Flatulence is a necessary part of being human. We all fart — on average more than 10 times a day — as a normal part of the digestive process. Some farts are caused by swallowing air while eating or drinking, while others are produced by foods such as beans, dairy products, onions, garlic, broccoli and cabbage.

This video from YouTube channel AsapScience explains the science behind what happens when humans pass gas and if it’s possible to outrun the embarrassing sound of a fart (you can’t) or more importantly, the smell.

Because we all have a unique set of scent receptors, we all perceive smells differently. So when we cut the cheese, the scent will be different to our noses than to someone else’s. Plus, the composition of each fart is distinct depending on what you ate, your food bacteria and the air you swallowed when you ingested your food.

According to the video, the average fart is composed of 59 percent nitrogen, 21 percent hydrogen, 9 percent carbon dioxide, 7 percent methane, 3 percent oxygen and 1 percent of the actual part that smells. The main takeaway from the video isn’t how farts are made and what they’re composed of, but how quickly we can get away from the smell.

Using the Kinetic Theory of Gases, AsapScience figures the smell particles of a fart can travel 243 meters per second, which is a lot faster than a human can move. But because the particles don’t move in a straight line but bump into each other and scatter into the air, so the gas cloud as a whole travels slower.

While you probably can’t outrun a fart smell, it’s good to know that no one else can either. Right?

For those folks who can’t get enough fart facts and want to learn more, AsapScience also created videos about silent farts and why we like our own farts.


Can you outrun a fart? Learn about the science of toots – CNET