Max Planck

"Denn auch eine Enttäuschung, wenn sie nur gründlich und endgültig ist, bedeutet einen Schritt vorwärts, und die mit der Resignation verbundenen Opfer würden reichlich aufgewogen werden durch den Gewinn an Schätzen neuer Erkenntnis."

"[...] der unermeßlich reichen, stets sich erneuernden Natur gegenüber wird der Mensch, so weit er auch in der wissenschaftlichen Erkenntnis fortgeschritten sein mag, immer das sich wundernde Kind bleiben und muß sich stets auf neue Überraschungen gefaßt machen."

"Die Naturwissenschaft braucht der Mensch zum Erkennen, die Religion aber braucht er zum Handeln."

"Eine neue wissenschaftliche Wahrheit pflegt sich nicht in der Weise durchzusetzen, daß ihre Gegner überzeugt werden und sich als belehrt erklären, sondern vielmehr dadurch, daß ihre Gegner allmählich aussterben und daß die heranwachsende Generation von vornherein mit der Wahrheit vertraut gemacht ist."

"Es braucht kaum hervorgehoben zu werden, daß diese neue Auffassung des Zeitbegriffs an die Abstraktionsfähigkeit und an die Einbildungskraft des Physikers die allerhöchsten Anforderungen stellt. Sie übertrifft an Kühnheit wohl alles, was bisher in der spekulativen Naturforschung, ja in der philosophischen Erkenntnistheorie geleistet wurde; die nichteuklidische Geometrie ist Kinderspiel dagegen. [...] Mit der durch dies Prinzip im Bereiche der physikalischen Weltanschauung hervorgerufenden Umwälzung ist an Ausdehnung und Tiefe wohl nur noch die durch die Einführung des Copernikanischen Weltsystems bedingte zu vergleichen."

"Es ist der stetig fortgesetzte, nie erlahmende Kampf gegen Skeptizismus und gegen Dogmatismus, gegen Unglaube und gegen Aberglaube, den Religion und Naturwissenschaft gemeinsam führen, und das richtungsweisende Losungswort in diesem Kampf lautet von jeher und in alle Zukunft: Hin zu Gott!"

"Welches ist nun die Richtung dieses Fortschrittes und welchem Ziel strebt er zu? Die Richtung ist offenbar eine beständige Verfeinerung des Weltbildes durch Zurückführung der in ihm enthaltenen realen Elemente auf ein höheres Reales von weniger naiver Beschaffenheit. Das Ziel aber ist die Schaffung eines Weltbildes, dessen Realitäten keinerlei Verbesserung mehr bedürftig sind und die daher das endgültig Reale darstellen. Eine nachweisliche Erreichung dieses Zieles wird und kann niemals gelingen."

"Wer es einmal so weit gebracht hat, daß er nicht mehr irrt, der hat auch zu arbeiten aufgehört."

"Was wir heutzutage aus der Sprache der Spektren heraus hören, ist eine wirkliche Sphärenmusik des Atoms, ein Zusammenklingen ganzzahliger Verhältnisse, eine bei aller Mannigfaltigkeit zunehmende Ordnung und Harmonie. Für alle Zeiten wird die Theorie der Spektrallinien den Namen Bohrs tragen. Aber noch ein anderer Name wird dauernd mit ihr verknüpft sein, der Name Plancks. Alle ganzzahligen Gesetze der Spektrallinien und der Atomistik fließen letzten Endes aus der Quantentheorie. Sie ist das geheimnisvolle Organon, auf dem die Natur die Spektralmusik spielt und nach dessen Rhythmus sie den Bau der Atome und der Kerne regelt."

"Farsighted theologians are now working to mine the eternal metal from the teachings of Jesus and to forge it for all time."

"We have no right to assume that any physical laws exist, or if they have existed up to now, that they will continue to exist in a similar manner in the future."

"I regard consciousness as fundamental. I regard matter as derivative from consciousness. We cannot get behind consciousness. Everything that we talk about, everything that we regard as existing, postulates consciousness."

"I also knew the formula that expresses the energy distribution in the normal spectrum. A theoretical interpretation therefore had to be found at any cost, no matter how high. It was clear to me that classical physics could offer no solution to this problem, and would have meant that all energy would eventually transfer from matter to radiation. ...This approach was opened to me by maintaining the two . The two laws, it seems to me, must be upheld under all circumstances. For the rest, I was ready to sacrifice every one of my previous convictions about physical laws. ...[One] finds that the continuous loss of energy into radiation can be prevented by assuming that energy is forced at the outset to remain together in certain quanta. This was purely a formal assumption and I really did not give it much thought except that no matter what the cost, I must bring about a positive result."

"New scientific ideas never spring from a communal body, however organized, but rather from the head of an individually inspired researcher who struggles with his problems in lonely thought and unites all his thought on one single point which is his whole world for the moment."

