When the sun’s rays hit the skin, processes inside the tissues start making vitamin D. People do not need to get a tan or burn to get vitamin D from the sun. The body will make all the vitamin D ...

Cosmic rays are particles from outer space that travel across the universe. They can be made by the sun, by other stars exploding, and even black holes. They move extremely fast, nearly the speed of ...

That means a gamma-ray burst can put out more energy than the sun would emit over many trillions ... a snazzy red facsimile of himself! In the real world, we would be spared Banner's frustrations ...