ℝ is, of course, the set of real numbers. It is uncountably infinite, but is far, far too small to be “everything”, certainly in a mathematical sense (though it is always going to be far larger than any merely countable number such as the number of points in space-time that could ever possibly exist).
A late addenda: the PERSON OF INTEREST Season 5 episode “SNAFU” included as one of the premise concepts the mathemetical symbol ℝ meaning–EVERYTHING.
ℝ is, of course, the set of real numbers. It is uncountably infinite, but is far, far too small to be “everything”, certainly in a mathematical sense (though it is always going to be far larger than any merely countable number such as the number of points in space-time that could ever possibly exist).