The Skeptical Teacher

Musings of a science teacher & skeptic in an age of woo.

Posts Tagged ‘mystic’

Firewalking is Just Physics, Not Mysticism

Posted by mattusmaximus on July 28, 2011

Fire is cool… well, not cool, because it’s actually pretty damned hot.  But what I mean is fire is really interesting to watch – what kid hasn’t at some point been fascinated simply staring into the depths of a campfire?  Do you know what’s more interesting?… the fact that some people actually like to walk on fire.  This in and of itself is just all-around awesome, but then some woo-meisters have to go and spoil it with a bunch of made-up New Age nonsense.  The purpose of this blog post is to show you why firewalking really works.

My skeptical physics colleague David Willey shows his stuff, sacrificing himself for science.  **THIS IS EXTREMELY DANGEROUS AND SHOULD NOT BE PERFORMED WITHOUT PROPER SUPERVISION**

And just to show you that I put my money where my mouth is, below is a video shot of me and my colleagues performing an experimental firewalk back in the summer of 1999…

We decided that we wanted to study the physics of firewalking for ourselves and made this video as a way of documenting the effect. There are (were) two basic competing, scientifically plausible ideas for why it is that firewalkers are not too damaged by the high temperatures during the walk across hot coals: low thermal conductivity and the Leidenfrost effect.

In the first hypothesis, it is the low thermal conductivity of ash, wooden coals, charcoal, or rocks that the firewalker traverses in their journey. Even though the temperatures are extremely high (on the order of 500-800 degrees Fahrenheit), the low thermal conductivity means the rate at which heat will transfer from the hot material to the walker’s feet is very slow. This is why when you check out a baking cake in the oven it is okay to touch the batter but not the metallic pan – the thermal conductivity of the cake batter is low whereas that of the metal pan is very high!

In the second hypothesis, the Leidenfrost effect protects the walker’s feet. The Leidenfrost effect is the same thing that prevents your finger from being burned when you touch a hot iron with a wet finger. The hot iron turns the spit into steam which forms a temporary insulating layer between the iron and the finger. In this argument, the sweat on the walker’s feet is what is vaporized and then protects the feet from the hot coals.

In the video we tested out these two ideas, and we found the Leidenfrost effect to be inadequate to explain the phenomenon. It is the low thermal conductivity of the coals which prevented our feet from being too damaged – I walked a total of four times, three times dry and once with very wet feet. After three dry walks my feet were fine, with only one very small blister (half the size of a pinky nail, barely visible on the video) on one foot, but during the walk with wet feet, to test out the Leidenfrost effect, I found the coals sticking to my feet… OUCH!!! That is where I got badly burned (which is apparent by the very end of the video).

One thing we found was clear: we successfully negotiated the fire bed without any appeals to New Age mysticism or supernaturalism – no prayers were muttered, no crystals stroked, and we never even bothered to measure our “chi” levels. Such appeals to woo are simply not necessary to explain what is happening here – in fact, I have a challenge: if any New Age firewalking guru wants to really convince me that they have paranormal powers, then they’ll walk barefoot across red hot METAL!

I submit that no one will ever seriously attempt such a stupid feat, and even if they did I guarantee they’ll only do it once 😉

For more information on the physics of firewalking, I suggest reading Dr. David Willey’s page at http://www.pitt.edu/~dwilley/Fire/FireTxt/fire.html

 

Posted in physics denial/woo | Tagged: , , , , , , , , , , , , , , , , , , , , , , , , , , , | 3 Comments »

Man Claims to Have Survived 70 Years Without Food or Water

Posted by mattusmaximus on May 13, 2010

There’s a story running all over the Interwebs like wildfire… about a man who is making the seemingly miraculous claim that he has survived for 70 years without food.  Essentially, the man – an Indian mystic named Prahlad Jani, is claiming that he can live on “spiritual energy” in the form of air & meditation.  These claims are equivalent to those made by a form of New Age nonsense called breatharianism.

I’m going to go out on a limb here and say that Mr. Jani and his followers are basically lying, because there is no physical way that a person can live for a month, much less 70 years, without food & water.  Skeptic Ben Radford has a really good take down on this nonsense…

As remarkable as his story is, Jani is not the first, nor the only, person to claim such a supernatural power. The claim that people can live without food or water is called inedia, and is actually somewhat of a common claim among religious fakirs and godmen of India. Unfortunately none of the cases have withstood scientific scrutiny. The human body needs both food and water to function; it’s as simple as that.

It’s easy for anyone to claim that he or she has not had anything to eat or drink for the past few weeks or months (or years). But unless the person has been carefully and continuously watched during that time, it’s impossible to prove the assertion true.

Several people who have claimed to survive without food or water were later caught eating and drinking. It can take only a few seconds to eat something, and other than in specific areas such as prisons, conducting a close around-the-clock surveillance on a person is not easy. Often the person will ask for privacy to sleep or go to the bathroom (which is suspicious in its own right) – and then snack surreptitiously. One well-known breatharian advocate in the 1980s, a man named Wiley Brooks, claimed he did not eat yet was caught consuming junk food.

And here’s a very interesting point that Radford brings up regarding the fact that Mr. Jani apparently lost weight during the time he was being observed…

This is not the first time that Jani has made this claim. He was examined in 2003 for about a week, during which time, he apparently did not eat or exercise – but he did lose weight. If Jani’s abilities are real, it seems odd that he would lose weight during the time that his food intake was being monitored. If he truly gets all the sustenance he needs from air and meditation, there’s no reason he would lose weight when he doesn’t eat.

What’s worse is this: it seems that some people in the Indian Armed Forces are actually spending time & money on researching the “secrets” behind Mr. Jani’s supposed miracle.  I’m not kidding… there are high level Indian military people who want to learn how Jani pulls this off so they can apply it the techniques to soldiers in the field who could supposedly go for long periods of time without food and/or water.  What a colossal waste!  This lunacy reminds me of the, now infamous, debacle by the U.S. military when they wasted millions of taxpayer dollars researching “psychic warfare” – as outlined in the recent movie The Men Who Stare At Goats.

If Mr. Jani wants to convince skeptics of his supposed paranormal powers, I have a simple solution: round-the-clock observation by multiple watchers, including via constant video recording and even live-streaming over the Internet, where he is locked away in an empty room with no access to any food or water at all… for a month or two straight.  If he survives, then maybe we’re onto something.  My guess is, for obvious reasons, he would never submit to such a test – I wonder why not?

Posted in ghosts & paranormal | Tagged: , , , , , , , , , , , , , , , , , , , , | 4 Comments »

 
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