Original: By combining space and time into a single manifold, physicists have significantly simplified a large number of physical theories, as well as described in a more uniform way the workings of the universe at both the supergalactic and subatomic levels.
Simplified: By combining space and time into a single manifold, physicists have simplified a good deal of physical theory, as well as described in a more uniform way the workings of the universe at both levels: the supergalactic and subatomic.