Eli5: How do heat sinks work?

Question

Curious how they work. Why do they look like lots of layers of fins.

In: 6

Answer 1

A heat sink is a drain (hence the word sink).Heat “flows” from a hot point(the top) to a cool point (the bottom) as molocules beat the heck out of each other as they heat up.
As air flows over the fins, the molocules in the metal whack the air molocules as they fly by bleeding off kinetic energy (heat) in the molocule.
Thus, for a heat sink to be effective it needs to have the maximum surface area possible so you have as many air molocules being assaulted by metal molocules as you can get.
Hence the packed in and often wavy shape of the super thin metal fins.