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EARTHDATE: November 19, 2006

Official News - page 7

REAL LIFE NEWS: RECHARGE YOUR GADGETS WITHOUT WIRES

by Hazed

Just occasionally, scientists come up with a breakthrough that makes you go "wow" at the realization that this could really change your life. Here's one that could see the end of the tangle of cables and plugs and connectors that you need to recharge your electronic gadgets - wireless power.

US researchers have outlined a relatively simple system that could deliver power to devices such as laptop computers and MP3 players wirelessly. You'd walk into your home or office and they would immediately start to recharge. How efficient is that!

The concept exploits physics that is a century old. The recharging could work over distances of "many meters", the researchers said, and although they haven't yet built or tested such a system, computer models and mathematics suggest it will work.

The way it works is to use resonance, which is the phenomenon that causes an object to vibrate when energy of a certain frequency is applied. You can see this most obviously in musical instruments - play a tune on one instrument and another with the same acoustic resonance will vibrate in sympathy.

Instead of using acoustic vibrations, the team's system exploits the resonance of electromagnetic waves (these include radio waves, infrared and X-rays). Usually, systems that use electromagnetic radiation, such as antennas, are not suitable for the efficient transfer of energy because it gets scattered in all directions which is very wasteful. To overcome this problem, the team has come up with a special class of objects which, instead of allowing the energy to escape into space, forms "tails" of energy many metres long that flicker over the surface. Bring another resonant object with the same frequency close enough and the energy can tunnel from one to the other.

It's an exciting idea!

This is not the first time wireless energy transfer has been suggested. You probably use one form of it in your home if you have a rechargeable electric toothbrush, which uses electromagnetic induction. This method has also been used by a company called Splashpower to produce wireless recharging pads - you just put your phone or i-Pod onto the pad to recharge it.

Nineteenth-century physicist and engineer Nikola Tesla experimented with long-range wireless energy transfer but his most ambitious attempt - the 29 metre high aerial known as Wardenclyffe Tower in new York - failed when he ran out of money. Nobody has been able to duplicate what he claimed to have achieved so the jury is still out on whether he was a genius or a madman.


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