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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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.

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In detective movies or TV shows like "CSI," photographers swarm in and take countless pictures of a crime scene. But how does crime scene photography really go down?

By Sarah Dowdey

Imagine spending your days racked with pain or losing pound upon pound because nausea leaves you unable to eat. Now imagine that someone offers you a wonder drug to cure all your ills. The problem? It's illegal.

By Jacob Silverman

If you were thrown into prison for a crime you didn't commit, you'd probably welcome DNA profiling. Although the use of this technology has recently helped bring justice, there may be cause for concern.

By Shanna Freeman

The bloodstain from a crime scene has a story to tell, if you know how to analyze it. Then it might explain the who, what and when of a murder.

By Shanna Freeman & Melanie Radzicki McManus

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Who made it possible to light up your home at night? Thomas Edison, right? Yes, but without the work of Nikola Tesla, we would be living in a different world.

By William Harris

Criminals always leave traces behind after a crime is committed. In fact, footprints, tire tracks and tool marks are often more prevalent than fingerprints at a crime scene. What can impression evidence tell an investigator?

By John Fuller

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

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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

In the comics, radiation exposure turned an average man into a pea green and angry Incredible Hulk. But in reality, what can radiation do to those exposed? Is it always a villain?

By Debra Ronca

Overtone is a sound accompanying the main tone produced by a vibrating body. The number and loudness of overtones determine the timbre, or tone color, of a musical sound.

An object free to vibrate tends to do so at a specific rate called the object's natural, or resonant, frequency.

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When sound waves strike the ear, these waves produce the sensation of sound. Let's take a look at how sound waves work.

Unlike the cheap microscopes you peered into in school, these advanced instruments can breathe rich detail into the tiny world around us, including the world of nanotechnology.

By Jonathan Atteberry

Mathematics achieves the sublime. Sometimes, as with tessellations, it rises to art. In their simplest form, tessellations consist of a single shape that repeats over a two-dimensional plane without any gaps. Why was M.C. Escher so fixated on them?

By Nicholas Gerbis

Fractals have been around forever but were only defined in the last quarter of the 20th century. Think you can wrap your brain around how fractals work?

By Craig Haggit & Yara Simón

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A world without math is unimaginable. It's a part of who we are. It's the analytical juice of our left brain. In the words of physicist Richard Feynman, even a fool can use it. So why do so many of us turn our backs on numbers?

By Robert Lamb

We're all exposed to tiny levels of radiation, but a blast of it can leave you in agony — that is, if it doesn't kill you outright. What is it, what causes it and how can we treat it?

By Ed Grabianowski

What happens when there's too much voltage? Learn about the difference between voltage surges and spikes from this article.

By HowStuffWorks.com Contributors

For many of us, a number is just a number, a bit of information that tells you, say, what time it is. But mathematicians look at that same number and divine relationships that underlie nature itself. Ready to enter the trippy world of number theory?

By Robert Lamb

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That's one seriously big number, and technically Amedeo Avogadro didn't even come up with it. So how did the Italian chemist make such an indelible (numerical) mark on the wonderful world of chemistry?

By Jonathan Atteberry

A venerable work of art hangs lifeless in a museum, the once brilliant scene dulled by centuries of dirt and grime. Can laser analysis and modern art restoration techniques save the masterpiece?

By William Harris