  Since the dawn of civilization, humanity has grappled with the big questions
of existence and creation. Modern cosmology seeks to answer some of these
questions using a combination of mathematics and measurement. The questions
people hope to answer include ``how did the universe begin?''; ``how will the
universe end?''; ``is space finite or infinite?''. After a century of
remarkable progress, cosmologists may be on the verge of answering at least one
of these questions -- is space finite? Using some simple geometry and a NASA
satellite set for launch in the year 2000, the authors and their colleagues
hope to measure the size and shape of space. This review article explains the
mathematics behind the measurement, and the cosmology behind the observations.
