The geomagnetic field is said to influence psychiatric hospital admissions — though whether it acts on the patients or the diagnostic skill of the admissions staff is not clear. And numerous permanent-magnet health gadgets are sold to those neurotics still at large. How can they work?

Daedalus reckons they stir the fluid axoplasm in the nerves. When a nerve fires, the axoplasm ions move radially. A magnetic field would deflect positive ions in one direction and negative ones in the other, stirring the fluid. And last week Daedalus decided that axoplasmic stirring greatly aids neural adjustment and learning. It speeds the delivery of material needed to update the information held by a synapse.

This makes excellent evolutionary sense. Even in the weak geomagnetic field, the more often a nerve fires, the faster its axoplasm will be stirred. The more it has to learn, the more its learning will be encouraged. Magnetic health gadgets may well help the nerves to adapt to local trouble, reducing pain or weakness.

So Daedalus is improving their design. His new resonant magnetic stimulator has a field reversing at 400 Hz. It thus reverses once during the typical firing-time of a brain nerve. This will stir the nerve powerfully: ions displaced during their outward movement will be displaced even further during their return flow. The axial flow of the axoplasm will be far more vigorous, speeding the nerve's adaptation.

The big use of the tuned stimulator, however, will not be in pain relief, but in education. Our vastly extended childish learning period is no longer adequate. Education fills our entire childhood, and much of young adulthood as well. It is, of course, largely a protection racket, designed to deny young people jobs they could learn perfectly well without the pointless paper ‘qualifications’ it forces them to waste years acquiring.

But with Daedalus's 400-Hz magnetic hat, they could outwit the system. They wouldn't think any faster; but their brains would be updated twice as fast. They would learn at twice the rate, and finish their education by the age of 10 or so, before puberty steps in. They would no longer turn into truculent teenagers, sexually mature adults resentful at their continued dependency; they could find work, marry, and become useful citizens, as they did in pre-technological society. And the malign youth culture which now exploits their plight would wither mercifully away.