Physicists From Austria

"It is useful to have a short expression for denoting the whole of the probabilities attached to the different attributes in a collective. We shall use for this purpose the word distribution."

"It has been asserted - and this is no overstatement - that whereas other sciences draw their conclusions from what we know, the science of probability derives its most important results from what we do not know."

"It seems to me that if somebody intends to marry and wants to find out 'scientifically' if his choice will probably be successful, then he can be helped, perhaps, by psychology, physiology, eugenics, or sociology, but surely by a science which centres around the word 'probable'."

"Mass phenomena to which the theory of probability does not apply are, of course, of common occurrence."

"No contradiction exists, if the events are correctly interpreted."

"I am prepared to concede without further argument that all the theoretical constructions, including geometry, which are used in the various branches of physics are only imperfect instruments to enable the world of empirical fact to be reconstructed in our minds."

"Apart from this older generation, there is scarcely a modern mathematician who still adheres without reservation to the classical theory of probability. The majority have more or less accepted the frequency definition."

"In games of chance, in the problems of insurance, and in the molecular processes we find events repeating themselves again and again. They are mass phenomena or repetitive events."

"We can only hope that statisticians will return to the use of the simple, lucid reasoning of Bayes's conceptions, and accord to the likelihood theory its proper role."

"Remember that algebra, with all its deep and intricate problems, is nothing but a development of the four fundamental operations of arithmetic. Everyone who understands the meaning of addition, subtraction, multiplication, and division holds the key to all algebraic problems."

"If the concept of probability and the formulae of the theory of probability are used without a clear understanding of the collectives involved, one may arrive at entirely misleading results."

"Starting from a logically clear concept of probability, based on experience, using arguments which are usually called statistical, we can discover truth in wide domains of human interest."

"The theory of probability can never lead to a definite statement concerning a single event."

"Insurance companies nowadays apply the principle of so-called 'selection by insurance'; this means that they take into consideration the fact that persons who enter early into insurance contracts are on the average of a different type and have a different distribution of death ages from persons from persons admitted to the insurance at a more advanced age."

"Because certain elements of geometry have for a long time been included in the general course of education, every educated man is able to distinguish between the practical task of the land surveyor and the theoretical investigation of the geometer. The corresponding distinction between the theory of probability and statistics has yet to be recognized."

"The whole financial basis of insurance would be questionable if it were possible to change the relative frequency of the occurrence of the insurance cases (deaths, etc.) by excluding, for example, every tenth one of the insured persons, or by some selection principal."

"I do not want to defend the occult sciences; I am, however, convinced that further unbiased investigation of these phenomena by collection and evaluation of old and new evidence, in the usual scientific manner, will lead us sooner or later to the discovery of new and important relations of which we have as yet no knowledge, but which are natural phenomena in the usual sense."

"Equally possible cases do not always exist, e.g, they are not present in the game with a biased die, or in life insurance. Strictly speaking, the propositions of the classical theory are therefore no applicable to these cases."

"The mean and variance are unambiguously determined by the distribution, but a distribution is, of course, not determined by its mean and variance: A number of different distributions have the same mean and the same variance."

"The main interest of physical statistics lies in fact not so much in the distribution of the phenomena in space, but rather in their succession in time."

"On a double-log plot, my grandmother fits on a straight line."

"Ludwig Boltzmann, who spent much of his life studying statistical mechanics, died in 1906, by his own hand. Paul Ehrenfest, carrying on his work, died similarly in 1933. Now it is our turn to study statistical mechanics. Perhaps it will be wise to approach the subject cautiously."

"In passing I have to mention a typical Ehrenfest anecdote, not such a nice one, perhaps. Lorentz lived in Haarlem and all these celebrities, Rutherford, Madame Curie, Bohr, Einstein and very many others travelled by train, a special train, from Leiden to Haarlem. And the week before one of those rare fatal train accidents had occurred and I said to Ehrenfest, "Wouldn't it be dreadful if that train had an accident?" And Ehrenfest replied: "Yes, that would be dreadful, but think of all the young physicists who then could get jobs .... "."

"You will get your difficulties with the point electron."

"The way he taught statistical mechanics and electromagnetic theory, you got the feeling of a growing science that emerged out of conflict and debate. It was alive, like his lectures, which were full of personal references to men like Boltzmann, Klein, Ritz, Abraham, and Einstein. He told us at the beginning that we should teach ourselves vector analysis in a fortnight—no babying. Ehrenfest's students all acknowledge how much his method of exposition has influenced their own teaching."

"Einstein, my upset stomach hates your theory — it almost hates you yourself ! How am I to provide for my students ? What am I to answer to the philosophers ?"

"I may be a minority of one in advocating that one should NOT separate science and politics—partly because I am old enough to remember the Weimar Republic before 1934..."

