Like, I can just rub my hands together and make them hot, but I don’t know how to make stuff colder
In: Physics
It’s natural for things to become the same temperature. If you put a cold thing in a hot environment it becomes hot. If you put a hot thing in a cold environment it becomes cold. In that sense they are equally easy.
But like you said, you can rub your hands and make them hot. That is because it’s possible to convert potential energy (chemical energy in your body from food, in this case) into heat. This conversion of useful energy into heat is natural. But it is not natural for heat to turn into useful energy. You won’t see decayed matter turn into food that you can eat, and you won’t see water and carbon dioxide turn into sugar. Those processes aren’t natural and need an input of useful energy (like sunshine giving energy to a plant to make sugar through a complex system) and generate heat in the process.
It’s easy to make things hot because energy naturally turns into heat. It’s hard to make things cold because any energy you use in the process generates heat and you have to be thoughtful about redirecting that heat away from the thing you want to make cold.
Or put another way, making a thing cold requires making something else hot. But you can make something hot simply on its own.
Latest Answers