This is probably a stupid question, but it has been bugging me.
We are severely limited in ground based observations due to atmospheric seeing effects distorting the image. Why then are we not concerned by the vast amounts of gas/planets/etc in the line of path to our source that should also...
Reading into some special relativity, I have seen E=mc^2 proposed from the assumption of four momentum conservation and the fact that the 'mass' component varies with velocity with the gamma factor, like a kinetic energy.
This seems a bit of a leap of faith to me so I was wondering if there...