ABSTRACT
A physicist can be defined as a person for whom a chicken is a uniform sphere of mass M. The point of this joke (which this author first heard from a physics professor) is that physicists shamelessly omit a lot of detail when they attempt to model and predict the behaviour of complex physical systems; indeed, one of the important skills that physics students must learn is knowing what to leave out when setting up a problem. This penchant for simplification does not necessarily mean that physicists are hopelessly out of touch with reality, however; for one can learn a surprising amount about how real things behave by thinking about apparently simplistic models.
