Resources
Beds of Nails and Indestructible Balloons
In India, fakirs and phony holy men pretend that they have special powers giving them the ability to sit and lie on beds of hundreds of sharp nails without coming to any harm.
A variety of explanations is given for why this is possible. The fakir's incredible concentration allows him to balance on the nails. Mind over matter helps overcome the incredible pain. He is levitating, slightly, over each nail.
The truth is much more interesting.
So why does this work?
In science, pressure is a force that is divided by the area it is being applied to.
The greater the area the force is applied to, the lower the pressure. That's why you can pop a balloon with a pin (small area) but not a banana (large area)
If a 100kg man was to stand on a single face up nail, it would go straight through his foot because 100kg of pressure would be pushing down on the sharp spike.
If the same man lay down on 1000 nails, he would not be hurt because now, only 100 grams is pushing down on each nail.
You can try this yourself without the hassle or potential injury of a bed of nails. You will need
- 10 balloons
- A large table
- A friend to help
- Double stick tape.
Flip the table upside so that it's legs point up in the air and gently place the table on the balloons. They will not pop because the weight of the table is spread evenly over the 10 balloons.
With your friends help, carefully stand on the table near the centre. The balloons will not pop.
Not only is the pressure evenly spread over the 10 balloons but, as more force is applied, the balloons squash creating an even greater surface area for the force to be applied to.
Try and pop a balloon with a pin. and you'll find it requires very little force. Try and pop a balloon with your finger and you'll find much more force is required!
