It is hard to conceive of a universe that does not exist in space and persist through time: space and time seem to be the basic framework of the cosmos. Yet what is space and what is time? Are they "things" or are they merely the language we use for organizing events we witness in the world? Moreover, are they even fundamental? Could it be that space and time conveniently summarize more basic ideas somewhat as temperature summarizes the motion of atomic constituents? Will we one day discover "atoms" of space and time---true, fundamental elements which space and time as we now know them are simply coarse approximations?