As black holes feed, they pull material into a disk around them. The material orbiting in this disk gets heated to extreme temperatures, and so it becomes a plasma — a state of matter in which some of ...

How fast can a galaxy build ordered magnetic fields spanning thousands of light-years? Existing theories say several billion years, but observations of galaxies in our universe imply shorter ...

It's well established that the universe is expanding, but there's serious disagreement among scientists over how fast it's happening. Two of our best ways of measuring the cosmic expansion rate, the ...

From time to time, the Earth's magnetic poles flip, leaving us without a protective magnetic field for up to centuries ...