Aluminium foil foil rolling mills to the desired thickness, or by continuously casting and cold rolling. To maintain a constant thickness in aluminium foil production, beta radiation is passed through the foil to a sensor on the other side. If the intensity becomes too high, then the rollers adjust, increasing the thickness. If the intensities become too low and the foil has become too thick, the rollers apply more pressure, causing the foil to be made thinner. The continuous casting method is much less energy intensive and has become the preferred process. For thicknesses below , two layers are usually put together
Tin foil hat telepathy. Some people have a belief that such hats prevent mind control by governments, spies, or paranormal beings that employ ESP or the microwave auditory effect. People in many countries who believe they are "targeted individuals" (TIs), subject to government spying or harassment, have developed websites, conference calls, and support meetings to discuss their concerns, including the idea of protective headgear. Over time the term "tin foil hat" has become associated with paranoia and conspiracy theories. The notion that a metal foil hat can significantly reduce the intensity of incident radio frequency radiation on the wearer's brain has some scientific