Optics

Kaleidoscopes have been fascinating people since the early 19th century. Whether you think of kaleidoscopes as toys or as works of art, no matter how often you look inside, you'll never see the same thing twice.

By Melanie F. F. Gibbs

Modern color theory got its start with, believe it or not, Sir Isaac Newton, who also discovered a little thing called gravity and invented calculus.

By Jesslyn Shields

Seven ounces a ray! No, that's a lie. Measuring the weight of light is not as straightforward as that. So what's the more complicated explanation?

By Kate Kershner & Yara Simón

When speed is everything and light marks the universe's speed limit, lasers are bound to be the answer. At least, that's what NASA and a bunch of Wall Street types are betting on.

By Nicholas Gerbis

Vantablack is one of the darkest substances known, able to absorb up to 99.965 percent of visible light. But is it the blackest of blacks on the planet?

By Cherise Threewitt

Light travels pretty rapidly, but when it comes to faraway galaxies, that light takes a while to reach our telescopes. In fact, the light you see might actually be from billions of years ago.

By Kate Kershner

It's a young lady! It's an old woman! It's a blue dress! No, it's gold! Why are we fooled by optical illusions and what do they tell us about how the brain works?

By Meisa Salaita

Your eyes aren't playing tricks on you. Those mountains way off in the distance really do look blue, and it's because of how light wavelengths scatter in the atmosphere.

By Mark Mancini