Starship Asterisk*

Bystander.
It is difficult to imagine something that has mass and volume yet no centre or edge.
I suppose that it will require some kind of spiritual and intuitive insight, rather than a purely scientific one, to fully understand the nature of this physical manifestation that we observe around us.

How do astronomers decide how big the universe is? If the theory of the Big Bang is true then there must be a central point in the universe with all space surrounding that point and expanding all the time. If this is the case where is our galaxy located relative to that point? Astronomers state that...

I have seen a number estimates on the size of M31 on this site and others, and there seem to be widely varying figures given. Some claim that M31 has about 200 billion solar masses while other sources claim that it might have as many as a trillion. Also, distances given to various galaxies seem to d...