[julie_m]

Lighting a discharge tube wirelessly is fairly easy. Remember in an electric field of so many volts per metre, what that means is that is the voltage that will appear between two points a metre apart and perpendicular to the direction of travel of the wave. And close up to the antenna, most of the energy will be in the electric field; it takes about five or six wavelengths for the energy to reach equilibrium between electric and the magnetic fields. If the voltage is enough to strike up a discharge, then the tube will glow; the current will be limited by the power density in W/m2. It's just like the trick where kids dare one another to stand under a pylon holding a fluorescent tube vertically upright, or the less-spectacular version involving bending the leads of a high-brightness LED apart and holding it near a mobile phone while it is talking to the cell tower.

The problem is, it doesn't actually transmit very much power to the load, and the old inverse-square law prevents it from scaling well. It's a very impressive conjuring trick, but that's really all it is; it can't be turned into anything practical. And that is not a limitation of present technology, that can be overcome by inventing the right thing; rather, it is a fundamental limitation of the universe. If you were feeling suitably masochistic, you could do the maths for yourself and see why it won't work. You have to get at least 50 watts into a house just for a modest level of illumination in a couple of rooms, never mind appliances. If it gets hot for a living and is any bigger than a soldering iron, forget about it.

The idea of plentiful cheap or free energy is undeniably an alluring one, and there is no shortage of easily-impressed people who don't understand intermediate-level thermodynamics as well as they think they do -- nor con-artists looking for investments in perpetual motion machines they are building (curiously, none of them appear to be able to afford an alternator to couple to their inventions .....).