The World

An MRI machine is more than just a big, claustrophobia-inducing tube. How much do you know about what's going on inside -- or what's going on inside your body while you're in there?

Your credit score plays a large part in whether you can buy a house or car. In certain circumstances, it even affects whether you can get a job. But where does the number come from?

If your phone talks through a wireless earpiece and your computer sends songs to speakers across the room, Bluetooth is probably behind it. But what's behind Bluetooth?

This ocean area has a reputation for devilry and danger. How much do you know about the Bermuda Triangle? Find out with our Bermuda Triangle Quiz.

By Nathan Chandler

In line at the corner deli, weaving through traffic, right next to you at a movie theater ... cell phones are everywhere. But are they really that different from walkie-talkies?

You can find batteries under the hood of your car, inside a TV remote -- even within hearing aids. Batteries were invented nearly two centuries ago, and they keep getting more sophisticated. But how well do you know what's at work inside these cans of chemicals?

Electric motors are inside all kinds of ordinary devices, using a power source to make motion. So what makes the motor go 'round?

With the constantly fluctuating price of gasoline, more people are looking into hybrid cars. But it's a good idea to know what you're getting into before purchasing one. Take the hybrid car quiz and see how much you know about them.

Fuel cells are still pricier than even premium-grade gas -- do you know why? Test your fuel cell know-how in this quiz and learn some cool fuel cell facts along the way.

If you find yourself locked out of your house, you might be tempted to learn your way around a lock pick. But while the theory is easy, getting a lock to open without a key is a little harder.

Not long ago, most Americans associated tattoos with sailors, bikers and sideshow artists. But tattoos have become more popular in recent years. What does it take to get an image under your skin?

Home networks are becoming common in homes that use more than one computer. With people using computers for shopping, home businesses and entertainment, it can be essential to link up not only PCs but also fax machines and TVs. What's going on behind this linked-up system?

Solar cells are on everything from pocket calculators to the roofs of buildings. So exactly how do they turn light into energy?

Wireless networks are easy to set up and inexpensive. They're also unobtrusive -- unless you're on the lookout for a place to use your laptop, you may not even notice when you're in a hotspot. But as you’ll find out in this quiz, there’s a lot more to them than meets the eye.

There are a lot of misconceptions regarding sadness and major depressive disorder (MDD). Knowing the differences, causes and treatments can lead to a better quality of life for you or someone you know. So how much do you really understand about the condition?

By Kevin P. Allen