Re: [Phys-l] Oxygen supply for a firewalk

[chuck britton <cvbritton@embarqmail.com>]

Jearl Walker is the 'master' of this feat (feet?)

after doing it a few times, he said, 'No sweat' so he didn't sweat  
and he got burned.

I think he did get a coal caught between a coupla toes once.

he wore sweat socks and plastic bags on his feet before some walks.  
(to increase the sweat factor)

50 meters seems an excessively long distance.

On Jul 10, 2008, at Jul 10(Thu) 7:25 , David Willey wrote:

> Ive been asked to do a 50 meter firewalk and was working on what I
> would say about the Physics involved. I agree with Leikand that the  
> low
> thermal conductivity of the coals is the most important factor as  
> to why
> not enough heat is transferred to burn someone, usually. A factor  
> that I
> have not seen mentioned though is that before walking on the coals,
> which by then are pretty much just carbon, they are always flattened
> down, often using the back of a shovel. This gives a flat surface to
> walk on that ones feet do not sink into. This morning I also I  
> realized
> (duh) that this compacting cuts off the oxygen supply to the lower
> coals, not completely, but enough, I'd speculate, to substantially
> reduce the rate of heat production. Im thinking this could be  
> quite an
> important factor. It seems to me to tie in with my casual observation
> that the flattened coals tend to go black after a short time. What do
> you good folks think? Thanks for any input generated,
> cheers,
> David Willey
>
>
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