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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.
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.
It's more an electrochemical signal, though, not really anything to do with the energy of radio waves. It's electrical in the sense that it's charged (ions), not in the sense that there's an actual stream of electrons moving along like wires.
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.