Expert Voices Paul Sutter: Explaining astrophysics and astronomy

Space is big — really big. And if you want to successfully navigate the interstellar depths of our galaxy, you're going to need some sort of reliable system.

Many theories of the early universe predict that the cosmos should be flooded with cracks in space-time, called cosmic strings, but no cosmic strings have been detected yet.

For decades, cosmologists have wondered if the large-scale structure of the universe is a fractal — that is, if it looks the same no matter how large the scale.

Physicists have long been unable to describe what happened just after the Big Bang when a teensy blip ballooned into the universe, a process called inflation. We may know why.

Galaxies are glittering cities, massive metropolises full of stars, dust, gas, black holes, magnetic fields, cosmic rays, dark matter and more.

For years, astronomers thought that the objects responsible for short gamma-ray bursts get kicked out of their home galaxies shortly after they're born. But new observations prove otherwise.

What if one mission could study the gravitational ripples triggered by some of the most violent events in the universe — on the way to observing the least-known planets of our solar system?

Believe it or not, physicists are attempting to understand the universe when it was only a handful of seconds old.

A team of physicists has proposed a clever plan to concoct a quantum theory of gravity: refine an age-old technique, and use it to probe the tiniest scales in the universe.

The hypothetical Planet Nine may not be a planet but rather a small black hole that might be detectable from the theoretical radiation emitted from its edge, so-called Hawking radiation.