A mysterious black hole in a distant galaxy just woke up after decades of silence—and it’s putting on a cosmic light show! ESA’s XMM-Newton and other X-ray telescopes are capturing massive bursts of ...

Einstein believed that black holes didn't really exist. But they do: that much we know. We don't know much else about them.

Dark matter is hypothesized to outweigh "ordinary matter" in the universe by a factor of five. That means all the stuff we ...

A new study in Monthly Notices of the Royal Astronomical Society by researchers including István Szapudi of the University of ...

Physicist Richard Lieu first explored the idea that gravity could exist without mass—now he’s got a new cosmological model ...