A physicist, an engineer and an economist are stranded in the desert. They are hungry and find a can of corn. They want to open it, but how?
The physicist says: “Let’s start a fire and place the can inside the flames. It will explode and then we will all be able to eat”.
“Are you crazy?” says the engineer. “All the corn will burn and scatter, and we will have nothing. We should use a metal wire, attach it to a base, push it in and crack the can open.”
“Both of you are wrong!” states the economist. “Where the hell do we find a metal wire in the desert?! The solution is simple: Assume we have a can opener…”