# Astronomers discover the largest structure in the universe

*Monthly Notices of the Royal Astronomical Society*.

Quasars are the nuclei of galaxies from the early days of the universe that undergo brief periods of extremely high brightness that make them visible across huge distances. These periods are 'brief' in astrophysics terms but actually last 10-100 million years.

Since 1982 it has been known that quasars tend to group together in clumps or 'structures' of surprisingly large sizes, forming large quasar groups or LQGs.

The team, led by Dr Roger Clowes from UCLan's Jeremiah Horrocks Institute, has identified the LQG which is so significant in size it also challenges the Cosmological Principle: the assumption that the universe, when viewed at a sufficiently large scale, looks the same no matter where you are observing it from.

The modern theory of cosmology is based on the work of Albert Einstein, and depends on the assumption of the Cosmological Principle. The Principle is assumed but has never been demonstrated observationally 'beyond reasonable doubt'.

To give some sense of scale, our galaxy, the Milky Way, is separated from its nearest neighbour, the Andromeda Galaxy, by about 0.75 Megaparsecs (Mpc) or 2.5 million light-years.

Whole clusters of galaxies can be 2-3 Mpc across but LQGs can be 200 Mpc or more across. Based on the Cosmological Principle and the modern theory of cosmology, calculations suggest that astrophysicists should not be able to find a structure larger than 370 Mpc.

Dr Clowes' newly discovered LQG however has a typical dimension of 500 Mpc. But because it is elongated, its longest dimension is 1200 Mpc (or 4 billion light years) - some 1600 times larger than the distance from the Milky Way to Andromeda.

Dr Clowes said: "While it is difficult to fathom the scale of this LQG, we can say quite definitely it is the largest structure ever seen in the entire universe. This is hugely exciting – not least because it runs counter to our current understanding of the scale of the universe.

'Even travelling at the speed of light, it would take 4 billion light years to cross. This is significant not just because of its size but also because it challenges the Cosmological Principle, which has been widely accepted since Einstein. Our team has been looking at similar cases which add further weight to this challenge and we will be continuing to investigate these fascinating phenomena."

Explore further

**Citation**: Astronomers discover the largest structure in the universe (2013, January 11) retrieved 26 June 2019 from https://phys.org/news/2013-01-astronomers-largest-universe.html

## User comments

joigusVendicarDEl_Noseit says quite plainly

meaning it is 4 billion light years across -- making readers of a science article do a little math in this case was not out of the question.

My question is how does this compare to the Sloan Wall based on mass.

yyzThe paper by Clowes et al finds a total mass for the "Huge-LQG" of ~6.1x10^18 Msun. The mass for the Sloan Great Wall, referenced in a 2011 paper, is given as 1.2x10^17 Msun: http://arxiv.org/abs/1105.3378

Compared with the mass expected to be found within a volume the size of the Huge-LQG, the Clowes paper notes the estimated mass represents a mass excess of 3.4x10^18 Msun, equivalent to ~1300 Coma Clusters or ~20 Sloan Great Walls!

Q-StarWhat?

Point A to point B is always the same distance whether you use inches, meters, miles, stadia, or light-years. "due to special relativity" means you can't get across that distance faster than light can.

By the By: Are you "that" fellow again?

extinctTorbjorn_Larsson_OM"(2) Monte Carlo simulations are an invaluable way to determine the expected deviations within the LCDM model. Claims of anomalies without Monte Carlo simulations are necessarily weak claims. (3) Some parameters are weak discriminants of cosmology because they take on a broad range of values for multiple realizations of the same model."

[ http://lambda.gsf...lies.pdf ]

So I'm not convinced for the time being.

cantdrive85[ http://www.scienc...0p07.htm ]

then it's likely these objects are not the largest, but close by and dim and the Cosmological Principle is not in jeopardy.

Torbjorn_Larsson_OMThe WMAP team has a long history of having to respond to people pushing anomalies, see my links, and Clowes' people are yet another team proposing a slew of such to shore up their prediction.

It is not impressive compared to the impressive record of WMAP to handle those, and an extraordinary claim need extraordinare evidence. This isn't that.

Btw, "do not assume" is a fundamental misunderstanding. Everything from experiments to resulting observations to theory is based on (testable) constraints (verifiable "assumptions"), or nothing could be done. Science is based on "_do_ assume"!

The rest is not even cogent. If the constraints et cetera were wrong, society wouldn't do science/technology.

