DEBRIS.COMgood for a laugh, or possibly an aneurysm

After writing a piece on firewalking, I had an interesting email exchange with a physicist named Bernard Leikind who has not only walked on fire, but also put forward some theories on why people can walk on 1200+ degree coals without reducing their feet to charred, crackling stumps.

According to Leikind, two factors prevent most of the risk of getting burned during a firewalk: heat conductivity and heat capacity. He summarizes it this way:

Embers have a relatively low thermal conductivity and a relatively low heat capacity. Your foot has a relatively high heat capacity and a moderate thermal conductivity. What this means is that the embers don’t have much energy to give to your foot, and they are not good at getting what they have into your foot, and your foot can absorb a lot without heating up too much.

No one does firewalks across red hot glowing aluminum frying pans, which have high thermal conductivity and high heat capacity, even though they are no hotter than similarly colored embers.

It’s true that there is no ready documentation of people doing “frying pan walks.” But there is at least one documented example of firewalking across hot metal, on Tolly Burkan’s firewalking website. What’s odd and somewhat unsettling about this incident is that Bernard Leikind was there, as was a film crew for the Discovery Channel, and yet the two accounts of the episode are radically different:

• Leikind says Burkan put the metal racks in the fire; Burkan says it was Leikind’s doing.
  
• Burkan says the grill was “glowing red;” Leikind says they were “not very hot” and goes on to deny that they were glowing.
  
• Leikind says they “probably did not” sear the raw steaks they put on the racks; Burkan says they did, “instantly.”

I hate it when facts are in dispute, especially when there is photographic (video) evidence of the facts, e.g. whether or not the racks were glowing red, whether they seared the steaks, whether they were deformed by people’s weight in a way that suggests the metal was softened. At some point, perhaps I’ll locate the Discovery Channel’s video of the event and see for myself which of the two representations I’ve heard is more accurate.

In the meantime, I’ve drawn my own conclusions, which I will leave to your imagination.

While you’re wondering, you might ask yourself if you would ever walk barefoot across 1200° coals. I know from personal experience that this will do less damage to you than the milk you poured on your breakfast cereal, but it doesn’t matter what I know… it matters only, and entirely, what you know.