Welcome to brain Stuff from How Stuff Works. Hey everybody, it's me Christian Seger, and I am back with another brain stuff question. Why can't we breathe underwater? I haven't met everybody, but everyone that I have met has not been able to breathe underwater, except for aquaman of course. And it's a good question when you think about it, because water is made up of hydrogen and oxygen, right, well, it goes in the chemicals. There's one thing we need
to remember though, about those chemicals. It's that once they react in certain ways, they form compounds that are often nothing like their original elements. Think of two solo artists from different bands and then they get together and they make an album that sounds nothing like the original music. For example, if you react carbon, hydrogen, and oxygen together one way, you get glue close, But if you react them together another way, you get vinegar. And if you
react them yet another way, you get fat. And if you react them yet another way, you get ethanol and gluclose. Fat, ethanol and vinegar are nothing like each other, but they're all made from the same elements. In the case of hydrogen and oxygen gas, if you react them together one way you get liquid water, and the reason we can't breathe liquid water is because the oxygen used to make the water is bound to two hydrogen atoms, and we
can't breathe that resulting liquid. The oxygen that fish breathe is not the oxygen that's in H two O. Instead, the fish are breathing O two oxygen gas, and that's dissolved in that water. Many different gases dissolve in liquids, and we can see an example of this all the time with carbonated beverages. In knees beverages, there's so much carbon dioxide gas dissolved in the water that it rushes
out in the form of bubbles. Fish breathe that dissolved oxygen out of the water using their gills, and it turns out that extracting the oxygen isn't that easy. Air has something like twenty times more oxygen in it than the same volume of water. Plus let's remember that water is a lot heavier and thicker than air, so it takes a lot more work to move it around. The main reason that gills work for fish is the fact
that fish are cold blooded. This reduces their oxygen demands tremendously warm blooded animals like whales breathe air like people do because it would be hard to extract oxygen using gills. Human beings can't breathe underwater because our lungs don't have enough surface area to absorb enough oxygen from water, and the lining of our lungs is adapted to handle air instead of water. However, there have been experiments with humans
breathing other liquids like fluorocarbons. Fluorocarbons can dissolve enough oxygen and our lungs can draw that oxygen out. It's just that first breath where you suck in the floral carbons and they enter your lungs. That is not very pleasant, but it is possible. And look, please, nobody out there try to breathe underwater, because unless you're an extraordinary person
or maybe a mutant, you're probably going to drown. Check out the brain stuff channel on YouTube, and for more on this and thousands of other topics, visit how stuff works dot com.