Using wireless power transmission, one day people might be able to recharge their laptops or cell phones or other gadgets without plugging them into an electrical socket. The technology makes use of some basic physics, as electric coils that resonate at the same frequency can transmit energy to each other at a distance.

Intel Corp. researchers demonstrated Thursday how to make a 60-watt light bulb glow from an energy source 3 feet away. They did it while retaining 75 percent of the energy they started with, which is remarkably high efficiency. Their work built upon research unveiled last year out of the Massachusetts Institute of Technology.