Monday, 14 March 2011

Fire Walking

Fire walking is a remarkable spectacle and looks very dangerous. So how does it work when it is obviously not a case of mind over matter or anything paranormal?

The key lies in the very poor thermal conductivity of the charcoal.  As long as you only touch the charcoal, however hot it is, the surface cools so quickly that it does not burn you, and the heat is not conducted from inside the charcoal to the surface quickly enough to be a problem.

By analogy it is like a cake in a tin in the oven.  You can touch the cake with your fingers to see whether it is cooked, but even touching the tin for the briefest possible moment you will be burnt.  Haven't we all done that?

Mind you - even understanding all that I'm not sure I want to try fire walking.


Julie Mellors said...

I think baking a decent cake would be harder than fire walking. Definitely the more appreciated skill!

Kenny Wyland said...

There is a great episode of Mythbusters which covers this in depth. It's also important to walk _calmly_ across the coals, because if you try to rush you end up slamming your foot down and the coal will stick to your foot. It's poor heat conductivity only matters if you are in contact for short periods of time. If the coal sticks to your foot, it gets longer to conduct and the heat transfers and BOOM! You've got a burn. :)

Derby Sceptic said...

Those firepits they use are both narrow and short. Common sense says walk round it and be assured of no burns to the feet!