Astronomers Discover Largest Structure In the Universe

KentuckyFC writes "Until now, the largest known structure in the Universe was the Huge-LQG (Large Quasar Group), a cluster of 73 quasars stretching over a distance of 4 billion light years. Now astronomers say they've spotted something even bigger in data from gamma ray bursts, the final explosions of energy released by stars as they die and the universe's most energetic events. Astronomers have measured the distance to 283 of these bursts and mapped their position in the universe. This throws up a surprise. At a distance of ten billion light years, there are more gamma ray bursts than expected if they were evenly distributed throughout the universe. This implies the existence of a structure at this distance that is about ten billion light years across and so dwarfs the Huge-LQG. What's odd about the discovery is that the Cosmological principle--one of the fundamental tenets of cosmology--holds that the distribution of matter in the universe will appear uniform if viewed at a large enough scale. And yet, structures clearly emerge at every scale astronomers can see. The new discovery doesn't disprove the principle but it does provide some interesting food for thought for theorists."

Comments

Turtles, all the way up!

[Anonymous Coward]

Maybe we're at the bottom of the turtles after all?

Re:Turtles, all the way up!

[paiute]

Don't know about that, maybe we just can't look at tiny enough particles to see it's turtles all the way down also? Who know what's inside quarks?

Very very very old clams.

Re:Turtles, all the way up!

[Anonymous Coward]

Who know what's inside quarks?

Some dabo tables and holodecks for starters.

Re:Turtles, all the way up!

[johanwanderer]

If you look further, you will find that there is a spherical structure with radius of approximately about 13 billion light years, and nothing outside of that.

The universe is lumpy

[fustakrakich]

Like carelessly made Cream of Wheat.

Re:The universe is lumpy

[Black LED]

Good Cream of Wheat should be lumpy.

Re:The universe is lumpy

[Scarletdown]

Isn't Kareem of Wheat what Buckwheat changed his name to after converting to Islam?

Re:The universe is lumpy

[Anonymous Coward]

THat's the short version, but technically it was Yusef Mohammed Karim bin Al-Bukwiti Shabam Blujeanie Haro.

Re:The universe is lumpy

[FilmedInNoir]

No, more like the cellulite riddled butt cheek of a MILF.

Re:The universe is lumpy

[cellocgw]

more like the cellulite riddled butt cheek of a MILF

From that description, sounds more like a MINWTF (never want to)

Re:The universe is lumpy

[Burz]

Like carelessly made Cream of Wheat.

Or not so much, and it just went through a phase 10G years ago that transitioned from producing a relative abundance of shorter-lived, supernova-prone stars to producing less of them.

Enter Metaphysics

[some old guy]

The real importance of such observations and discoveries lies not in their ability to test existing hypothesis but in furthering our ability to form new ones.

Re:Enter Metaphysics

[atomicxblue]

I don't have mod points today, so take a virtual +1 Insightful

Re:Enter Metaphysics

[icebike]

By forming new ones, I presume you mean taking a collection of some random radio emissions scattered around the universe and arbitrarily deciding they are a "structure"?

Re:Enter Metaphysics

[kruach aum]

But it does test our existing hypothesis. It disconfirms that at a scale of 10 billion light years, matter in the universe is uniformly distributed. If you're into Bayesian epistemology, this means confidence in the Cosmological principle has just been adjusted downwards because of the evidence that has been discovered.

It is of course also important in the formulation of new hypotheses, as you rightly point out, but to imply the one is more important than the other is simply untrue.

Re:Enter Metaphysics

[fuzzyfuzzyfungus]

Given that we have a relatively well developed mathematical articulation of 'random', and the likelihood of various outcomes arising from a random distribution, it should presumably be possible to determine that a given observed outcome is more or less probable as the result of a random distribution. That doesn't necessarily supply any causal suspicion of having arisen other than randomly; but it's still measurable.

"Structure" seems like a poor word, given the heavy connotations of purposeful design or systemic interaction; but choosing a statistical cut-off and taking particular interest in outcomes less probable than that, given the assumptions about the underlying distribution, is in principle sound enough(though it may simply mean that an improbable outcome happened, rather than that the assumptions about the underlying distribution were wrong).

