Cosmology

The spins of some early galaxies could be a clue that the entire observable universe exists within a black hole—except, that is, for all the evidence to the contrary

A long-simmering disagreement over the universe’s present-day expansion rate shows no signs of resolution, leaving experts increasingly vexed

A new map of cosmic expansion suggests that dark energy evolves over time, hinting that the universe doesn’t work the way we thought it did

The final results from the Atacama Cosmology Telescope offer the sharpest, most sensitive view of the early cosmos that anyone has ever seen

New simulations suggest that habitable worlds could have begun forming only 200 million years after the big bang

A nearly century-old offshoot of Einstein’s general theory of relativity may hold promise for solving the mysteries of dark matter, dark energy and more

Physicists are finding new ways to model false vacuum decay, a terrifying, albeit remote, cosmic endgame

According to a tenet scientists call the cosmological principle, our place in space is in no way exceptional. But recent observations could overturn this long-held assumption

The universe’s light-starved early epochs, as well as the first stars and galaxies, lie beyond the reach of conventional observatories but could be revealed by a new generation of radio telescope arrays

Called Olbers’ paradox, the seemingly simple mystery of the sky’s darkness is something that stumped astronomers for centuries

Estimates of how fast the universe is expanding disagree. Could a new form of dark energy resolve the problem?

A new biography of astronomer Henrietta Leavitt celebrates meaning making in science