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

Helicopters, ceiling fans, even tricked-out car tire rims: Sometimes they can even look like they're going backward, or bending.

By Laurie L. Dove

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

We first reported on the possibility of an invisibility cloak last year. Now a different invisibility cloak is making the news -- one that uses metamaterials to redirect light away from the wearer.

By Cameron Lawrence

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

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

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

By Allison Troutner

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

By Craig Freudenrich, Ph.D.

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.

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

A group of scientists from Duke University have demonstrated a simplified cloaking device. Learn about the cloaking device that the Duke scientists created and find out if a real-life cloaking device is actually possible.

By Jacob Silverman

Unlike the cheap microscopes you peered into in school, these advanced instruments can breathe rich detail into the tiny world around us, including the world of nanotechnology.

By Jonathan Atteberry

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

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

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

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

Is it its own special type of particle? A wave that's flowing through another medium? Or is there some creepy, unknown substance surrounding us that we simply don't perceive or understand?

By Nathan Chandler