The Mystery of How to Lie on a Bed of Nails: Proverbial Indian Trick

.Herbert Ponting took a photograph of a Hindu fakir or sadhu in 1907. This man was a yogi who had perfected the control of mind over body and as such could withstand pain to his body as a routine. The Fakir sat on a bed of nails completely oblivious to any pain the nails might cause him. The question that must be answered is whether the fakir was doing something extraordinary or it was something which could be done by others. The practice of lying on a bed of nails and meditating has perhaps originated from India. The practice however has a perfect scientific explanation and with a little bit of practice can be done by anyone. It is advisable to have a look at Newton's third law of motion and the principle of pressure in physics. Newton's third law states that to any action there is a reaction.

 Thus when a man lies on a bed of nails he exerts a pressure on the nails, which in turn exert a pressure back on the man. The principle of pressure brings out that nails exert a pressure proportional to the area. Thus a single nail when pressed by a foot is likely to pierce the skin and enter the body. This is because the pressure of the nail is concentrated at one point on the human body. But when there are a large number of nails and an entire body lies down on them, the pressure is distributed and the nails do not enter the body. There is a well known equation which is derived from Newton's laws which states that pressure is equal to force divided by area. 

If all the nails are uniformly placed the force will get distributed, but even if one nail is not synchronized than it will pierce the skin as the entire pressure of the body comes down on that one nail. The clue to sleeping or lying down on a bed of nails is to distribute the pressure evenly. In such a case the act of the Hindu sadhu will not` be an enigma. An interesting way is to check the pressure exerted by a nail. In case it can be wired to a gauge one can work out how much pressure a nail exerts. The trick is to press your finger on the nail up to point where it does not puncture your skin. In case the pressure exerted by one nail is one pound, then 200 nails will exert a pressure of 200 pounds. 

Thus for a man weighing 200 pounds, 200 nails evenly spread on a board will not pierce the skin and the man can safely lie on the board with the nails. The nails must however have a uniform surface and be similar to each other. No nail must protrude out as then the laws of physics will not apply. The clue to emulating the feat of the Hindu fakir is to ensure that a man's weight is evenly distributed on the bed of nails.