Empiricism and theory

So, the experimentalist is giving a little in-house symposium one day, presenting some unexpected results that he had encountered. He puts his graph up on the screen, showing a sharp peak. Immediately the prominent theoretician interrupts him, saying "It is obvious what is happening, you would expect to see that peak in precisely that location." She then continues with a long derivation explaining the results. Before she finishes, though, the experimenter interrupts her and says "Oh, sorry, my mistake; the figure is upside down!" He corrects it, and the theoretician resumes, "It is obvious what is happening, you would expect to see that trough in precisely that location..."

Always keep this in mind when perusing theoretical armchair musings; my own as much as those of everyone else!