Talk:Dark matter

Dark matter has been observed: See follows these links for the news story.

http://home.slac.stanford.edu/pressreleases/2006/20060821.htm

http://www.sciencenews.org/articles/20060826/fob1.asp

Hello David E. Volk,

Not convinced. It has not been directly observed--no surprises there. They presume its existence because it does clear up some problems and they insist that they have the gravitational lensing effect that also supports their theory.

The dark matter is supposed to interact gravitationally but why are the two types separating as they pass through the mass of another galaxy? Why doesn't the dark matter interact? It is supposed to be quite dense in comparison with the luminous matter.

See NASA Finds Direct Proof of Dark Matter. "The hot gas in this collision was slowed by a drag force, similar to air resistance. In contrast, the dark matter was not slowed by the impact, because it does not interact directly with itself or the gas except through gravity. This produced the separation of the dark and normal matter seen in the data. If hot gas was the most massive component in the clusters, as proposed by alternative gravity theories, such a separation would not have been seen. Instead, dark matter is required."

So it did not interact with the baryonic matter but it has mass, why do they say that? They are missing something crucial. --Thomas Simmons 06:53, 12 January 2008 (CST)

Hello Thomas, Neither one of us needs to be convinced (neutrality issue) to report it in the encyclopedia. The news stories I suggested point to some of the latest data, and observation of dark matter. Many physicists I know believe in dark matter, but are more dubious of dark energy. Clearly there is still something we do not know, but we should report the most up to date thoughts on the subject. David E. Volk 08:25, 12 January 2008 (CST)