Welcome to the age of precision cosmology, a scientific era in which astronomers and physicists have measured almost everything about our universe—except for its deepest mysteries: dark matter and ...

What is dark energy? Why does dark energy seem to be weakening? Is our universe part of a larger multiverse? What lies beyond the boundary of a black hole? The universe seems to be rotating, and if ...

One of the big mysteries of the universe is how it's expanding. The phenomenon causing that expansion is known as dark energy — and recently, scientists have started to wonder if its changing. Now let ...