Expert Voices Paul Sutter

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.

An ambitious new fleet of spacecraft could reveal whether space-time is smooth or chunky, and in doing so the ultimate nature of reality.

Two legendary scientists gave us an understanding of gravity, and how to apply that understanding to the motion of the sun, planets and moons.

A brand-new particle has possibly emerged and is altering the future destiny of our entire cosmos, a physicist says.

Different measurements of the universe's expansion yield different results. Are we getting something wrong, or do we need brand-new physics to figure it out?

These weird defects in space-time should be out there, somewhere.

You might not recognize Peebles' name, but he theorized the existence of dark matter and has been a key player in painting the portrait of the universe that we now understand.

The 1995 discovery showed that the sun isn't the only star to host a family of planets — something we had long figured but never demonstrated — and also that the universe is really, really weird.

Obviously, some chain of unfortunate events led to the ejection of 'Oumuamua from its home system. But what could possibly cause such a catastrophe?

Interstellar flight is a real pain in the neck.

There are some odd little particles out there that are bound by the strong nuclear force, but physicists can barely get a glimpse of them before they flit out of existence.

The two giant blobs remain mysterious, nearly a decade after their discovery.

A giant linear collider the size of Manhattan could finally help us find new physics, scientists argue.

Saturn's largest moon, Titan, is one of the most enigmatic bodies in the solar system.

These stars, though extremely common, are tough to study.

Our lives here on Earth are small and insignificant and inconsequential — but only in a certain frame of reference, and that frame of reference doesn't necessarily apply to cosmic scales.

The ever-brightening sun will evaporate our oceans, too.

Moons of "hot Jupiter" alien worlds may detach from their parent planets and begin orbiting stars on their own.