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Largest object in the universe?

You mamma so fat when she fell off the porch yesterday she crushed the Large Quasar Group to bits!!!
 
Damien Evans said:
Not actually an object though.
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I was thinking the same thing.

It's a little tricky to define "large" when you are talking about astronomical objects. Do you mean the greatest volume? or the greatest mass? Do you count clouds of gas? Or clouds of dark matter? Or areas of space where clusters of galaxies congregate along web-like columns of dark matter?
 
Can we take this to a metaphysical level? Say for instance that this cluster is the result of interactions between galaxies where an active quasar in one galaxy triggers the activation of a quasars in one or more nearby galaxies. These galaxies would be acting like neurons triggering on the pulse inputs and their own internal state of the distribution of gas near the core. Once triggered, for a brief eon, the galaxy would be emitting it's own signal.

The question is, with the vastness of the universe, could this signaling form a vast logic network? And if this logic network is truly vast, is it possible for it to form a consciousness?
 
Whoah, that would be one big ET. So big it might be considered a God or someth........oh crap now I've done it.
 
Conceivably, the intergalactic thoughts of such a universal god would have played a role on the separation of the firmament which led to the creation of our solar system and thus the earth. However, there is no requirement for there to have been consciousness behind that thought.

In fact, there appears to be no mechanism for feedback or natural selection to insure the spread and propagation of beneficial structures over the inherent randomness. Can the random firing of neuron like structures even be considered a thought? And if not, does this make us the product of a thoughtless God?
 
Travis said:
Largest object in the universe?
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There's a "your momma" joke in there somewhere... :p;):D

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Ok, joking aside:
The large quasar group (LQG) is so large that it would take a vehicle travelling at the speed of light some 4 billion years to cross it.
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Good God, that's huge. That inspired me to look up the size of our own galaxy, and that's pegged at around 100,000 to 120,000 light years across. That's crazy big. Beyond a certain point, the numbers are mind numbing and it's hard to wrap your head around how big that must be.
 
So how exactly does this structure challenge the cosmological principle like they talk about in the article? Does this observation really falsify the prediction that the universe is homogeneous and isotropic? I gather that perhaps Big Bang Cosmology has an upper range on the size of structures it predicts could have formed, but this LQG is still made from the same stuff as we see in every other direction we look in, it's aranged in the sort of cluster we see in every other direction we look in, and what observations we have do conform to the notion that the laws of physics are the same there as they are here.

Am I overlooking something? Or is this no real challenge for the cosmological principle, just for the current best cosmological theory that uses it as one of it's assumptions?
 
Turgor said:
So how exactly does this structure challenge the cosmological principle like they talk about in the article? Does this observation really falsify the prediction that the universe is homogeneous and isotropic? I gather that perhaps Big Bang Cosmology has an upper range on the size of structures it predicts could have formed, but this LQG is still made from the same stuff as we see in every other direction we look in, it's aranged in the sort of cluster we see in every other direction we look in, and what observations we have do conform to the notion that the laws of physics are the same there as they are here.

Am I overlooking something? Or is this no real challenge for the cosmological principle, just for the current best cosmological theory that uses it as one of it's assumptions?
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I hate to set the conversation back for a layman who's interested but not educated in astronomy, but: What about current cosmological knowledge argues against something this big forming? I'm presuming that there's something about the mechanisms for matter accretion that dictate what the upper bound should be, but that's just a presumption I'm making from context. I'm simply asking to see 1. If I'm right, and 2. If the reasoning can be laid out in a way a humble lil layman like me can understand. :)
 
You'd usually start out assuming a certain background of fluctuations originating from quantum mechanical wibblyness (technical term) just after the big bang. These wibbles are also observable in the cosmic microwave background, so you get a good measure of how big these are from that too, and going on from those to form structures is generally pretty straightforward physics. Basically you just have to look at how much gravitational collapse can happen from that in the time available.
http://en.wikipedia.org/wiki/Structure_formation for more details. And less abuse of the word 'wibble'.
 