It's like watching the payouts of N slot machines over the course of an evening: If you know, or have a hypothesis, about the odds of the game, you can tell how far a given outcome deviates from the expected distribution, though even observing an extraordinarily unlikely one cannot prove that the game was being rigged, though it can suggest it strongly enough to send you looking for clues in that direction.

Re:Enter Metaphysics

[some old guy]

I never said it didn't form a test, and I would not hesitate to imply that original thinking in pondering the unknown is always intrinsically more important than endlessly testing the ostensibly "known". Of course, YMMV.

Re:Enter Metaphysics

[Vitriol Angst]

I'd like to propose a "hypothesis" that the reason we see these anomalous structures where we should be seeing more randomness would also explain some anomalies we currently blame on dark matter; the influence via gravity of either other dimensions, or extra-Universe objects (basically, other Universes not directly tied to our own). It would mean Gravity is also an "extra dimensional" force or particle that isn't normally observable in our Space/Time.

I'm not totally convinced of this hypothesis -- but I think it's worth throwing it in there, because I think that the early Universe models are probably quite good, and these superstructures should not exist except for forces we are not yet currently aware of.

Re:Enter Metaphysics

[neonKow]

This is as oppsed to the physical +1 Insightful atomicxblue would be sending you in the mail on a normal day.

Re:Enter Metaphysics

[fuzzyfuzzyfungus]

I'm no cosmologist, so I have no comment there; but the difficultly of looking at what is basically a black box (almost 300 objects at 10 billion light years? Voyager might be a few years away...) statistically is somewhat maddening.

Even a trivially simplified case (say I have a coin, that I allege is fair, and you get to flip it as many times as you want before deciding if you believe me) cannot be decided with certainty. Any finite sequence of flips is equally likely as any other (though sequences that are approximately 50/50 should be overwhelmingly more common if the coin is in fact fair, I have no idea how the behavior changes if you choose infinitely many flips), and you can only gain greater or lesser doubt in the fairness of my coin.

For a much more complex phenomenon, like the origin of the universe, deciding whether you are simply looking at an improbable; but perfectly possible, local perturbation, or whether there is some 'tilt' in the system not covered by current accounts... It's a mathematically cogent exercise; but 'mathematically cogent' and 'easy' are very, very, very different things.

Re:Enter Metaphysics

[asliarun]

This is as oppsed to the physical +1 Insightful atomicxblue would be sending you in the mail on a normal day.

Do you think that keyboard you are holding is ... real?

Hmmm.

Re:Enter Metaphysics

[HiThere]

I think you're serious, so I'll try to answer.

The things being observed are evidence of huge collections of small events (atoms, etc.) So their not being in the predicted distribution is very good evidence that something unexpected is happening. As to WHAT unexpected...that's less clear, which is part of what makes this interesting.

Even at normal human scales, random processes are rare. (Chaotic are less so, and it's often difficult to tell them apart. E.g., I suspect dice throws of being mainly chaotic rather than random.) If a die is thrown several times, and an unexpected sequence appears, people tend to suspect that something is interfering with the expected "random" sequence. And a die is a LOT smaller than a quasar. (I.e., it has a lot fewer apparently random, as opposed to chaotic, elements.)

Re: Enter Metaphysics

[fuzzyfuzzyfungus]

I was attempting emphasis through understatement. Even if Voyager had the correct instruments, it might as well be sitting in my living room for all the difference its travel has made on this kind of scale (and, even if it could reach the site, we'll be waiting a longer than life has so far existed for the reports to come back...)

Unless physics are radically different than suspected, and in a deeply convenient way, something like this is observation only, period, full stop.

Re:Enter Metaphysics

[atomicxblue]

hahaha cute.. :D That usually takes the form of freshly baked cookies.. :D

Re: And I should care?

[Anonymous Coward]

Probably because they're Hungarian

What, again?

[the_arrow]

It wasn't such a long time since they discovered the (now second) largest before, was it?

Re:What, again?

[mynamestolen]

1989
http://en.wikipedia.org/wiki/CfA2_Great_Wall
The Great Wall (also called Coma Wall), sometimes specifically referred to as the CfA2 Great Wall, is one of the largest known superstructures in the Universe, (the largest being the Huge-LQG). It is a filament of galaxies approximately 200 million light-years away and has dimensions which measure over 500 million light-years long, 300 million light-years wide and 16 million light-years thick, and includes the Hercules Supercluster, the Coma Supercluster and the Leo Cluster.[1]
It was discovered in 1989 by Margaret Geller and John Huchra based on redshift survey data from the CfA Redshift Survey.

