For those among us who struggled to understand this joke ( I didn't go to Uni unfortunately, and they never taught quantum physics in the Army either) the attached link will help enormously.Heisenberg and Schroedinger we driving on the freeway when they get pulled over by the highway patrol. The cop comes around to the driver side and says to
Heisenberg, "Do you know how fast you were going?"
And so Heisenberg says, "No, but I knew where I was". The cop scratches his head, and says, "Pop the trunk, I want to take a look".
He walks back, looks in and then walks around to the right side and says to Schroedinger, "Do you know you have a dead cat in the trunk?" Schroedinger says, "I do now".