ElMondoHummus said:
I hate to set the conversation back for a layman who's interested but not educated in astronomy, but: What about current cosmological knowledge argues against something this big forming? I'm presuming that there's something about the mechanisms for matter accretion that dictate what the upper bound should be, but that's just a presumption I'm making from context. I'm simply asking to see 1. If I'm right, and 2. If the reasoning can be laid out in a way a humble lil layman like me can understand. :)
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I am a layman too to be honest. I've searched a bit for what upper limit the ΛCDM model predicts for structures, but couldn't find anything that way.

But upon reading the paper (http://mnras.oxfordjournals.org/content/early/2013/01/07/mnras.sts497.full) I found they reference a paper (http://mnras.oxfordjournals.org/content/405/3/2009.full) that calculates the upper limit of the scale at which ΛCDM models appear to be homogeneous. They arrive at a figure of 260 Mpc. They already note in that paper that several structures that are larger have been found.

The math is often too hard for me to follow, but one of the ways they explain what they are doing is comparing at what scale the fractal dimension of a cosmological simulation of N points is (nearly) equal to a homogeneous distribution of N points. They used 5123 particles in a cube with sides of 1024 Mpc, using WMAP data for the cosmological parameters.

All of this doesn't bring me a step closer to understanding whether the assumed large scale homogeneity from the cosmological principle would be falsified by this LQG, or whether the ΛCDM model itself makes the wrong prediction about what the upper limit for this scale is. But it was fun to read :)

ETA: "upper limit for this scale" means that using a larger scale makes no difference anymore.
 
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Squeegee Beckenheim said:
This can help.
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Oh yeah, I love these. I've seen similar ones, but this one's awesome too. I saw one that had the same idea but had a black background, didn't cover buildings or anything other than the obvious big animals (elephants, giraffes, whales), and covered more stellar objects, but I lost the link. So I'm glad to see this one; I'm bookmarking it!
 
Travis said:
So a multigalactic structure 4 billion light years across.

Rather mind blowing.

http://www.ras.org.uk/news-and-pres...iscover-the-largest-structure-in-the-universe

"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."
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That's probably a construct made by a Type IV civilization. :cool:

"In 1964, Kardashev defined three levels of civilizations, based on the order of magnitude of the amount of power available to them:

Type I: "Technological level close to the level presently (here referring to 1964) attained on earth, with energy consumption at ≈4×1019 erg/sec[2] (4 × 1012 watts.) Guillermo A. Lemarchand stated this as "A level near contemporary terrestrial civilization with an energy capability equivalent to the solar insolation on Earth, between 1016 and 10 17 watts."[3]

Type II: "A civilization capable of harnessing the energy radiated by its own star (for example, the stage of successful construction of a Dyson sphere), with energy consumption at ≈4×1033 erg/sec.[2] Lemarchand stated this as "A civilization capable of utilizing and channeling the entire radiation output of its star. The energy utilization would then be comparable to the luminosity of our Sun, about 4 × 1026 watts."[3]

Type III: "A civilization in possession of energy on the scale of its own galaxy, with energy consumption at ≈4×1044 erg/sec."[2] Lemarchand stated this as "A civilization with access to the power comparable to the luminosity of the entire Milky Way galaxy, about 4 × 1037 Watts."[3]" -- http://en.wikipedia.org/wiki/Kardashev_scale
 
jhunter1163 said:
This is a great opportunity to watch the scientific process in action. We see something that, under present theory, can't exist. But there it is. Obviously, theory is wrong. We need a better theory*. Someone will come up with one, and we'll revise our understanding of the universe accordingly.

* - "Goddidit" is not a better theory.
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Well said.
My favourite quote from the article, "Dr. Clowes said, 'This is hugely exciting-not least because it runs counter to our current understanding of the scale of the universe.'"
 
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