Re:What, again?

[boristhespider]

That was superceded 14 years later by the Sloan Great Wall: http://en.wikipedia.org/wiki/Sloan_Great_Wall

Re:What, again?

[dwater]

They didn't discover the largest before; they were just wrong in thinking it was the largest, just like they probably are this time. It's just arrogance to claim it is the largest when one hasn't yet examined the *entire* universe.

Re:What, again?

[RaceProUK]

And that's why they say it's the largest known.

Re:What, again?

[boristhespider]

Yeah, I was just meaning that the CfA Great Wall was superceded by the Sloan Great Wall. If this current structure turns out to genuinely be a structure, it supercedes the Sloan Great Wall by some considerable size.

God is great?

[AmiMoJo]

Who tagged this "godisgreat"? Is it a joke?

All this seems to suggest is that God cooks up lumpy pudding.

Re:God is great?

[Idetuxs]

"yourmom"

Re:God is great?

[Aboroth]

I don't see how it matters one way or another.

Re:God is great?

[Lennie]

Especially as it is 10 billion light years away from us, by the time the gamma rays and light have reach us, whatever was there, might not even exist anymore.

Re:God is great?

[Sabriel]

Heh. Be thankful for the lumps, we might not exist without them.

http://en.wikipedia.org/wiki/Baryon_asymmetry

Re:God is great?

[Hatta]

All this seems to suggest is that God cooks up lumpy pudding.

That makes me feel a lot better about how my pudding turns out.

Random distribution

[Andtalath]

Random distribution means that lumps will form.

This is relatively obvious chaos theory.

Even more so when objects can grow closer due to huge centers of mass.
This might be how black holes start for all we know...

Re:Random distribution

[boristhespider]

Thank God we have people on Slashdot to tell us things like this. Where would we have been if generations of cosmologists were entirely ignorant of statistics or gravitational physics? The mind boggles!

Sorry, but the problem isn't that there are lumps - if there weren't our existence would be a bit suspect since we live on the edge of a reasonably large lump (the Virgo supercluster) ourselves. The problem (if you want to call it a problem; it's more an interesting question) concerns the *size* of the lumps. We can predict with reasonable certainty the probability of a bound structure of such and such a size appearing in the universe. That's quite straightforward in principle. And structures this big are pushing the bounds of the standard cosmological model quite hard; basically, they shouldn't really be there. I don't know the actual probability but it's extremely low, and low enough that we would not expect to see it. That there are now three structures that are rather too large (this one, if it comes to be accepted as a genuine structure; the Sloan great wall, if it turns out to actually be a structure; and the CfA great wall) is getting interesting.

Re:Random distribution

[fractoid]

Yeah, said principle seems to be an ass-pull to me. I'd have expected the universe to be evenly self-similar on a large enough scale, but not perfectly even and homogeneous.

Re:Random distribution

[Chalnoth]

Yes. That and the primordial density fluctuations were nearly scale-invariant. That is, originally, there were structures of all scales. Gravity over time amplified some of these scales (the most significant being at around 240 million light years), but the natural expectation is still structures at all scales. It would take finding a few extremely large structures that are in excess of the number expected to really throw the standard cosmology into question.

Re:Random distribution

[boristhespider]

Yes, of course. Thing is that we can't apply that logic here. We know that very large structures are extremely unlikely - in a brute force, frequentist approach which is the nearest analogy to flipping a coin a hundred times, we can make a hundred simulations. If in those hundred simulations we do not see a structure that size, we know that the likelihood of it occuring *within the confines of the model tested* - and that is a very important proviso; we can only assign probabilities in this manner with respect to a given concrete model - is less than 1 in 100. If we do 10,000 simulations nad a structure of that size occurs in 1 of them, we know the probability is approximately of the order of 1/10,000. I simplify, of course, but in this manner we can gain a feeling on the likelihood that such a large structure would just happen to crop up in our particular realisation of the universe.

