect to see rings sometimes if this is a
       | random noise kind of distribution no?
        
         | sapling-ginger wrote:
         | Supposedly if you scan the sky long enough, you'd find a copy
         | of Shakespeare's play written in the stars.
        
           | 0xedd wrote:
           | Why? It's not random.
        
           | The_Colonel wrote:
           | The upper estimate of the number of galaxies in the
           | observable universe is 2 trillion, which is far too few to
           | find Shakespeare written with "galaxy dots".
        
         | roenxi wrote:
         | Yeah, maybe. Certainly a theory. But that artist impression has
         | 24 dots, so the odds of getting a circle might be the same as
         | getting a well drawn rabbit, or a "lol :)" (pencilling it out
         | 24 dots seems reasonable for a "lol :)").
         | 
         | But the fact we got a circle rather than something funny
         | suggests it is probably a phenomenon that causes circles
         | responsible. Circles are far more common in nature than
         | statistics might suggest. Nature well knows circles.
        
           | boxed wrote:
           | I mean.. this could be a circle just from our point of view
           | if the distance measurements are off for a bunch of them...
        
             | roenxi wrote:
             | Why would it matter if that were true or not?
        
         | mr_mitm wrote:
         | Yes, that is why the scientists did a statistical analysis,
         | otherwise it wouldn't be worthy of publication. From the arXiv
         | paper:
         | 
         | > Using the Convex Hull of Member Spheres (CHMS) algorithm, we
         | estimate that the annulus and inner absorbers of the BR have
         | departures from random expectations, at the density of the
         | control field, of up to 5.2s.
         | 
         | 5 sigma is the gold standard at which we can safely exclude the
         | noise explanation.
        
           | Lammy1 wrote:
           | The artist impression in the article is heavily misleading
           | IMHO. The actual "ring" is much more jagged and looks very
           | similar to all the nearby so called "filaments" they labeled.
           | I'm not sure if it's crossing the threshold from
           | constellation-ism to real astronomy. Download the arXiv paper
           | and see for yourself.
        
         | pwatsonwailes wrote:
         | Structures yes, but not at this sort of scale. For reasons*,
         | there's a soft limit on the scale that you'd expect
         | structures** to scale to. There's no technical reason why they
         | can't get bigger, it just becomes spectacularly unlikely that
         | you'd ever get one. The fact that we've found two so far means
         | 1. There's probably more we haven't found yet, and thus they're
         | probably*** more common than we'd expect, and 2. There may be
         | some mechanism we don't yet understand which leads to the
         | emergence of astronomical structures at this sort of scale.
         | 
         | * Actually quite interesting reasons, but which take a lot of
         | maths to explain that I'm not going in to here.
         | 
         | ** In this case, defined as a thing or set of things in a
         | mathematically simple shape - spheres, rings etc.
         | 
         | *** Assuming any bit of the universe is roughly like any other
         | bits, and we didn't just happen to fluke on literally the only
         | place where these exist, and there's two.
        
           | fsloth wrote:
           | Can you give references on the *reasons? Would love to try to
           | do some maths reading in a long while.
        
             | pwatsonwailes wrote:
             | If you want to do some research on the subject, you're
             | looking for violations of homogeneity, as implied by the
             | Lambda-CDM model of the universe. The lambda in this case
             | is the cosmological constant. You'll need to read up on
             | that too.
             | 
             | The shortest, simplest way I can think to explain it is
             | that we expect the universe to look alike, anywhere we
             | look. Think of it like a biopsy - we assume that anywhere
             | we look should be much like anywhere else, because there's
             | no reason to think any area of the universe has special
             | conditions where physics plays by different rules.
             | 
             | That sets up some implications around what we think the
             | universe should look like, at different scales. However, we
             | recently have been running into structures which are bigger
             | than we'd expect.
             | 
             | Where we get into the maths is to do with the value of the
             | cosmological constant. We currently think it's positive,
             | because the universe is expanding, and its rate of
             | expansion is accelerating. To look into the maths for this,
             | have a Google around the maths behind the accelerating
             | expansion of the universe.
        
           | moralestapia wrote:
           | >but which take a lot of maths to explain that I'm not going
           | in to here
           | 
           | Yeah, bs.
           | 
           | Provide sources to support you argument, that's entry level
           | discourse.
        
             | ziddoap wrote:
             | If you follow the link from this article to the preprint,
             | you'll find some explanations, references to other papers,
             | as well as enough terminology to do some Googling.
             | 
             | Have fun! It's quite interesting.
        
               | moralestapia wrote:
               | Yeah, read the site guidelines, yo.
               | 
               | I actually read the article, as you can see by the other
               | comments I've made, and found none of that, but please
               | feel free to correct me and cite here the portions of the
               | paper where that is mentioned.
               | 
               | And sure, I could specialize in cosmology and find out
               | the reasons on my own, but also, the burden of proof on
               | that argument is not on me.
        
               | ziddoap wrote:
               | Introduction, paragraph 2:
               | 
               | > _The multiple discoveries of LSSs made throughout the
               | past few decades are well known to challenge our
               | understanding of the Standard Cosmological Model (LCDM)
               | [2, 8-12], in particular due to a possible violation of a
               | fundamental assumption, the Cosmological Principle (CP),
               | which states that our Universe is both homogeneous and
               | isotropic on large scales_
               | 
               | That gives you a couple papers and a few terms that you
               | can get started with. Unless your goal is to argue,
               | instead of learn, which it seems like it might be.
        
               | moralestapia wrote:
               | Context, as it seems to have been missed:
               | 
               | >For reasons*, there's a soft limit on the scale that
               | you'd expect structures** to scale to.
               | 
               | The content you cited acknowledges the premise of the
               | Cosmological Principle, but it does not say anything
               | about what these "reasons" could be.
               | 
               | So, nope, that's not an adequate argument.
               | 
               | Again, I could waste my time on a PhD in Cosmology to
               | come back and actually make a good argument for why
               | homogeneity in structure is favored at large cosmological
               | scales ... but why should I? I didn't bring that
               | particular argument into the conversation [1].
               | 
               | 1: https://en.wikipedia.org/wiki/Burden_of_proof_(philoso
               | phy)
        
               | ziddoap wrote:
               | > _So, nope, that 's not an adequate argument._
               | 
               | I'm not trying to argue, lol. You're asking for more
               | information but in such a weirdly aggressive way.
               | 
               | The reason there is a soft limit (in our current
               | theories) is _because_ of the cosmological principle
               | 
               | Big lol at the wiki linking of burden of proof. Not every
               | conversation is an argument, holy.
               | 
               | As much as I love HN, this type of aggressiveness and
               | desire to converse as if defending a dissertation can get
               | bloody exhausting.
        
