Physicists From Germany

"It is widely believed that in our quantum world physical facts about occurrences in space time must be grounded in the wave function. There are several long recognized and much discussed difficulties with this view."

"Jacob Leupold (1674-1727) German engineer who collected, for the first time in print, the basic principles of mechanical engineering."

"Leupold is also credited as an early inventor of air pumps. He designed his first pump in 1705, and in 1707 he published a book Antlia pneumatica illustrata. In 1711 following an advice of its president Wilhelm Leibniz, Prussian Academy of Sciences acquired Leupold's pump. In 1720 Leupold started to work on the manuscript of his prominent encyclopedie Theatrium machinarum, a nine-volume series on machine design and technology, published between 1724 and 1739 . It was the first systematic analysis of mechanical engineering in the world."

"I had not only opportunity of seeing how different things have been made, but also manual work made me strong."

"[His work is addressed]... not to the learned and experienced mathematicians who are already, or should be, better acquainted with them... [and most of whom] have studied mechanics more as a subject of curiosity and a hobby, than with any view of service to the public. The people we had in mind were rather the mechanic, handicraftsman and the like, who, without education or knowledge of foreign languages have no access to many sources of information..."

""Theatrum machiuamm universale," &c. by Jacob Leupold, Leipsic, seven volumes, folio, 1724, 1727,1774. This is the greatest and most complete work of this kind that ever was published. The first volume is little more than an introduction to the work; the second and third volumes contain a description of hydraulic machines; the next two volumes relate to machines for raising weights, the theory of levelling, and other subjects; and the sixth treats principally on machines connected with the construction of bridges; the seventh volume is entitled, "Theatre arithmetico geometrique," where the author treats of all instruments employed in these two sciences This work would have been much more considerable if its author had lived to complete the immense task he had undertaken."

"In the Histoire de l'Academie for the year 1725, p. 78, it is stated that when M. du Fay was at Strasbourg, M. Jacob Leupold had a pump which threw water in a continuous stream, using only one piston, and that he made a great mystery of it; but that M. du Fay immediately stated the reason of it."

"Most often it is the case that people know that something big can be manipulated with it [i.e., the screw], but not how and in what way it is connected to time, and that untold time, and finally such force of machines, wheels, and shafts is necessary as cannot be produced nor be had."

"Now it is a universal law of the perceptions obtained through the senses that we pay only so much attention to the sensations actually experienced as is sufficient for us to recognise external objects. In this respect we are very one-sided and inconsiderate partisans of practical utility; far more so indeed than we suspect. All sensations which have no direct reference to external objects, we are accustomed, as a matter of course, entirely to ignore, and we do not become aware of them till we make a scientific investigation of the action of the senses, or have our attention directed by illness to the phenomena of our own bodies. Thus we often find patients, when suffering under a slight inflammation of the eyes, become for the first time aware of those beads and fibres known as mouches volantes swimming about within the vitreous humour of the eye, and then they often hypochondriacally imagine all sorts of coming evils, because they fancy that these appearances are new, whereas they have generally existed all their lives."

"Every great deed of which history tells us, every mighty passion which art can represent, every picture of manners, of civic arrangements, of the culture of peoples of distant lands or of remote times, seizes and interests us, even if there is no exact scientific connection among them. We continually find points of contact and comparison in our own conceptions and feelings; we get to know the hidden capacities and desires of the mind, which in the ordinary peaceful course of civilised life remain unawakened. It is not to be denied that, in the natural sciences, this kind of interest is wanting. Each individual fact, taken by itself, can indeed arouse our curiosity or our astonishment, or be useful to us in its practical applications. But intellectual satisfaction we obtain only from a connection of the whole, just from its conformity with law."

"There is a kind, I might almost say, of artistic satisfaction, when we are able to survey the enormous wealth of Nature as a regularly ordered whole — a kosmos, an image of the logical thought of our own mind."

"The formation of scales and of the web of harmony is a product of artistic invention, and is in no way given by the natural structure or by the natural behaviour of our hearing, as used to be generally maintained hitherto."

"As you are aware, no perceptions obtained by the senses are merely sensations impressed on our nervous systems. A peculiar intellectual activity is required to pass from a nervous sensation to the conception of an external object, which the sensation has aroused. The sensations of our nerves of sense are mere symbols indicating certain external objects, and it is usually only after considerable practice that we acquire the power of drawing correct conclusions from our sensations respecting the corresponding objects."

"The last decades of scientific development have led us to the recognition of a new universal law of all natural phenomena, which, from its extraordinarily extended range, and from the connection which it constitutes between natural phenomena of all kinds, even of the remotest times and the most distant places, is especially fitted to give us an idea of what I have described as the character of the natural sciences, which I have chosen as the subject of this lecture."

