Is the universe finite or infinite? That is, does it go on forever in at least one direction, or is there unlimited detail in at least one place? This question has been asked as long as we’ve understood the concept of infinity, and many feel we are making substantial progress lately. In particular, many cosmology papers consider the differing physical implications of infinite vs. finite space or time, and these papers are often reported on more widely as perceptibly changing our estimates about whether the universe is infinite.