Physical Science

One of the most influential ideas in forensic science history is known as Locard's exchange principle. This simple, yet groundbreaking idea forever changed the way we fight crime. But who was Edmond Locard, anyway?

By John Fuller

Imagine walking through a field and stumbling upon scads of corpses, all in various states of decomposition. It's not the setting for your next nightmare, but rather a very real discipline of forensic anthropology.

By Tom Scheve

The Fibonacci sequence has been a numerical sequence for millennia. But what does it have to do with sunflower seeds or rabbits?

By Robert Lamb & 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

Atoms: the building blocks of life and the universe. We're all made of these microscopic bits of matter, but how many does it take to make a complete human being? And exactly what kinds of atoms do we have inside us?

By Laurie L. Dove

It's a force of habit to shake spray canisters, but when it comes to canned air, that inclination could cause frostbite.

By Laurie L. Dove

The International Thermonuclear Experimental Reactor plant aims to demonstrate that nuclear fusion could be a viable source of power in the future.

By Patrick J. Kiger

Why do most of us start relaxing as soon as we smell lavender or vanilla? Is it the memories they conjure up or is there a chemical reason?

By Dave Roos

You know that sound synonymous with a certain laser blaster from a galaxy far, far away? Yeah. It sounds like that.

By Mark Mancini

Our fingerprints serve to definitively identify us forever, right? But do they? How long do fingerprints remain usable as identification after we are dead?

By Patrick J. Kiger

You've heard of Google, but what about a Googol? If not, then this tutorial is for you.

By Mark Mancini

Spanish researchers recently uncovered a new geometric shape that allows human tissue to curve. But how?

By Robert Lamb

Marijuana isn't just a recreational drug for hippies and philosophy majors -- its psychoactive history ranges from Egyptian mummies to modern U.S. politics. What's the big deal about this leafy, green plant?

By Kevin Bonsor & Nicholas Gerbis

You know how chocolate sometimes turns white? Why does that happen and is it still OK to eat?

By HowStuffWorks.com Contributors & Desiree Bowie

Without gasoline, the world as we know it would grind to a screeching halt. The U.S. alone consumes well over a hundred billion gallons of gasoline per year. Learn all about this vital fuel.

By Marshall Brain

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

Have you seen investigators on crime shows who spray some stuff on a "clean" carpet and suddenly -- blood stains! Well, of all the fictional technology on TV, it turns out this stuff is real! Find out how luminol reveals the blood.

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.

More than 2.3 billion people across the globe drink alcohol, but most don't consider it a drug. But if you've ever seen someone who's had too much, you know alcohol has profound effects on the mind and body.

By Craig Freudenrich, Ph.D. & Michelle Konstantinovsky

Smoking or chewing tobacco makes many people feel good, even mildly euphoric. It's the nicotine that produces the buzz. Find out how nicotine affects the human body and what makes it so addictive.

By Maria Trimarchi & Ann Meeker-O'Connell

Do you remember holding a large conch shell up to your ear to hear the ocean? Why does this work even when you're far away from the sea?

What exactly is an atom? What is it made of? What does it look like? The pursuit of the structure of the atom has married many areas of chemistry and physics in perhaps one of the greatest contributions of modern science!

By Craig Freudenrich, Ph.D.

Biting on aluminum foil can be painful -- basically, when you bite on foil, you build a battery in your mouth. Ouch!

Nuclear materials get used in many forms of nuclear medicine -- everything from PET scans to chemotherapy uses them. Learn how nuclear medicine works.

By Craig Freudenrich, Ph.D.

On the one hand, nuclear power offers a clean energy alternative that decreases fossil fuel dependence. On the other, it summons images of quake-ruptured Japanese power plants leaking radioactive water. What happens in reactors in good times and bad?

By Marshall Brain, Robert Lamb & Patrick J. Kiger