Proof of "Dark Matter"?

[reason.on]

http://www.world-science.net/othernews/060821_darkmatter.htm

A colossal crash between two clusters of galaxies has wrenched apart “dark matter” and normal matter, proving the mysterious dark substance exists, astronomers say.

Researchers have believed for decades that normal, visible matter makes up only around a sixth of the material in the universe. The rest is an unseen, enigmatic “dark matter,” which reveals itself only through its gravitational pull.

Some scientists, though, propose that there is no dark matter, and that our understanding of the laws of gravity is wrong instead.

The new finding was based on observations from five telescopes including NASA’s Chandra X-ray Observatory, an orbiting station that captures X-rays emanating from cosmic structures.

“This is the most energetic cosmic event, besides the Big Bang, which we know about,” said team member Maxim Markevitch of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. Researchers have produced an animation of the collision (see sidebar).

“These results are direct proof that dark matter exists,” added Doug Clowe of the University of Arizona at Tucson, and leader of the study. He acknowledged, though, that the finding reveals nothing about what dark matter actually is.

RCR