Monday, April 11, 2011

Cosmology: "The 'Great Walls' Of the Universe"

"The 'Great Walls' Of the Universe"
by Ashwini Kumar Lal, Ph.D.

"In recent years, there have been a number of very serious challenges to the current theory of cosmic evolution and the belief the universe began just 13.7 billion years ago. These include the observation of large chains of galaxies spread throughout the universe forming gargantuan stellar structures separated by vast voids. The system of galactic superclusters forms a network permeating throughout the space, on which about 90% of the galaxies are located. The existence of these "Superclusters", "Great Walls" and "Great Attractors" could have only come to be organized and situated in their present locations and to have achieved their current size, in a universe which is at least 80 billion to 250 billion years in age. The largest superclusters. e.g., "Coma", extend up to 100 Mpc!

In 1986, Brent Tully of the University of Hawaii reported detecting superclusters of galaxies 300 million light years (mly) long and 100 mly thick - stretching out about 300 mly across. At the speeds at which galaxies are supposed to be moving, it would require 80 billlion years to create such a huge complex of galaxies. In 1989, a group lead by John Huchra and Margaret J. Geller at the Harvard-Smithsonian Center for Astrophysics discovered "The Great Wall"- a series of galaxies, lined up and creating a "wall" of galaxies 500 million light years (mly) long, 200 mly wide, and 15 mly thick. This superstructure would have required at least 100 billion years to form.

A team of the British, American, and Hungarian astronomers have reported even larger structures. As per their findings, the universe is crossed by at least 13 'Great Walls', apparent rivers of galaxies 100Mpc long in the surveyed domain of 7 billion light years. They found galaxies clustered into bands spaced about 600 millon light years apart. The pattern of these clusters stretches across about one-fourth of the diameter of the universe, or about seven billion light years. This huge shell and void pattern would have required nearly 150 billion years to form, based on their speed of movement, if produced by the standard Big Bang cosmology.

The "Sloan Great Wall" of galaxies, above, as detected by the Sloan Digital Survey has earned the distinction of being the largest observed structure in the Universe. It is 1.36 billion light years long and 80% longer than the Great Wall discovered by Geller and Huchra. It runs roughly from the head of Hydra to the feet of Virgo. It would have taken at least 250 billion years to form, if produced following a "Big Bang" creation event.

As summarized by Van Flandern, "The average speed of galaxies through space is a well-measured quantity. At those speeds, galaxies would require roughly the age of the universe to assemble into the largest structures (superclusters and walls) we see in space, and to clear all the voids between galaxy walls. But this assumes that the initial directions of motion are special, e.g., directed away from the centers of voids. To get around this problem, one must propose that galaxy speeds were initially much higher and have slowed due to some sort of "viscosity" of space. To form these structures by building up the needed motions through gravitational acceleration alone would take in excess of 100 billion years."

Then there is the problem of gravity. "Hubble length" Universe, which consists of those galaxies and stars which can be observed by current technology, appears, therefore, to be organized as titanic walls and clusters of galaxies separated by a collection of giant bubble-like voids. The Great Walls are far too large and massive to have been formed by the mutual gravitational attraction of its member galaxies alone.

Discovery of the Great Walls of galaxies and filamentary clumping of galactic mater has greatly upset the traditional notion that galactic matter should be uniformly distributed. If the universe began with a Big Bang 13.7 billion years ago, the awesome size of these large-scale structures is baffling because there is apparently not sufficient time available for such massive objects to form and to become organized.

Based on the cosmological principle, which is one of the cornerstones of the Big Bang model, cosmologists predicted the distribution of matter to be homogeneous throughout the universe, implying thereby that the distribution of the galaxies would be essentially uniform. There would be no large scale clusters of galaxies or great voids in space. Instead, contrary to the "Big Bang" universe, we exist in a very "lumpy" cosmos."

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