Forces of Nature

Learn how avalanches form, how long you can stay alive while buried under an avalanche and what steps you can take to survive.

By Tracy V. Wilson

The wall of water that struck northern Japan on March 11 claimed more than nearly 16,000 lives. While the human and cultural extents of this natural disaster are difficult to grasp, we can explain the physical properties that led to it.

By Robert Valdes, Nathan Halabrin & Robert Lamb

You've heard the warnings about thunderstorms: Stay out of the tub, unplug your TV and don't call people from your land line. But can you really get struck by lightning while you're inside?

Rainbows are one of nature's most beautiful effects. Have you ever wondered how the colors end up in seemingly perfect bands? And, what about double rainbows -- how does that happen? Find out how rain and sun can align to put color in the sky.

By Tom Harris

The raging wildfires in southern California have claimed lives and destroyed hundreds of homes. Learn how wildfires start and spread, and find out what firefighters do to battle the blaze.

By Kevin Bonsor

Around 1,800 thunderstorms are occurring on the Earth at any given time. But how do they form, and what causes them?

We hear about humidity in just about every weather report on the nightly news. There are several different ways meteorologists measure humidity, but relative humidity is the most common measurement. What is relative humidity, though?

By Nathan Chandler

Flooding has claimed more lives than any other natural disaster. Find out how a gentle stream becomes a raging torrent.

By Tom Harris

Do scientists really think a massive earthquake could break California in two?

Acid rain is caused by emissions of sulfur dioxide and nitrogen oxides from power plants, cars and factories. Find out how acid rain is produced, how it affects natural and man-made objects and how governments aim to reduce it.

By Sarah Dowdey

There are obvious craters on Earth (and the moon) that are evidence of a long history of massive objects hitting planet Earth. But what would happen if an asteroid hit Earth today?

By Marshall Brain & Sarah Gleim

There may be a time when all that stands between your home and the rising floodwaters are some sacks full of sand. Will this defense keep you safe?

By Kim Williamson

A perfect climate means different things to different people. These 10 countries span the globe and offer a wide range of climates to satisfy any taste -- hot, cold or in-between.

By Jennifer Horton

Is hurricane intensity increasing? It all depends on who you ask. How have scientists come to so many different conclusions about the ferocity of these seasonal storms?

By Jessika Toothman

Simon and Garfunkel. Peanut butter and jelly. Thunder and lightning. Some things are just better when they roll in pairs. But while we know that '60s folk singers and classic foodstuffs can also roll solo, what about these stormy BFFs?

By Kate Kershner

Your grandfather may swear that he can feel the onset of a harsh winter in his bones - and your family may swear it's true - but a lot of us would prefer a more scientific method for predicting what the winter may have in store for us.

By Kate Kershner

In the days of Ancient Greece, it was easy enough to chalk up a bolt from the blue to Zeus, the great curmudgeon of Mt. Olympus. But while Ancient Greeks probably never felt safe from their grumpy god, today we know a bit more about lightning safety.

By Kate Kershner

Mother Earth seems to have a love/hate thing going on with humans. While the planet we call home has all the essentials we need for life, it also has some nasty - and deadly - surprises.

By Nathan Chandler

You've probably heard that no two snowflakes are alike, but how can that be true? Find out how molecules of water vapor come together to form these winter wonders.

By Nathan Chandler

Ever hear that saying that a cow lies down when rain is coming? This superstition may not be as udderly ridiculous as you think.

By Nicholas Gerbis

Black ice is hazardous. Even worse, it's nearly invisible on the road surface. Learn more about black ice at HowStuffWorks.

By Kristen Hall-Geisler

Separating fact from fiction when it comes to tornado safety could mean the difference between life and death.

By Clint Pumphrey

It's hard to resist a movie where bloodthirsty beasts fall from the sky, especially if Ian Ziering stars! How might the science behind this B movie work?

By Meisa Salaita

Only a few natural events pack the power to knock global civilization on its heels. One is a planet-killing meteor. Care to guess the other?

By Nicholas Gerbis

When a hurricane or flash flood strikes a city, it can leave residents stranded in their cars, homes or other buildings waiting for rescue. How do rescue teams know where to go first?

By Laurie L. Dove