Today we're talking about adiabatic processes. What in the world does adiabatic mean?

Well, imagine that you have a magic balloon and you want to change the temperature of the gas inside the balloon. You're probably thinking to yourself, "Ya - ya put it out in the sun, Maddie! You let it heat up. If you want to cool it down, put it in your freezer. This is not hard." And you're totally right, but those are both examples of diabatic processes.

A diabatic process is anything that is going to change the temperature of a system by either adding or removing heat from that system. So if that's what a diabatic process is, then an adiabatic, usually pronounced adiabatic, an adiabatic process is one that's going to change the temperature of our system without adding or removing heat.

Well, how in the world does that work? Great question. But we've actually seen this type of process. Uh, I think last video, when we did the ideal gas law. Imagine that we let our balloon go. Timmy here is sad. As the balloon rises, the pressure exerted on the balloon is going to decrease.

Fun Navy fact. In the Navy, you're not actually supposed to say increasing or decreasing. You're supposed to say goes up or goes down. Because increasing and decreasing sound too close to each other that if you're on an old like sound powered phone, then you might get them mixed up. So you're always supposed to say goes up or goes down when you're - for proper phone talking procedures. Believe it or not, every word in that sentence was correct.

So we're going to have to see temperature as well in order to keep the equation balanced. So density is going to go down. Now, assuming that we tied our knot really tight and no air is leaking out of the balloon, that change in density will look like an increase in volume. So we - we get a big balloon.

And then we'll also see the temperature go down. And that's what we're interested in here. So this drop in temperature was caused by an adiabatic process. The dark, dark science magic of being able to change temperature without actually doing anything to the heat energy of the system.

We actually usually think about adiabatic processes so that we can like eliminate them. Adiabatic processes don't drive the weather generally. They don't drive storms. So if I'm interested in something like how does the temperature change in the atmosphere leading up to storm "X" over here, um, matter for the storm's development, something like that, then what I would want to do is look at the change of temperature and first remove or subtract out all of the adiabatic changes in temperature so that all I'm left with are the diabatic changes.

The diabatic changes are generally the interesting, complex bits. So it helps to remove the adiabatic processes first. Or to think about those as separate things. Moving forward we're going to talk a lot about adiabatic and diabatic processes and now, good job you, you know the difference.