Physical Science
Physical science is the study of the physical world around you. Learn about everything from electricity to magnetism in this section.
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When the power goes out and is later restored, how do you know what time to set your clocks to? Have you ever wondered how time is regulated? Learn how scientists determine exact time.
About 90 percent of Americans consume some form of caffeine every day: It's our most popular drug by far. What's so special about this stimulant?
Helium balloons tend to fascinate adults and children alike (and it's not just the Donald Duck voice thing, though that is a big draw). Learn all about helium and why it floats!
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Nuclear radiation can be extremely beneficial or extremely harmful -- it all depends on how it's used. Learn what nuclear radiation is all about.
Whether the circle is as big as planet Mars or as small as a tennis ball, the ratio of its circumference divided by its diameter will always equal pi (3.14). But why?
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?
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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.
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?
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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.
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.
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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?
Radar is used to track storms, planes, and weapons and also to create topographic maps. Learn about radar, radar technology and Doppler shift.
The Diamond synchrotron is a massive facility that houses a beam of light 10 billion times brighter than the sun. But is that all it does?
Most of us have heard the talk about oysters and chocolate, and maybe you've read an article about the stimulating effects of ginseng. But garlic, licorice and cucumber? Learn about the history of aphrodisiacs and whether they've been proven to be effective.
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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.
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.
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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.