Lightning, says Daedalus, is universal. Not only are there about a thousand thunderstorms going on around the Earth at any one time, but lightning has been observed in the atmospheres of other planets, with different chemistry from that of Earth. The complex organic molecules built up by earthly lightning, precursors of life itself, should therefore exist on other planets. They may have given life a start there too.

Daedalus can think of two bases for lightning. First, phase changes, like that of water going to ice, must extrude charge. No solution or melt can have the same electron affinity as the solid, so a solidifying droplet must push charge ahead of the solid front. Second, any charged gas must expand, by self-repulsion. A big enough voltage (150 megavolts for air) would give a vacuum; smaller charges, of just a few megavolts, would merely provide strong lift. So solidification of any sort, coupled with charge sharing to an atmosphere, must give rise to convection. Couple this with a feedback mechanism, such as the return of charge in falling raindrops that partly freeze, and you soon build up enough charge separation for lightning.

To test these ideas, DREADCO physicists are building a large-scale lightning machine. They are starting with a hollow cooling tower. At the top, water will be sprayed down it from perforated pipes. It will lose heat and should partly freeze. The charge thus generated will be expelled into the remaining liquid. This should pass on charge to the surrounding air, which will expand and rise in its turn. At the top of the tower, copper electrodes will capture charge from the rising air and return it to the falling drops. In this way the tower will build a charge separation. It may also be done with brine. Brine is a conductor, but its freezing expels solid, insulating salt. Again, the physicists will look for the accumulation of charge. Any surplus high-voltage electricity from the tower will be bled from its top for use.

Sadly, Daedalus's tower may not generate much power. Even a full-scale thunderstorm only creates some 20 gigawatts. But he hopes to identify the aeroelectric processes that are important in lightning, on Earth or on other planets. The expansion of charged gas, and its resulting speed of uplift, are well worth knowing; so is the feedback of charge by falling drops. Both may help us to understand the biochemistry of other planets.