Physical science is the study of the physical world around you. Learn about everything from electricity to magnetism in this section.
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.
We need oxygen to live, so it seems to me that if we got more oxygen, we would be better off. Is it harmful to breathe 100-percent oxygen? What will happen?
Nuclear materials get used in many forms of nuclear medicine -- everything from PET scans to chemotherapy uses them. Learn how nuclear medicine works.
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?
Nuclear radiation can be extremely beneficial or extremely harmful -- it all depends on how it's used. Learn what nuclear radiation is all about.
Why do newspapers turn yellow over time?
Rust is the common name for iron oxide, which is created when iron bonds with oxygen. In fact, pure iron is only rarely found in nature because it interacts with oxygen so easily.
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?
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.
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?
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?
Here's something to consider: The place you call home likely has walls and glass windows. Both are adept at keeping rain, snow and wind from bothering you in your abode. Only one, though, allows light to enter. Why is that?
Dynamite is simply some sort of absorbent material (like sawdust) soaked in nitroglycerin. But what makes this chemical so explosive?
Ever wondered exactly what they "artificial flavors" in your candy are, and why no specific ingredients are listed? Find out in this article.
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.
If you took all of the imaginable tones that a human can hear and combined them, you would have white noise. This phenomenon gets its name from white light -- what do the two have in common?
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?
Scenario: A helium balloon is up against the ceiling one day, and the next day it's on the floor. Does the balloon fall because the helium leaks out, or because the helium molecules slow down due to decreased pressure?
Helium is the second lightest element on the Periodic Table. How is helium created?
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?
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?
I have heard that carbon monoxide is extremely poisonous. Can you explain why?