And "civilization type 1" size is impossible due to the universal speed limit, it is pseudoscience.

Torbjorn_Larsson_OMThis paper do MC, but the result rests on a model [ http://arxiv.org/...0617.pdf 9 that

1) uses very old parameter values (5 year release instead of the much improved 9 year)

2) doesn't verify (3) above

3) is inconsistent with LCDM (assumes fractal dimensions so constant spectral index 1, but LCDM has a running s.i. < 1. [ http://lambda.gsf...ults.pdf ]

@ cantdrive: But Arps' claim has been soundly rejected, so that isn't working either.

No, the robust WMAP stands until extraordinary claims of anomalies gets extraordinary evidence. None of this comes close.

Phil DePayneShootistYeah. Gravity.

Torbjorn says, "And "civilization type 1" size is impossible due to the universal speed limit, it is pseudoscience."

Kardashev scale? A Type I civilization is capable of orbital spaceflight and colonization, medical and technological singularity, planetary engineering, trade and defense, and stellar system-scale influence:

What. Does. G. R. Have. To. Do. With. It?

MeyerEarth time for two reasons:

1. A vehicle moving at the speed of light wouldn't experience any passage of time.

2. It's 4 billion light years as seen from Earth. It could be larger or smaller to other observers, depending on how they are moving.

fmfbrestelThats just how science works. Hypothesis and test.

I will not argue that some scientists are not arrogant, but they test their assumptions.

I suggest you test your own assumptions before trying to pass judgement.

GSwift7I agree. Monte Carlo isn't deterministic.

ValeriaTHuskyValeriaTkvanttikvanttiWhat...? This is untrue. According to the Big Bang theory the universe can be infinite in size with infinite amount of galaxies - and according to observations, it probably is (the blobal geometry of the universe is flat to a 99% observational accuracy). The observable universe does not equal the universe itself. I can't believe the misconceptions people have on this site...

ValeriaTkvanttiAre you trolling?

The Universe is immensely large and possibly infinite in volume. The region visible from Earth (the observable Universe) is a sphere with a radius of about 47 billion light years, based on where the expansion of space has taken the most distant objects observed.

Also I can already think of way of explaining this 1.2 Gpc cluster of quasars in the BB Cosmology as one of the densest regions of our nearby space in the very dense early universe where galaxies hadn't even formed yet. It's an anomaly - not a contradiction. Let's see when this gets truly peer reviewed by credible BB researchers who know what they are talking about.

ValeriaTValeriaTPkunk_Also what does something so humongous imply for the idea that gravity is propagated through "graviton" particles , i.e does it instead favor the idea that gravity acts as a field effect almost instantly even over light year distances?

ValeriaTkvanttiNo offense but the ignorant one seems to be you. You didn't even know the observable universe is different from the universe itself - and now you try to preach people to learn about the Big Bang theory? And a link to the Aether Wave Theory site for "evidence" against the BB with unverified crackpot sources, really? Please don't try to be an expert on a field you clearly don't seem to understand, and please refrain from misguiding people who actually want to learn stuff. Regards, a physics student.

kvanttiIf the global curvature/geometry of the universe is flat, then according to General Relativity (and the BB theory therefore) the universe is infinite in size containing infinite amount of galaxies and will continue to expand infinitely. So no, an infinite universe is not impossible in BB theory. In fact, it's one of it's predictions.

ValeriaTkvanttiAssuming you mean "of INfinite size", you are wrong. If the universe is of infinite size, it was alrady infinite at the time of the Big Bang. In this case singularity doesn't mean an infinitesimal point but a state where relative distances were non-existent and the density of the universe was at it's maximum.

Please stop posting nonsense that is only true inside your own head. Dark energy doesn't affect the global curvature. The global geometry of the universe is flat up to a 99.6% observational accuracy, as stated by NASA:

"We now know (as of 2013) that the universe is flat with only a 0.4% margin of error. This suggests that the Universe is infinite in extent; however, since the Universe has a finite age, we can only observe a finite volume of the Universe."

OjorfOf course it can!

I assume you meant 'infinite' size.

But even so, of course it can!

OjorfOf course it can!

I assume you meant 'infinite' size.

But even so, of course it can!

ValeriaTguillaume_pussettoAlso, the dark era has nothing to do with the possibility of larger structures that we cannot see due to the limitations imposed by the special relativity and the expansion of the universe.

