**Question: **What makes a fart funny?

**Short answer: **Long duration.

**Long answer: **Farts must surely be mankind’s first joke, since they predate the evolution of language by millions of years. Indeed, the first recorded joke, from 1900 BCE, is a fart joke, as shown here:

For those readers who are unfamiliar with ancient Sumerian, this reads, “Something which has never occurred since time immemorial; a young woman did not fart in her husband’s lap.” Good one!

More recently, someone named Helen Pilcher has proposed an equation that predicts how funny a fart will be from its sound and a number of other factors. Here is the equation:

The variable *I* is the sound intensity, *L* the duration, *S* the “social embarrassment”, *k* the number of kids present, *A* the age of the listener, and *g* is a factor that represents the gender of the farter (1 for males, 1.05 for females).

The equation cannot be correct as written, since farts are funny in the absence of children (when *k* = 0). And loud farts are funnier, even when no one is the least bit embarrassed about them (when *S* = 0). Dr. Pilcher is apparently a neuroscientist, so it’s not clear why she is dabbling in flatology, but it’s a good try.

In any case, excluding the nonsensical aspects of the equation, there is a prediction that fart funniness is proportional to the product of sound intensity and duration:

This struck as intuitively plausible, so we have begun to conduct our own analysis. Over the last few weeks, members of the College have been rating the funniness of the farts in our extensive database, which has well over 2000 entries. At this point, we are using a simple rating system, in which each member of the College can vote each fart up or down. At some point in the future, the rating system will be open to the public.

Rating 2000 farts is a challenging task for many reasons, one of which is that some members consider *all *farts to be funny. Therefore, the ratings reflect the funniness of each fart relative to the funniness of the average fart. Here are some preliminary results, in which we relate fart funniness to the duration *L* of the corresponding sound recording:

These results are consistent with Dr. Pilcher’s claim that funniness is proportional to duration, with a linear regression yielding a p–value of <0.000001. The slope of the regression line indicates that each second of fart duration is equivalent to an average of 0.24 upvotes in our rating system. Nevertheless, the linear fit only gives an R^{2} of 0.22, which means there are other factors at work, including in all likelihood the sound intensity factor *I* that is hypothesized in the Pilcher equation. This factor, along with our standard measures of stink and sound frequency, will be considered in a future post.

For now, here is the funniest fart on record, which also happens to be the longest:

* Title taken from The Clouds, by Aristophanes, an early classic of farting humor.