Chances are, if you've been using computers for more than a few years, you've encountered a hard disk failure at some point or another. And if you don't have your data backed up, these failures can be heartbreaking to say the least.
To help you forget about the loss of those priceless photos of your child's first steps and the great American novel you were writing in your spare time, know this: a dead hard drive is a great source of some sweet and powerful magnets! Behold:
At the base of the arm that rapidly whisks back and forth over the spinning data platters inside your hard disk are two strong rare-earth magnets (the area labeled "actuator" in this drawing). At the end of the actuator arm is a coil which acts as an electromagnet, moving back and forth within the magnetic field created by the rare-earth magnets allowing for quick and precise movements without any moving parts. These are your prize—all it takes is a special star-shaped Torx screwdriver set and a little patience to reveal them. Check out the video above to see how it's done. —John Mahoney
Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.