Light travels incredibly quickly. But just how fast is it? Microwaves and light waves move at the same speed, so if you have a microwave oven, you can work out the speed of light yourself.

That light can be both particles and waves is one of the most illogical—but at the same time fundamental—characteristics of quantum mechanics. This is called wave-particle duality. The theory ...

But since he knew light was a wave composed of changing magnetic and electric fields, it couldn't truly be still. "One sees in this paradox the germ of the special relativity theory is already ...

Shamir's findings lend support to the century-old "tired light" theory instead of the Big Bang. The findings are published in ...