Thursday, June 23, 2011

Cosmology: “The Largest ‘Structures’ in the Universe”

“The Largest ‘Structures’ in the Universe”
by Casey Kazan

"Just as a fish may be barely aware of the medium in which it lives and swims, so the microstructure of empty space could be far too complex for unaided human brains."
- Sir Martin Rees, Astronomer Royal, physicist, Cambridge University

"Our known Hubble length universe contains hundreds of millions of galaxies that have clumped together, forming super clusters and a series of massive walls of galaxies separated by vast voids of empty space.

Click image for larger size.

Great Wall: The most vast structure ever is a collection of superclusters a billion light years away extending for 5% the length of the entire observable universe. It is theorized that such structures as the Great Wall form along and follow web-like strings of dark matter that dictates the structure of the Universe on the grandest of scales. Dark matter gravitationally attracts baryonic matter, and it is this normal matter that astronomers see forming long, thin walls of super-galactic clusters. If it took God one week to make the Earth, going by mass it would take him two quintillion years to build this thing - far longer than science says the universe has existed, and it's kind of fun to have those two the other way around for a change. Though He could always omnipotently cheat and say "Let there be a Sloan Great Wall."

The Great Wall is a massive array of astronomical objects named after the observations which revealed them, the Sloan Digital Sky Survey. An eight year project scanned over a quarter of the sky to generate full 3-D maps of almost a million galaxies. Analysis of these images revealed a huge panel of galaxies 1.37 billion light years long, and even the pedantic-sounding .07 is six hundred and sixty billion trillion kilometers. This is science precisely measuring made-up sounding numbers.

This isn't the only wall out there - others exist, all with far greater lengths than width or depth, actual sheets of galaxies forming some of the most impressive anythings there are. And these walls are only a special class of galactic filaments, long strings of matter stretched between mind-breaking expanses of emptiness. Some of these elongated super clusters have formed a series of walls, one after another, spaced from 500 million to 800 million light years apart, such that in one direction alone, 13 Great Walls have formed with the inner and outer walls separated by less than seven billion light years. Recently, cosmologists have estimated that some of these galactic walls may have taken from 80 billion to 100 billion, to 150 billion years to form in a direct challenge to current age estimates of the age of the Universe following the Big Bang. The huge Sloan Great Wall spans over one billion light years. The Coma cluster is one of the largest observed structures in the Universe, containing over 10,000 galaxies and extending more than 1.37 billion light years in length.

Current theories of "dark energy" and "great attractors" have been developed to explain why a created universe did not spread out uniformly at the same speed and in the same spoke-like directions as predicted by theory. But as Sean Carroll of the Moore Center for Theoretical Cosmology and Physics at Cal Tech is fond of saying, "We don't have a clue." Britain's Astronomer Royal, Lord Rees, says some of the cosmos's biggest mysteries, like the Big Bang and even the nature of our own self awareness, might never be resolved. Rees, who is also President of the Royal Society, says that a correct basic theory of the universe might be present, but may be just too tough for human beings' brains to comprehend.”

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