HowStuffWorks Engineering Guide  Tags: engines engineering auto cars science science_questions science_explanations aviation buildings structures bridges transportation robotics materials equipment tractors  

With the help of Q, James Bond can breeze through a security system that requires the villain's irises, voice and handprint. Biometrics isn’t just for the movies. Real-life businesses and governments are using it. Check it out.

Learn all about BrainPort, a device for sensory substitution by electrotactile stimulation.

The Rehabilitation Institute of Chicago introduced a new bionic arm that can be controlled by reading a person's thoughts. How does this technology work? Can you control a machine with thoughts? Learn about the bionic arm in this article.

The crossbow, a weapon popular with Wookiees, vampire slayers and some modern hunters, looks like a cross between a bow and a rifle. Read about it’s fascinating history and uses.

Electromagnets are found in motors, tape decks, hard drives, VCRs and tons of other devices. Find out what makes an electromagnet "electro" and learn how to make one at home.

Did you know that airplanes and space shuttles use the utterly low-tech gyroscope for navigation? Discover the secret behind gyroscopic motion!

Rail guns leave gunpowder-based weapons in the dust (one can hit a target 250 miles away in six minutes). So why isn't the military using them? Find out how rail guns can be used and learn about the limitations of this technology.

A friend of mine told me that his watch flew off his arm and was sucked into the MRI machine at the hospital. Could this really happen? How strong are the magnets in an MRI machine?

Lobsters possess one of the most unique vision systems in the animal world. Researchers are working on applying that system to X-ray scanners that will make steel walls about as transparent as tissue paper. How will they do it?

In a lot of movies you see windows that are "bulletproof." Does bulletproof glass really exist, and if so, how does it work?

Unlike a regular SCUBA regulator which creates bubbles when the person wearing the apparatus exhales, a rebreather produces no bubbles when someone exhales. What exactly is a rebreather and how does it work? Find out in this article from HowStuffWorks.

See "Back to the Future 2"? Drool much over those hoverboards? Find out how these devices will work and see one that already does!

I've heard that bug zappers can actually help transmit diseases -- how does that happen? Once the mosquito dies, how can a disease it was carrying be transmitted?

Why does air cool down when pushed around by an electric fan? You would think that air molecules in motion would be creating friction, and therefore increasing the ambient temperature instead of decreasing it. So why do you feel cooler?

I am curious about the ignition system in my lawn mower. I know that a spark plug creates a high-voltage spark, and I know in my car the electricity for the spark comes from the battery. My lawn mower doesn't have a battery, so where does the electricty c

A friend of mine showed me this card that the image changed depending on the angle that you view it at. How does that work?

Watch this video from the University of Florida showing a new prosthetic arm that is learning by itself. This could be a breakthrough for amputees if they could have a robotic arm that moves by processing their own thoughts.

Watch this University of Florida research video to see how hurricane simulators work. Good Morning America's Sam Champion recently visited the University of Florida to experience hurricane force winds at the UF hurricane simulator.

Watch this Reuters video to see how a man took it upon himself to find gas for himself. He drilled a hole and found natural gas. He also found oil. And now he has a full-scale pumping operation.

Watch this Reuters video showing how Japanese researchers are always able to remember where they put their keys. The "key" is to wear a pair of video goggles that identifies and records everything you see for instant playback.

Watch this video about a printer that can print objects on HowStuffWorks. This printer can already print flexible electronic circuits. See how this amazing printer works in this video from ScienCentral.