Friday, July 4, 2008

How Firewalking Works?

I would like for you to imagine the following situation: You get a call one day offering you the chance to win a million bucks. It's a new reality show that takes ordinary people and asks them to do extraordinary things. All that you have to do to win $1 million is a little firewalking -- simply saunter across a bed of burning coals on live TV.


Photo courtesy The Florida Pagan Gathering

Would you do it? Firewalking is one of those strange things that lots of us wonder about -- people seem to be able to do it without getting burned. But could just anybody do it? Is there some kind of gimmick that makes firewalking possible?

If you ever watch a firewalking event on TV or in a movie, you know that what you always see is a large, glowing bed of burning coals. The bed may be 10 feet long or so. And the glowing coals are real. People actually do walk across the red coals in bare feet. The firewalker makes his way across the coals as though by magic. How is this possible, and can any other person do it just as easily?

In this article, you will learn exactly how "firewalkers" walk across a bed of glowing coals without getting burned!

Firewalking Events

First of all, there is no gimmick to firewalking. It is not like a firewalker soaks his feet in water before going across the coals. And it is not like some extreme sweat reaction happens and his feet are suddenly soaked in sweat. His bare feet really do touch the red-hot coals.

What makes this possible is a combination of factors that play on certain qualities of the coals themselves...

Think about this. Let's say you took a 10-foot long iron plate and heated it up red-hot with blow torches. Now you walk across that. What would happen?

Walking across a red-hot metal plate would be insane. Think about a hamburger when it hits a hot iron skillet. Bare feet on red-hot metal would give you third-degree burns in milliseconds.

There are a couple of things to notice about any firewalking event:

  • Firewalkers are not actually firewalkers. They are really coalwalkers. The fire is lit well ahead of time to allow the wood to burn down to non-flaming coals.

Photo courtesy The Florida Pagan Gathering
The fire is lit long before the firewalking starts.
  • The event is always held at night. If it were done during daylight, the bed of coals would look instead like a bed of ashes. There is always a layer of ash covering the coals. By doing it at night, the glowing red light is still visible through this layer of ash.

    Photo courtesy The Florida Pagan Gathering
    The hot coals are covered with a layer of ash.
  • The firewalker never dawdles. Now, no self-respecting firewalker would run across the coals -- that would be undignified. But firewalkers certainly are walking briskly. You never see firewalkers standing on the coals.
So what is going on here? Firewalking depends on a combination of poor conduction, insulation and a short time span.

Firewalking and Science


Photo courtesy The Florida Pagan Gathering

Why is it possible for bare feet to touch red-hot coals without getting burned? The coals start out as pieces of wood. The wood consists of lots of carbon, some "volatile organic molecules," and water.

A volatile organic molecule is a carbon-based molecule that evaporates when you heat it. Gasoline is a volatile organic chemical. We see these volatile organic molecules from wood as smoke rising from the fire. The heat of the fire evaporates all the volatile organics, as well as all the water. Because they've been burning for a while before the stunt, the coals have burned down to nearly pure carbon.

If you were to pick up one of these pure-carbon coals, you would notice that it is extremely light. Carbon is a lightweight element -- that's why carbon-fiber bike frames and tennis rackets don't weigh very much. A coal is mostly lightweight carbon atoms and air spaces (it does contain a few other elements, like potassium and calcium -- that's what left behind in the ash).

This lightweight carbon structure is a poor conductor of heat. It takes a relatively long time for heat to transfer from the glowing coal to your skin. If the coal were made of red-hot metal, heat transfer through conduction would be almost instantaneous -- you would get a severe burn.

Now, add to that the fact that ash is a very good insulator. People used to use ash to insulate ice boxes and such. The red-hot coals covered with ash transfer their heat even more slowly because the ash acts as a layer of insulation.

Then there is the short time span. Heat transfer from a red-hot coal is slow, but it still happens. If you were to stand still on the coals for several seconds, you would definitely get a burn. By walking briskly, you limit your contact with individual coals to a very short time span. You also get across the bed of coals very quickly, and that limits your total amount of coal time. So, your foot never gets hot enough to burn.

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