Tin foil hat radio with a metal bucket. The AM radio is completely inside a metal enclosure. This leads to a noticeable reduction in signal strength received by the AM radio. The efficiency of a metal enclosure in blocking electromagnetic radiation depends on the thickness of the foil, as dictated by the "skin depth" of the conductor for a particular wave frequency range of the radiation. For half-millimetre-thick aluminum foil, radiation above about 20 kHz (i.e., including both AM and FM bands) would be partially blocked, although aluminum foil is not sold in this thickness, so numerous layers of foil would be required
Foil (fencing) torso, where the vital organs are. In 1896, foil (and saber) were included as events in the first Olympic Games in Athens. Women's foil was first competed at the Olympics in 1924 in Paris, and was the only Olympic fencing event in which women competed until women's epeé was introduced at the 1996 Olympics. Nowadays, women's fencing is just as popular as men's, and consists of all weapons (foil, epee, and sabre). Ratings exist in order to separate different level fencers from each other in order to create an even-playing field. A higher ranking is earned by performing well at