What is the Science Behind Wireless Power Demonstrations?

[swanee22]

Several years ago, I was at a science/art exhibit in Los Angeles where a box was on a pedestal and it had a couple hundred jellybean sized light bulb-type things in it. They appeared to be just a filament in a glass encasement. When they were just sitting in the box, they were dark, however, when you put your hand in the box, the ones nearest your hand lit up. IN fact, you could scoop up a hand full and hold them as much as 8-10 inches above the box (if I remember correctly) and they would be alight in your hand. I don't remember standing on a platform of any kind, but it is possible. I don't recall them being florescence-based bulbs but that is possible. I would like to recreate that, but I don't know what it is called, or even how it was accomplished. Any insight or assistance would be GREATLY appreciated.

Rob Swanson

 

[0xDEADBEEF]

I do have an idea how this could work. But I am not sure how save it is. So maybe it is not what they did. If you have a strong radio emitter, or maybe even a near field device, and then you have a little antenna or induction coil in the bulb that is off resonance. Touching it with you hand which is a big dielectric medium, could shift the resonance frequency enough for the antennas to become resonant, and receive energy from the field.
As far as I remember there was an idea by Nikola Tesla to supply the whole world with energy through radio emission, instead of copper wire. And I think he build a prototype that illuminated the world exhibition in Paris, with nothing but a strong radio emitter and small antenna stubs on the contacts of the light bulbs.
But you should do calculations on the sensitivity of an Antenna to off resonance radio waves, and to the currents that you can produce. You don't want to fry peoples fingers because their wedding ring happens to hit the resonance too.

There is the rumor that holding a Fluorescent tube when you are standing next to a radio station or power lines will make the tube light up. For similar antenna reasons.
http://www.treehugger.com/files/2008/02/emf_richard_box.php
http://www.doobybrain.com/2008/02/03/electromagnetic-fields-cause-fluorescent-bulbs-to-glow/
http://www.bbceng.info/Operations/transmitter_ops/Reminiscences/Woofferton/Woofferton_2.htm

Another possible way would be to use the skinning Effekt. If you put someone under high voltage at very high frequencies, the electricity will be conducted by the outer layer of the skin http://en.wikipedia.org/wiki/Tesla_coil#The_.27skin_effect.27_and_high_frequency_electrical_safety
But cannot think of a good setup to make this work.

 

[mgb_phys]

The same thing is used to power the RFID tags on things like gas pump and toll bridge speedpay devices.