I use the word "realisation" statistically. In cosmology we have knowledge of the statistical nature of hte universe. What we have no knowledge of, a priori, is the actual distribution of matter in the universe. Instead, we have the assumption that fields were initially Gaussian (strongly borne out by CMB observations, and also currently borne out by large-scale structure, although non-linear evolution does introduce a measure of non-Gaussianity), and we have their power spectrum. From this we can make a realisation of the statistical field. The simulations I'm referring to are just such realisations. In the most complex case (such as n-body simulations like the surprisingly old Millenium Simulation) the realisations are made when the universe was a tiny fraction of its current size when all available data suggests linear theory held, and then evolved forwards. That's a punishingly slow procedure, so various other approaches can be used. In all cases, it's about trying to see what the probabiiity of, in this context, a given structure appearing in our universe is.

Again, cosmology is not a science of people entirely ignorant of statistics. In many ways, cosmology is one of the most statistical of the natural sciences, since by its very nature we can *only* ever know statistics, or else have an entirely descriptive and non-predictive survey of the sky. That isn't to say that all cosmologists are master statisticians - I'm very willing to admit that my own statistics aren't the strongest of the cosmologists I know - but at least a passing knowledge of statistics is a prerequisite.

Re:Random distribution

[boristhespider]

In the big bang theory there is no outside, so it isn't a lump. Indeed, it's exactly the opposite. In a true "big bang" theory the universe is totally smooth and featureless, and evolving. It's built on "homogeneous and isotropic surfaces". The main observational motivation for this is the microwave background, which to one part in 1000 is identical everywhere we look. That 1/1000 discrepency is a pure dipole -- nothing but a Doppler shift. What *causes* that is mildly debatable, but the effect has to mimic the Earth's motion with respect to the microwave background so closely that an alternative is liable to fall to Occam's razor. In any event, no matter what its source, we know how to remove pure dipoles, so we remove it. And we're left with something that is identical everywhere we look to one part in ten thousand!

So the microwave background is "isotropic" around Earth - everywhere we look it is identical, for all practical purposes. Any model of cosmology has to be able to explain that, and as a bonus also explain what those tiny fluctuations are doing on there and where they came from, and predict their statistical nature. (The big bang theory, plus inflation, does this as perfectly as we could ever ask. No-one seriously suggests that inflation is other than, at best, an effective field theory that describes a more fundamental underlying theory. Well, no-one except people who believe they can boil a moduli inflation out of one string theory or another, but those are still somewhat contrived. But the success of inflation tells us something that acted exactly like it had to happen. (The answer is easy: so-called R^2 inflation. The first inflationary model is believed in the West to be due to Alan Guth, of MIT. This isn't, strictly speaking, true, and Guth would never claim it was. Guth - and Tye - presented the first quantum field theoretical model of inflation, which they based on the Higgs. The first actual inflation came a few years earlier, behind the Iron Curtain, and due to Starobinsky who is a big name in cosmology but deserves to be bigger. Starobinsky was examining what happens when you look at the 'low-energy' limits of a wide variety of modified gravities. General relativity can be described by the equation L=R. Here L is the "Lagrangian density" from which the equations of the theory can be derived while R is the "Ricci scalar" which describes the curvature of spacetime; for comparison, the Lagrangian of normal classical mechanics is L=K-V where K is the kinetic energy and V the potential energy. I'm brushing over the difference between a Lagrangian and a Lagrangian density but it's exactly what it sounds like... Anyway, Starobinsky started from the observation that virtually any modification of gravity will end up reducing, at energies beginning to approach sanity, to something of the form L=R + alpha * R^2 +... where the dots include a wide variety of grotesquely ugly terms alongside the expected R^3. The interesting thing here is that when R gets very large, as would happen in the very early universe, the Lagrangian becomes L=alpha R^2. Solve this and you find you have an exponentially growing universe -- inflation. Study it in more detail, and you find it acts exactly like a more normal inflation (with a potential V proportional to phi^2, I think; it may be phi^4, I forget which), including exactly predicting the form of the perturabtions on the CMB. Actually, if you look at the recent Planck results, R^2 inflation is still stubbornly by *far* the best result... if you judge by eye. Its nearest widely-known competitor is only excluded at the one sigma level, which you'd be laughed at if you seriously tried to say that excluded it, but R^2 lies slap in the middle of every contour and will never be budged from there as long as we live, unless there is a significant detection of cosmological gravitational waves.)

