Optics

The iconic "school bus yellow" was the invention of an educator named Frank Cyr. But if yellow is so good for visibility, why don't all fire trucks use it too?

By Dave Roos

It’s true: In 6 easy steps, you too can draw an impossible shape.

All colors that you see fall into the visible light spectrum. Learn about the colors in the visible light spectrum in this article.

By Sascha Bos

Imagine wearing a T-shirt with lettering on it while brushing your teeth. Why are the letters on the T-shirt reversed in the mirror, while your head appears right side up?

Lasers are used in dental drills, eye surgery and even tattoo removal. But what exactly is a laser? There are numerous types, but all lasers work basically the same way. Learn how they generate such concentrated beams of light.

By Matthew Weschler

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

Just how far can the human eye see? There's no exact formula to figuring it out, but we do have an idea.

By Patrick J. Kiger

I have a thin piece of plastic mounted on the back window of my RV. It magnifies things so I can see better when I'm backing up. How can such a thin piece of plastic magnify things? A regular glass magnifying lens would have to be curved on both sides and much thicker.

By Austin Henderson

Just about everyone has seen a television show or movie in which a criminal suspect is questioned while detectives watch from behind a one-way mirror. How does a piece of glass manage to reflect light from one side while remaining clear on the other?

If you want to see a hologram, you don't have to look much farther than your wallet. But the most impressive holograms are large scale and illuminated with lasers or displayed in a darkened room with carefully directed lighting. Learn how a hologram, light and your brain work together make clear, 3-D images.

By Tracy V. Wilson

Some of the brightest minds in history have focused their intellects on the subject of light. Einstein even tried to imagine riding on a beam of light. We won't get that crazy, but we will shine a light on everything scientists have found so far.

By William Harris & Craig Freudenrich, Ph.D.

NASA's Mars rovers are sending 3-D images to Earth, so we can see depth and texture on the Martian surface. And how do we see this depth and texture? 3-D glasses, of course! Check out how they work.

By Marshall Brain

An invisibility cloak seems perfectly believable in the magical world of Harry Potter, but in the real world, it's impossible, right? Not so fast.

By William Harris & Robert Lamb

You're driving down the road on a sunny day, and you see a puddle of water coming up. You look again and it's gone! What happened? You’ll be able to answer that question if you read our miraculous mirage article.

By Tom Harris

The Diamond synchrotron is a massive facility that houses a beam of light 10 billion times brighter than the sun. But is that all it does?

By Jacob Silverman

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

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

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

What if there are colors within the visible spectrum that our brains can't perceive? In fact, there are. They're called impossible colors. But some researchers think they've discovered a way to see the impossible.

By Dave Roos

Cosmological redshift: sounds like the latest blockbuster coming to a theater near you, doesn't it? In reality, it has to do with how light itself travels -- and understanding how it works is essential to advanced space telescope technology.

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

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

For centuries, curious observers have probed the heavens with the aid of telescopes. Today, both amateur and professional scopes magnify images in a variety of ways.

By Craig Freudenrich, Ph.D.

The human eye misses a lot -- enter the incredible world of the microscopic! Explore how a light microscope works.

By Craig Freudenrich, Ph.D.

A venerable work of art hangs lifeless in a museum, the once brilliant scene dulled by centuries of dirt and grime. Can laser analysis and modern art restoration techniques save the masterpiece?

By William Harris