               | moralestapia wrote:
               | >The reason there is a soft limit (in our current
               | theories) is because of the cosmological principle
               | 
               | What? That's a circular argument.
               | 
               | HN is definitely not the place for "me vs. you" grudges,
               | so I stick to making arguments and try to drive the
               | conversation forward, however,
               | 
               | >Have fun! It's quite interesting.
               | 
               | >Unless your goal is to argue, instead of learn, [...]
               | 
               | >Big lol at the wiki linking of burden of proof.
               | 
               | You don't seem to be the one arguing in good faith,
               | though. "You're being aggressive", laughable.
        
               | ziddoap wrote:
               | My "Have fun!" was genuine, I had a lot of fun learning
               | about this stuff despite not pursuing a PhD in cosmology.
               | Anton Petrov covers this specific topic in a few videos,
               | as well as other large structures, and it's truly
               | fascinating.
               | 
               | The rest was probably a bit uncalled for, you're right. I
               | was immediately put on edge by "Yeah, read the site
               | guidelines, yo." (which, uhh, not sure how that is
               | focused on moving the conversation forward but lets leave
               | it at we were both touchy!)
        
       | valval wrote:
       | Wait till they find a grouping of galaxies of a phallic shape.
        
         | Towaway69 wrote:
         | The giant red arc in the image has a certain similarity.
        
         | hprotagonist wrote:
         | "The Long Man describes what is possibly a collection of three
         | burial mounds, the middle one oblong and the ones to the sides
         | round, quite frankly, in a suggestive arrangement that Nanny
         | Ogg approves of. If geography could talk, this bit of it would
         | be boasting: the whole landscape saying "I've got a great big
         | tonker""
        
       | denton-scratch wrote:
       | > 9.2 billion light-years from Earth
       | 
       | > cosmological neighbours
       | 
       | These structures are more than halfway across the observable
       | Universe. It's ludicrous to claim that they are neighbours.
        
         | kuschku wrote:
         | The circle and the arc are cosmological neighbours _to one
         | another_ , not _to us_.
         | 
         | They are close enough to _each other_.
        
           | denton-scratch wrote:
           | Fair enough; but the article doesn't mention _how_ close
           | together they are. Judging from the diagram, they 're
           | separated by an angular distance roughly the same size as the
           | larger structure; so about 3 billion LY.
        
             | kuschku wrote:
             | If you've got two structures of size X, with a distance of
             | X between them as well, that's relatively close.
             | 
             | That's as if Paris had a second Eiffel tower three blocks
             | away.
        
               | denton-scratch wrote:
               | Yeah, that makes sense if Paris is just 15 blocks across,
               | and the Eiffel Tower is a couple of blocks wide, and
               | there's nothing (observable) outside Paris.
        
             | Gooblebrai wrote:
             | And that doesn't even mean they are really close between
             | them linearly.
        
         | namenotrequired wrote:
         | They're saying the Big Ring is a neighbor not of earth, but of
         | the "giant arc of galaxies" which "appears in the same region
         | of sky at the same distance from Earth as the Big Ring".
        
       | incognito124 wrote:
       | Strong Expanse vibes
        
       | ur-whale wrote:
       | Time to revisit Larry Niven's work I think.
        
       | ganzuul wrote:
       | If the ring rotated, and black hole density decreases with size
       | (https://www.youtube.com/watch?v=71eUes30gwc), could a rotating
       | Godel universe exist within our universe?
       | 
       | Could a region of space be engineered to allow for a limited form
       | of time travel?
        
         | pwatsonwailes wrote:
         | No, is the short answer. What you'd need is _space-time_
         | rotating, not something physical rotating. If you could make
         | the things rotate because space-time was rotating, not because
         | they were, then yes, but there 's no mechanism we know of which
         | could do that.
        
           | ganzuul wrote:
           | Are you familiar with the equations? I'm not prepared to
           | simply take your word for it.
           | 
           | In short, this seems to say the exact opposite of your claim:
           | https://en.wikipedia.org/wiki/Dust_solution
        
             | pwatsonwailes wrote:
             | You're on the wrong thing there. I could be wrong but I
             | think you're outside your field on this one.
        
               | ganzuul wrote:
               | It says that spacetime exists as an interaction of
               | gravity alone. This implies that there is no other frame
               | of reference in this type of solution to GR. i.e. without
               | mass there is no time in such a universe. Not a new idea.
               | 
               | > I could be wrong but I think you're outside your field
               | on this one.
               | 
               | And in contrast what would that make of you??
               | 
               | I'm saying that if there in some point in the future
               | (because we can see it now) is sufficient mass density in
               | the region of space of that big ring, and it is rotating,
               | we tick every box we know of to theoretically allow for
               | an eternal circle. "Engineering" it would mean that
               | someone _wanted_ some type of eternal existence, which is
               | the profound idea at play here.
               | 
               | Engineering things without the technology to manufacture
               | it happens all the time. Just because we can't imagine
               | how to build it does not mean we can't calculate if it
               | could exist.
        
             | qsi wrote:
             | Where in the Wikipedia page does it seem say so? I can't
             | find anything relevant but then again I don't understand
             | all of it.
        
               | ganzuul wrote:
               | > A perfect and pressureless fluid can be interpreted as
               | a model of a configuration of dust particles that locally
               | move in concert and interact with each other only
               | gravitationally, from which the name is derived.
               | 
               | That "only" is important but unintuitive. It means space
               | and time can not be separated from mass.
        
           | tomthe wrote:
           | I agree with the no, but you can make space itself rotate
           | because things in space rotate:
           | https://en.wikipedia.org/wiki/Frame-dragging And that in turn
           | would rotate things in space... or not?
        
             | pwatsonwailes wrote:
             | The Lense-Thirring effect is absolutely a thing, and we
             | have direct evidence for it. To be clearer (I totally
             | wasn't clear enough on this tbf), there's nothing we know
             | of which can do it _at the required scale_ to allow for
             | time travel.
             | 
             | What we're talking about here are closed timelike curves.
             | There's models which suggest they could exist inside a
             | singularity, but they're not going to outside without
             | something which seriously breaks other areas of physics
             | (Tipler cylinders etc).
        
               | ganzuul wrote:
               | > There's models which suggest they could exist inside a
               | singularity, but they're not going to outside without
               | something which seriously breaks other areas of physics
               | (Tipler cylinders etc).
               | 
               | A singularity is a dimensionless point. It has no inside.
               | Did you mean a black hole? If so, the Kurtzgesagt cartoon
               | explains this.
               | 
               | The second part of you sentence seems to have a broken
               | sentence structure. Can't make sense of it.
        
               | tempestn wrote:
               | To clarify the rest of the sentence for you:
               | 
               | ...but [closed time-like curves are] not going to [exist]
               | outside [of a singularity] without something which
               | seriously breaks other areas of physics (Tipler cylinders
               | etc. [are examples of such theoretical instances which
               | would break other areas of physics]).
        
         | matja wrote:
         | Similar to the plot of
         | https://en.wikipedia.org/wiki/Ring_(Baxter_novel)
        
           | ganzuul wrote:
           | Yes, though the Kurtzgesagt video seems to allow for a Kerr
           | metric to be habitable in a very normal sense.
        
       | Brajeshwar wrote:
       | Please be un-natural and custom-made.
        