"There have been applied sciences throughout the ages. … However this so-called practice was not much more than paper in nearly all of these cases, and the various applied sciences were only lacking a bagatelle, namely proper scientific practice. The applied sciences show the application of theoretic doctrines in existing events; but that is precisely what it does, it merely shows. Whereas the scientific practice autonomously puts to use these theories."

"Self-confidence is an important ingredient that makes for a successful physicist."

"… conferences with open attendance are very important for the stimulation of young people or other people who are new in the field. … The field of high-energy physics is, as you know, very strongly in the hands of a clique and it is hard for an outsider to enter."

"The question of the origin of the universe is one of the most exciting topics for a scientist to deal with. It reaches far beyond its purely scientific significance, since it is related to human existence, to mythology, and to religion. Furthermore, it deals with questions are connected with the fundamental structure of matter, with elementrary particles."

"In 1936 Weisskopf proposed to set aside in quantum electrodynamics the divergent effects at small distances, and to consider only the charge of the particle observed at long distances. This assertion anticipated charge and mass renormalization. Later he showed that the self-energy of an electron in Dirac theory diverges only logarithmically, a result that was important for the later development of renormalization theory."

"It is possible to apply statistical methods to the calculation of nuclear processes provided that the energies involved are large in comparison with the lowest excitation energies of nuclei."

"Almost all of the material phenomena which occur under terrestrial conditions are recognized as quantum mechanical consequences of the electrical attraction between electrons and nuclei and of the gravitational attraction between massive objects. We should be able, therefore, to express all the relevant magnitudes which characterize the properties of matter in terms of the following six magnitudes: M, m, e, c, G, and h; M is the mass of the proton, m and e are the mass and electrical charge of the electron, c is the light velocity, G is Newton's gravitational constant, and—most importantly—h is the quantum of action ..."

"I think there is a need for something completely new. Something that is too different, too unexpected, to be accepted as yet."

"It was easy in the early nineties to make a list of great things that could be done, now that there was such a convenient source of entangled pairs. Anton's claim to fame is that he went and did them."

"In principio it is impossible to prove from experiments that something is non-existent."

"Wie steht es bei dem Kreisen der sogenannten Elektronen um ihren zentralen Kern? Was ist hier wirklich unmittelbar wahrgenommen worden? Nichts von den bewegten Teilchen; was vielmehr beobachtet wurde, sind Erscheinungen, welche auf den ersten Blick mit der Bewegung von Körpern gar nichts zu tun haben. Alles übrige, was zum Atommodell geführt, ist eine lange Kette von Schlüssen."

"Then I went to the Cavendish and there I took Rutherford’s course in nuclear physics. He was a very dramatic lecturer and full of anecdotes. He made it come alive. So this was very impressive--also very phenomenological, everything he did; very simple derivations. I think that’s very important for the first learning and this is perhaps something students now miss. They get the theory of nuclear physics thrown at them; sometimes before they ever know there is a phenomenon they have the complete theory of it. The phenomena are not sufficiently emphasized, I think, in teaching today."

"Paris somehow lends itself to conceptual new ideas. I don't know why it is. There is a certain magic to that city."

"Bring forward what is true, Write it so that it is clear, Defend it to your last breath!"

"Which is more remarkable fact about America: that millionaires are idealists or idealists become millionaires."

"I am conscious of being only an individual struggling weakly against the stream of time. But it still remains in my power to contribute in such a way that, when the theory of gases is again revived, not too much will have to be rediscovered."

"O! immodest mortal! Your destiny is the joy of watching the evershifting battle!"

"Eleganz sei die Sache der Schuster und Schneider"

"Available energy is the main object at stake in the struggle for existence and the evolution of the world."

"The most ordinary things are to philosophy a source of insoluble puzzles. With infinite ingenuity it constructs a concept of space or time and then finds it absolutely impossible that there be objects in this space or that processes occur during this time.... the source of this kind of logic lies in excessive confidence in the so-called laws of thought."

"We want first to solve the problem... namely to calculate the probability of state distributions from the number of different distributions. We want first to treat as simple a case as possible, namely a gas of rigid absolutely elastic spherical molecules trapped in a container with absolutely elastic walls. Even in this case, the application of is not easy. The number of molecules is not infinite... yet the number of velocities each molecule is capable of is effectively infinite... to facilitate understanding, I will... consider a limiting case."

"[I]t is our main purpose not to limit our discussion to thermal equilibrium, but to explore the relationship of this probabilistic formulation to the second theorem of the mechanical theory of heat."

"We assume initially, each molecule is only capable of assuming a finite number of velocities...0, \frac{1}{q},\frac{2}{q},\frac{3}{q},...\frac{p}{q}where p and q are arbitrary finite numbers. ...but after the collision both molecules still have one of the above velocities ...the actual problem to be solved is re-established by letting p and q go to infinity."