DILUTE PORK

The sun emits not only light and other electromagnetic radia-tion, but also electrons and other elementary particles, especially during periods of elevated solar activity. When charged particles enter the magnetic field of the earth, their path is deflected by the rules of electromagnetism, essentially the same that deflect the electron beam in a picture tube of a TV set. Depending on their angle of arrival, velocity and the sign of their charge, the particles are deflected into paths spiraling round the globe toward the polar regions, and as they enter the atmosphere with high velocities, they will shock-ionize the atoms of the gases with which they collide. In a physical mechanism that is not drastically different from that in a fluorescent light, these atoms emit light that forms patterns known as the Northern Lights (aurora borealis).

As usual in nature, the total energy (of the charged particles, here) is vast, but its flux per unit area is very dilute; nevertheless, the ever-gluttonous fund raisers of academia managed to persuade Sen. Ted Stevens (R-Alaska) to push a DoD grant of $37 million for research at the U. of Alaska to harness some of this energy, and after a speech on the Senate floor of what this would do for mankind he got the cash for his constituents. He is now being ridiculed for this piece of pork, and the gluttons of the U. of Alas-ka have retrenched from research on an alleged energy source to touting general knowledge and the benefits to science (Science, 11/23/90)

That this is pure pork I won't deny, but Stevens, like most of his colleagues, is a lawyer; he is a victim of the fund raisers who talked him into it. A geophysicists's business is to study the physics of the globe and its environment; a Congressman's is to steal from the taxpayers. In today's close relationship between science and government, it is not surprising that their roles got interchanged.

Even so, at a paltry $37 million, the fantasy was a lot cheaper than the billions spent on the ozone, greenhouse, and acid rain hoaxes, which have been swallowed by hundreds of dummies whose Ph.D is not in law, but in geophysics.

And there is another interesting aspect to the scheme. There really is a gigawatt of energy in the aurora borealis, but it is spread over a vast area in the Arctic; it is many orders more dilute even than solar energy, which at 900 W/m2 at the earth's surface is itself too dilute to be used as a significant energy source unless it has a very large collecting area, such as agriculture. (This use of solar energy was discovered 10,000 years ago, strangely, without the help of any Department of Energy.) For smaller collecting areas such as rooftops, little energy is available: a solar water heater will not pro-vide many showers per day. When the collecting area is down to that of an aircraft wing or a car rooftop, the power developed is pitiful and not usable for driving as most Americans know it.

It is most difficult to make this point of indisputable numerical values sink in. The great solar car race across the Australian con-tinent is an interesting sports event and no small (or cheap) feat that I greatly respect as long as it is not palmed off as a step toward the development of a solar car for regular transportation. Until you get a new sun with a greater power flux (watts per square meter) there is nothing substantial to develop: the cars racing in Australia are already fairly close to the inherent limit imposed by the sun's dilute power flux, at least by the sun in this galaxy.

To see the point, take a look at the solar car by the Swiss com-pany Swatch. It won the 1800 mile race, outclassing 40 other com-petitors including those sponsored by General Motors and Honda. Its solar cells are 17% efficient, and after that fraction of the col-lected solar energy has been accumulated in a battery, it is con-verted to mechanical energy with an efficiency of 83%.

I unreservedly take off my hat to the Swiss engineers who achieved this feat of technology and to the drivers who crossed the grueling desert track in 6 days (47.5 hours net driving time).

So it is quite incidental to mention the car's cost: $700,000.