Physicists Promise Wireless Power

StrongGlad writes "The tangle of cables and plugs needed to recharge today's electronic gadgets could soon be a thing of the past. Researchers at MIT have outlined a relatively simple system that could deliver power wirelessly to devices such as laptop computers or MP3 players. In a nutshell, their solution entails installing special 'non-radiative' antennae with identical resonant frequencies on both the power transmitter and the receiving device. Any energy not diverted into a gadget or appliance is simply reabsorbed. The system currently under development is designed to operate at distances of 3 to 5 meters, but the researchers claim that it could be adapted to factory-scale applications, or miniaturized for use in the 'microscopic world.'"

Comments

Re:Loss

[jimstapleton]

Actually, the ironic thing is, if this is using Tesla's principles, it's extremely efficient. Maybe not as much as copper wire, but still rather higher than would be expected.

Re:Am I missing the point here...

[Apocalypse111]

Even cell phones are proved to cause cancer...

No, they're not. Cellular phones don't emit ionizing radiation, all their communications happen in the microwave band. This is not powerful enough to cause cell damage on its own. The thermal effects raise cell temperature a fraction of a degree on the surface of the head (an order of magnitude less than the change experienced by standing in sunlight), and the non-thermal effects show no rigorous evidence of genetic damage. Now, near a base station, the situation is a little different, but don't try to scare John Q. Citizen with unfounded FUD about cellular phones causing cancer.

More info here.

RTFA??!?!?

[EComni]

Maybe the summary got edited to take out the word "discovered", but too many people are chiming in with "Tesla did it!". From the article itself:

...
US researchers have outlined a relatively simple system that could deliver power to devices such as laptop computers or MP3 players without wires.
The concept exploits century-old physics and could work over distances of many metres, the researchers said.
...
Old technology
The team from MIT is not the first group to suggest wire-less energy transfer.
Nineteenth-century physicist and engineer Nikola Tesla experimented with long-range wire-less energy transfer, but his most ambitious attempt - the 29m high aerial known as Wardenclyffe Tower, in New York - failed when he ran out of money.

Yes. Tesla did it. We know it. The article knows it and states it plainly. The credit has been given. So can we discuss the actual feasibility for short distances, now?

Re:That would be really cool to see...

[smellsofbikes]

Ummm ... I don't know if you're really unaware of physics here, but if you stick a mouse in a microwave and turn the power to 11, the mouse sort of dies.

The absorption frequencies of DNA might not specifically match cellphone radiative frequencies, but high-power microwave radiation absolutely is dangerous to living tissue. Water absorbs very nicely at most microwave frequencies, and thermally-induced damage to water-containing tissues means the cell has to repair the damage. The thermal damage may be to the DNA, and it may be just to random proteins in the cell, but either way the cell has to start translating/transcribing, and when DNA is unravelled and depaired for transcription, there's a much greater chance of damage to the DNA happening from random processes, free radicals, stuff like that.

The question is: does sufficient damage happen to living tissue from radiation at the frequency and power density seen in cellphones, and I don't think anyone has positively answered that question yet.