Quantum Gravity: Is it Physics?

Quantum gravity is purported to be the theory which underlies both
quantum theory and general relativity. I will introduce the subject,
emphasizing recent results of one approach to the problem which suggest
that spatial geometry is discrete. Such discrete geometry may have an
observational signature. I will describe limits on discrete geometry by
astrophysical observations and will also argue that, in the not too
distant future, quantum gravity may become physics and enjoy contact
with observation and even experiment.