 So let's try and put a number to this. The air you're breathing, how fast are the atoms really moving around in there because of the heat? Well, we know that the kinetic energy on average of the air molecules in the room is three-halves kT. We also know that kinetic energy is half mv squared. So we set them equal half mv squared, the definition of kinetic energy, equals three-halves kT from the definition of temperature. Now we can cancel the two's, then we can divide both sides by m. So we get that v squared equals three kT over m. Take the square root of both sides of that equation and we find that the velocity equals the square root of three kT over m. So that's an equation that will tell us how fast a typical atom or molecule or whatever is moving. Okay, so for this we need to know Boltzmann's constant, we need to know the temperature, we need to know the mass. So let's imagine we're in a room at 20 degrees centigrade. So the temperature has to be in Kelvin, so that's equal to 20 Celsius plus 273.15, which comes out as 293.15 Kelvin. But how about the mass? Well air is mostly nitrogen, and nitrogen is diatomic, so it's two nitrogen atoms combined. Now nitrogen atom has an atomic mass of 14. That means the mass of one hydrogen atom is 14 times the atomic mass unit. Atomic mass unit is roughly speaking the mass of a proton or a neutron, they're both about the same. The electrons are kind of irrelevant because they don't weigh very much. So the atomic mass unit is 1.66 by 10 to the minus 27 kilograms, roughly the mass of a proton. So one hydrogen atom has 14 times that, but because hydrogen is diatomic, there are two of them in the molecule, it's actually going to be 28 times that. So the mass of nitrogen molecule equals not very big. So now we have all the numbers we need to put into the equation. So we end up with the velocity equals the square root 3 times Boltzmann's constant, which is 1.38 by 10 to the minus 23 times the temperature, which is 293.15, all divided by the mass, which is 4.6 by 10 to the minus 26. And if you put that in your calculator, it comes out as 513 meters per second. Now that's fast. 500 meters in a second means you get a kilometer in two seconds. Not many cars can do that. We can convert it into kilometers per hour. So that's 513 meters, so that's 513 divided by 1,000 kilometers per second. But a second is 60 times, multiply by 60 times 60 to convert it to hours, because there you go 60 times further than a minute and another 60 times further than an hour, because there are 60 minutes in an hour, 60 seconds in a minute, which comes out as 1,847 kilometers per hour. So the air molecules in your lungs around you right now are hooning along. That's fast. It's a supersonic fighter jet.