Physicists From Germany

"Doing physics is much more enjoyable than just learning it. Maybe 'doing it' is the right way of learning, at least as far as I am concerned."

"If we fight a war and win it with H-bombs, what history will remember is not the ideals we were fighting for but the methods we used to accomplish them. These methods will be compared to the warfare of Genghis Khan, who ruthlessly killed every last inhabitant of Persia."

"Together with Peierls, he developed a theory of the deuteron in 1934 which he extended in 1949. He resolved some contradictions in the nuclear mass scale in 1935. He studied the theory of nuclear reactions in 1935-1938, predicting many reaction cross sections. In connection with this work, he developed Bohr's theory of the compound nucleus in a more quantitative fashion. This work and also the existing knowledge on nuclear theory and experimental results, was summarized in three articles in the Reviews of Modern Physics which for many years served as a textbook for nuclear physicists."

"You should look at all the experimental information at hand, not only the most relevant, and be prepared to make conjectures if that helps."

"We have more nuclear warheads than the Russians, and I consider this to be the most important measure of relative strength. In addition, as Dr. Kissinger stressed many years ago, at the present level of strategic armaments superiority in numbers or megatons has no meaning."

"In the beginning was mechanics."

"Quantum physics, which in contrast to the earlier theory, is characterized by the appearance of the elementary action quantum h and the designation of states in material systems by whole numbers, dates as theory only from the beginning of the twentieth century... However, some of its experimental roots extend far back into the nineteenth century. Of course, the measurements of the intensity of heat radiation which brought the change are a product of the last decade of that century. However, the photoelectric effect, and the wavelengths of the line and band spectra and also the dependence of the specific heats of certain substances on temperature had been known decades earlier. The older physics had hoped to arrive at an explanation of these findings; otherwise it is difficult to understand why Philipp von Jolly (1809-1884) told the inquiring young Planck that physics was essentially worked out and the pursuit of this science accordingly could hardly be very profitable. What appeared from time to time concerning line spectra could no longer stand up under rigid criticism when the discussion was based on the older ideas. On the other hand, quantum physics handled these problems more or less easily and in addition elucidated much of the newly acquired experimental observations."

"Though the churches, in general, abstained from interfering officially, the scientific activities of the physicists have always been influenced by their private religious views. The latter, of course, were not necessarily identical with the ecclesiastical doctrines, but the philosophical attitudes of the scientists were affected, at least to some extent, by the prevailing religious thought. Kepler, Descartes, Leibniz, and Newton freely acknowledged this influence; it played a part in the principle of least action in the eighteenth century. After this period, in which Kant's philosophy proclaimed the complete independence of scientific understanding and religious belief, not much more about it is found in physical writings. However, this by no means signifies that the investigational urge of later scientists was not intimately connected with their religiosity. The tenet that the scientific experience of truth in any sense is "theoria," i.e., a view of God, might be said sincerely about the best of them. The search for knowledge without regard to its applicability for use has been "an essential trait of man through the centuries, a sign of his higher origin.""

"You only have one life. Whatever crops up, crops up."

"The pretention that some of us are better than others, I don't think is a very good thing. And who is contributing what to our progress in science is not so obvious and many who don't get that Nobel Prize are better than people than some of us that do get the Nobel Prize. … I think we should not be interested in prizes, we should be interested in learning about nature."

"The problem of transmitting scientific knowledge is a very difficult business."

"According to my attempts to understand them, reality is systematically denied in the Copenhagen interpretation in order to circumvent consistency problems (such as “Is the electron really a wave or a particle?”). If there is no reality, one does not need a consistent description!"

"… still many physicists are convinced to "see" the particle in a cloud chamber or on a scintillation screen, therefore accepting classical particle coordinates as pieces of reality. But what one concludes to see depends on the chosen model of reality, and this model can only be judged by its success in consistently and economically describing the observations (therefore interpolating between them)."

"After a painful but largely successful struggle with courses and qualifying exams, I began my thesis work under Professor Townes. I was given the task of building a maser amplifier in a radio-astronomy experiment of my choosing; the equipment-building went better than the observations. In 1961, with my PhD thesis complete, I went in search of a temporary job at Bell Laboratories, Holmdel, New Jersey. Their unique facilities made it an ideal place to finish the observations I had begun during my thesis work. “Why not take a permanent job? You can always quit,” was the advice of Rudi Kompfner, then Director of the Radio Research Laboratory. I took his advice, and remained a Bell Labs employee for the next thirty seven years. Since the large horn antenna I had planned to use for radio-astronomy was still engaged in the ECHO satellite project for which it was originally constructed, I looked for something interesting to do with a smaller fixed antenna. The project I hit upon was a search for line emission from the then still undetected interstellar OH molecule. While the first detection of this molecule was made by another group, I learned quite a bit from the experience."