         | Aardwolf wrote:
         | Too bad a ring is still too easy to get created naturally. If
         | it would have had the shape of a square, or a dogecoin, that'd
         | get really interesting
        
         | Galatians4_16 wrote:
         | < monks, chanting >
        
           | Brajeshwar wrote:
           | Fifth Element!
        
             | Galatians4_16 wrote:
             | And Halo...
        
         | barbequeer wrote:
         | custom made arrangement of galaxies??
        
           | Brajeshwar wrote:
           | Aliens - custom-made. I didn't want to say man-made!
        
         | elorant wrote:
         | This can't be alien-made. That's 9.2 billion years old. The
         | universe was too young back then to allow life to evolve. Not
         | only that, but for a civilization to reach that kind of
         | technological level it could easily have taken them another
         | billion years.
        
       | ungamedplayer wrote:
       | Its a smiley face being drawn in progress.
        
         | petepete wrote:
         | Possibly an owl.
        
           | donbox wrote:
           | Or an eye. Almost.
        
       | breck wrote:
       | https://arxiv.org/abs/2402.07591
        
       | jen729w wrote:
       | My partner, mocking: "they found heaven!"
        
       | p0w3n3d wrote:
       | Ring of galaxies? That's puppeteers traversing the space...
        
         | kevindamm wrote:
         | A Klemperer rosette of galaxies instead of planets? That would
         | be more impressive than a ringworld.
        
       | davedx wrote:
       | It's obviously a Kardashev Type III[1] civilization.
       | 
       | [1] https://en.wikipedia.org/wiki/Kardashev_scale
        
         | iiio8 wrote:
         | It's not just one galaxy. It's a _ring of galaxies_.
        
           | wrsh07 wrote:
           | I'm reading Stephen Webb's book (If the Universe Is Teeming
           | with Aliens ... WHERE IS EVERYBODY), and he describes how a
           | partial Dyson sphere can turn a star into a spaceship which
           | blew my mind (just cover all but one side, the released
           | energy will push it the other direction). Imagine doing that
           | at the Galactic scale.
        
             | hollerith wrote:
             | >just cover all but one side, the released energy will push
             | it the other direction
             | 
             | What is to stop the star from just crashing into the
             | sphere?
        
               | wrsh07 wrote:
               | In the book he discusses the shkadov thruster which
               | reflects the energy so the shell would move, too.
               | 
               | Obviously if it's not reflective you could absorb the
               | energy and use it as needed
               | 
               | https://en.m.wikipedia.org/wiki/Stellar_engine
        
         | Sharlin wrote:
         | Type IV or V, more like.
        
           | astral_drama wrote:
           | Adjust some galaxies in the early timeline and changes would
           | appear downstream as if they were always there. For affected
           | lifeforms, these structures (e.g. a smiley face or
           | whathaveyou) would appear upon waking in the present morning
           | to the data, yet when the affected search their memories, the
           | structure would have always been there.
           | 
           | Unlikely configurations could be interpreted as communication
           | from beings more advanced than typically imagined, or as
           | cosmic engineering projects, or perhaps more likely, the
           | shape of the universe is just different than previously
           | imagined.
        
         | pfdietz wrote:
         | While I doubt that explanation will hold, it is true that
         | cosmological distances are where we should be looking for ET
         | civilizations, as at those distances one can avoid the Fermi
         | argument (although such a discovery would be pretty firm
         | evidence we'll never achieve FTL travel.)
        
           | andrewflnr wrote:
           | I don't know, cosmological distances might be too early for
           | biological life to form _and_ evolve intelligence _and_
           | expand across galaxies. My understanding is that there weren
           | 't necessarily enough of the basic chemicals of life formed
           | until relatively recently. (Phosphorus particularly is a
           | problem, I'm less sure about the others) And doing anything
           | visible across light years also takes a long time, especially
           | if FTL is impossible, which it almost certainly is.
        
             | pfdietz wrote:
             | That's all true, to some extent, but at least it's not
             | ruled out by Fermi.
        
         | hinkley wrote:
         | Or a weird lens effect. Gravitational lensing has a logarithmic
         | effect doesn't it? Theres the old joke about fitting a line to
         | log scale data with a fat enough pen. These galaxies aren't
         | perfectly circular to each other.
         | 
         | I think the fact that the arc has a similar focus to the ring
         | is going to turn out to be something.
        
       | hoseja wrote:
       | Fairy ring.
        
       | andyjohnson0 wrote:
       | Interesting article. I'm not an astronomer, or any kind of
       | scientist, but I tried perusing the paper anyway. What I expected
       | to find was some indication that the stars in question are
       | aligned on a plane - rather than being varying distances [1] from
       | our pov and only looking like a ring to us. Is this information
       | present and I missed it?
       | 
       | My other thought, with all respect to the expertise of the
       | scientists involved, is that when we observe the _universe_ at
       | this massive scale it may be inevitable that structures will just
       | appear out of the data, even with very high statistical
       | significance. I don 't know if this is a scientifically
       | defensible position to take though.
       | 
       | Again - I'm not a scientist and I don't know what I'm talking
       | about. Just musing, but interested in the opinions of others more
       | informed than me.
       | 
       | [1] I'm aware that determining distance over cosmological
       | distances is very difficult
        
         | Sharlin wrote:
         | > stars
         | 
         |  _Galaxies_. And determining the approx relative distance of
         | distant galaxies is in fact easy thanks to cosmological
         | redshift (the _z_ values the article refers to). Anyway, given
         | the number of galaxies in the ring, being at different
         | distances but their projections just happening to form a rough
         | circle would be even _more_ astonishing than the galaxies in
         | fact sharing a causal history due to some unknown early-
         | universe mechanism.
         | 
         | The article also mentions that either the circle or the arc in
         | itself could be just a statistical coincidence - as long as we
         | dok't find more such structures - but the existence of both the
         | circle and the arc, in the same part of the sky, is highly
         | suspicious.
        
           | andyjohnson0 wrote:
           | Woops. Yes, _galaxies_. Too late to edit.
           | 
           | > Anyway, given the number of galaxies in the ring, being at
           | different distances but their projections just happening to
           | form a rough circle would be even more astonishing than the
           | galaxies in fact sharing a causal history due to some unknown
           | early-universe mechanism.
           | 
           | I don't understand what you mean by this. Why would it be
           | "more astonishing" than an actual causal connection? Surely
           | astronomers are more interested in causal connections than
           | observational coincidences?
           | 
           | To illustrate: the stars making up the constellation of Norma
           | [1] form a rough square when seen from earth, but as their
           | distances from Earth vary greatly this is just an illusion
           | caused by Earth's relative orientation to them. Given the
           | Copernican principle (which I accept is not a physical law)
           | I'm struggling to see why a group of galaxies that form a
           | circle only when seen from "near" earth [2] are actually
           | cosmologically significant.
           | 
           | I accept that the ring contains more than four galaxies, and
           | this makes the ring more statistically significant than a
           | square of galaxies. But it still implies a privileged
           | viewpoint in order for it to be _actually significant_. I
           | still have the gut feeling that this potential significance
           | is more than offset by the enormously greater observational
           | scale.
           | 
           | tl/dr: why is this more than just naming a new constellation?
           | 
           | (Just to re-iterate: I'm interested in understanding the
           | errors in my mental model - and I'm not trying to poke holes
           | in the work of scientists more qualified them me.)
           | 
           | [1] https://en.wikipedia.org/wiki/Norma_(constellation)
           | 
           | [2] And also, I guess, from a similar point on the other
           | "side" of the ring
        
