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Nokia Developed Wireless Power-Harvesting Phones
Al writes "An engineer from Nokia's UK research labs says that the company is developing technology that can harvest ambient electromagnetic radiation to keep a cellphone going. The researcher says that his group is working towards a prototype that could harvest up to 50 milliwatts of power — enough to slowly recharge a phone that is switched off. He says current prototypes can harvest 3 to 5 milliwatts. It will require a wideband receiver capable of capturing signals from between 500 megahertz and 10 gigahertz — a range that encompasses many different radio communication signals. Other researchers have developed devices that can harvest more modest power from select frequencies. A team from Intel previously developed a compact sensor capable of drawing 6 microwatts from a 1.0-megawatt TV antenna 4.1 kilometers away."
Crystal radio sets harvested enough power to drive an earphone-sized speaker.
In some circumstances, florescent light bulbs can draw enough power from a nearby power source to light up.
Knowledge is how to play a game, intelligence is how to win, wisdom is knowing what game to play.
Where do you put your mobile phone when not in use?
Exactly.
One that hath name thou can not otter
They are asking about radio, not noodles.
Shouldn't be too hard to harvest energy from changes of momentum and orientation, similar to how many mechanical watches have for years been able to wind themselves.
-- In the beginning was the WORD, and the WORD was UNSIGNED, and the main(){} was without form and void...
10 seconds on high should be plenty
I'll stop putting my phone in my pocket the moment someone proves that this "possible harm" is anything more than luddite hysteria.
Another great example as to how Tesla has shaped our future. Truly ahead of his time by leaps and bounds.
I know Tesla is a posterboy for the Slashdot community, but I think you mean http://en.wikipedia.org/wiki/Heinrich_Hertz. Hertz was responsible for the discovery that you could generate and detect radio waves.
That lead to the use of radio for communications, which is why such a modern device as the article describes. Tesla envisioned pumping energy into the air via dedicated stations. I don't think he envisioned a situation where we would be pumping so much energy into the air for communications, that there would be usable power as a byproduct.
I find it frightening, not "cool", that such a device is possible, given that my body relies on faint electrical signals.
Please help metamoderate.
It's called a lightning rod, although a clock tower and a sufficient length of cable will work in a pinch. Figuring out how to get lightning to strike a DeLorian while traveling at 88mph is left as an exercise for the reader.
Any insufficiently advanced magic is indistinguishable from technology.
This is useful knowledge to have. Imagine being lost and in need of rescue. If you could create a device that siphoned sufficient power from radio signals to reduce their range, not only would you have power for a beacon but also the FCC would take care of tracking down your location so that you'd stop doing it.
Oh, say does that Star-Spangled Banner entwine / The myrtle of Venus with Bacchus's vine?
no more so than a bunch of radios tuning in. If an antenna or chunk of metal is between you and a signal, your signal quality will be degraded. If not, you have a virtual line of sight (or LOS via reflections from the ground, buildings, etc) and can receive like normal. Its like worrying about your lawn receiving less light because your neighbor has solar panels on his roof. If the panels were between you and your lawn, it wouldn't matter if they were generating power, or just made of plywood, your lawn would be in the shade, but since they're not, your grass will be just as green. Its not like these antennas suck up the power, it won't bend the radio waves towards it like a magnetic pole would affect magnetic fields.
Is it sad that I am more likely to recognize you and your posts by your sig than your name or UID?
I call BS on the phone call. I think your prof may have been pulling your legs. For one thing, 60 watts is a drop in the bucket compared to megawatt transmitters, for another, radio waves behave like light waves, there isn't a return loop or any sort of return transmission involved in radio waves.
Its not like these antennas suck up the power, it won't bend the radio waves towards it like a magnetic pole would affect magnetic fields.
Well, actually they do. It's not at all significant in the grand scheme of things, but antennas do affect (reduce) the signal in the area near them. Antenna designers refer to an antenna's "aperture", the effective area in space from which it can "suck" signal. This is a very abstracted view, but is a useful analogy to understand how antennas affect electromagnetic waves passing near them. It is as if your power-sucking cell phone device creates a radio shadow a couple feet in diameter, instead of only the size of the antenna. Fortunately, the effect only extends a few wavelengths from the antenna at most (the so-called near field region) and has absolutely no impact on receivers outside that space.
I am a geek attorney, but not your geek attorney unless you've already retained me. This is not legal advice.
This is an easy project for a 16 year old provided mummy or daddy is a full professor of physics at Stanford.
From scarped cliff or quarried stone she cries "A thousand types are gone, I care for nothing, no not one."