Dark matter tries to account for the high velocities of stars far from the galactic core. These velocities are too high to be accounted for by simple inverse-square law newtonian gravity.
A = expected velocities
B = observed velocities
So if velocities are too high, then the galaxy must contain more mass than can be observed from luminous stars and gases. This is the image of the Sombrero Galaxy that we are used to seeing. As you can see, more distant galaxies are plainly visible around it, apparently unobscured by so-called "dark matter". But if we zoom out, and do an extremely long exposure of the Sombrero Galaxy, we see a very, very large extended halo of matter. The visible galaxy that we are used to seeing is a tiny dot in the very middle.
<img src="http://www.seds.org/messier/Jpg/m104.jpg";
Source: The halo of the Sombrero Galaxy
Space/Science » in reply to Alternative proposal to modified Newton dynamics (MOND)
Dark Matter theory is probably correct
The whole thread (11 posts)
- Do one million stars confirm dark matter is the major mass of the Milky Way Galaxy?