At first I thought that this is some peculiar quality of bizarre american unit system that energy released by kiloton of TNT divided by one month equals power of one horse. As opposed to usual joules, seconds and watts.
Amazing how fast you can do "back of the envelope" calculations with such tool empowered by default with unit conversions.
You can do exactly the same thing sans frink with google, except you have to look up the KT --> J conversion yourself (google is still missing some obscure units).
Just as operating systems are not all the same, farts are not all the same. Some really stink, while others don't. Some pack a lot of energy while others don't.
The paper doesn't dig deep enough for the facts. (sorry!)
There are many hundreds of different kinds of bacterial active in the gut. The bacterial mix varies from person to person. The mix of the fuel varies too.
Even without advanced analysis (anal-ysis?) it isn't hard to confirm some of the differences. For example those with flora producing high metane more frequently produce floaters. Do yours float?
Probably the best demonstration I've seen was a group of bored college guys sitting around having something of a farting contest. Being the educated group they were, they went a step beyond that and dug out the propane lighters to see who could throw the biggest flame. (warning, don't try this nude, some got pretty hot even with some protection from clothing)
It turns out some threw substantial flames while others just couldn't get lit. Aside from the bacterial and solid-food variations, it seems that beer farts don't burn.
Perhaps someone can get a grant for continued study...
A simple knowledge of thermodynamics demonstrates the sheer impossibility of the myth. The last calculation on the first section of the page will suffice: If you have a 1-inch pipe, shooting out pure natural gas at 28 MPH, you would have the equivalent of the Hiroshima bomb in 6 years 9 months. The methane produced in the gut has nowhere near that concentration, so it would have to be blowing much faster. A 1/10 ratio would mean 280 MPH.
I read the page, and don't disagree with the conclusions.
The myth has already been sufficiently clubbed to death.
But if by extension this topic invites us to ask how much energy there actually is, there are some things missing from the analysis. The distinction between farts that burn and those that won't is a huge variation. In the case of farts that don't burn, the easily extracted power may be only what a micro-turbine could produce.
I'm not sure why my comment got negative ratings. It wasn't meant as a troll or flamebait and opens a related area of scientific analysis to the topic.
I think it would also be interesting to ask what could be potentially powered by farts? Is it possible to make a thin fuel cell in underwear that can produce some power? What useful things might be run with the expected amount?
To whoever down-modded me... please try to be a little more open-mined. Otherwise a fart in your general direction...
The assumption is the energy released from farting = 280HP and MPH has nothing to do with it. Also a 280HP engine is measuring the output, thermal energy is easily 3x that.
So a better way to think about it is BTU / seconds * (time) = BTU of an A bomb. If you assume at it's peak a high end fart releases 10x the daily average per second you come to vary different numbers. Basically divide his number by (10 * 60 * 60 * 24) and you get a little over 2 years.
PS: His "average" fart has the energy equivalent of ~9% methane but it's moving a lot faster than 30MPH and it's at more than 1atm (speed without pressure is meaningless).
Under "Advanced Farting," isn't the molar volume wrong? I think the program is assuming STP, but the human body is much warmer and possibly under more pressure as well.
I think it's telling that this technology that has been used to wage wars, create and drive industry, and save lives has matured to a point where we can afford the CPU cycles for such calculations.
Perhaps one day it will be able to test "your momma" jokes. :)
