Expert Voices Paul Sutter

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

Physicists have certainly achieved a lot, but many mysteries about the universe remain.

What if I told you that our universe was flooded with hundreds of kinds of nearly invisible particles and that, long ago, these particles formed a network of universe-spanning strings?

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.

If we want to learn new things about everything from the first galaxies to the chance for life on other planets, the James Webb is our only hope.

Gamma-ray bursts are even worse than we thought.

We have much to learn from the rocks of the asteroid belt.

Scientists are on the verge of being able to detect the "memory" left behind by gravitational waves.

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.