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  • So.

  • How do you weigh a fart?


  • Dr. Michael Levitt, who has decades

  • of research experience in flatology,

  • indicates that the typical daily volume

  • output is between half a liter and 2 liters

  • of gas once cooled to room temperature.

  • If you pretend that the fart obeys the ideal gas

  • law from high school chemistry class, which it probably

  • does to a decent approximation, you

  • could work out the mass of the fart

  • once you know the average molecular mass

  • of a fart particle.

  • To get that, we need to know what gases are in a fart

  • and what ratio they're found in.

  • This turns out to vary a lot by person and by diet.

  • I ballparked some average numbers from a paper

  • in a medical journal that measured the gas

  • mix in 10 subjects who had been fed

  • a normal diet plus a bunch of baked beans each day.

  • I got a density of around 1 gram per liter.

  • Now, I'm going to assume that our intrepid astronaut has

  • recently downed a burrito or two,

  • and would produce 1 full liter, i.e.

  • 1 gram worth of fart mass over a 24 hour period.

  • For a per fart analysis, assuming a typical 10

  • to 20 individual farts over the same period,

  • you would get somewhere between 0.05

  • and 0.1 grams of mass per fart.

  • That number may be off by a factor of two or so,

  • but I doubt it's off by a factor of 10.

  • And that's how you weigh a fart.



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How to Weigh a Fart | Space Time | PBS Digital Studios

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    Derrick Chen posted on 2015/05/27
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