"Als Physiker, der sein ganzes Leben der nüchternen Wissenschaft, der Erforschung der Materie widmete, bin ich sicher von dem Verdacht frei, für einen Schwarmgeist gehalten zu werden. Und so sage ich nach meinen Erforschungen des Atoms dieses: Es gibt keine Materie an sich. Alle Materie entsteht und besteht nur durch eine Kraft, welche die Atomteilchen in Schwingung bringt und sie zum winzigsten Sonnensystem des Alls zusammenhält. Da es im ganzen Weltall aber weder eine intelligente Kraft noch eine ewige Kraft gibt—es ist der Menschheit nicht gelungen, das heißersehnte Perpetuum mobile zu erfinden—so müssen wir hinter dieser Kraft einen bewußten intelligenten Geist annehmen. Dieser Geist ist der Urgrund aller Materie."

"Eine neue wissenschaftliche Wahrheit pflegt sich nicht in der Weise durchzusetzen, daß ihre Gegner überzeugt werden und sich als belehrt erklären, sondern vielmehr dadurch, daß ihre Gegner allmählich aussterben und daß die heranwachsende Generation von vornherein mit der Wahrheit vertraut gemacht ist. … Eine neue große wissenschaftliche Idee pflegt sich nicht in der Weise durchzusetzen, daß ihre Gegner allmählich überzeugt und bekehrt werden — daß aus einem Saulus ein Paulus wird, ist eine große Seltenheit —, sondern vielmehr in der Weise, dass die Gegner allmählich aussterben und daß die heranwachsende Generation von vornherein mit der Idee vertraut gemacht wird. Auch hier heißt es wieder: Wer die Jugend hat, der hat die Zukunft."

"The energy and entropy of the world have no meaning, because such quantities admit of no accurate definition."

"Experimenters are the shocktroops of science… An experiment is a question which science poses to Nature, and a measurement is the recording of Nature’s answer. But before an experiment can be performed, it must be planned – the question to nature must be formulated before being posed. Before the result of a measurement can be used, it must be interpreted – Nature’s answer must be understood properly. These two tasks are those of theorists, who find himself always more and more dependent on the tools of abstract mathematics."

"Under these conditions it is no wonder, that the movement of atheists, which declares religion to be just a deliberate illusion, invented by power-seeking priests, and which has for the pious belief in a higher Power nothing but words of mockery, eagerly makes use of progressive scientific knowledge and in a presumed unity with it, expands in an ever faster pace its disintegrating action on all nations of the earth and on all social levels. I do not need to explain in any more detail that after its victory not only all the most precious treasures of our culture would vanish, but — which is even worse — also any prospects at a better future."

"It [science] has as its highest principle and most coveted aim the solution of the problem to condense all natural phenomena which have been observed and are still to be observed into one simple principle, that allows the computation of past and more especially of future processes from present ones. ...Amid the more or less general laws which mark the achievements of physical science during the course of the last centuries, the principle of least action is perhaps that which, as regards form and content, may claim to come nearest to that ideal final aim of theoretical research."

"Experiments are the only means of knowledge at our disposal. The rest is poetry, imagination."

"That God existed before there were human beings on Earth, that He holds the entire world, believers and non-believers, in His omnipotent hand for eternity, and that He will remain enthroned on a level inaccessible to human comprehension long after the Earth and everything that is on it has gone to ruins; those who profess this faith and who, inspired by it, in veneration and complete confidence, feel secure from the dangers of life under protection of the Almighty, only those may number themselves among the truly religious."

"To believe in science, one must believe in the rationality of the world."

"It is not the possession of truth, but the success which attends the seeking after it, that enriches the seeker and brings happiness to him."

"In other words, the fundamental principles and indispensable postulates of every genuinely productive science are not based on pure logic but rather on the metaphysical hypothesis — which no rules of logic can refute — that there exists an outer world which is entirely independent of ourselves. It is only through the immediate dictate of our consciousness that we know that this world exists. And that consciousness may to a certain degree be called a special sense."

"But science sets out confidently on the endeavor finally to know the thing in itself, and even though we realize that this ideal goal can never be completely reached, still we struggle on towards it untiringly. And we know that at every step of the way each effort will be richly rewarded."

"The first and most important quality of all scientific ways of thinking must be the clear distinction between the outer object of observation and the subjective nature of the observer."

"Anybody who has been seriously engaged in scientific work of any kind realizes that over the entrance to the gates of the temple of science are written the words: Ye must have faith. It is a quality which the scientist cannot dispense with."

"Again and again the imaginary plan on which one attempts to build up that order breaks down and then we must try another. This imaginative vision and faith in the ultimate success are indispensable. The pure rationalist has no place here."

