Question: Is it possible to spread fart smell by walking around?
Short answer: No.
Long answer: Many people like to fart while walking around in a crowded environment. There are ostensibly two reasons to do this:
- To escape blame for the smell.
- To spread the smell around, often as some sort of prank or revenge plot.
Readers of this blog will understand that neither justification for cropdusting makes much sense, for the simple reason that the movement of fart smell is determined almost entirely by the ambient air flow. But it’s probably true that one could escape blame by leaving the area immediately after farting.
The second reason is what is most often referred to as “cropdusting”. In one popular definition of the term, cropdusting is “dragging the smell around with you”. The idea of spreading or even directing fart smell has a certain appeal, but it is not likely to succeed, for several reasons. First, fart smell passes largely unhindered through clothing, so that it is probably not possible to “drag it around”. Second, even if it were possible to somehow drag the smell, the effect would probably be overpowered by the movement of the air, even indoors.
Nevertheless, in keeping with our mission, we have tested these ideas empirically, by constructing a device for measuring the effectiveness of cropdusting. The device is depicted here:
In this setup, two air quality meters were placed one meter apart, and a fart was released near one (the source). The farter then moved one meter to a nearby air quality meter. The results are not encouraging for those interested in cropdusting:
The plot on the left shows the smell recorded at the source (blue) and the cropdusting destination (red). Barely any of the smell travels with the farter, even over a distance of one meter. The cropdusting data are magnified in the plot on the right, which does indicate a slight increase in VOC content upon the arrival of the cropduster. However, this increase could equally well be attributed to the baseline miasma that follows people around, even when they are not farting. In the best-case scenario, fart smell is attenuated by 97.7% after the would-be cropduster has traveled one meter, which suggests that the only way to spread fart smell is to fart continuously while walking and hope for the best.