We've known that the universe is expanding since 1929, and that its expansion is accelerating since 1998. The culprit behind ...

Most of the universe is slipping away from the Milky Way, carried outward as space itself expands. Yet one giant neighbor is bucking the trend, racing straight at us while almost every other major ...

That the universe is expanding has been known for almost a hundred years now, but how fast? The exact rate of that expansion ...

We have known for several decades that the universe is expanding. Scientists use multiple techniques to measure the present-day expansion rate of the universe, known as the Hubble constant. These ...

A physicist proposes that the universe is not empty space, but is a viscous fluid, fueling the expansion and contraction we see.

The expansion of the universe may be slowing down rather than accelerating, according to a new study that challenges the Nobel Prize-winning theory of dark energy. “If confirmed, this would have ...

Most messages are press releases about astronomical discoveries—okay, scratch that; most of them are spam, but science announcements are an easy second place. But I also get questions from readers ...