Physical Science

Fusion reactors will use abundant sources of fuel, will not leak radiation above normal background levels, and will produce less radioactive waste than current fission reactors. Learn about this promising power source.

By Patrick J. Kiger & Craig C. Freudenrich

Learn what really goes on when a CSI "processes a crime scene" and get a real-world view of crime scene investigation from a primary scene responder with the Colorado Bureau of Investigation.

By Julia Layton

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

I was watching an old movie today, and two kids (neighbors) were talking to each other using two tin cans and a string. Does that really work? If so, why does it work?

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.

What makes sound a weapon? Review the basics of sound and discover exactly how the LRAD produces its "beam of sound." We'll also explore LRAD's hailing and warning abilities and other uses for sound.

By Tracy V. Wilson

If water is made up of hydrogen and oxygen, why can't we breathe underwater? It has to do with how molecules combine and how the human lung functions.

Ever wondered exactly what they "artificial flavors" in your candy are, and why no specific ingredients are listed? Find out in this article.

By HowStuffWorks.com Contributors & Yara Simón

Electricity completely surrounds us whether you're charging your cell phone or watching the sky light up during a violent thunderstorm. For most of us, modern life would be impossible without it, and the natural world relies on it.

By Marshall Brain, William Harris & Robert Lamb

The thought of an autopsy usually provokes fear, apprehension or extreme anxiety in people. Cut through the mystery of this process and learn the details of the preparation, procedures and tools used to perform an autopsy.

By Robert Valdes & Patrick J. Kiger

Viagra is one of the best-known drugs of all time. Nearly every adult in America has heard of the drug and can tell you what it does. Find out how this high-profile medication works its magic.

By Marshall Brain & Katie Lambert

When you watch crime drama on TV, you don't usually see what happens after the police and ambulance leave a murder scene. One thing those people do not do is clean up the blood. That's the work of a whole different team.

By Julia Layton

Atom smashers tell us about the fundamental structure of matter, the forces holding it together and the origins of the universe. Discover how scientists use particle accelerators to break atoms apart to learn about the nature of reality.

By Craig Freudenrich, Ph.D.

Pianos lose their tuning, guitars fall out of key -- even church organs need to be tuned every now and then. For centuries, the only sure-fire way to tell if an instrument was in tune was to use a tuning fork.

By Tristin Hopper

Wavelengths are used to measure the size of a wave. Learn about wavelengths in this article.

By HowStuffWorks.com Contributors

Voltage is how we measure the difference in electric potential energy. Learn about what voltage is from this article.

By HowStuffWorks.com Contributors

Thanks to our voracious appetite for energy, the element long linked with nuclear weapons is taking on a new role. Where does the hunt begin for uranium?

By Marianne Spoon

Did you ever wonder how to measure how fast sound travels in the air? Read this article to learn how to measure sound travel in the air.

By HowStuffWorks.com Contributors

Thanks to the Faraday cage, we can control electricity and make it safer for our computers, cars and other inventions.

By Chris Pollette & Nathan Chandler

You want to learn how to read the electric power meter in your home to see if the meter reader sent by the electric company was accurate. This article will teach you how to read a power meter.

By HowStuffWorks.com Contributors

First there was Volvo. Then came IKEA. Well get ready for the next major Swedish export: snus, a smokeless tobacco product, similar to dip or chew.

By Matt Schwarzfeld

We've been observing and experimenting in the name of science for centuries. But who deserves the honor of being humanity's very first scientist? Is it Euclid, Darwin, Galileo or someone else?

By William Harris

Explosions, fires and dangerous radiation levels dominated the headlines after the March 11 earthquake and tsunami sparked a nuclear crisis in Japan. How did so many safety measures fail?

By Marshall Brain

A unit circle is an important part of trigonometry and can define right angle relationships known as sine, cosine and tangent.

By Nokware Knight & Austin Henderson

A multiplication table is an easy-to-use grid of numbers that can help you learn to multiply quickly by using the chart and, eventually, your memory.

By Kristen Hall-Geisler & Austin Henderson