A bed of nails is an oblong piece of wood, the size of a bed, with nails pointing upwards out of it. [1] 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. [2]
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. [3] : 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; [4] 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 used by some for meditation, particularly in Asia, and for certain alleged health benefits, such as back pain relief, through acupressure. [5]
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.
A hammer is a tool, most often a hand tool, consisting of a weighted "head" fixed to a long handle that is swung to deliver an impact to a small area of an object. This can be, for example, to drive nails into wood, to shape metal, or to crush rock. Hammers are used for a wide range of driving, shaping, breaking and non-destructive striking applications. Traditional disciplines include carpentry, blacksmithing, warfare, and percussive musicianship.
In North America, a sideshow is an extra, secondary production associated with a circus, carnival, fair, or other such attraction.
Pressure cooking is the process of cooking food under high pressure steam and water or a water-based cooking liquid, in a sealed vessel known as a pressure cooker. High pressure limits boiling and creates higher cooking temperatures which cook food far more quickly than at normal pressure.
Bernoulli's principle is a key concept in fluid dynamics that relates pressure, speed and height. Bernoulli's principle states that an increase in the speed of a fluid occurs simultaneously with a decrease in static pressure or the fluid's potential energy. The principle is named after the Swiss mathematician and physicist Daniel Bernoulli, who published it in his book Hydrodynamica in 1738. Although Bernoulli deduced that pressure decreases when the flow speed increases, it was Leonhard Euler in 1752 who derived Bernoulli's equation in its usual form.
Recoil is the rearward thrust generated when a gun is being discharged. In technical terms, the recoil is a result of conservation of momentum, as according to Newton's third law the force required to accelerate something will evoke an equal but opposite reactional force, which means the forward momentum gained by the projectile and exhaust gases (ejectae) will be mathematically balanced out by an equal and opposite momentum exerted back upon the gun.
Hydraulic rescue tools, also known as jaws of life, are used by emergency rescue personnel to assist in the extrication of victims involved in vehicle accidents, as well as other rescues in small spaces. These tools include cutters, spreaders, and rams. Such devices were first used in 1963 as a tool to free race car drivers from their vehicles after crash.
Archimedes' principle states that the upward buoyant force that is exerted on a body immersed in a fluid, whether fully or partially, is equal to the weight of the fluid that the body displaces. Archimedes' principle is a law of physics fundamental to fluid mechanics. It was formulated by Archimedes of Syracuse.
A siphon is any of a wide variety of devices that involve the flow of liquids through tubes. In a narrower sense, the word refers particularly to a tube in an inverted "U" shape, which causes a liquid to flow upward, above the surface of a reservoir, with no pump, but powered by the fall of the liquid as it flows down the tube under the pull of gravity, then discharging at a level lower than the surface of the reservoir from which it came.
A lifting bag is an item of diving equipment consisting of a robust and air-tight bag with straps, which is used to lift heavy objects underwater by means of the bag's buoyancy. The heavy object can either be moved horizontally underwater by the diver or sent unaccompanied to the surface.
Levitation is the process by which an object is held aloft in a stable position, without mechanical support via any physical contact.
Newton's cradle is a device, usually made of metal, that demonstrates the principles of conservation of momentum and conservation of energy in physics with swinging spheres. When one sphere at the end is lifted and released, it strikes the stationary spheres, compressing them and thereby transmitting a pressure wave through the stationary spheres, which creates a force that pushes the last sphere upward. The last sphere swings back and strikes the stationary spheres, repeating the effect in the opposite direction. The device is named after 17th-century English scientist Sir Isaac Newton and was designed by French scientist Edme Mariotte. It is also known as Newton's pendulum, Newton's balls, Newton's rocker or executive ball clicker.
The Jim Rose Circus is a modern-day version of a circus sideshow. It was founded in Seattle in 1991 by Jim Rose and his wife BeBe Aschard Rose. The sideshow, then called the "Jim Rose Circus Sideshow", came to prominence to an American audience as a second stage show at the 1992 Lollapalooza festival. although they had toured the Northwest and Canada and had several US TV appearances before this time. Rolling Stone magazine called the show an "absolute must-see act" and USA Today termed Rose's troupe "Lollapalooza's word-of-mouth hit attraction".
Memory foam consists mainly of polyurethane with additional chemicals that increase its viscosity and density. It is often referred to as "viscoelastic" polyurethane foam, or low-resilience polyurethane foam (LRPu). The foam bubbles or ‘cells’ are open, effectively creating a matrix through which air can move. Higher-density memory foam softens in reaction to body heat, allowing it to mold to a warm body in a few minutes. Newer foams may recover their original shape more quickly.
A subungual hematoma is a collection of blood (hematoma) underneath a toenail or fingernail. It can be extremely painful for an injury of its size, although otherwise it is not a serious medical condition.
Standup paddleboarding (SUP) is a water sport born from surfing with modern roots in Hawaii. Standup paddleboarders stand on boards that are floating on the water and use a paddle to propel themselves through the water. The sport was documented in a 2013 report that identified it as the outdoor sporting activity with the most first-time participants in the United States that year. Variations include flat water paddling, racing, surfing, whitewater SUP, yoga, and fishing.
A wheelchair is a mobilized form of chair using 2 or more wheels, a footrest and armrest usually cushioned. It is used when walking is difficult or impossible to do due to illnesses, injury, disabilities, or age related health conditions.
Algodoo is a physics-based 2D freeware sandbox from Algoryx Simulation AB as the successor to the popular physics application Phun. It was released on September 1, 2009 and is presented as a learning tool, an open ended computer game, an animation tool, and an engineering tool.
Johnny Strange, nicknamed "the man with ears of steel", is an English world record breaking performance artist, producer, street performer and bestselling author based in London, England. He is known for performing daredevil stunts with a comedic twist.
Stencyl is a video game development tool that allows users to create 2D video games for computers, mobile devices, and the web. The software is available for free, with select publishing options available for purchase. The software was originally called "StencylWorks" while in development and for the initial release but was later shortened to just "Stencyl".
Brad Byers is an American entertainer known for his extreme performances, including sword swallowing, lying on beds of nails and inserting various tools into his nasal cavity. For the latter he is also referred to as a "Human toolbox". He holds several World Records. His brother Rod assists him in some performances.