Physics

Astronomers have known where the universe’s missing matter has been hiding for the past 20 years. So why did it take so long to find it?

Cosmologists have predicted the existence of an oscillating signal that could distinguish between cosmic inflation and alternative theories of the universe’s birth.

For decades, astronomers weren’t able to find all of the atomic matter in the universe. A series of recent papers has revealed where it’s been hiding.

The 19th-century discovery of numbers called “quaternions” gave mathematicians a way to describe rotations in space, forever changing physics and math.

Rosaly Lopes has visited dozens of active volcanoes on Earth and discovered even more elsewhere in the solar system. Her work is helping to establish whether volcanoes on distant moons could create conditions friendly to life.

Computer simulations and custom-built quantum analogues are changing what it means to search for the laws of nature.

String theorists elide a paradox about black holes by extinguishing the walls of fire feared to surround them.

A controversial new paper argues that universes with dark energy profiles like ours do not exist in the “landscape” of universes allowed by string theory.

Black holes occasionally reveal themselves when passing stars get ripped apart by their gravity. These tidal disruption events have created a new way for astronomers to map the hidden cosmos.