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From Science Daily...

Biggest Structure in Universe: Large Quasar Group Is 4 Billion Light Years Across

Jan. 11, 2013 — An international team of astronomers, led by academics from the University of Central Lancashire (UCLan), has found the largest known structure in the universe. 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.

The team publish their results in the journal 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."

http://www.sciencedaily.com/releases/2013/01/130111092539.htm

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Posted

And, all this time, I thought my back yard was not big enough. ^_^

This is all very interesting but the most intriguing question is, where else is there life forms other than on earth? There are so many low life and high life forms here that I have to assume there are others elsewhere. ^_^

Best regards,

RA1

Posted

As comic strip loafer Andy Capp (& many others) have said, "There must be intelligent life up there. After all you don't find them searching for it down here!"

You may know the Drake equation which suggests the odds are very tiny that there is NOT intelligent life elsewhere. The trouble for us, of course, lies in the vast scales of cosmological space and time versus our impatience -- from both our short lives as individuals and the species' short lifetime as a technological civilization -- that in 50 whole years of listening we have not found anything yet.

My idol Arthur Clarke was as avid a SETI proponent as anyone, but even he had to point out, more or less: Look, cool your jets -- give it a millenium at least before concluding maybe we are looking for the wrong things the wrong ways.

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Posted

I am perfectly willing to give it a millenium and more but neither I nor my non-existent progeny are likely to be around for any results, good or otherwise. ^_^ Therefore Obamacare, SS and many other facets of today's society as well as far into the future will not be mine to observe. :( Regardless, it is interesting to contemplate the arrival of "others" to guide or motivate earth as we know it. ^_^

Best regards,

RA1

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Posted
Regardless, it is interesting to contemplate the arrival of "others" to guide or motivate earth as we know it. :smile:

Or, just possibly, to build an interstellar off-ramp.

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Posted

I didn't realize this was a domination thread. ^_^

Best regards,

RA1

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Posted

I didn't think you meant, to serve Man on a platter. ^_^:(

Best regards,

RA1

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