I was watching movie,about dark matter. Scientists say,dark matter have mass. Well,i think,they could calculate it from supernovas exposion,how bigg that bang is and how fast that explosions cloud stop its expanding in space. What u think about this? Im just free mind person.

Sorry about any mistakes,my English is not perfect,...

I'm not sure what supernova explosions could tell us about the mass of dark matter. For one thing, the amount of dark matter in and around a star is very small. It is only because dark matter is spread throughout the galaxy that its total mass is so large.

 

Also, the dark matter in a star will not interact significantly with the exploding material (other than very slightly increasing the mass of the star).

 

And, I don't think we can calculate the expected behaviour of a supernova accurately enough to detect any unexpected behaviour.

 

The mass (and distribution) of dark matter is calculated from the observed effect on the rotational speeds of galaxies (and relative speeds of galaxies in clusters, and gravitational lensing).