"Millimeter-wave spectral studies have proven to be a particularly fruitful area for radio astronomy, and are the subject of active and growing interest, involving a large number of scientists around the world. The most personally satisfying portion of this work for me was using molecular spectra to explore the isotopic composition of interstellar atoms — thereby tracing the nuclear processes that produced them. Most notably our 1973 discovery of DCN, the first deuterated molecular species found in interstellar space, enabled me to trace the distribution of deuterium in the galaxy. This work provided us with evidence for the cosmological origin of this unique element, which had earned the nickname “Arno’s white whale”. Of all the nuclear species found in nature, deuterium is the only one whose origin stems exclusively from the explosive origin of the Universe. Because deuterium’s cosmic abundance serves as the single most sensitive parameter in the prediction of cosmic background radiation, these measurements provided strong support for the “Big Bang” interpretation of our earlier discovery."

"I was born in Munich, Germany, in 1933. I spent the first six years of my life comfortably, as an adored child in a closely-knit middle-class family. Even when my family was rounded up for deportation to Poland it didn’t occur to me that anything could happen to us. All I remember is scrambling up and down three tiers of narrow beds attached to the walls of a very large room, and then taking a long train trip. After some days of back and forth on the train, we were returned to Munich. All the grown-ups were happy and relieved, but I began to realize that there were bad things that my parents couldn’t completely control, something to do with being Jewish. I learned that everything would be fine if we could only get to “America”."

"Well, if we read the Bible as a whole we would expect order in the world. Purpose would imply order, and what we actually find is order."

"In retrospect, the research organization which emerged from the decade following the Bell System’s breakup deployed a far richer set of capabilities than its predecessor. In particular, our work featured a growing software component, even as we strove to improve our hardware capabilities in areas such as light-wave and electronics. The marketplace upheaval brought forth by increased competition helped speed the pace of technological revolution, and forced change upon the research and development institutions of all industrialized nations, Bell Labs included. While change is rarely comfortable, I am happy to say that we not only survived but also grew more capable in the process — seeding much of the information revolution which now pervades the world in which we live. Except for two or three papers on interstellar isotopes, my tenure as Bell Labs’ Vice-President of Research brought my personal research in astrophysics to an end. In its place, I pursued my interest in the principles which underlie the creation and effective use of technology in our society, and eventually found time to write a book on the subject Ideas and Information, published by W.W. Norton in 1989. In essence, the book depicts computers as a wonderful tool for human beings but a dreadful role model for what we humans know as intelligence. In other words, “If you don’t want to be replaced by a machine, don’t try to act like one!”"

"Astronomy leads us to an unique event, a universe which was created out of nothing and delicately balanced to provide exactly the conditions required to support life. In the absence of an absurdly-improbable accident, the observations of modern science seem to suggest an underlying, one might say, supernatural plan."

"A closed universe, one that explodes, expands, falls back on itself and explodes again, repeating the process over and over eternally, that would be a pointless universe. … But it seems to me that the data we have in hand right now clearly show that there is not nearly enough matter in the universe, not enough by a factor of three, for the universe to be able to fall back on itself ever again. My argument, is that the best data we have are exactly what I would have predicted, had I had nothing to go on but the five books of Moses, the Psalms, the Bible as a whole."

"The Bible talks of purposeful creation. What we have, however, is an amazing amount of order; and when we see order, in our experience it normally reflects purpose."

"It was taken for granted that I would go to college, studying science, presumably chemistry, the only science we knew much about. “College” meant City College of New York, a municipally-supported institution then beginning its second century of moving the children of New York’s immigrant poor into the American middle class. I discovered physics in my freshman year and switched my “major” from chemical engineering to physics. Graduation, marriage and two years in the U.S. Army Signal Corps, saw me applying to Columbia University in the Fall of 1956."

"In any case, one needs to accept nature's teachings."

"Probably in most education systems in a sense we are stuck with the disciplines as we created them last, last century and before that."

"It’s the boundaries where the excitement is and where we will be in the future."

"Röntgen was an experimental physicist of the old school and built most of his own equipment. ...It was Rontgen's custom, when beginning new investigations, to repeat important experiments made previously by others in the same field. Since he was repeating Hertz' and Lenard's experiments with cathode rays, he used an armamentarium employed by those workers... he extended his experiments to include a Hittorf-Crookes' tube... when he discovered the new rays. The whole room was darkened... Röntgen suddenly saw a few brightly fluorescent crystals which lay on the table at some distance from the tube."

"The lesson of the laboratory was eloquent. Compared, for instance, with the elaborate, expensive, and complete apparatus of, say, the University of London, or any of the great American Universities, it was bare and unassuming to a degree. It mutely said that in the great march of science it is the genius of the man, and not the perfection of the appliances, that breaks new territory in the great territory of the unknown. ...the discoverer himself had done so much with so little."

"I was working with a Crookes tube covered by a shield of black cardboard. A piece of barium platino-cyanide paper lay on the bench there. I had been passing a current through the tube, and I noticed a peculiar black line across the paper. … The effect was one which could only be produced, in ordinary parlance, by the passage of light. No light could come from the tube, because the shield which covered it was impervious to any light known, even that of the electric arc. … I did not think; I investigated. I assumed that the effect must have come from the tube, since its character indicated that it could come from nowhere else. I tested it. In a few minutes there was no doubt about it. Rays were coming from the tube which had a luminescent effect upon the paper. I tried it successfully at greater and greater distances, even at two metres. It seemed at first a new kind of invisible light. It was clearly something new, something unrecorded."