Anyway, I digress.

There are two conclusions we can draw from the CMB:
1) The Earth is at the centre of the Universe. I don't know why religious crazies ne

Re:quasardilla supreme

[Anonymous Coward]

Thats what science is all about...

Define a structure...

[JohnStock]

These bunch of gamma ray bursts, are they in any way related to each other than in form?

Re:quasardilla supreme

[Thanshin]

Yes.

But don't worry, most people stupid enough not to understand that it's still better to try follow the scientific method than to just invent concepts and believe them, don't read Slashdot. so it won't be us who'll have to deal with them.

"the largest in the universe?"

[master_p]

That's what she said!!!

(that's what you get from watching The Office).

Re:Distribution in distance or time?

[rusty0101]

The observation that we are not seeing them commonly appearing across the universe at a distance of some 10 billion light years.

Re:quasardilla supreme

[kruach aum]

Science is the systematic observation of everything in our world and universe; it is the best and most successful way we have discovered for determining what is true and what is not. That does not mean that it cannot make mistakes, but it does mean that mistakes can be noticed, making it a self-correcting process, trudging ever forward towards greater accuracy and understanding. Pointing out that science makes mistakes is pointing out a part of how the scientific process works and achieves progress; it's not a bane, it's a boon.

Re:quasardilla supreme

[tstur]

Yep, if only that were widely understood... I'd like to see more things prefaced with, "Here's what we think we know as of today..." in order to help the larger population realize it's good to question things and continue researching, developing, and exploring. Often the first whack or two are not particularly correct.

Arrogant much?

[dwater]

Are they really that arrogant? Perhaps they just don't know English too well.

I mean, iinm, they previously claimed they had discovered the largest and now they claim it again. There is only *one* largest - it makes no difference if you know about it or not. If you find something new that is larger than what you thought was the largest, then all you have proved is that you were previously wrong. To then claim that the new thing is the largest is arrogant.

How about adding some words to fix it, like 'known' or 'probably'?

I *suppose* there might be some way to *prove* (or otherwise justify) such confidence. For example, if they know the entire volume of the universe and the newly discovered one takes up more than half, then it would seem reasonable to assume that it is the largest.

yo mama ...

[ExKoopaTroopa]

Cue the yo mama jokes

Re:quasardilla supreme

[Anonymous Coward]

And the assumption that all of these corrected errors will ultimately lead to truth that requires no further correction, is a conjecture based on sheer faith.

Re:quasardilla supreme

[kruach aum]

That's true, which is why I'm not making it. I don't adhere to Popper's views on the philosophy of science in the main, but I think the idea of verisimilitude (we're only ever approaching reality closer and closer, but may never get 100% accurate descriptions) is spot on. Science is for claims about accuracy, and predictive and explanatory power. The Truth is in the domain of metaphysics.

amazing

[cascadingstylesheet]

It's amazing what we think we "know", by trying to interpret the electromagnetic radiation that falls on us.

Next week: more amazing complete revisions of what we "know".

Re:Fractal Cosmology

[SuricouRaven]

The surprise here is that the cutoff is so big.

Then again....

[meglon]

What's odd about the discovery is that the Cosmological principle--one of the fundamental tenets of cosmology--holds that the distribution of matter in the universe will appear uniform if viewed at a large enough scale. And yet, structures clearly emerge at every scale astronomers can see.

Beings as we can only ever see a very small fraction of the universe, and don't even know how big it is in its entirety, it's certainly possible we simply can't view a large enough area for the distribution to "even out."

Re:Then again....

[painandgreed]

Beings as we can only ever see a very small fraction of the universe, and don't even know how big it is in its entirety, it's certainly possible we simply can't view a large enough area for the distribution to "even out."

If the universe is smaller or larger than the observable universe is still a matter of debate. Quite likely, it will be observations like this that will lead us to the answer by what we can figure out about the very early universe and its expansion.

Re:Fractal Cosmology

[myowntrueself]

"That which is above is as that which is below and that which is below is as that which is above, for the purposes of the workings of the one thing."
-- very very old.

