ABSTRACT
There is a joke that is well known in the physics community, and it goes something like this:
A dairy farmer asks a physicist friend to solve a problem the farmer is having at his dairy farm. The physicist investigates the dairy farm and then goes away. He returns a week later, and the farmer asks the physicist if he has come up with a solution to the problem. The physicist says, “Yes, I have an excellent solution, but it applies only to a spherical cow in a vacuum.”
