[cja23]

Just in case you are not joking and for anyone not familiar with the terminology: Physics, and a lot of the hard sciences, are often broadly divided into "theoretical" and "experimental" halves. Experimental physicists design and run experiments, i.e. they "get their hands dirty", or at least the hands of their graduate students and post-doctorates. Their end goal is to find some actual fact about the actual universe, usually a quantified measurement. Theoretical physicists, on the other hand, create theories: mathematical and conceptual models that hopefully explain how or why the universe is the way it is. Ideally, the created theory not only explains the measurements that the experimental physicist has already observed, but also predicts the results of new measurements not yet observed.