Re:quasardilla supreme

[kruach aum]

And then I expanded upon my conception of truth as I used it there later with the part about achieving greater accuracy. However, since I realize that this is not necessarily the standard idea of The Truth as others might conceive of it, I then made my views explicit in the follow-up by distinguishing those two conceptions of truth.

Re:quasardilla supreme

[utnapistim]

No; Something the scientific community thought was well understood is still thought to be well understood. We just have some more data.

Why are the surprised?

[ciderbrew]

Space is big. You just won't believe how vastly, hugely, mind- bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space.
- Douglas Adams, The Hitchhiker's Guide to the Galaxy.

Re:Why are the surprised?

[Chemisor]

Time is big. You just won't believe how vastly, hugely, mind- bogglingly big it is. I mean, you may think it's been so long since anybody has seen a "Chemist's", but that's just peanuts to time.

Re:Why are the surprised?

[NoImNotNineVolt]

"Chemist" is the British English equivalent of the American English "Pharmacist" or "Drug store".

That being said, pharmacology is bigger now than ever.

Re:quasardilla supreme

[Vitriol Angst]

I just think it's ironic that people have to state "what science is" on Slashdot. I'm not criticizing the practice -- I'm concerned by how much we NEED to inform people of WHY science is good, even if it is never settled, and what the scientific process is.

This is just sad. This is a culture in decline. Forget about Rock Music, long hair, tattoos -- whatever shocking thing the next generation comes up with; SCIENCE is one of the first targets of a society in decline.

Of course, anyone I have to explain this to based on historical examples is probably also someone who has been told why science is necessary and important and still doesn't get it. *sigh*

Why "there are"?

[jopet]

What I never inderstand about articles that talk about very distant objects: they always use "are" as if this large structure would be there now, when, if at all and we interpret the data correctly, it was there billions of years ago. Something that "stretches" over 4 billion ligth years may also (depending on in which direction it stretches) also stretch over a time span of at least 4 billion years.
It is weird to think that what we see is not our universe at all: it is a picture that is a collage of times of what the universe was.

But what does it mean about our understanding of the universe now? Obviously we have no idea if Quasars "exist" -- the ones we observed so far are at least 600 million years away and thus have existed 600 million years ago.

600 Million years is a very long time. But 10 billion years is much closer to the beginning of the universe than to now. Does this make the violation of that "principle" then even more or qutie less significant?

Re:Why "there are"?

[Lord Lemur]

Since we sit in the light cone for the event currently, to us it does exist now, as it's state 10 billion years ago/10 billion light years away can causely affect us, but not its state 999,999,999 years ago and 10 billion + light years away.

http://en.wikipedia.org/wiki/Light_cone

Re:quasardilla supreme

[JimSadler]

One mind numbing possibility is that the laws of physics may change depending upon location in the universe. Drawing conclusions by observation of remote objects and events may it self be irrational.

Re:Size of universe?

[P-niiice]

I think the universe expands faster than light. Someone correct me if I'm wrong, please.

Re: And I should care?

[bhartman34]

If I only had mod points for you. :)

Could it be the multiverse that's uniform?

[bhartman34]

If there's structure everywhere we look in the universe, maybe it's the multiverse that's uniform. (Disclaimer: I'm not a scientist of any type. I'm just thinking out loud here.)

How is this a 'structure'?

[RevWaldo]

Is it simply the fact that these objects are all relatively closer to each other that expected? Do they interact in any fashion, or were they all formed at the same time and/or from the same source?

.

"enlightened age of man"?

[denzacar]

We never had that.
At best, we had precious few enlightened men during some ages. Everyone else always danced and still dances to the witchdoctor's drum.

Presently we are in an age where we have more enlightened men than ever before - but we also have a lot more witchdoctors and dancers.
But we did win a battle or two along the way.
E.g. You won't be burned at a stake for using a match or a lighter any more, or be accused of stealing someone's soul when taking a photo of them.
It adds up.

Couple of thousand years more and no one will believe in astrology anymore. Probably.

Re:"enlightened age of man"?

[Oligonicella]

Couple of thousand years more and no one will believe in astrology anymore. Probably.

That depends on what the Mayan Calender says.

Bazinga.

[ihtoit]

the distribution of matter in the universe is uniform if you view it on the scale of the entire universe. Which, if held to be infinite, definitively proves the theory.

Mine's bigger.

