Tricks With Magnets

"M" is for magnet.

Magnet tricks, like magnets themselves, come in many varieties. Their uses can be prosaic and practical or whimsical and humorous; sometimes they're actually awe-inspiring. Whether you want to hang a picture on a wall, play a funny prank on a friend, or amaze an audience, there's a magnet trick to help you accomplish it.

Find Wall Studs

You're hanging a picture. You don't want to pound the nail through hollow drywall. To solve this problem, you can tap the wall with your knuckles and "feel" where the stud behind the drywall is. Or you could spend $15 to $70 on an electronic stud sensor. Or you could start from a corner of the room and do measurements, based on the conventional wisdom that wall studs are usually 16 to 24 inches apart from each other.

But there is another option: find a tiny magnet and move it around the drywall. Studs have nails; nails are made of metal; magnets are attracted to metal. Once your magnet has bonded with the nail, you can leave it as a place marker while you grab your own nail, your hammer and your picture of Grandma. Problem solved.

Hypnotize Laptops

Many laptops have magnetic sensors that trigger "sleep" mode when the lid is closed. Wave a magnet over that sensor and your laptop will find itself getting sleepy. If you really want to freak out a buddy while he's working on a term paper or watching YouTube videos, conceal a magnet in your hand and find a subtle way to get it near the sensor.

Be sure to use a weak magnet and keep it away from the computer's hard drive. You just want to put the laptop to sleep--not kill it.

Make a Magnet Levitate

For this trick, you'll need a vitrium-barium-copper superconductor; kits are available through Arbor Scientific (arborsci.com) or Edmund Scientific (scientificsonline.com). You'll also need liquid nitrogen. If you can't find a local supplier of it in the Yellow Pages, you may be able to get it from a welding shop or a college chemistry department--but you'll need to assure them you know how to handle it safely.

Place the superconductor in a ceramic dish and bath it in liquid nitrogen. (Wear goggles when handling the liquid.) Hold a magnet above the soaked superconductor, let go--and the magnet will float in the air like magic.

If you really want to impress your friends, mention that this is a demonstration of the Meissner Effect.

References

• Evil Mad Scientist: 17 Cool Magnet Tricks
• Cool Magnet Man: Superconductors
• Steve Spangler Science: Floating Magnet

Resources

• Steve Spangler Science: Liquid Nitrogen Safety