Werner Heisenberg, Kurt Gdel, and Noam Chomsky walk into a bar...

[The Velveteen Ocelot]

2. Good one! And another:

Heisenberg, Schrödinger and Ohm are in a car, with Heisenberg driving. They get pulled over. The cop asks Heisenberg, "Did you know you were doing 65 in a 45 zone?" Heisenberg says, "Great! Now I'm lost!" The cop thinks this is odd and orders him to pop open the trunk. Upon checking on the trunk the cop says, "Do you know you have a dead cat back here?" "We do now, asshole!" yells Schrödinger. The cop starts to arrest them. Ohm resists.