A couple of years ago, Italian car owners started hanging CDs from their rearview mirrors, as if compelled by some crazy fashion.
The first time I saw this, I opened my mental notebook labeled "stupid human tricks" and wondered why your average driver would trade a nice, pine shaped air freshener with a 11.5 cm disk of iridescent aluminium.
I came up with three reasons, which were quite sensible, fit the observed facts and were completely wrong. Even the resident cynic that usually supervises my thought processes didn't think of the fourth (and real) reason.
Relax. Streets are full of dangers. A properly-oriented CD can block a sizeable part of your field of view, preventing you from seeing at least some of those dangers. It's a well-known fact that the less perils you see, the more peaceful you feel (this is known as the Joo-Janta effect).
Entertainment. Our brains have evolved from those of small furry animals. From an animal point of view, a moving object might mean that food is coming. Consider your average cat: he is far more interested in a squeaky, fast-moving mouse rather than in a 12-ton semi slowly approaching from the wrong lane.
Masochism. What, you still have to fulfill your headaches quota for this month? Don't worry, a shiny object flashing brain-splitting reflections of the sun is guaranteed to give you the mother of all migraines.
Truth is far stranger: all those people were trying to fool speed traps.
Some unsung genius had apparently made a deliciously illogical connection:
- CDs are read by laser light.
- Speed traps work by flashing a laser light at incoming cars.
- Therefore, ehm, the reflecting surface of the CD will interfere with the Lidar gun.
I am not making this up.
I learned about the fourth reason by watching the news on TV (during particularly slow summers, when there are no wars or murders, Italian networks usually pad the newscast with "curious" items).
The reporter interviewed a policeman who debunked the urban legend about CDs, and even showed some tests where CD-protected speeding cars were caught by the Lidar.
The interview tickled some conspiracy theorists, who reasoned that "if they take time to debunk it, it must be true". Maybe they visualized a Lidar gun softly broadcasting the latest Spice Girls hit, to the utter bafflement of the policemen. The percentage of "protected" cars soared.
A couple of years later this foolish practice disappeared, after reaching absurd peaks: I received an e-mail with the photo of a truck whose rear window was literally framed by CDs.
Needless to say, the photo had been taken by a speed trap.