Physical Science

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!

I recently bought a pair of mirrored sunglasses and they are already scratched. Isn't there a way to make them scratch-resistant?

They stick around long after death and compete with the likes of Dracula, Frankenstein's monster and the Wolfman as one of the great figures of classic horror movies. Are you brave enough to unravel the history of these real-life, tangible ghosts?

By Tom Harris

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

By Craig Freudenrich, Ph.D.

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.

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.

Thorium is in many ways safer than uranium for nuclear power production. But is it safe enough to bet on for our energy future?

By Jesslyn Shields

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

Helium is the second lightest element on the Periodic Table. How is helium created?

By Patrick J. Kiger

You may know a bit about polygraphs, but do you know which physical reactions it actually monitors?

The decibel scale measures sound based on human hearing, which makes it one of the most unusual scientific measurements. How are decibel calculated and what do they tell us about sound?

By Sascha Bos

I recently used chlorine bleach to clean the siding on my house, and I was amazed at how well it worked! What is bleach? How does it remove stains? Is the chlorine in bleach the same as the chlorine in drinking water or in swimming pools? Is chlorine safe to use?

By Yara Simón

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 once saw this device shaped like a light bulb. It had a vertical support inside it, and on that support there were four vanes with four diamonds on the end. One side of the diamond was black and the other was white. I did a little research and found out that it was called a Crookes' radiometer -- how does it work?

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

Bullet size is measured in calibers, but how are wires and nails measured? Learn about bullet size and caliber in this article.

Many ads for new clocks advertise their ability to automatically synchronize themselves with the atomic clock in Boulder, Colorado. This atomic clock is more precise because it uses the frequencies of atoms as its resonator.

Chemical formulas provide a concise explanation for reactions. In this article, we explain the formula for the reaction in a smoke detector.

When an airplane flies faster than the speed of sound, you hear a large booming sound. But how can something that seems so simple cause such a boom?

By Austin Henderson

Radar is used to track storms, planes, and weapons and also to create topographic maps. Learn about radar, radar technology and Doppler shift.

By Marshall Brain

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