
1
Chapter 1
OVERVIEW AND UNDERVIEW
1.1 SIMPLIFICATION VERSUS
OVERSIMPLIFICATION
ere is a joke that is well known in the physics community, and it goes some-
thing like this:
A dairy farmer asks a physicist friend to solve a problem the farmer
is having at his dairy farm. e 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. e physicist
says, “Yes, I have an excellent solution, but it applies only to a spherical
cow in a vacuum.”
is joke reects the propensity of (and indeed the need for) physicists to make
simplifying assumptions ...