Bed of nails 2849673 186249747 2008-01-23T01:22:32Z Quintote 1613101 Moved electronic reference to a {{ for }} template at top of article {{ For|the device used to test printed circuit boards|bed of nails tester }} A '''bed of nails''' is typically an [[oblong]] piece of wood, the size of a bed, with [[nail (engineering)|nail]]s pointing upwards out of it. It appears to the spectator that anyone lying on this "bed" would be injured by the nails, but this is not so, assuming the nails are numerous enough, since the weight is distributed between them such that the force exerted on each nail is not enough to break the person's skin. One use of such a device is for [[magic (illusion)|magic tricks]] or [[physics]] demonstrations. A famous example requires a volunteer to lie on a bed of several thousand nails, with a board on top of him. [[Cinder block]]s are placed on the board, and then smashed with a [[sledgehammer]]. Despite the seemingly unavoidable force, the volunteer is not harmed: the force from the blow is spread among the thousands of nails, and the breaking of the blocks also dissipates much of the energy from the hammer. This demonstration of the principles of weight distribution requires that the weight of the volunteer be spread over as many nails as possible. The most dangerous part is the moment of lying down or getting up, when one's weight may briefly be supported on only a few nails. Some "beds" have rails mounted at the sides to help users lie down and get up safely. The bed of nails is also used by some for [[meditation]], particularly in [[India]] and other parts of [[Asia]]. [[Image:Nagelbrett ganz.jpg|thumb|bed of nails]] [[Image:Nagelbrett Ausschnitt.jpg|thumb|zoomed]] ==External links== *[http://www.keypoint.com.au/~skeptics/Bed_of_Nails Australian Skeptics] -- how the bed of nails works and how to make one *[http://www.darylscience.com/Demos/BON.html DarylScience's E-World ] -- the bed of nails in use as a school physics demonstration [[Category:Circus skills]] [[he:מיטת מסמרים]] [[sv:Spikmatta]]