{{verify|date=April 2024}} {{Short description|Large piece of wood with nails pointing upwards from it}} {{Other uses}} thumb|A bed of nails [[File:Sem medo da cama de pregos.jpg|thumb|Children on a bed of nails used for science popularization in Brazil]]
A '''bed of nails''' is an oblong piece of wood, the size of a bed, with nails pointing upwards out of it.<ref>{{cite web|url=http://phun.physics.virginia.edu/demos/nail_bed.html |title=Phun Physics – Demonstrations |archive-url=https://web.archive.org/web/20180927225358/http://phun.physics.virginia.edu/demos/nail_bed.html |publisher=Phun.physics.virginia.edu |archive-date=2018-09-27}}</ref> While it appears at first glance that anyone lying on such a "bed" would be injured by the nails, if the nails are numerous enough, the weight is distributed among them so that the pressure exerted by each nail is not enough to puncture the person's skin.<ref>{{cite web|last=Wilson |first=Tracy V. |url=https://entertainment.howstuffworks.com/arts/circus-arts/bed-of-nails.htm |title=HowStuffWorks "Lying on a Bed of Nails" |publisher=Entertainment.howstuffworks.com |date=2007-06-26}}</ref>
==Uses== [[Image:Bed of nails with cinder blocks.jpg|thumb|Magic trick with smashing cinder blocks placed on a "fakir"]]
One use of such a device is for magic tricks or physics demonstrations. For example, the bed of nails was used in vaudeville in the United States, as well as in sideshows of circuses and carnivals.<ref name="nickell">{{Cite book |last=Nickell |first=Joe |title=Secrets of the sideshows |date=2005 |publisher=University Press of Kentucky |isbn=0-8131-7179-2 |location=Lexington, Ky. |oclc=65377460|author-link=Joe Nickell}}</ref>{{rp|246}} A famous example requires a volunteer to lie on a bed of several thousand nails, with a board on top of him. Cinder blocks 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, resulting in reduced pressure;<ref>{{cite web|url=https://www.physics.ucla.edu/demoweb/demomanual/mechanics/first_law_inertia/bed_of_nails.html |title=Bed of Nails |publisher=Instructional Research Lab: UCLA physics |access-date=2024-08-23 |work=Lecture Demonstration Manual}}</ref> 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.
[[Image:Fakir on bed of nails Benares India 1907.jpg|thumb|Herbert Ponting's 1907 photograph of "a fakir in Benares" (Varanasi, India)]] thumb|A Hindu yogi on a bed of spikes, 1913
Less traditional settings, such as science centers, may use an electronic retractable bed of nails, where the user lies on a flat plastic bed with holes in it, and can then activate the machine to have nails rise up all at once. The nails should retract before getting off the bed. This retraction eliminates the most dangerous part of a traditional bed of nails, getting on and off the bed.<ref>{{Cite web |last=Bainbridge |first=Abby |date=2018-06-30 |title=Nailed It! |url=https://wonderlab.org/nailed-it/ |access-date=2024-08-23 |website=WonderLab |language=en-US}}</ref>
==See also== * Firewalking
==References== {{Reflist}}
==External links== * {{usurped|1=[https://web.archive.org/web/20040106181239/http://www.darylscience.com/Demos/BON.html The bed of nails in use as a school physics demonstration]}}. Darylscience.com
{{DEFAULTSORT:Bed Of Nails}} Category:Sideshow attractions Category:Asceticism Category:Nail (fastener)