So a mathematician walks into a bar...

In a comment to the previous post, John Cowan told an engineer vs. mathematician joke. I am married to an engineer, co-teach a course with a mathematician, have published jointly with a biologist, and am in the midst of an enormous project with a computer scientist and another mathematician and a biologist. There is some truth in all the stereotypes. So here are my two favorite jokes that poke fun at the different disciplines.

First joke

An engineer, a chemist and a mathematician are all staying at a hotel after a conference. Three small fires simultaneously break out in the wastepaper baskets in their rooms.

The engineer wakes up, looks at the fire, makes a quick calculation, puts exactly the right amount of water into the ice bucket, and pours it on the fire. Fire is out and no water spills out of the basket.

The chemist wakes up, looks at the fire, fills up five different vessels and dumps them onto the fire and then, just for good measure, runs the shower on the wastepaper basket for an hour. There's a lot of water damage, but the fire is out.

The mathematician wakes up, looks at the fire, looks at the ice bucket, looks at the water tap, and says "There is a solution." Then he goes back to sleep.

Second joke

A physicist, a biologist and a mathematician are sitting in a cafe and chatting. They notice two people go into a house. A few minutes later, three people come out.

The physicist says "The initial measurement was in error."
The biologist says "They must have reproduced."
The mathematician says "If one person goes back into the house, it will then be empty."

Gratuitous completely nerdy math joke

Q: What do you get when you cross rabbit and elephant?
A: Rabbit elephant sine theta.

Gratuitous completely nerdy physics joke

2+2=5 for very large values of 2 or small values of 5.