sonnejw0 writes: "Dark matter, a theoretical substance that lines the galaxies of outer-space, was postulated to account for the observed rotational energy in neighbouring galaxies which could not be accounted for in current theories of gravity. NewScientist is reporting on a new sky survey that has found constant ratios of dark matter deposited in these newly studied galaxies. This is a problem because galaxies should not have a constant ratio of dark to regular matter; this ratio should depend on the processes of their formation. These results point to a possible new theory of gravity:
"Now, the tale has taken a deeper turn into the unknown, thanks to an analysis of the normal matter at the centres of 28 galaxies of all shapes and sizes. The study shows that there is always five times more dark matter than normal matter where the dark matter density has dropped to one-quarter of its central value.
The finding goes against expectations because the ratio of dark to normal matter should depend on the galaxy's history â" for example, whether it has merged with another galaxy or remained isolated during its entire existence. Mergers should skew the ratio of dark to normal matter on an individual basis."