             | _xerces_ wrote:
             | I think of it in terms of degrees of freedom and
             | statistical likelihood. If I throw a bunch of marbles on
             | the floor and a few of them form a interesting shape that
             | is one thing as they can only move on a plane. If I throw
             | them in the air it is less likely to form a circle as now
             | they are free to move in multiple directions and are not
             | constrained to the plane. If 4 of those marbles align that
             | is less likely than 20 of them happening to do so in a
             | recognizable shape. 20 marbles in the air, each one being
             | in just the right place relative to the 19 others in order
             | to look like a circle when they can be in any position in
             | space (vs. limited to a flat plane) is exceedingly
             | unlikely.
             | 
             | Even more unlikely is that an arc appears next to the ring,
             | that would make me start to wonder if something is
             | affecting the marbles I throw into the sky.
        
               | financypants wrote:
               | Is it less likely even if we can view the marbles in the
               | air from any angle?
        
             | mannykannot wrote:
             | It does not seem very plausible that professional
             | astronomers have _twice_ made this rookie mistake and no-
             | one has noticed yet. Furthermore, if they were just doing
             | what amounts to drawing circles and lines on a map of
             | galaxies, they could have discovered thousands by now!
        
               | mentalpiracy wrote:
               | The rate at which we are collecting data far, far
               | outpaces the speed at which it is being analyzed.
               | 
               | There will almost certainly be more discoveries like this
               | as we continue surveying the cosmos with increasingly
               | sensitive instruments.
        
               | mannykannot wrote:
               | Well, yes, but my point is that, if these astronomers are
               | finding circles and other structures without doing basic
               | checks such as distance, they could find thousands _right
               | now,_ using nothing more than a chart of the known
               | galaxies - and even bigger ones than they are reporting
               | here. Thus, it is not plausible that they are omitting
               | these basic checks.
        
             | alfiopuglisi wrote:
             | > Woops. Yes, galaxies. Too late to edit.
             | 
             | Not even galaxies, but massive galaxy clusters. The spatial
             | smoothing used for the ring image is a 2D gaussian with an
             | equivalent width of 11 Mpc, or 37 million light years, big
             | enough to contain all the 2000 galaxies in the nearby Virgo
             | cluster with room to spare. That's for each point in the
             | ring (and that's why they all look so nice and round. These
             | astronomers are playing a statistical game where a pixel
             | combines information from trillions of stars) It's called
             | the Big Ring for a reason. Our own Laniakea supercluster
             | [1], whose dimensions are bigger than anyone imagined up to
             | a few years ago, can be tiled inside the ring several times
             | over.
             | 
             | At that spatial scale, the Universe is supposed to be
             | homogeneous. We do not have plausible mechanisms to
             | generate structures on such a massive scale.
             | 
             | Regarding your analogy with a constellation, yes you can
             | always draw arbitrary squares and triangles among bright
             | stars. But if you had 20+ stars arranged in a circle like
             | that ring, no one would think it was a chance projection,
             | you would demand a physical explanation. We do in fact have
             | such a ring around us: the Gould Belt [2], made of young
             | stars all around the Sun. It is difficult to recognize
             | precisely because we are inside it, and its stars are
             | spread all around the sky. And, of course, some kind of
             | physical explanation is invoked for this ring as well.
             | 
             | Moreover we do know it's an actual ring, and not some
             | chance alignment, because we can derive the distance of
             | each point from its redshift, and it turns out that they
             | are all quite similar. The authors spend quite a few pages
             | describing the 3D ring structure, showing that it's a ring
             | only when seen from our direction, and how it would appear
             | like an arc or a strange shape from other viewpoints. It
             | would still be a kind of overdense structure, but maybe
             | more difficult to recognize.
             | 
             | BTW the mechanism used to detect the ring is quite clever:
             | it's not a sky image, but rather an absorption map:
             | thousands of background quasars provide a sort of uniform
             | illumination, and they look where this light is removed by
             | clumps of matter.
             | 
             | [1] https://en.wikipedia.org/wiki/Laniakea_Supercluster
             | 
             | [2] https://en.wikipedia.org/wiki/Gould_Belt
        
               | andyjohnson0 wrote:
               | Thank you for taking the time to write such an
               | informative response.
        
               | Retric wrote:
               | > We do not have plausible mechanisms to generate
               | structures on such a massive scale.
               | 
               | Actual structure no. But, random chance can make things
               | look like a structure on this scale.
               | 
               | > But if you had 20+ stars arranged in a circle like that
               | ring, no one would think it was a chance projection, you
               | would demand a physical explanation.
               | 
               | I would generally assume it to be random. In galaxies
               | stars move around far to much for any structure from
               | their initial formation to remain for long, and forming a
               | ring long after creation would just be happenstance.
        
               | pests wrote:
               | > I would generally assume it to be random.
               | 
               | But its not, it has structure - it looks like ring or
               | arc. The universe should be homologous at this scale.
        
               | Retric wrote:
               | Every formation of galaxies has structure.
               | 
               | Random processes can appear to have meaningful structure,
               | but that's just because we value some outcomes more than
               | others.
               | 
               | > The universe should be homologous at this scale.
               | 
               | That doesn't mean we're going to perceive it as
               | homologous. A true random number generator spitting out
               | 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 would be freaky as fuck to
               | see, but that doesn't make it non random.
        
               | jakeinspace wrote:
               | This is true, but at this scale, aren't we looking at a
               | moderate portion of the visible universe? This is
               | hundreds of thousands or millions of galaxies appearing
               | with some strong correlation, I believe. There are only a
               | few trillion galaxies in the observable universe, so it's
               | not like we have 10^20 chances to observe random chance
               | correlations like this.
               | 
               | I'm just talking without actually having done a close
               | reading or done the statistics for myself, so I could be
               | quite wrong.
        
               | Retric wrote:
               | Check out the preprint: https://arxiv.org/pdf/2402.07591
               | 
               | It's less impressive when looking at the background data
               | than how it's described.
        
               | beltsazar wrote:
               | > Random processes can appear to have meaningful
               | structure, but that's just because we value some outcomes
               | more than others.
               | 
               | No. It's because some structures are much much _much_
               | less likely to form randomly than other structures.
               | 
               | If you throw 1000 dices, is it possible to get all one?
               | Yes. Is it likely? Not at all.
               | 
               | Why do planets look like a sphere (approximately)?
               | Because that's the most probable shape if things happen
               | randomly. If a pyramid-shaped planet was found,
               | scientists would freak out. This galaxy ring phenomenon
               | is similar to that (but not that crazy).
        