"Science cannot solve the ultimate mystery of nature. And that is because, in the last analysis, we ourselves are part of nature and therefore part of the mystery that we are trying to solve."

"Both religion and science require a belief in God. For believers, God is in the beginning, and for physicists He is at the end of all considerations… To the former He is the foundation, to the latter, the crown of the edifice of every generalized world view."

"Natural science wants man to learn, religion wants him to act."

"Long and tedious reflection cannot enable us to shape our decisions and attitudes properly; only that definite and clear instruction which we gain can form a direct inner link to God. This instruction alone is able to give us the inner firmness and lasting peace of mind which must be regarded as the highest boon in life. And if we ascribe to God, in addition to His omnipotence and omniscience, also the attributes of goodness and love, recourse to Him produces an increased feeling of safety and happiness in the human being thirsting for solace. Against this conception not even the slightest objection can be raised from the point of natural science, for as we pointed it out before, questions of ethics are entirely outside of its realm."

"No matter where and how far we look, nowhere do we find a contradiction between religion and natural science. On the contrary, we find a complete concordance in the very points of decisive importance. Religion and natural science do not exclude each other, as many contemporaries of ours would believe or fear. They mutually supplement and condition each other. The most immediate proof of the compatibility of religion and natural science, even under the most thorough critical scrutiny, is the historical fact that the very greatest natural scientists of all times—men such as Kepler, Newton, Leibniz—were permeated by a most profound religious attitude."

"Religion and natural science are fighting a joint battle in an incessant, never relaxing crusade against scepticism and against dogmatism, against disbelief and against superstition, and the rallying cry in this crusade has always been, and always will be: "On to God!""

"I... turned to the main topic of my... work... the study of... thermodynamics."

"[T]he writings of Rudolf Clausius... through their simplicity, clarity, and... preciseness made me... dedicate myself... to the... laws of theory."

"I was interested in the concept introduced by Clausius, entropy.., (in addition to energy,) one of the most important variables of nature."

"Energy remains constant and entropy always grows and can never be reduced... [T]his is the essence of the second law of thermodynamics...the entropy of a system of bodies can... only increase."

"In the limiting case, entropy] stays the same. If it increases.., the process is irreversible. If it remains the same.., the process is reversible... [i.e.,] you can let it run backwards."

"When occurs, entropy has reached... maximum. If entropy can no longer grow.., no change can occur. This... I applied to physical-chemical and to radiation equilibria."

"In physical-chemical equilibria, an American was faster... John Willard Gibbs... Regarding radiation equilibrium... I... built the foundations."

"I did not find the entropy of heat radiation... purely theoretically in the beginning. I only found it by reference to experimental measurements... To interpret these laws... found experimentally.., I was guided by the thoughts of Ludwig Boltzmann.., who was able to interpret the entropy of a from... atomic theory, as the logarithm of the probability of the state of the gas."

"The application of Boltzmann's procedure to could only succeed if one considered radiation as atomistic.., as a combination of... quanta... of a specific size.., known... by the previous measurements."

"At first I did not like this... as it contradicted... classical atomistics, and later... thanks to... numerous colleagues, it was shown to correspond to reality."

"It took a number of years until the physics community took notice of my theory... [I]t was misunderstood by many... and... ignored..."

"Due to more precise measurements... the values of the... physical constant.., the electric elementary quantum.., were getting closer to the value... I predicted from the radiation measurements."

"I generally always turned my interest to questions which possibly lead to a simplification... of ."

"[[Quantum mechanics|[Q]uantum theory]] has not reached its full maturity... [W]e still need... generalizations.., abstractions... This is... unsatisfactory, but... also... appropriate and joyful, because we will never reach the final conclusion about nature."

"Scientific pursuit will never stop. It would be terrible if it would... If there were no more problems, one would... turn one's head off and... not work any more. Such tranquility is stagnation and... death in a scientific sense."

"[[Happiness|[H]appiness]] of the scientist lies not in possessing the truth, but in discovering..."

"No burden is so heavy for a man to bear as a succession of happy days."

"There is no particular mystery about mathematical analysis; its only distinguishing feature is that it is more trustworthy, more precise, and permits us to proceed farther and along safer lines. Consider, for example, the well-known change of colour from red to white displayed by the light radiated through an aperture made in a heated enclosure, as the temperature increases. From this elementary fact of observation Planck, thanks to mathematical analysis, was able to deduce the existence of light quanta and thence the possibility that all processes of change were discontinuous, and that a body could only rotate with definite speeds. Obviously, commonplace reasoning unaided by mathematics would never have led us even to suspect these extraordinary results."