[ZecretZquirrel]

My object. It's bigger.

Re:Size of universe?

[cellocgw]

I think the universe expands faster than light. Someone correct me if I'm wrong, please.

No, you're correct, as light doesn't expand. (depending on whether it feels like being a wave or a particle just now)

Re:not a structure.

[TangoMargarine]

It sounds like the leftovers of some event. I'm apparently missing how that means that a really, really big wave (sphere?) of expanding gamma rays constitutes a "thing"...

Although I suppose surfers consider a wave a 'thing.' Hmm.

I have issus with "structure"

[whitroth]

I have issues with the whole report. If the Universe is 13.xG years old, and it's been expanding...
    1. How is 31 bursters over 10G ly a "structure"?
    2. How big was the Universe 10G years ago? If it was then 10G ly wide, then the expansion is
                clearly slowing down, only growing another 3G ly in 10G yrs, after doing 10G ly in 3.xG yrs.

            mark "or maybe the Universe burst through an extradimensional wall, which resulted in
                              a number of bursters as they ripped through the wall for the rest"

Re:I have issus with "structure"

[Bengie]

Someone else pointed out that if this one "normal", we would be seeing the same rate of GRB from any direction, but we are not, so it must be true only in that direction, meaning it is something different that normal.

Re:quasardilla supreme

[Unordained]

Meanwhile Dawkins is so confident of the *truth* of his extrapolatory creation myth that he feels the need to call believers of any other extrapolatory creation myth "deluded" ... while the details of his myth get rewritten every 5-10 years.

Yes. And it's justified.
(a) just because two things are extrapolatory doesn't mean they are supported by equivalent qualities of models nor quantities of data.
(b) the Bible is not extrapolatory. it just states.
(c) the details of Big Bang and Evolution may get rewritten constantly, but:
    (1) it's just the details
    (2) even if it were rewritten wholesale, because of new discoveries, at least it would be based on observation, modeling, hypothesis, peer review, and all the other trappings of actual science and search for truth, not mere attachment to passed-down mythology
(d) if you think creation myths don't get rewritten, please think again. see the catholic church, for example, for how religion will eventually change its tune when overwhelmed with facts and logic. it takes a lot, sure, but eventually they'll give way. baptists? they invent whole new myths (around the Flood, for example) to explain anything and everything -- but they're still having to change their story, too, to survive.

Yes, I know, don't feed the trolls ... but seriously. You may apples and oranges look identical.

Re:Fractal Cosmology

[Bengie]

My laymans understanding is that are processes feedback into themselves, which is what makes fractals. Watched a fun BBC video on on fractals. Plants even space themselves out in fractals, even when inter-species. The size of plants are fractals, the limbs are fractals.. etc etc. They covered a lot of other things, but the whole plant thing stuck the best. Another one was the it seems your hear-beat is based on fractals and non-fractal like hear-beats seem to be highly correlated with heart issues, but more testing is still required before that becomes generally accepted as "fact".

Power Law Scaling

[dsdtzero]

We see power-law scaling everywhere and it looks a lot like the statement in the article. If the size of cars obeyed a power law distribution it would be hard to tell how far you were away from the ground by looking at the apparent size of the cars. The wider you make your gaze the larger cars you will find. We see power-law scaling in continuous phase transition when the system can't really "decide" what scale to prefer so it kind of exists in all scales. Perhaps this means the universe is undergoing some sort of continuous phase transition. Very cool.

Somebody didn't study astronomy

[govett]

Must I remind yet again? The largest structure in the universe is the universe, because it's a subset of itself. No more largest structure pronouncements, please. The matter is settled. Also sprach Zarathustra.

Re:Somebody didn't study astronomy

[bhartman34]

We only can only observe part of the universe anyway, right?

Re:Somebody didn't study astronomy

[boristhespider]

The universe isn't a structure. By "structure" they mean "gravitationally-bound object". The universe is a conglomeration of objects that are not gravitationally-bound. Phrased another way, a "structure" is governed by a metric which is distinctly non-trivial but which you'd hope would be approximated by a Schwarzschild, whereas the universe as a whole is governed by a Robertson-Walker metric which is as trivial as one can get. Put it another way, a "structure" is virialised, while the universe very much is not.

