Tin foil hat to achieve this effect. A belief also exists that aluminum foil is a protective measure against the effects of electromagnetic radiation (EMR) for many unspecified EMR frequencies. Despite some allegations that EMR exposure has negative health consequences, no published experimental scientific evidence has established that tinfoil hats are effective. In 1962, Allan H. Frey discovered that the microwave auditory effect (i.e., the reception of the induced sounds by radio-frequency electromagnetic signals heard as clicks and buzzes) can be blocked by a patch of wire mesh (rather than foil) placed above the temporal lobe. Foil hats have appeared in the films
Foil (fencing) Olympics, although some organizations still fence competitively with non-electric swords. Foil have standardized, tapered, quadrangular (rectangular) blades that are made of tempered and annealed, low-carbon steel—or maraging steel as required for international competitions—and are designed to bend upon striking an opponent in order to prevent both injuries and breakage of the blade. The foil blade is no more than 90 cm in length with a blunted (or "foiled") tip, the maximum length of the assembled weapon is 110 cm, and the maximum weight is 500g; however, most competition foil are lighter, closer to 350g. The blade itself is subdivided into