"Having discovered the existence of a new kind of rays, I of course began to investigate what they would do. … It soon appeared from tests that the rays had penetrative power to a degree hitherto unknown. They penetrated paper, wood, and cloth with ease; and the thickness of the substance made no perceptible difference, within reasonable limits. … The rays passed through all the metals tested, with a facility varying, roughly speaking, with the density of the metal. These phenomena I have discussed carefully in my report to the Würzburg society, and you will find all the technical results therein stated."

"I am not a prophet, and I am opposed to prophesying. I am pursuing my investigations, and as fast as my results are verified I shall make them public."

"We shall see what we shall see. We have the start now; the developments will follow in time."

"Röntgen retained the characteristic of a strikingly modest and reticent man. Throughout his life he retained his love of nature and outdoor occupations. Many vacations were spent at his summer home at Weilheim, at the foot of the Bavarian Alps, where he entertained his friends and went on many expeditions into the mountains. He was a great mountaineer and more than once got into dangerous situations. Amiable and courteous by nature, he was always understanding the views and difficulties of others. He was always shy of having an assistant, and preferred to work alone. Much of the apparatus he used was built by himself with great ingenuity and experimental skill."

"Röntgen has familiarized us with an order of vibrations of extreme minuteness compared with the smallest waves with which we have hitherto been acquainted, and of dimensions comparable with the distances between the centers of the atoms of which the material universe is built up; and there is no reason to suppose that we have here reached the limit of frequency."

"The design of this Memoir is to deduce strictly from a few principles, obtained chiefly by experiment, the rationale of those electrical phenomena which are produced by the mutual contact of two or more bodies, and which have been termed galvanic; its aim is attained if by means of it the variety of facts be presented as unity to the mind."

"In 1875 he accepted... the chair of at Berlin where he became associated with his former colleague von Helmholtz."

"His contributions extend over optics, heat, fluid, motion, electricity, elasticity, etc., and all bear the imprint of the great genius..."

"His papers and lectures... form one of the enduring monuments in physical science."

"[N]one of the gases giving line spectra at temperatures heretofore used, do so by simple , but essentially by luminescent actions (chemical, electrical, and photogenic), so... we cannot, in general, apply the law of Kirchhoff of the proportionality between radiation and absorption to either terrestrial or celestial substances. In these cases the principle of usually holds, since in luminescence the radiation of line spectra is accompanied by selective absorption of the same spectral lines, so that the law may be used qualitatively, which is... the way Kirchhoff and Bunsen... attempted to confirm it."

"The formulation of the complete law for radiations of a is only given in part by Kirchhoff. The formula of Wien, and more particularly the most recent one of Planck, deduced on theoretical grounds, approximates closely the latest observations on a black body at different temperatures and over different wave lengths."

"By 1845 he had investigated electric currents, and established the two so-called Kirchhoff's laws for current conduction."

"[M]ost radiations from gases are not exclusively thermal... [T]he substances, cited by Kirchhoff and Bunsen, also give off... chemical.., electrical and fluorescent radiations which Kirchhoff excluded in the proof of his law."

"Why do you want to come into physics? All is done and understood."

"We owe to Kirchhoff..., the first rigorous proof of the celebrated law (...Kirchhoff's law) of the emission and absorption of light and heat, and the application of the same by both Kirchhoff and Bunsen to Spectrum Analysis. The radiation of solids and liquids and gases follows the law exactly when the conditions upon which he founded it are rigorously fulfilled, namely, the complete transformation from one to the other of radiant energy and their intrinsic ."

"In 1854 he... became associated with Bunsen. ...[H]e ...for twenty years ...in connection with Bunsen achieved some of the most important discoveries in the history of physical science."

"Conversely, upon the body there falls through the openings 2 and 1 a pencil of rays having the wave length \lambda, polarized in the plane a; of this, the body absorbs a part while it reflects or transmits the remainder; let the ratio of the intensity of the absorbed rays to the incident rays be A and let this be called the absorptive power of the body... The quantities E and A depend upon the nature of the condition of the body.., also upon the form and position of the openings.., the wave length \lambda and the direction of the plane a."

"Under these conditions the following law holds : The ratio between the emissive and the absorptive power is the same for all bodies at the same temperature."

"This law will be proven, first, for the case where only black bodies are compared with each other, that is, those whose absorptic power = 1; i.e., it will be shown that the radiating power of all black bodies is the same at the same temperature."

"The quantity E is called the emissive power of the body."

"Before a body... imagine two screens, S1 and S2 placed in which are two openings 1 and 2, whose dimensions are infinitely small with respect to their distance apart, and each of which has a center."

"Through these openings passes a pencil of rays sent out by the body... consider the part [of the pencil], whose lies between \lambda and \lambda + \partial \lambda, and let this be divided into two polarized components, whose planes of polarization are the [perpendicular] planes a and b... passing through the axis of the ray pencil."