(On a different note, this is why people asking why Earth isn't pulling itself apart as space expands have missed the point. Space itself is not expanding, even in the normal cosmological model. The space *between virialised structures* is, but in a manner of thinking, a "structure" is disconnected from the universal expansion and is now interacting with itself.)

Anyway, it sounds like quibbling with semantics, but the way they're using the word "structure" is a particular bit of cosmological jargon, by which definition the universe is definitely not a structure. Put it another way, if you look at the universe as a whole it becomes featureless - there are no structures. (In the model; whether this is true in reality is open to question, hence this kind of study.) If you look on a smaller scale, you see the emergence of structure. What looked smooth is now pretty lumpy and stringy. Each of those lumps and strings is what they're meaning as "structure".

http://www.mpa-garching.mpg.de/galform/data_vis/ is a pretty good website for seeing this kind of difference.

Re: And I should care?

[Anonymous Coward]

That explains why the website told me its nipples exploded with delight when I tried to sign up.

Are you saying...

[warrax_666]

Are you saying that gravitational lensing is just an anomaly?

Gravitational lensing seems to be one of the major evidences in favor of dark matter/mass, but it'd be interesting to see you (or anyone for that matter) argue that it's just an anomaly given that it can be observed in multiple distinct locations.

(Now, I think we both agree that dark energy is still just a hypothesis, but I think you'd have to come up with something better than claiming that it's "just an anomaly" to explain the existing evidence.)

But Big + Speed of Light + Expansion = Small

[recurve7]

When they see large structures billions of light years away, then they're also looking back billions of years in time and the universe was a lot smaller then, so they're not really looking at something that large, they're looking at something that was small and has been stretched out subsequently, so these reports of 'large structures' don't make sense.

Re:Distribution in distance or time?

[rusty0101]

If the bursts happened 10 billion years ago were common all over at that time, (as was asked by the ggp a/c) then the observations would be dirstributed much more randomly across the sky than observation indicates. Observation suggests that the large number of gama ray bursts that happened 10 billion years ago, appear to have happened across a region of space that is heavily weighted in one direction. A circle with a radius of 10 billion light years has a circumfrence of 2*pi*10 billion light years, or a bit over 68 billion light years. In that circumfrence, a region of 4 billion light years spans (4/68 * 360 = 360/17 = ~ 21.17) or just over 21 degrees of arc. This is a little more than the arc of the sky that the sky moves in a period of an hour.

That is not to say that we are not observing gamma ray bursts in other directions at an approximate distance of 10 billion light years, just that there appears to be an unusually large number from within this region of space at that time.

You have asked a separate question, which is 'if aliens did the same measurement far away, would they see a sphere-like structure centered around us or them?' While I think it's a reasonable question, it does have an ambiguity, and based on my understanding of Einstein's general relativity law may not be such a reasonable question. The ambituity is 'far away', what is 'far away'? Accross the solar system, galaxy, or the visible limit of the universe?

However a thought experiment based on the question seems to me to be reasonable. Let's assume that some level of simultaniousness can exist. (which has problems I won't get into.) Let's presume that both the cluster of events we're seeing, and we, have a sphere 10 billion years in diamater centered on each of us. There should be a 'ring' where those two spheres intersect, that is 10 billion years from each of us. Take a point on that ring, and lets assume your aliens are there. That point would appear to us to be some 60 degrees across the sky from this cluster of events some 10 billion years ago. What would they see across the sky at a distance of some 10 billion light years? Well, we know they won't be seeing us for at least another 9.5+billion years. Additionally what we are seeing as an arc of approx 4 billion light years across is unlikely to be a perfect match for what they see at 10 billion light years, however we'll allow for the fact that they should see some variation of what we see. That said, a sphere some 4 billion light years across from the point in common 10 billion light years away from each of us, would still span an arc of approx 21 degrees for them, as it does for us. Based on the information I'm mentally working with, they are likely to see a cluster of gamma ray bursts from within this region as well. They are likely seeing a different appearance of the structure than we do, but they would be seeing it from a different angle anyway. They are unlikely to be able to perceive the events as a sphere around either of us, just as we do not perceive of this structure as a sphere around us, or anyone else at this time.

Does that help? (And if someone with a better understanding of cosmology than I have want's to pipe in with a correction, I'm OK with that.)