FART SCIENCE

Hey, Vsauce Michael here, and today we are going to talk about farts. What are they, how do they define us, and how much weight do we lose every time we fart?

Now, it's easy to think that talking about farts is immature, but they are incredibly complicated, and by analyzing them because they're funny, you could accidentally learn a lot of science. Plus, we are in great company. Mozart wrote songs and poems about flatulence, and even Benjamin Franklin once wrote an essay titled, "Fart Proudly."

So first things first, where do farts come from? A lot of the gas that makes up a fart comes from the outside because you swallowed it. That's right, you swallow a lot of air when swallowing spit or food or beverage. Now, some of this will come back up as a burp, but if it doesn't soon enough, it will go deeper into your digestive system.

But it's where the other portion of the gas that makes up a fart comes from that makes farts so unique. No two people's farts smell alike. The pungent part of a fart is unique to you, and it comes from things that are inside you and are not you. Inside your intestines are completely separate organisms, bacteria, and microbes that digest food you haven't or can't.

Now, these little guys have a great collective name—gut flora. And because they are so much smaller than the average human cell, their numbers are staggering. Believe it or not, your body contains about ten trillion cells, but the number of bacteria and microorganisms inside your intestines is nearly 100 trillion.

As these microorganisms digest food that you haven't or can't, they produce helpful things like vitamin K, but they also produce chemicals that lead to the reason that farts smell. And we all fart every day about a pint of fart every day.

And if you say that you don't fart, you probably release that gas when you're in the bathroom, or at night when you're asleep and your muscles are more relaxed. But if this amount of gas used to be inside you and now it's not, that must mean that every time you fart, you lose mass. You lose weight, but how much weight?

Well, luckily, some researchers have already figured this out. Assuming this average chemical makeup of a fart, and what studies have shown is the typical volume of a fart, it can be calculated that the average fart weighs about three hundredths of a gram, and the part of it that actually stinks only weighs .0008 grams.

Okay, so a fart weighs three hundredths of a gram, I mean, what does that really mean? Well, here's a fun way to think about it. As you move further away from the center of the earth, the gravitational attraction between the two of you decreases, and your weight decreases.

In fact, according to this fantastic book about the scale of things, your weight decreases by about .5 percent for every six miles you are above earth. In fact, the average fart causes you to lose an amount of weight equivalent to being about a third of an inch further from earth.

The way your gut flora process the food that you eat and influence how your farts smell is established within the first two to three months of your life. When you're first born, your gastrointestinal tract is completely sterile. There are no microorganisms living in it.

In fact, unlike the rest of your life, the very first poop that you take is almost completely sterile. It's so significant it has a special name, meconium. Now, I will spare you any pictures, but if you ever want to call someone a poop head, try instead calling them a meconium head. It's like a poop head, but with no experience.

As soon as you leave your mother, you begin collecting microorganisms inside your digestive system. In fact, within the first five to ten minutes of being born, the gut flora that you have are almost exactly equivalent to the microorganisms living in your mother's birth canal.

Now later, these microorganisms come from your environment, especially from what you eat—milk or formula. This early in your life, microorganisms train your immune system to not attack them, and so, within the first two or three months of your life, whatever microorganisms are there have largely established themselves as the exact colonial makeup of your gut flora for your entire life.

That's all cool, but how loud can a fart get? Well, the Guinness Book of World Records doesn't know. In fact, there are a lot of records it doesn't keep, some of which it doesn't keep because they're dangerous. For instance, speed drinking. It's possible to open up your throat and literally pour liquid straight down your esophagus into your belly, but it is really dangerous and should never be done by anybody.

Now, burping they do have records of. The world record for the largest burp belongs to Paul Hunt from the United Kingdom whose burp registered 109.9 decibels, about as loud as a car horn.

Oh, and also, many of these microorganisms that live inside your gut and digest food and make farts smell bad also create gases that are flammable. We've all seen this, and it is very, very true. The Mythbusters even did an episode where they prove that farts can be lit on fire, but the episode was deemed too gross and never aired.

Another thing you should know about farts is that when you hold them in, many of the gasses inside them will get reabsorbed back into your blood stream through the intestinal lumen. Now, the smelly stinky stuff doesn't travel this way, but the nutrient stuff like oxygen will.

And the blood stream brings these gasses back to the lungs where you exhale them, so if you hold in your farts a lot, you, in a way, will have literal fart breath. The Fitzroy River Turtle does one better. It can do what I like to call a reverse fart. Because it spends so much time underwater, it's developed a way to breathe through its butt. It actually can get up to 68 percent of the oxygen it needs by simply opening up that cavity and getting oxygen from the water.

Finally, I want to leave you with the art of the fart. The way your farts sound is determined by the speed and the shape of their exit. But a select few cannot only make themselves create flatus on command, but can also modulate the pitch and tone of their farts.

These people are known as flatulists. And one of the most famous right now is Mr. Methane. Amazing, right? Well, now that we've talked about farts, let's move on to outer space. On YouTube.com/Spacelab, go over there now and you can ask me any question about outer space that you want, and every week I will answer three of them.

So what are you waiting for? Go check that out. And as always, thanks for watching.