This history will necessarily be incomplete given the fact that binging “tin foil hats” came up with 14.7 million hits. Even I am not that curious. The tinfoil hat was first mentioned in a 1927 Julian Huxley science fiction story ” in which the protagonist discovers that “caps of metal foil” can be used to block the effects of telepathy.”

The Urban Dictionary defines a tinfoil hat as the “Number 1 fashion accessory for unemployed conspiracy theorists around the world!” Hey, what about the employed conspiracy theorists? Tinfoil hats are now associated with paranoid conspiracy theorists everywhere. Some people think that they will prevent the government from controlling their minds. In popular culture the 2002 movie Signs popularized the tinfoil hat.

The scientific name for a tinfoil hat is a Faraday Cage. In 1936 Faraday discovered that foil blocks the transmission of certain radio waves. The ability of the foil to deflect radio waves depends on its thickness. The tin foil hats made by most amateurs are clearly not thick enough to maximize their deflective properties. FYI-You need at least half-millimeter thick foil for good results. I personally will be using the phrase, “Did you forget your Faraday Cage?” as a way to introduce science back into our daily discussions.

The tinfoil hat phenomenon has been studied by graduate students at MIT, and the National Ground Intelligence Center.

During the Cold War, electromagnetic hearing was clinically studied in the United States for applications including covert message transmission and use as a non-lethal weapon. As a declassified National Ground Intelligence Center document points out:

It may be useful to provide a disruptive condition to a person not aware of the technology. Not only might it be disruptive to the sense of hearing, it could be psychologically devastating if one suddenly heard “voices within one’s head.”

Odd that the voices one seeks to block may actually be induced by the wearing of the very same gear. There’s a conspiracy right there.

For DIYers, has a web page on how to make your very own tinfoil hat. For the patriotic or tea party readers there are separate instructions on how to make a trifold hat. Under tips and warnings is this:

It is very important for the shiny side of the aluminum foil to be showing when the hat is complete to make sure it is effective against alien rays or mind control signals.

Electech has a not to be missed video featuring The Tinfoil Hat Song.

My own version is to take thin twisted strips of tinfoil and work them into my braids. I’ll let you know if and when I hear voices.