It's a good thing Nikola Tesla never figured out how to time travel, because that cord jungle behind your entertainment center would break his heart—again. It's been more than a century since he lit incandescent bulbs wirelessly in his lab, and yet you're still plugging into the wall.
Even your three-pronged socket looks surprised.
There are plenty of ways to beam volts through the air. Unfortunately, none of them are as cheap, efficient, convenient, or, well, safe as a cord. Radio waves can carry electromagnetic radiation to your devices, but radiation tends to peter out over long distances, leaving a thirsty gadget on the receiving end. Sure, you can crank up the amps to compensate for the loss, but then you end up frying passersby. Not good.
Lasers provide a better long-distance solution—but only if there is direct line of sight between source and device. Hey... down in front!
MIT spinoff WiTricity has worked out how to transmit juice to any gadget that enters a certain magnetic field. Using two magnetically resonant coils that operate at the same frequency—one in the transmitter and one in the device—the company has successfully transferred watts of electricity over a couple of meters. Unfortunately, when you increase the space between the coils, charging efficiency goes down the toilet. This solution also litters your house with magnetic fields. While the company says these fields are orders of magnitude weaker than those found in an MRI machine, your tinfoil-hat-wearing neighbor is likely already imagining exploding pacemakers and brain tumors.
Other firms are banking on magnetic induction. You might already have a gadget that charges this way: Electric toothbrushes have used the technology for years. Recently PowerMat started using it for a charging pad that lets you gas up any gadget for which the company makes a compatible adaptor. But magnetic induction is barely wireless: It relies on superclose proximity between two coils to transfer power. It's also unclear whether it can supply enough power for the amp-hungry gadgets in your living room.
Bottom line? Get used to gear with tails. While we can definitely cut down on a few of the cords in our lives, slicing through that final wire may take a sharper technological knife that we currently have.