"Inasmuch as both Rayleigh's and Wien's laws of radiation, though incorrect, appear to express facts correctly at opposite limits of temperature and frequency, we may presume that the correct law must have an intermediary form, passing over into Rayleigh's when [temperature] T is large and [frequency] ν small, and into Wein's when the reverse situation... Planck, guided by these considerations, devised a new theory of radiation which he called the "Quantum Theory." From this theory Planck was able to derive a radiation law which satisfied Wien's relation, ...the displacement law [when the temperature is increased, intensities of all the frequencies increase, while the radiation of maximum intensity is directly proportional to the absolute temperature] and Stefan's law, and which was in excellent agreement with experimental measurements at all temperatures."

"Besides inventing quantum theory, Planck had made another great contribution to science by welcoming and generously supporting the young Albert Einstein. In 1905, when Einstein, then an unknown employee of the Swiss patent office in Bern, sent five revolutionary papers to the physics journal that Planck edited in Berlin, Planck immediately recognized them as works of genius and published them quickly without sending them to referees. He did not agree with all of Einstein’s ideas, but he published all of them. He helped Einstein to move ahead in the academic world, and in 1913 invited him to a full professorship in Berlin. For twenty years Planck and Einstein were friends and colleagues in Berlin, leaders of a scientific community that remained creative and vibrant, in spite of the political and economic disarray that surrounded them. Planck was the rock-solid central figure of German science, with the vision to promote the unorthodox and unpatriotic citizen-of-the-world Einstein."

"A man to whom it has been given to bless the world with a great creative idea has no need for the praise of posterity. His very achievement has already conferred a higher boon upon him."

"It was Planck's law of radiation that yielded the first exact determination—independent of other assumptions—of the absolute magnitudes of atoms. More than that, he showed convincingly that in addition to the atomistic structure of matter there is a kind of atomistic structure to energy, governed by the universal constant h, which was introduced by Planck. This discovery became the basis of all twentieth-century research in physics and has almost entirely conditioned its development ever since. Without this discovery it would not have been possible to establish a workable theory of molecules and atoms and the energy processes that govern their transformations. Moreover, it has shattered the whole framework of classical mechanics and electrodynamics and set science a fresh task: that of finding a new conceptual basis for all of physics."

"Max Planck says, The opposition never yields; they just die off. It’s just a question of time. They are dying off."

"It is clear, however, that the distinguishing mark of the whole development of theoretical chemistry and physics is the elimination of the anthropomorphic elements, especially specific sense-impressions, from the concepts. This process is called by Prof. M. Planck the objectification of the physical system."

"In early physical systems we have optics dealing with phenomena perceived by the eye; acoustics treating of auditory percepts, and so on. The subjective concepts of "tone" and "colour" have now been replaced by the objectified concepts of frequency of vibration; and wave-length. The object of this process of elimination is, according to Planck, the striving towards a unification of the whole theoretical system, so that it shall be equally significant for all intelligent beings."

"Planck ...devised his quanta theory, according to which the exchange of energy between the matter and the ether—or rather between ordinary matter and the small resonators whose vibrations furnish the light of incandescent matter—can take place only intermittently. A resonator can not gain energy or lose it in a continuous manner. It can not gain a fraction of a quantum; it must acquire a whole quantum or none at all."

"Planck was interested in physics, so he sought out the advice of Philipp von Jolly of the University of Munich, which he was to enter. Jolly... told Planck that "in this field, almost everything is already discovered, and all that remains is to fill a few unimportant holes." ...Planck replied that he didn't wish to discover new things, only to understand what was already known in the field."

"So by December 1900 Planck had changed everything in physics and chemistry. The only problem was he didn’t realize it. [...] Although he didn’t realize it, Planck had removed a foundation stone from the edifice of classical physics; it would take another twenty-five years for the entire structure to collapse. However, the immediate reaction was ... nothing. For the next five years neither Planck nor any of the great physicists of the era took up the meaning and extension of Planck’s ideas."

"Planck had slipped the quantum of action into his not fully consistent reasoning. He had, without wholly realizing it, introduced an essential element of discreteness into the description of nature, an element alien to the theories of mechanics and electromagnetism as they then existed. To the young Einstein, however, the imperfections were all too clear... he was hit with a new paradox: Planck was deriving empirically correct equations from hypotheses that contradicted the principles of physics..."

"Many kinds of men devote themselves to science, and not all for the sake of science herself. There are some who come into her temple because it offers them the opportunity to display their particular talents. To this class of men science is a kind of sport in the practice of which they exult, just as an athlete exults in the exercise of his muscular prowess. There is another class of men who come into the temple to make an offering of their brain pulp in the hope of securing a profitable return. These men are scientists only by the chance of some circumstance which offered itself when making a choice of career. If the attending circumstances had been different, they might have become politicians or captains of business. Should an angel of God descend and drive from the temple of science all those who belong to the categories I have mentioned, I fear the temple would be nearly emptied. But a few worshipers would still remain -- some from former times and some from ours. To these latter belongs our Planck. And that is why we love him."