               | moralestapia wrote:
               | Finding ~50 dots arranged in a (very loosely defined)
               | circle, from any projection, of a dense set of 2 trillion
               | of them is _very_ plausible.
               | 
               | Actually, you would have a hard time producing this set
               | in such way that no "circles" like that are found at all.
               | It would have to be a very artificial distribution of
               | points in space for you not to observe this, like all of
               | them arranged in a single line, or a giant rectangle,
               | idk.
        
               | beltsazar wrote:
               | > Finding ~50 dots arranged in a (very loosely defined)
               | circle, from any projection, of a dense set of 2 trillion
               | of them is very plausible.
               | 
               | It depends on the size of the circle, though. The smaller
               | the size, the more likely the probability is. But that's
               | only for a particular combination of 50 dots. Now we have
               | to average out of all possible circle sizes and all
               | combinations of 50 dots. Can someone do the math (or the
               | simulation)?
        
               | moralestapia wrote:
               | On a first glance it seems so, but ... could it be the
               | opposite?
               | 
               | I'm thinking, the larger the space, the larger the number
               | of points contained within it, so the larger the
               | probability of them being arrange in such way that blah
               | blah ...
               | 
               | We need a math guy to chime in. I have a hunch there may
               | be a theorem about something like this already.
        
               | unusualmonkey wrote:
               | > If you throw 1000 dices, is it possible to get all one?
               | Yes. Is it likely? Not at all.
               | 
               | That's literally as likely as _any_ other possible
               | outcome.
               | 
               | Let's simplfy this to a coin toss, which is more likely:
               | 
               | HHHHHH
               | 
               | or
               | 
               | HHTHTT
               | 
               | or
               | 
               | HTHTHT
               | 
               | They all have the exact same odds of appearing, we might
               | just tell ourselves one formation is more special than
               | any other.
        
               | beltsazar wrote:
               | Of course each instance has the same probability. But
               | we're not talking about the probability of an instance,
               | but rather that of a set of instances.
               | 
               | In the dice example, it's obvious that the probability of
               | getting at least one dice facing two is much more likely
               | than the probability of getting all dice facing one.
               | 
               | Similarly, in the planet shape example, I hope you don't
               | think that a pyramid-shaped planet is as likely to form
               | as a sphere-shaped planet.
        
               | unusualmonkey wrote:
               | Yes, a large set of instances is more likely than a
               | single instance (all things being equal).
               | 
               | However that doesn't mean that a sphere is any more or
               | less likely than any specific other structure. It's an
               | small but important distinction.
               | 
               | No, a pyramid shaped planet is not as likely to form as a
               | sphere shaped pyramid. Definitionally a pyramid shaped
               | planet is impossible.
        
               | beltsazar wrote:
               | > However that doesn't mean that a sphere is any more or
               | less likely than any specific other structure.
               | 
               | A shape/structure doesn't have an intrinsic probability.
               | Your sentence is underspecified. Shape of what under what
               | process?
               | 
               | In the context of the shape of galaxies, I think we can
               | agree that if we found galaxies forming a shape like this
               | sentence: "WE ARE COMING", everyone would freak out. So
               | yeah, in this context, some shapes are more likely to
               | form (randomly) than others.
        
               | unusualmonkey wrote:
               | > So yeah, in this context, some shapes are more likely
               | to form (randomly) than others.
               | 
               | Again I think you are confused. Assuming random
               | distribution, 'We Are Coming' is just as likely as any
               | other similarly long structure to form. You just happen
               | to care about that structure more than others - however
               | that doesn't make it more or less likey to form.
               | 
               | That message, in morse code is .-- . / .- .-. . / -.-.
               | --- -- .. -. --..
               | 
               | There are 200B to 2T galaxies in the obeservable
               | universe. If you found lines of galaxies and interperated
               | them as morse code, I'm sure you'd find some interesting
               | words/phrases being said.
               | 
               | You'd expect that phrase in every 2^28 = 268,435,456
               | random 28 digit binary strings - which is not very many.
               | Keep in mind a galaxy could be part of many, many strings
               | (different index position, different orientation of
               | string).
        
               | pfortuny wrote:
               | No: precisely that is the definition of randomness as
               | "lack of information " or "incompressibility".
        
               | unusualmonkey wrote:
               | HH is just as compressible as HT or TH or TT.
               | 
               | You can easily build a compression scheme for any one of
               | these values, but not one that encapsulates all values
               | while using less data than the raw values themselves.
        
               | glandium wrote:
               | > Why do planets look like a sphere (approximately)?
               | Because that's the most probable shape if things happen
               | randomly.
               | 
               | That has actually nothing to do with randomness, and
               | everything to do with gravity.
               | https://spaceplace.nasa.gov/planets-round/en/
        
               | ineptech wrote:
               | For any allegedly-random distribution, it's possible to
               | statistically determine an upper-limit on the size of
               | non-random-appearing structures. The upper limit for such
               | structures in our universe is thought to be about 370
               | MPc, about 1/3rd of the size of this ring.
               | 
               | A lot of these questions are much more clearly addressed
               | in the previous paper by the same authors, which is much
               | more layperson-friendly: https://academic.oup.com/mnras/a
               | rticle/516/2/1557/6657809?lo...
        
               | btilly wrote:
               | Actually I do have a plausible mechanism whose numbers
               | have been sanity checked by a couple of cosmologists, but
               | has never been published.
               | 
               | Here's the idea. The expansion of the universe is
               | currently accelerating. If this continues indefinitely,
               | we get the https://en.wikipedia.org/wiki/Big_Rip model.
               | What happens if the Big Rip proceeds to the point where a
               | lot of https://en.wikipedia.org/wiki/Vacuum_energy gets
               | released, and that release stops the Rip by creating the
               | next Big Bang? This could form a cycle since the next
               | Bang creates cosmos that in turn will Rip.
               | 
               | It doesn't sound entirely crazy to me. The Casimir effect
               | shows that you should release vacuum energy when you
               | constrain the volume that a particularly bit of space can
               | interact with. The incredible expansion of a Rip should
               | constrain such interactions. So a large release of vacuum
               | energy seems expected. And who knows how releasing vacuum
               | energy interacts with the acceleration of the expansion
               | of the universe?
               | 
               | Let's do a back of the envelope estimate. Theory
               | estimates vacuum energy at something like 10^113 joules
               | per cubic meter of vacuum energy. For comparison the
               | visible universe is estimated at 10^53 kg. Using
               | Einstein's E = mc^2, that's around 10^70 joules. Current
               | cosmological models say that at the hottest part of the
               | Big Bang, the universe must have already been larger than
               | a cubic meter. Yes, there is a lot of energy not in the
               | form of visible matter. Even so, there's a lot of room
               | for a release of vacuum energy to explain the energy
               | density needed at the beginning of a Big Bang.
               | 
               | We at least pass the most basic sanity check.
               | 
               | This would offer interesting answers to some key
               | cosmological questions.
               | 
               | Current Big Bang models struggle with how a large volume
               | started out very uniform. Inflation has been proposed for
               | this, but it has some problems. But in this model,
               | extreme uniformity over a large volume is predicted. If
               | you add in quantum fluctuations starting the vacuum
               | release, that have spread out before we go from Rip to
               | Bang, then you can also explain arbitrarily large
               | structures in the universe.
               | 
               | This also explains the arrow of time. How could we start
               | off with such low entropy when entropy is always
               | increasing? Well as the universe expands, entropy
               | increases. But volume increases faster. We wind up with a
               | giant universe filled with very low entropy/volume. When
               | a small piece of that forms a new Big Bang, it again
               | starts with very low entropy.
               | 
               | Unfortunately, this involves an insane lack of
               | conservation of energy. But GR provides no easy way to
               | even state what conservation of energy means. At least
               | not outside of limited classes of models. Which this is
               | not one of. So the idea of energy not being conserved at
               | cosmological scales is at least not entirely
               | unprecedented by current theory.
        
