Stardate 20010914.1003 (On Screen): The detectors currently used at airports are actually rather crude. The one you walk through is really little more than a big coil. It's looking for large conductors. When you put a conductive material into an operating inductor, the magnetic field sets up eddy currents in the conductor, which feeds back to the inductor's magnetic field -- and changes it. This can be detected by the electronics driving the coil and if the change is too great it sets off a buzzer and a light. But it doesn't work for insulators like plastic or ceramic. The new detectors use different principles; one technique which uses a very low level X-ray scan is actually looking for objects which are dense irrespective of whether they conduct electricity. Not only will it detect such objects but it will actually image them quite closely.
This raises concerns, naturally, about our Fourth Amendment right to be secure against unreasonable searches without probably cause. I don't think it's a problem, actually. If it were not possible to go through life without being searched, then that would be unreasonable. But no-one actually has to ride on a jet, and it's clear now that there is a substantial danger for the passengers and for everyone else associated with not doing adequate security for jets. I don't see any constitutional issues here; if someone doesn't want to be subjected to this kind of security scan, let them take a train or a bus or a boat or a car. (Also, the security scan is not being done by the government; it's being done by the airlines themselves as a condition of buying a ticket. As such, the Fourth Amendment doesn't even apply, since it bans the government from performing searches.) (discussion in progress)