GigelThe meaning is quite unclear. If you travel for 4 billion years at light speed you might experience space expansion. Thus you may be actually traveling for more than 4 billion light-years. A distance that big should not be given in time travel units, but in space units.

mayanmayanUniversal Cosmological Constant etc is just an axiom but not correct, its just a temporary property, Look at Laghima, Anima, Garima described by certain books........

BenniIf it can be observed to be "flat" then by no stretch of the finite imagination can it be "infinite", certainly not in Einstein's GR.Any object that is flat in appearance must by definition be an object with a boundary or it could not appear "flat" & thus cannot be "infinite" which by definition means "without boundary of any shape", flat or otherwise.

The present data really suggests we cannot see 99.6% of the Universe which is why we see only a 0.4% rise/run curvature of the sphere of the universe that Einstein discusses in his GR on the shape of the Universe. You should read what he more emphatically stated about the "spherical universe".

Torbjorn_Larsson_OM@GSwift7: "Monte Carlo isn't deterministic." That is not a problem, it is a statistical valid method. WMAP recommends it.

@ValeriaT: The result isn't the extraordinary evidence that would be needed to make the extraordinary claim standard cosmology is wrong. And there is no aether, it has been known for over a century now, it only looks extraordinary stupid to try to inject it on science blogs.

WMAP has shown over an over, now latest in its 9 year data release, that the universe is perfectly homogeneous and can't be else. That is alsoe predicted from inflation.

@Husky: No, we see ~ 10 times the current radius out due to cosmic variance, see the WMAP papers I linked to.

Torbjorn_Larsson_OMThe inflationary standard cosmology universe can have a topology admitting infinite spatial extent several ways. The simplest is eternal inflation infinite space.

But if new vacuums tunnel out of old, such bubble universes will internally have a topology that makes them behave spatially infinite. The wonders of GR in many dimensions. Simplest way to see that is to study Linde's pocket universes, since they grow as the embedding still inflating universe grows and it is evident even for a 3D guy looking at a 2D image that it works out.

@LarryD: We know GR is true on all scales (down to um), it is what the standard cosmology predicts and what is observed. No way to move that observation, since it is self consistent.

@mayan: No axioms are used in these theories. You use testable constraint. That is how we can observe the cc and its value.

@rubberman: Missing the point. SC predicts an upper limit, and it is seen.

BenniThen you should comport your conclusions to what Einstein actually stated before you start lecturing: In Section 30, Part 3: The Structure of Space according to General Relativity. Give it a read.

That's for sure, in the meantime give Section 30, Part 3 of GR a good read. Einstein knew a lot about Conservation of Energy that the rest of you who don't work in the field find incomprehensible.

BenniWritten: 1916 (this revised edition 1924)

Part III: Considerations on the Universe as a Whole

The Structure of Space According to the General Theory of Relativity

If we are to have in the universe an average density of matter which differs from zero, however small may be that difference, then the universe cannot be quasi-Euclidean. On the contrary, the results of calculation indicate that if matter be distributed uniformly, the universe would necessarily be spherical (or elliptical) . Since in reality the detailed distribution of matter is not uniform, the real universe will deviate in individual parts from the spherical, that is the universe will be quasi-spherical. But it will be necessarily finite. In fact the theory supplies us with a simple connection between the space-expanse of the universe and the average density of matter in it.

(See also Mach's Principle which was the basis for Einstein's concept of a "closed universe")

....cont'd

BenniFleetfootThe "very beginning" was Friedmann's publication of the equations that bear his name which he derived from GR. For a flat or negatively curved universe, those equations give an infinite universe so you are wrong again, the spatially infinite solution has been part of the model from the very first day.

FleetfootIf you learn the maths you'll find that in GR a flat universe MUST be infinite.

Rubbish, an infinite plane is flat even in high school geometry.

In this case "flat" means that the interior angles of a triangle sum to 180 degrees hence even the surface of a cylinder is mathematically "flat" and in 4D you can even have a flat torus:

http://en.wikiped...at_torus

Try learning something about the subject instead of spouting disinformation.

FleetfootYou omitted the preceding paragraph where he said

"We might imagine that, as regards geometry, our universe behaves analogously to a surface which is irregularly curved in its individual parts, but which nowhere departs appreciably from a plane: something like the rippled surface of a lake. Such a universe might fittingly be called a quasi-Euclidean universe. As regards its space it would be infinite."

What you quoted is true of the Einstein-deSitter model but that has a zero cosmological constant. Including the non-zero value of the modern model gives Einstein's "quasi-Euclidean" infinite plane.

