WATCH: Could You Outrun a Fart?

Science weighs in.

15 APR 2016

Alright, we've got a scenario here and it's very important - if you fart, and you know the smell is coming, could you react fast enough and outrun it? You're not going to outrun the sound, that's impossible, but could you get your nose out of the vicinity of all those objectionable chemicals in time? Fortunately for us all, the boys at AsapSCIENCE have investigated the science behind this emergency procedure, and it's actually more complicated than you'd think.


First off, the sound problem. The bad news is if you want to cover up what you've done, there's no chance of you maneuvering yourself away from the noise of a fart, because the speed of sound (through air at sea level at 15 degrees Celsius, if you want to be specific) is about 340 metres per second.

That's way faster than the fastest man on Earth, Usain Bolt, who can only move 12.4 metres per second at his absolute best, so let's just hope there's a crowd of people around for you to blame it on instead.

While the speeds of sound and light waves are generally pretty easy to measure, smell is its own unique beast. As the video above explains, while sound waves and visible light travel through the air, smell is made up of the odour compounds that create the air. So how do you measure the speed of something travelling through the air, if it's part of the air itself?

Basically, when you fart, odour molecules disperse into the air, and make their way to the receptors in your nose for processing. We all process scents differently, thanks to our unique set of odour receptors, which could explain why you're much less likely to try and outrun your own fart than someone else's.

So how exactly do odours end up mingling with the rest of the particles that make up our air? As AsapSCIENCE explains, the process is called diffusion, which describes how particles tend to move from a place of high concentration to low concentration so they can reach a state of equilibrium, and the type of particles that will be diffusing out of your butt will depend on what you ate, the types of bacteria in your gut, and the air you've been breathing in.

With all that considered, can we figure out exactly how fast that unique cloud of gas will diffuse into the air? I'll let the video above explain that one, but let's just say there's a little something called the Kinetic Theory of Gases that was just made for stupid scenarios like this.

Thanks, science?

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