Expert: James Gort - 4/30/2007

Question
It seems too unlikely that the formation of the Sloan Great Wall is due to coincidence. Is there some theory as to what sort of force is responsible for creating such a colossal gathering of galaxies? My understanding is that it is not a structure as such, but there must be some reason for its existence. If there is no likely answer do you have any theories?  

Answer
Hi Cameron,

The Sloan Great Wall is not a structure, as such, since the galaxies are not gravitationally bound.  The role of gravity to create such a large grouping was carefully studied, including the role of density waves, and no significant role could be found.  One possible explanation is described in the following GREAT and very readable book, written by three eminent cosmologists (p. 294).  That book (available from amzon.com or elsewhere) is:      

A Different Approach to Cosmology: From a Static Universe through the Big Bang towards Reality by F. Hoyle, G. Burbidge, and J. V. Narlikar.

They talk about "mini-creation" events (a 5-step process to give shape to the inhomogeneous, filamentary large scale structure).  It's a bit long to describe all the steps, but I urge you to get a copy of that book.  To me, their explanation sounds reasonable, and I can find no other competing explanation which even attempts to give reason for the Great Wall.

Prof. James Gort