               | stouset wrote:
               | > But if you had 20+ stars arranged in a circle like that
               | ring, no one would think it was a chance projection...
               | 
               | Of course we would? This is absolutely backwards.
               | 
               | A random plot of billions of points will have all sorts
               | of coincidental shapes and clusterings. A uniform field
               | might look more random but would actually demand
               | explanation, as lacking those coincidental clusterings is
               | strong evidence for structure.
               | 
               | And as I understand the topic, the scales involved
               | preclude those galaxies physically interacting and being
               | able to form structure. So they _should_ appear randomly
               | distributed.
               | 
               | Edit: To be clear I'm assuming my own ignorance here. I
               | presume there _is_ a reason this is significant, I just
               | don't understand it. But arguments like yours aren't
               | convincing to me because we _should_ expect to see random
               | structure, the same way a series of a billion coin flips
               | is likely to have a giant run of alternating heads and
               | tails.
        
             | vikingerik wrote:
             | There is also the multiple-endpoints principle to think
             | about. The likelihood of _this particular set_ of galaxies
             | forming a ring is very low. The chance of _some_ set of
             | galaxies among all the billions in the sky doing this is
             | much higher. Then we notice and cherry-pick only the one
             | interesting data point, we never notice all the mundane
             | ones.
             | 
             | It's always difficult to tell if a popular-science article
             | is really describing something unusual or if it's using
             | selective perception to create the illusion of one. (I have
             | no idea in this case.)
        
               | SubiculumCode wrote:
               | It's unusual, at the very least. Because it's relatively
               | close to us.
        
               | beltsazar wrote:
               | > The chance of some set of galaxies among all the
               | billions in the sky doing this is much higher.
               | 
               | Of course in relative terms it's much higher, but it
               | doesn't matter--what matters is the absolute value.
               | 10^-100 is much larger than 10^-10000, but if something
               | with the probability of 10^-100 happens, it's still
               | "astonishing."
               | 
               | The probability of a particular planet has a shape of
               | pyramid is so low. And yes, the probability of finding
               | any planet in the universe that has a shape of pyramid is
               | much higher, but still very low. If one was found,
               | scientists would freak out.
        
             | szvsw wrote:
             | The infinite does not necessarily contain everything. I
             | would be surprised to find an even number in an infinite
             | list of odd numbers. I would be even more surprised to find
             | cantor's diagonalized number in a list of rational numbers.
             | And yet even more surprised to find Hamlet encoded within
             | Pi.
             | 
             | Structure is still interesting.
             | 
             | In re: the non-causal alignment being even more astonishing
             | - a simple argument to illustrate this is to ask- would you
             | be more amazed if you threw 100 bouncy balls in a room,
             | took a photo and they formed a perfect circle in mid air at
             | that instant from that angle, or if you went and placed the
             | marbles one by one in a perfect circle on the ground and
             | took a photo?
             | 
             | The latter might be more meaningful, but the former is more
             | miraculous - not in a religious sense of course, but just
             | in the sense of the extraordinary unlikelihood of catching
             | such a moment of chance alignment in noise, apophenic
             | divinity, in how it seems to violate the second law, etc
             | etc.
             | 
             | It might be instructive for you to try look up Piero Della
             | Francesca's method of generating perspective images from a
             | point cloud (from the 14th century no less - he invented 3D
             | face scanning then!) and try a few manual examples to
             | really wrap your head around how difficult it would be for
             | a perfect circle to emerge from a truly random point cloud.
        
               | gcanyon wrote:
               | If Pi is normal, which we haven't proven but do suspect
               | to be true, then it contains Hamlet, and indeed the
               | entire works of Shakespeare in chronological order, an
               | infinite number of times.
               | https://en.wikipedia.org/wiki/Normal_number
        
               | szvsw wrote:
               | Of course! But we haven't been proven it yet. And in any
               | case, knowing something exists is quite different than
               | actually observing it. I know every night in Vegas, so
               | many people will hit my lucky number (7, boring I know)
               | on a roulette wheel that it is a perfectly ordinary event
               | with no significance, and yet I would be ecstatic if it
               | happened to me and would certainly be _feeling lucky_
               | (and so I don't gamble!). Even if Pi is indeed normal, it
               | would still certainly be beyond surprising to stumble
               | across the complete works of Shakespeare. In fact, from a
               | cultural point of view, it would be a somewhat earth-
               | shattering event! Imagine the headlines! Maybe not, maybe
               | no one would care. It would certainly be shocking to
               | anyone with half a brain cell, even if they knew it had
               | to be somewhere... to find one such particular region is
               | just so improbable that it would be undeniably... cool?
               | 
               | My point is that structure emerging out of noise, even if
               | by mere coincidence, is still deeply interesting on a
               | human, psychological level. Another commenter described
               | the original paper as astrology, essentially arguing that
               | it is bad science... maybe that is the case, but I think
               | there is still room for some form of... confusion,
               | estrangement, awe? in observing these sorts of
               | phenomenon, even in scientific discourse every now and
               | then. It's vaguely like a piece of meaningless but none-
               | the-less captivating art emerging out of the complex
               | technological and discursive apparatuses of science.
        
           | stouset wrote:
           | Looking at the angular size of the region in question, it
           | surely would have to be that they're equidistant from us in
           | order to be at all interesting. There should be innumerable
           | galaxies in and around the ring, from our perspective.
        