"The quantity of force which can be brought into action in the whole of Nature is unchangeable, and can neither be increased nor diminished."

"In speaking of the work of machines and of natural forces we must, of course, in this comparison eliminate anything in which activity of intelligence comes into play. The latter is also capable of the hard and intense work of thinking, which tries a man just as muscular exertion does."

"The external work of man is of the most varied kind as regards the force or ease, the form and rapidity, of the motions used on it, and the kind of work produced. But both the arm of the blacksmith who delivers his powerful blows with the heavy hammer, and that of the violinist who produces the most delicate variations in sound, and the hand of the lacemaker who works with threads so fine that they are on the verge of the invisible, all these acquire the force which moves them in the same manner and by the same organs, namely, the muscles of the arm. An arm the muscles of which are lamed is incapable of doing any work; the moving force of the muscle must be at work in it, and these must obey the nerves, which bring to them orders from the brain. That member is then capable of the greatest variety of motions; it can compel the most varied instruments to execute the most diverse tasks."

"According to Sir W. Thomson's theory of Vortex Atoms, the substance of which the molecule consists is a uniformly dense plenum, the properties of which are those of a perfect fluid, the molecule itself being nothing but a certain motion impressed on a portion of this fluid, and this motion is shewn, by a theorem due to Helmholtz, to be as indestructible as we believe a portion of matter to be."

"And we know what Helmholtz, the highest authority in Europe on the subject, has said about the human eye; that if an optician had sold him an instrument so carelessly made, he would have thought himself fully justified in returning it."

"Formerly an anti-Semite was somebody who hated Jews because they were Jews and had a Jewish soul. But nowadays an anti-Semite is somebody who is hated by Jews."

"Auschwitz existed within history, not outside of it. The main lesson I learned there is simple: We Jews should never, ever become like our tormentors ...Since 1967 it has become obvious that political Zionism has one monolithic aim: Maximum land in Palestine with a minimum of Palestinians on it. This aim is pursued with an inexcusable cruelty as demonstrated during the assault on Gaza. The cruelty is explicitly formulated in the Dahiye doctrine of the military and morally supported by the Holocaust religion.I am pained by the parallels I observe between my experiences in Germany prior to 1939 and those suffered by Palestinians today. I cannot help but hear echoes of the Nazi mythos of "blood and soil" in the rhetoric of settler fundamentalism which claims a sacred right to all the lands of biblical Judea and Samaria. The various forms of collective punishment visited upon the Palestinian people — coerced ghettoization behind a "security wall"; the bulldozing of homes and destruction of fields; the bombing of schools, mosques, and government buildings; an economic blockade that deprives people of the water, food, medicine, education and the basic necessities for dignified survival — force me to recall the deprivations and humiliations that I experienced in my youth. This century-long process of oppression means unimaginable suffering for Palestinians."

"If we want to stay really human beings, we must get up and call the Zionists what they are: Nazi criminals. The hate of the Jews by the Germans was less deeply rooted than the hate of the Palestinians by the Israeli Jews. The brainwashing of the Jewish Israeli populations is going on for over sixty years. They cannot see a Palestinian as a human being."

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

"In electron microscopy, the difficulties took considerably more time to surmount, and therefore the doubters held the field for a longer period. I can, however, also confirm from my own experience the observation of my colleagues that the doubt of the others has the advantage of leaving the field uncrowded. Mostly, this is understood only much later, in the beginning one is very disappointed."

"Das Lichtmikroskop öffnete das erste Tor zum Mikrokosmos. Das Elektronenmikroskop öffnete das zweite Tor zum Mikrokosmos. Was werden wir finden wenn wir das dritte Tor öffnen?"

"Were it not for this inalterable armony, pre-established by God, between subject and object, all our thinking would be necessarily without fruit."

"Nature has put itself the problem of how to catch in flight light streaming to the Earth and to store the most elusive of all powers in rigid form. The plants take in one form of power, light; and produce another power, chemical difference."

"My early feeling that scientific truths are to the Christian religion much what brooks and rivers are to the ocean, has become my most vital conviction. Tempted as I was to drift with the tempest of passion, I had made shipwreck in these latter years, had not in my heaviest hours the Mercy of God, through your instrumentality, kept me always on the right path."

"With heartfelt conviction I say it: A sound philosophy must and can be nothing else than a propaedeutic to Christianity."

"A physicist must be able to saw with a file and to file with a saw."

