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

We all have favorite colors. But have you ever considered why you like one color more than another?

By Allison Troutner

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

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

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

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.

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

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

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

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

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

If you're one of those people who chooses invisibility as your desired superpower, it could mean you have a dark side.

By Alia Hoyt

Why do we love looking at a perfectly stacked display of soup cans or six flower petals around a stamen? Our brains seem wired for it -- but why?

By Dave Roos

Primary colors are the blocks from which all other colors are built. But there's a lot more to know about them than the basic red, yellow and blue we learned about in kindergarten.

By Michelle Konstantinovsky & Desiree Bowie

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

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

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.