         | moralestapia wrote:
         | To be honest it's not clear if it's from our point of view or
         | not, since they don't mention it explicitly in the paper, but
         | it seems to be the case since they start from observations made
         | by the Apache Point Observatory, which is on Earth ...
         | 
         | If you think about it, it doesn't matter which point of view it
         | works on, if the thing is an actual circle that's interesting
         | on its own, or presumably a sphere(?) but they don't even touch
         | on that because "3D is hard"? Anyway, for some reason they
         | implicitly choose our point of view as the "interesting one",
         | funny (/s, actually lame and sad) to see the geocentric model
         | is still alive after two millennia!
         | 
         | They also didn't check if other stars would form circles from
         | _any_ arbitrary point of view (how many circles are actually up
         | there, not just the apparent ones), which would be a trivial
         | calculation, but I guess  "matrix transformations are hard" as
         | well?
         | 
         | The whole paper is pretty weak. They calculate the "thickness"
         | of this "circle", i.e. the distance from the galaxy closest to
         | us to the galaxy further from us if you undo the projection;
         | and they come up with a value of ~400 Megaparsecs. Now, you may
         | be inclined to think "yeah, but the universe is HUGE and on
         | that scale they may be kind of tighly packed?". Nope! It's on
         | the order of the largest (actual) cosmological structures that
         | we have identified, so, pretty much, they are _as further away
         | as they can be from each other_ , lol.
         | 
         | This is pretty much astrology.
         | 
         | Source: I read the paper.
        
           | MetaWhirledPeas wrote:
           | > To be honest it's not clear if it's from our point of view
           | or not, since they don't mention it explicitly in the paper,
           | but it seems to be the case since they start from
           | observations made by the Apache Point Observatory, which is
           | on Earth
           | 
           | Would the perspective difference be significant even if it
           | were far out into the solar system?
        
             | moralestapia wrote:
             | Yes, of course, a 2D circle could appear as a line from a
             | certain perspective in 3D space.
        
               | sp332 wrote:
               | I don't think a ring of galaxies is going to look very
               | different from anyplace within the solar system. Anyway I
               | think moralestapia's point is that the circle might not
               | be centered on us, so the redshift of the galaxies would
               | not be the same. We could still determine that a circle
               | exists by plotting the galaxies in 3D.
        
               | moralestapia wrote:
               | No, I mean, a 2D circle could appear as a line from a
               | certain perspective in 3D space.
               | 
               | Spin up your mental model of a circle in 3D space, look
               | at it from a vector perpendicular from its diameter,
               | rotate it 90 degrees in any other axis but the one you're
               | looking at it; on that 2D projection, it will be a line.
        
               | glenstein wrote:
               | >No, I mean, a 2D circle could appear as a line from a
               | certain perspective in 3D space.
               | 
               | Right, and as a matter of fact that's exactly what we DO
               | see with the Milky Way galaxy. It can be conceived of as
               | a circular disc, more or less, but in our sky we see it
               | from the side, as a streak or a band rather than a disc.
        
               | beltsazar wrote:
               | But of all perspectives in 3D space, there are only a
               | fraction of perspectives that see it as a line. Most
               | other perspectives see it as a circle/ellipse. So, the
               | earth's perspective is not that unique--in fact, it's the
               | most common.
        
           | lelanthran wrote:
           | > Anyway, for some reason they implicitly choose our point of
           | view as the "interesting one", funny (/s, actually lame and
           | sad) to see the geocentric model is still alive after two
           | millennia!
           | 
           | > They also didn't check if other stars would form circles
           | from any arbitrary point of view (how many circles are
           | actually up there, not just the apparent ones),
           | 
           | I think (not sure of the proof) that any set of points that
           | form a circle from a specific PoV would, from any arbitrary
           | PoV form a regular shape (ellipse) or a straight line.
           | 
           | So we can probably tell if any group of
           | stars/galaxies/bright-lights-in-the-sky form a "structure"
           | (i.e. a regular shape).
        
         | spdustin wrote:
         | I would argue that your keen interest in learning more about
         | natural things that are mysterious to you by asking questions
         | and doing research literally makes you a scientist.
         | 
         | Not a professional one in the field, sure. But scientist? Most
         | assuredly.
        
           | xutopia wrote:
           | Carl Sagan would agree. In his book The Demon Haunted World
           | he explains science in very similar terms as you. He also
           | gives examples of primitive humans doing science.
        
           | andyjohnson0 wrote:
           | Thank you!
        
           | GeoAtreides wrote:
           | But is he doing research? Has he read on the Cosmological
           | Principle? Maybe some reading on what standard deviation
           | (5.2s on this paper) is and what it means to things being
           | naturally random? How about reading the original paper? The
           | Discussion section makes it very, very clear how the
           | scientists reached the conclusion and how the Big Ring is
           | statistically significant -- and in the process literally
           | answering OP's question.
        
           | lelanthran wrote:
           | > Not a professional one in the field, sure. But scientist?
           | Most assuredly.
           | 
           | Of course he's not a professional scientist!!!
           | 
           | To be one you have to partake in academic politics, with its
           | legendarily low stakes, in a publish or perish environment
           | ... for little more than minimum-wage.
        
         | sandworm101 wrote:
         | If they are in a ring, equidistant, then whatever caused their
         | arrangement would be local and roughly the same size/shape. But
         | if there are at varying distances, then they would be arranged
         | into a cone, a cone pointing directly at our galaxy. That would
         | be a much more massive structure and, frankly, rather
         | terrifying.
        
         | lelanthran wrote:
         | I don't think you have to add a disclaimer that you're not a
         | scientist to (what looks to me to be) not-unreasonable
         | speculations.
         | 
         | I mean, even if you _were_ a scientist[1], odds are good you
         | 're not _that_ kind of scientist.
         | 
         | Sort of like _" I'm not a lawyer, but even if I were, I'm not
         | YOUR lawyer."_
         | 
         | [1] I _was_ a scientist, and but not this kind of scientist, so
         | your musings look just as plausible, if not more, than my own
         | would.
        
         | michae4 wrote:
         | from Figure 1 (page 5 of the PDF)
         | https://arxiv.org/pdf/2402.07591:
         | 
         | > The tangent-plane distribution of Mg II absorbers in the
         | redshift slice z = 0.802 +- 0.060.
         | 
         | the ring is visible in the slice, which corresponds to a
         | distance range based on those redshift values and cosmological
         | parameters. I think this is effectively a spherical shell of a
         | certain thickness.
        
       | igtztorrero wrote:
       | Pi constant appears again
        
       | willis936 wrote:
       | The Cosmological Principle has been suspect for a long time. It
       | just adds so little value and costs so much to our understanding
       | of the universe. Best to stick to provable things.
        
         | mr_mitm wrote:
         | Little value? It's one of the assumptions that lead us to the
         | prediction of the CMB which we then found. It's proved very
         | fruitful, I'd say. Without the cosmological principle, modern
         | cosmology is a complete non-starter. I'm not aware of any
         | serious theories whatsoever that even attempt to explain
         | anything without the cosmological principle or at least an
         | approximation thereof.
        
           | andrewflnr wrote:
           | I recall the CMB being found accidentally, and then becoming
           | evidence for the big bang. You don't need cosmological
           | homogeneity to predict the CMB.
        
             | mr_mitm wrote:
             | Your memory deceives you. The CMB was found accidentally in
             | the sense that its discoverers were simply trying to reduce
             | noise and found this one stubborn source, but it was
             | predicted by Alpher twenty years prior.
             | 
             | Can you go into how you would predict it without
             | homogeneity? Without homogeneity you don't get the FLRW
             | metric, so you won't get the big bang or expansion, so no
             | hot dense state in the past, thus no CMB.
        
