Some say advances in perovskite solar cells mean we are on the brink of the next solar energy revolution. Others aren't so sure.

Photons are odd little beasts. They can act like waves. They can act like particles. They are teeny tiny messengers of force. They are carriers of energy. If you're enjoying this article, consider ...

Some things we see in space appear to outpace light. Now we are learning to harness these bizarre optical illusions to ...