History Memes

Okay so this is really neat.

The compressor squeezes the refrigerant (a substance which has a low boiling point, usually it's a gas at atmosphere) until it is a liquid, but because of the pressure, is above its boiling point (the temperature at which it would become a gas under normal atmospheric pressure).

Then the liquid is allowed through an expansion valve and into the evaporator, which is a chamber with lots of space inside it. Once the high pressure liquid refrigerant has the space to become a gas - which it must, because its temperature is higher than its boiling point, remember - its temperature falls to its boiling point. This is because when a substance experiences a phase change (liquid to gas in this case), that substance is at the temperature where the phase change occurs, even if it was a different temperature just before.

Now the cold gas makes the metal body of the evaporator cold, air is passed over the evaporator, and heat from the air is transferred to it, and by extension, the refrigerant.

Now the refrigerant passes through to the compressor, which squeezes it into the condenser, where it becomes liquid again.

"The box of cold is a divine instrument blessed by Boreas and driven by the power of Zeus."

Thermodynamics is literally eldritch knowledge

You suck the pixies into a tube and spit them out elsewhere. As long as the de-pixied space is sealed off from the space where you release them, you can continue repeating the process until the pixie level is reduced to the desired amount.

The Oracle:

If you unplug your refrigerator, you will save a great deal of money from your electricity bill

Me:

unplugs refrigerator, proceeeds to die from food poisoning a week later, and doesn't have to pay for electricity ever again

Refrigerator works because of a Santa elf, who keeps throwing out the heat using a magical bucket. That's why it is cold in the fridge and in the North Pole.

It works by taking advantage of how gasses become hotter or colder when you squeeze them.

You might be aware of the ideal gas formula from high school: PV=nRT.

This formula is cool and all, but it only works for ideal gasses, and one of the crucial assumptions is that ideal gas molecules don't interact with each other. Of course, this is not true at all in the real world. Gas molecules can have attractive or repulsive forces to each other, which can have some interesting consequences.

The main one is that if gas molecules attract and you spread them out, they will need to absorb energy in order to overcome those attractive forces. In other words, its surroundings gets colder. Vice versa, if you squeeze the gas molecules together, they will release energy, and the surroundings get hotter.

You might start to see where we're going with this. Building a refrigerator just involves smartly squeezing and releasing a gas in the right order. Expand the gas to cool it down, then pass it through the fridge interior so that it can absorb heat. Then, take out the gas, and squeeze to get it hotter. Pass the gas through a radiator to dissipate the heat. Rinse and repeat.

This concept is also why leaks in pressurized gas tanks tend to freeze over - the gas inside is constantly expanding, and is therefore constantly absorbing heat. On the other hand, hydrogen gas, which is repulsive instead of attractive, will get hotter when it leaks, which can lead to an explosion.

Since the Oracle of Delphi did run a quite extensive intelligence network, the Oracle's interpretation of the Pythia's gibberish at least contained some real intelligence, albeit packet in a liberal dose of ambiguity.