I noticed in the paper this weekend that firewalking is coming to Ireland. A guru from New Zealand will teach (for 299 euros) seekers of transcendence how to walk on red hot coals -- fields of consciousness, life energy, mind over matter, that sort of thing.
Poppycock. The heat capacity of wood ash is small. Although the temperature of the glowing coals is high, the amount of heat energy contained within them is deceptively low. The same is true for the air in a hot kitchen oven, which is why you can safely put your hand in the oven. Also, wood ash doesn't conduct heat well. During the fraction of a second that the foot is in contact with the coals, there is not enough time for a damaging amount of heat to transfer to the skin.
I know, because I did it once in my backyard in preparation for a Globe column debunking claims of firewalking transcendence. In that column I offered $1000 to any entrepreneurial guru who would walk across a steel plate heated to the same temperature as the hot wood ash. I got no takers.
The laws of physics are made to be broken, say the gurus, if we can harness the spiritual power that lies deep within our souls. As a way overcoming fear and developing self-confidence, firewalking might have something to recommend it. As an extreme sport, it ranks right up there with sky-diving and bungee-jumping. But as for overcoming the laws of physics, it's a penny miracle indeed.