CNet

Using powerful electromagnets and a fingerprint scanner, an electrical engineer builds a replica of Thor's hammer Mjolnir that can only be lifted by the worthy.

In Marvel comics, Thor's legendary hammer Mjolnir is famous for being able to be wielded only by the worthy. For the unworthy, i.e., literally everyone except Thor and the odd someone else from time to time (a handy loophole for writers), Mjolnir simply cannot be lifted off the ground. . It is this property that electrical engineer Allen Pan, aka Sufficiently Advanced on YouTube, decided to replicate in his very own take on a "working" Mjolnir. To make the hammer immoveable, he decided that strong magnets were the best method. Inside the head of his Mjolnir, he packed a microwave oven transformer electromagnet, which uses electricity to produce a magnetic field. This creates a very strong magnetic pull, strong enough that the hammer, when placed on a metal surface (that can't be lifted, such as a locked manhole cover), feels too heavy to lift. To read further and view the video, please visit http://www.cnet.com/news/engineer-builds-working-thors-hammer-only-he-can-lift/.