Despite its name, the big bang theory is not really a theory of a bang at all. It is really only a theory of the aftermath of a bang.
Alan GuthIn 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 Guth