For a generation, cosmologists have worked with a simple story: the universe is not only expanding, it is expanding faster ...

An expanding universe complicates this picture just a little bit, because the universe absolutely refuses to be straightforward. Objects are still emitting light, and that light takes time to travel ...

For much of the twentieth century, scientists expected the expanding universe to slow over time. The opposite turned out to be true. Space is stretching faster today than in the past, and the precise ...