In the context of general relativity, space almost is a substance. It can bend and twist and stretch, and probably the best way to think about space is to just kind of imagine a big piece of rubber that you can pull and twist and bend.
Alan GuthSpace is certainly something more complicated than the average person would probably realize. Space is not just an empty background in which things happen.
Alan GuthThe question of the origin of the matter in the universe is no longer thought to be beyond the range of science - everything can be created from nothing. It is fair to say that the universe is the ultimate free lunch.
Alan Guth