               | andrewflnr wrote:
               | Well, I'm not a physicist, but, from Wikipedia:
               | 
               | > In a strictly FLRW model, there are no clusters of
               | galaxies or stars, since these are objects much denser
               | than a typical part of the universe. Nonetheless, the
               | FLRW model is used as a first approximation for the
               | evolution of the real, lumpy universe because it is
               | simple to calculate...
               | 
               | So unless there's a really strong dependency on the size
               | of the lumps, what breaks on the path from there to
               | something observationally close-enough to the CMB? I
               | mean, I know inflation is a factor there, but that very
               | much postdates the first ideas of the big bang so it
               | can't invalidate the basic idea.
               | 
               | Ed: basically what I'm saying is, there are a lot of
               | routes to a CMB-like prediction based on our
               | observations, and I very much doubt they all get broken
               | by lack of a cosmological principle.
        
               | mr_mitm wrote:
               | I don't like playing that card, but I am a physicist, a
               | cosmologist actually, and I wrote in my last post how it
               | breaks. And I used the qualifier "approximation" in my
               | first post of this thread. If you don't assume
               | homogeneity _on large scales_ you don 't get a big bang.
               | Or at least I'm not aware of any of the routes you are
               | talking about. Even observing receding galaxies does not
               | necessarily imply a big bang, which is why the debate
               | wasn't settled until the discovery of the CMB. Until
               | then, the steady state universe was still viable, which
               | is basically an eternally expanding universe.
        
               | andrewflnr wrote:
               | Are the features in the article big enough to break the
               | CMB predictions? I'm kind of taking it from the article
               | and surrounding works that they're big enough to break
               | cosmological homogeneity as commonly understood, but
               | maybe that's wrong too.
        
             | wizzwizz4 wrote:
             | It was predicted, _then_ found accidentally. https://www.if
             | i.unicamp.br/~assis/Apeiron-V2-p79-84(1995).pd... gives a
             | date of 1948 for the following (Ralph Alpher and Robert
             | Herman):
             | 
             | > The temperature of the gas at the time of condensation
             | was 600 K., and the temperature in the Universe at the
             | present time is found to be about 5 K. We hope to pub- lish
             | the details of these calculations in the near future.
             | 
             | https://en.wikipedia.org/wiki/Discovery_of_cosmic_microwave
             | _... describes the kinda-accidental confirmation of this
             | theory.
        
       | scaglio wrote:
       | _*The Three-Body Problem intensifies*_
        
         | Galatians4_16 wrote:
         | Oh give me a locus, where the gravitons focus, and the three-
         | body problem is solved... [1]
         | 
         | 1. https://www.youtube.com/watch?v=dRns6u5bHuw
        
       | moralestapia wrote:
       | Within 2 trillion galaxies and 10^24 stars, it would be
       | statistically rare _not_ to find any arrangement following a
       | shape that 's familiar to us.
        
       | ojosilva wrote:
       | I found a enlightening yet brief conference Alexia Lopez gave on
       | the Big Ring discovery:
       | 
       | https://youtu.be/fwRJGaIcX6A?t=173
       | 
       | Here's an in-depth seminar on the findings of the Giant Arc in
       | the Sky, her work prior to the Big Ring discovery:
       | 
       | https://www.youtube.com/watch?v=-zkGk6EPMC8
       | 
       | She was also featured in a pop-sci BBC Four documentary:
       | 
       | https://www.youtube.com/watch?v=S36MqEzUzIw
       | 
       | Unfortunately all videos are of quite bad quality, but the
       | explanations are a good introduction to the work.
        
       | gmuslera wrote:
       | Could we be watching in the wrong direction? Finding patterns
       | where there is random noise is one of our characteristics. Or
       | something closer than distorts our view of that region.
       | 
       | In the other hand, complexity sometimes lead to unexpected
       | regularities, maybe things were not so even around the Big Bang.
        
       | throwup238 wrote:
       | Does anyone know how fast the big ring in the sky keeps on
       | turning?
        
         | barbequeer wrote:
         | a year or more
        
         | spdustin wrote:
         | I don't know where I'll be tomorrow, but I understood your
         | reference today.
        
           | lelanthran wrote:
           | Interesting journey.
        
       | layer8 wrote:
       | That's clearly a Cyclops smiley face.
       | 
       | Or a weak wifi signal.
        
       | codelikeawolf wrote:
       | It's obviously the result of a construction project by a hitherto
       | unknown Type IV civilization on the Kardashev scale. /s
        
       | markus_zhang wrote:
       | Do we have a guess what does the ring look like X million/billion
       | years ago?
        
         | undersuit wrote:
         | Yes, we have direct observations. /s
         | 
         |  _The light we are viewing now was emitted billions of years
         | ago, we don 't know what it looks like today._
        
           | profsummergig wrote:
           | Something so key to the news, and yet not mentioned in this
           | article.
           | 
           | The ring we see is how it looked 9 billion years ago. The
           | universe is 14 billion years old. So, when the universe was
           | still a baby.
        
           | markus_zhang wrote:
           | Sorry I meant to say...eh...maybe something from a few
           | decades ago so to capture tiny changes.
        
       | qD29Lno-oKXPLEv wrote:
       | This is pretty incredible...I honestly would be facinated to find
       | out what sort of early universe event might have precipitated
       | such a massive structure
        
       | Nifty3929 wrote:
       | Is this the center of the universe then? Maybe the big band
       | originated from the center of that ring.
        
         | astrostl wrote:
         | The universe is not believed to have a center.
        
         | ajmurmann wrote:
         | The big bang was everywhere. Space itself was created by the
         | big bang. It's not like a bomb going off in space somewhere
         | even though that's more intuitive to imagine.
        
       | EVa5I7bHFq9mnYK wrote:
       | Looks like Galactic Union )
        
       | Joel_Mckay wrote:
       | It is a weird structure because it is a helix, and not a ring.
       | 
       | Dr. Becky covers these sorts of phenomena in an accessible
       | format:
       | 
       | https://www.youtube.com/@DrBecky/videos
        
       | ThouYS wrote:
       | I'm not an astronomer either, but pretty sure if I generated
       | uniformly random points on the scale of number of visible
       | galaxys, I could find a circle in there
        
         | dan_mctree wrote:
         | Pretty sure you wouldn't find many circles containing galaxies
         | all at a similar approximate distance
         | 
         | There might be some, so it could be lucky and just random
         | chance, but the stats seem to say that it's very unlikely
        
       | moonlion_eth wrote:
       | that people refuse to accept that it is a structure and not
       | mirage formed by a privileged angle gives homage to its
       | statistical improbability
        
       | riskable wrote:
       | Wild speculation: It's the result of another universe poking into
       | our own, forcing a bunch of galaxies near the center point to
       | spread out in a circular fashion.
        
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       (page generated 2024-05-27 23:01 UTC)