BenniThe results of calculation indicate that if matter be distributed uniformly, the universe would necessarily be spherical. I must not fail to mention that a theoretical argument can be adduced in favor of the hypothesis of a finite universe. The general theory of relativity teaches that the inertia of a given body is greater as there are more ponderable masses in proximity to it, and the other bodies in the universe, as indeed, ever since Newton's time, gravity has been completely reduced to interactions between two bodies. (Albert Einstein 1954)

Closed Universe- density of the matter is above critical density producing a spherical universe caused by gravitational attraction exceeding outward expansion.

Open Universe- density of matter is below critical density curved like a saddle because gravitational attraction is insufficient to stop outward expansion.

Flat Universe- density of matter is equal to critical density causing expansion to cease after infinite time.

BenniYour problem is a fundamental lack of knowledge of Conservation of Energy. You need to bone up on ENTROPY & learn about why Entropy cannot occur in a "space" that has no boundaries, Einstein understood that, and, well, so do I.

El_NoseThink of the BB like this. At first all you had were the Integers and then some deity said - let there be Reals. And the real numbers came into existence and made a continuum between every point that existed before. the BB is like that. there was obviously something before the BB -- but we recognize it is probably pretty impossible to look back before the BB. But it getting bigger left a lot of energy out there to observe today.

FleetfootThat's correct but those graphs only show the scale factor as a function of time. The graph marked "open" is applies to a universe which is spatially infinite.

You're thinking about it the wrong way round, the models are built on the maths of GR. Friedmann solved the equations based on the assumption that the universe was homogenous and isotropic. The big bang model is the outcome of the calculation, not the basis for it.

Calculate for an average energy density of exactly the critical value or less, the maths tells you the model is spatially infinite, if the density is above critical, it is finite.

Observations say it is within 0.4% of the critical value but not whether it is above or below.

FleetfootAnd the open and flat universes are infinite. Einstein assumed it was closed.

All the above is correct for a universe where lambda is zero but you still haven't covered the case of a non-zero cosmological constant. Einstein died in 1955, Perlmutter showed the CC was non-zero in 1998 so you won't find much in his writings about what he mistakenly called his "greatest blunder", you need to look at modern sources. Add the CC and the open and flat cases expand forever.

FleetfootTry reading the Physics FAQ before claiming you understand conservation of energy in GR:

http://math.ucr.e..._gr.html

vidyunmayaCosmology needs best of brains trust where cosmic function of the Universe can high-light with better space vision.

vidyunmayaCosmology needs best of brains trust where cosmic function of the Universe can high-light with better space vision.

vidyunmayaThe study reveals almost 30 dwarf galaxies orbiting the larger Andromeda galaxy in this regular, solar system-like plane.

I do expect more according to my Cosmology Vedas Interlinks-projectections

Hevyash17The Big Bang Theory followers; please enjoy this finding.

kevinrtrsHow did light travel accross such a vast infinite distance to give such an even radiation? There's not enough time at current light speed. Are you proposing an earlier much faster speed of light?

If you now want to throw in the so-called "inflation" then it raises the question of what started that miracle and even more miraculous - what stopped it once it got started?

This research clearly shows that the copernican principle is bogus - the universe is much more non-homogeneous than the scientists would like.

Soon after the initial proposal, they of course discovered galactic clusters and paths and realized that it cannot apply anymore. So, to bring theory in line with the observations, they changed it.

Now, they'll repeat that trick.

FleetfootIt didn't, we can only see a tiny fraction of the universe. The contents were almost uniform everywhere.

No, the speed of light has been measured in material in a distant source 10 billion years ago. It has the same value as today. The measurements have an accuracy of about 5 parts per million.

This grouping is interesting but previous similar false claims (e.g the "dark flow") have later been shown to be within normal statistical variations.

kvanttiThe Big Bang theory (or the researchers working on it) doesn't claim to have all the answers to all the open questions, but saying the BB theory is straight out wrong is just being ignorant towards how physical theories work. Physical theories are not absolute truths written in stone tablets; they are - or atleast try to be - the best mathematical descriptions of the observed dynamics of the universe, ie. the qualitive and quantative descriptions of the "laws of nature".

That in mind, the standard Lambda Cold Dark Model (ΛCDM) of the Big Bang does a wonderful job explaining the properties of the earliest, oldest universe we can see: http://www.astro....-DT.html

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more