What is Life?

by Erwin Schrödinger

From an investigation, due to M. Polanyi and E. Wigner,3 the ‘time of expectation’ largely depends on the ratio of two energies, one being just the energy difference itself that is required to effect the lift (let us write W for it), the other one characterizing the intensity of the heat motion at the temperature in question (let us write T for the absolute temperature and kT for the characteristic energy).4

Now I would not go so far as to say that all these statements and distinctions are quite wrong. For practical purposes they are sometimes useful. But in the true aspect of the structure of matter the limits must be drawn in an entirely different way. The fundamental distinction is between the two lines of the following scheme of ‘equations’: molecule = solid = crystal. gas = liquid = amorphous.

Scientific theories serve to facilitate the survey of our observations and experimental findings. Every scientist knows how difficult it is to remember a moderately extended group of facts, before at least some primitive theoretical picture about them has been shaped. It is therefore small wonder, and by no means to be blamed on the authors of original papers or of text-books, that after a reasonably coherent theory has been formed, they do not describe the bare facts they have found or wish to convey to the reader, but clothe them in the terminology of that theory or theories. This procedure, while very useful for our remembering the facts in a well-ordered pattern, tends to obliterate the distinction between the actual observations and the theory arisen from them. And since the former always are of some sensual quality, theories are easily thought to account for sensual qualities; which, of course, they never do.

Maybe I ought to say something about my years at university between 1906 and 1910, as there might not be any chance of doing so later on. I mentioned earlier that Hasenöhrl and his carefully conceived four-year course (five hours a week!) influenced me more than anything else. Unfortunately I missed the last year (1910/11), as I could no longer postpone my national service. As it turned out this was not quite as unpleasant as I had anticipated, for I was sent to the beautiful old town of Cracow and I also spent a memorable summer near the Carinthian border (near Malborghet).