by Cynthia Drake
Monday, March 1, 2010
Will your credit card become unreadable if it's exposed tomagnets? In a previous story, we said yes, but many of you begged to differ. Seeing that, we took the challenge of clearing things up once and for all.The result: With the help of a junkyard magnet, a garden–variety refrigerator magnet and a professor with a vast knowledge of magnetics, we were provedright –– eventually.
A highly charged debate ensued after our "How to destroy a credit card" was published in September of 2009. Folks started weighingin on whether magnets –– especially those of the refrigerator persuasion –– actually had the power to strip a stripe. "Running a magnet across the stripwill do nothing," said one commenter on our video at YouTube.com. Others chimed in with their own experiences with credit cards and magnets.
So we putour cards to the test against a barrage of different magnets, even heading to the junkyard to swipe stripes with some serious electromagnetic forces.
Butbefore we get to the results, let's take a step back.
The Mystery of the Stripe
Credit card magnetic stripes carry more than just your preciousfinancial data; they carry some mystery, too.
The stripe you see on the back of your card is a collection of magnetic particles –– each a very small magnetabout 20 millionths of an inch long. It's a commonly held belief that exposure of these particles to an external magnet can scramble the information and