"In der Quantenphysik dagegen bedeutet jede Beobachtung einen Eingriff in das Beobachtete; eine Zustandsveränderung am Beobachteten ist auf Grund der quantenphysikalischen Naturgesetze mit dem Beobachtungsprozess zwangslaüfig verknüpft. Also nicht ein sowieso, unabhängig von diesem Experiment vorhandener Tatbestand wird wahrgenommen, sondern wir selber rufen die Tatbestände hervor (oder: nötigen sie in bestimmter Richtung zu einer Klärung), die dann zur Wahrnehmung gelangen."

"Sind wirklich im ganzen unendlichen Raum Sonnen vorhanden, sie mögen nun in ungefähr gleichen Abständen von einander, oder in Milchstrassen-Systeme vertheilt sein, so wird ihre Menge unendlich, und da müsste der ganze Himmel ebenso hell sein, wie die Sonne. Denn jede Linie, die ich mir von unserm Auge gezogen denken kann, wird nothwendig auf irgend einen Fixstern treffen, und also müßte uns jeder Punkt am Himmel Fixsternlicht, also Sonnenlicht zusenden."

"Most probably some law hitherto undiscovered exists."

"In closing, I should like to cite a line from William Blake. “To see a world in a grain of sand - - - ” and allude to a possible parallel to see worlds in an electron."

"The problem was well expressed by Max Delbrück, one of Schrödinger's contemporaries, who expressed it in this way... so to encapsulate what Delbrück was saying is that, at the level of atoms it's just known physics, but at the level of the living cell, it's some sort of magic."

"If you're too sloppy, then you never get reproducible results, and then you never can draw any conclusions; but if you are just a little sloppy, then when you see something startling, (...) you nail it down (...). So I called it the "Principle of Limited Sloppiness"."

"The progress of science is tremendously disorderly, and the motivations that lead to this progress are tremendously varied, and the reasons why scientists go into science, the personal motivations, are tremendously varied. I have said … that science is a haven for freaks, that people go into science because they are misfits, and that it is a sheltered place where they can spin their own yarn and have recognition, be tolerated and happy, and have approval for it."

"The particular thing about science is to combine that [the dreams of obtaining power] with a retreat from the world. Other people want to obtain power by going out into the world, but the scientist really wants to obtain power by retreating from the world."

"Any living cell carries with it the experiences of a billion years of experimentation by its ancestors. You cannot expect to explain so wise an old bird in a few simple words."

"The scientist addresses an infinitesimal audience of fellow composers. His message is not devoid of universality but it's universality is disembodied and anonymous. While the artist's communication is linked forever with it's original form, that of the scientist is modified, amplified, fused with the ideas and results of others, and melts into the stream of knowledge and ideas which forms our culture. The scientist has in common with the artist only this: that he can find no better retreat from the world than his work and also no stronger link with his world than his work."

"The curiosity remains... to grasp more clearly how the same matter, which in physics and chemistry displays orderly and reproducible and relatively simple properties, arranges itself in the most astounding fashions as soon as it is drawn into the orbit of the living organism. The closer one looks at these performances of matter in living organisms the more impressive the show becomes. The meanest living cell becomes a magic puzzle box full of elaborate and changing molecules, and far outstrips all chemical laboratories of man in the skill of organic synthesis performed with ease, expedition, and good judgment of balance."

"Whenever I teach my semiconductor device physics course, one of the central messages I try to get across early is the importance of energy band diagrams. I often put this in the form of "Kroemer's Lemma of Proven Ignorance":"

":: If, in discussing a semiconductor problem, you cannot draw an Energy Band Diagram, this shows that you don't know what you are talking about,"

": with the corollary"

"Ultimately, progress in applications is not deterministic, but opportunistic, exploiting for new applications whatever new science and technology happen to be coming along."

"There are many examples in physics showing that higher precision revealed new phenomena, inspired new ideas, or confirmed or dethroned well-established theories."

"Whenever I came to him (Fritz Sauter) with a pure physics idea, he would invariably say, with slight sarcasm: "But Mr. Kroemer, you ought to be able to formulate this mathematically! " If I came to him with a math formulation, I would get, in a similar tone: "But Mr. Kroemer, that is just math, what is the physics?" After a few encounters of this kind, you got the idea: You had to be able to go back and forth with ease. Yet, in the last analysis, concepts took priority over formalism, the latter was simply an (indispensable) means to an end."

":: If you can draw one, but don't, then your audience won't know what you are talking about."

"The principal applications of any sufficiently new and innovative technology always have been—and will continue to be—applications created by that technology."

"You need only a sheet of paper and so mathematics starts."