Natalie Wolchover

Sometimes a mirror that reflects 99.9999% of light isn’t good enough.

In a new paper, physicists argue that hypothetical particles called axions could explain why the universe isn’t empty.

Glass is anything that’s rigid like a crystal, yet made of disordered molecules like a liquid. To understand why it exists, researchers are attempting to create the perfect, still-hypothetical “ideal glass.”

A problem confronts cosmology: Two independent measurements of the universe’s expansion give incompatible answers. Now a third method, advanced by an astronomy pioneer, appears to bridge the divide.

By teaching machines to understand our true desires, one scientist hopes to avoid the potentially disastrous consequences of having them do what we command.

A study challenged the evidence for the mysterious antigravitational force known as dark energy. Then cosmologists shot back.

By considering simple symmetries, physicists working on the “bootstrap” can rediscover the basic form of the known forces that shape the universe.

Three physicists stumbled across an unexpected relationship between some of the most ubiquitous objects in math.

Most every cosmologist believes the universe is flat. A new analysis argues that it’s closed.