Operations research

IN THE physical sciences — physics, chemistry, and many branches of engineering — one starts studying a phenomenon by picking some phase or aspect of it, by observing some part of its manifold behavior. According to folklore, Newton started his study of gravitation by watching the fall of an apple, not the breaking of the apple stem, not the apple´s bounce as it hit, but its falling to the ground. Next, after observation, in the physical sciences one tries to form a quantitative hypothesis, a mathematical model of the aspect observed, which will duplicate quantitatively some of its behavior. If one has been clever, or lucky, in his choice of model, its mathematical framework will go beyond the observations, will predict what might happen in other circumstances. Newton´s gravitational hypothesis, for example, his mathematical model of action at a distance, predicted the possible motions of a baseball, of a bullet, and of the moon.