Universe

The accelerating expansion of the universe is the observation that the universe appears to be expanding at an increasing rate.

The metric expansion of space is the increase of the distance between two distant parts of the universe with time. It is an intrinsic expansion whereby the scale of space itself changes. This is different from other examples of expansions and explosions... Show More

Before answering this, what is "nothing"? Let's define "nothing" first before answering the question.

We have to define the meaning of "expanding"...

It has been observed that galaxies are moving apart but we have not seen the edge of the universe. So how can we say the universe is expanding?