A Physicist Looks at Biology

A mature physicist, acquainting himself for the first time with the problems of biology, is puzzled by the circumstance that there are no "absolute phenomena" in biology. Everything is time bound and space bound. The animal or plant or micro-organism he is working with is but a link in an evolutionary chain of changing forms, none of which has any permanent validity. Even the molecular species and the chemical reactions which he encounters are the fashions of today to be replaced by others as evolution goes on. The organism he is working with is not a particular expression of an ideal organism, but one thread in the infinite web of all living forms, all interrelated and all interdependent. The physicist has been reared in a different atmosphere. The materials and the phenomena he works with are the same here and now as they were at all times and as they are on the most distant stars. He deals with accurately measured quantities and their causal interrelations and in terms of sophisticated conceptual schemes. The outstanding feature of the history of his science is unification: two seemingly separate areas of experience are revealed, from a deeper point of view, to be two different aspects of one and the same thing. Thus, terrestrial and celestial mechanics, for thousands of years totally separate sciences, were reduced to one science by Newton, at a price, it is true that of introducing the abstract notion of force acting at a distance and the notions of calculus. Thus, also, thermodynamics and mechanics were shown to be one and the same thing through the discovery of statistical mechanics, as were chemistry and electricity through the discovery of the proportionality between charge transport and mass transport in electrolysis, at a price that of introducing atomicity into the concept of electric charge. Thus, optics and electromagnetism turned out to be two aspects of one theory, Maxwell's theory of the electro-magnetic field, at the price of introducing further abstract concepts, those of the field vectors. Thus, above all, chemistry and atomic physics were unified through the conceptual scheme of quantum mechanics, at the highest price of all -that of renouncing the ideal of a causal description in space and time.