Cut the cord

Demonstrating the ability to turn on a lightbulb is not usually the sort of thing to elicit a gasp of amazement from the world's technophiles.

But when Justin Rattner, computer giant

technology chief, flicked the switch on a 60W bulb at the firm's recent developers' forum, that was precisely the reaction he achieved.

For while lightbulbs usually dangle from a ceiling fitting or are screwed into a lamp, this one was powered wirelessly by a strange looking device placed several metres away. It was, claimed Rattner, the latest development in a journey that could one day complete our transition to a 'wireless world', enabling us to say goodbye to the power cable and charge everything from our mobile phones to our laptops simply by walking into a room.

Intel's so-called Wireless Resonant Energy Link (WREL) exploits the phenomenon of resonant coupling, where an object is caused to vibrate when energy of a certain frequency is applied. The concept is analogous to the effect that enables opera singers to shatter glasses of corresponding frequencies, while others remain intact.