Paul Sutter

In one upside-down, hypothetical version of the universe, a bizarre type of black hole could exist that is stranger than an M.C. Escher sketch: charged black holes.

Black holes can get big … really big. But just how big? It's possible they could top out at over a trillion times more massive than the sun.

Hair may record the information swallowed by the gravitational monsters.

All you need is some string.

A few scant equations can explain a variety of phenomena in our universe, over vast gulfs of space and time. Here's a taste of just how powerful modern physics can be.

For the past few years, the possibility of a new (and big!) planet hanging around in the far outer solar system has tantalized scientists and the public alike. Is "Planet Nine" out there or not?

Otherwise, they'd be ferociously unstable.

A physicist proposes that the moon is a great place to build a particle collider and conduct high-energy physics experiments.

Physicists are figuring out how close you can get to a black hole before you are unlikely to escape. That threshold is called the innermost stable circular orbit (ISCO).

Magnetars — highly magnetized, rapidly rotating super-dense stars — are among the most enigmatic creatures to inhabit the cosmos and their origins are shrouded in mystery.

The answer to the dark-matter mystery may be under our feet.

We all know that iconic scene: Luke Skywalker staring forlornly — and perhaps wistfully — at the double sunset of his home planet, Tatooine.

String theory is a purported theory of everything that physicists hope will one day explain … everything.

A dark web ties the universe together. Now, we can see it.

As far as we can tell, we're alone. But it could be that we're looking in the wrong places.

It was a big moment for our cosmos when the first stars awoke, but it's an elusive one for scientists.

These supremely stable particles could explain dark matter.

String theory is a powerful idea, unfinished and untested, but one that has persisted for decades despite inauspicious beginnings.

Researchers recently released simulations of the Large Magellanic Cloud — a satellite galaxy of the Milky Way — and found that cosmic rays from a starburst event are starting to rip it apart.

We may soon find out whether we live in an axiverse.

Gamma-ray bursts are even worse than we thought.

Gravitational waves leave behind a memory — a permanent bend in space-time — as they pass through.

A new study has called into question the prevailing notion that the universe is "flat." The stakes of this cosmological debate are huge.

At some point, the rules of the subatomic give way to the rules of the macroscopic. But how? We're not exactly sure, and it's been a long, strange journey in trying to answer that question.