[music playing] There are 10 types of clouds.

Fluffy, swooshy-- I kid.

But really, there are 10 types of clouds.

And beyond that, people have categorized them into subvarieties.

Capillatus, mammatus, lenticular, fallstreak, cirrus vertebratus, cumulus congestus, pyrocumulus, stratiformis, altocumulus.

But today we're going to create an entirely new type of cloud.

I like to call it maculus ridiculous, because it makes you look ridiculous when you make this type of cloud.

Seriously.

The first thing you have to do is to click your tongue on the roof of your mouth, like this-- but with your mouth closed and full of air.

After 30 seconds of that, you pressurize your mouth, meaning you hold your mouth closed and try to blow out, like this.

Then let go and let the cloud slowly escape.

Now as Bob Ross would say-- (SINGING) Let's build a happy little cloud.

Here goes.

[clicking] I'm not making this up.

This really works.

There's some simple physics going on here to make this cloud work.

And it relies on both steps.

You can try it without one, but it's not gonna work.

The first step, clicking your tongue, works to create tiny water droplets in your mouth that can evaporate more easily and create warm, humid air.

The second step, when you pressurize your mouth, it heats up the air even further.

Your friendly neighborhood ideal gas law tells you that when the pressure goes up, the temperature goes up, and that warmer air can hold even more moisture in the form of H2O gas or water vapor.

After all this, when you let the air out, you release the pressure, which causes the temperature to drop.

That, and the outside air is cooler.

When the humid air cools, it can no longer hold all of the water vapor, and some of it condenses out into itty-bitty water droplets.

And you get a cloud billowing out of your mouth.

This is the same process that occurs when you create a cloud in a bottle, as Bearded Science Guy is demonstrating here.

It's the water vapor in the bottle, pressurization, and then release that causes H2O to condensed, water droplets to form, and you get a cloud.

That's exactly what clouds in the sky are.

They are tiny, little water droplets that condense as warm humid air rises and cools down.

So clouds are made of liquid water, not water vapor.

So a bunch of tiny water droplets, all hanging out, surrounded by air.

What a special gathering.

Which is likely why there's a Cloud Appreciation Society, to appreciate nature's photo-bomber.

And it has 38,000 cloud appreciators.

Honestly, I couldn't find an appreciation society for anything else that wasn't man-made or an animal.

I hope you all prove me wrong, though.

Now, I know it doesn't have any clouds, but what about a Moon Atmosphere Appreciation Society?

Most people don't even seem to appreciate that the moon has an atmosphere.

This photo of the lunar horizon glow was taken during the Apollo missions.

Although the atmosphere there is so thin that some consider a surface boundary exosphere, which is like the dwarf planet of atmospheres.

So thin-- so thin that while there are 10 million trillion molecules in a cubic centimeter of air on Earth, there are less than one million molecules in a cubic centimeter of the moon's atmosphere.

In a lab, that would be considered a really good vacuum.

Those molecules would rarely ever interact or collide, which would mean no wind, virtually no air pressure, no heat, no clouds.

And if their were clouds, they'd be made out of the strange elements we found the moon's atmosphere, like argon, sodium, and potassium.

That's not a cloud I'd want to make in my mouth.

So we'll stick with maculus ridiculous here on Earth.

Thanks for watching.

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