Correct, and that's more detailed than I'd even expect. I'd be satisfied with "I think it has something to do with the rule we learn in physics or chemistry about gasses warming up and cooling down when compressed and decompressed. So a gas gets squeezed, cooled down, and let out and it's even cooler then".

Sometimes I wonder how much more interesting school would be if it just explained how everything works instead of random concepts no one remembers apparently long enough to tie to objects in their life.