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April 10, 2026
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"Mechanical knowledge may... be distinguished into three kinds; purely scientific knowledge, purely practical knowledge, and that intermediate kind of knowledge which relates to the application of scientific principles to practical purposes, and which arises from understanding the harmony of theory and practice."
"The objects of instruction in purely scientific mechanics and physics are, first, to produce in the student that improvement of the understanding which results from the cultivation of natural knowledge, and that elevation of mind which flows from the contemplation of the order of the universe; and secondly, if possible, to qualify him to become a scientific discoverer."
"The ill-success of the projects of misdirected ingenuity has very naturally the effect of driving those men of practical skill, who, though without scientific knowledge, possess prudence and common sense, to the opposite extreme of caution, and of inducing them to avoid all experiments, and to confine themselves to the careful copying of successful existing structures and machines; a course which, although it avoids risk, would, if generally followed, stop the progress of all improvement. A similar course has sometimes... been adopted by men possessed of scientific as well as practical skill: such men having, in certain cases, from deference to popular prejudice, or from a dread of being reputed us theorists, considered it advisable to adopt the worse and customary design for a work in preference to a better but unusual design."
"But a class of structures fraught with much greater evils exist in great abundance throughout the country—namely, those in which the faults of an unscientific design have been so far counteracted by massive strength, good materials, and careful workmanship, that a temporary stability has been produced, but which contain within themselves sources of weakness, obvious to a scientific examination... that must inevitably cause their destruction within a limited number of years."
"Another evil, and one of the worst which arises from the separation of theoretical and practical knowledge, is the fact that a large number of persons, possessed of an inventive turn of mind and of considerable skill in the manual operations of practical mechanics, are destitute of that knowledge of scientific principles which is requisite to prevent their being misled by their own ingenuity. Such men too often spend their money, waste their lives, and it may be lose their reason in the vain pursuits of visionary inventions, of which a moderate amount of theoretical knowledge would be sufficient to demonstrate the fallacy ; and for want of such knowledge, many a man who might have been a useful and happy member of society, becomes a being than whom it would be hard to find anything more miserable. The number of those unhappy persons — to judge from the patent-lists, and from some of the mechanical journals — must be much greater than is generally believed."
"In this branch of study exactness is an essential feature; and mathematical difficulties must not be shrunk from when the nature of the subject leads to them."
"The most absurd of all their delusions commonly called the , or to speak more accurately, the inexhaustible source of power—is, in various forms, the subject of several patents in each year."
"A hypothetical theory is necessary, as a preliminary step, to reduce the expression of the phenomena to simplicity and order before it is possible to make any progress in framing an abstractive theory."
"The evil influence of the supposed inconsistency of theory and practice upon speculative science, although much less conspicuous than it was in the ancient and middle ages, is still occasionally to be traced. This it is which opposes the mutual communication of ideas between men of science and men of practice, and which leads scientific men sometimes to employ, on problems that can only be regarded as ingenious mathematical exercises, much time and mental exertion that would be better bestowed on questions having some connection with the arts, and sometimes to state the results of really important investigations on practical subjects in a form too abstruse for ordinary use; so that the benefit which might be derived from their application is for years lost to the public; and valuable practical principles which might have been anticipated by reasoning, are left to be discovered by slow and costly experience."
"The ascertainment and illustration of truth are the objects; and structures and machines are looked upon merely as natural bodies are; namely, as furnishing experimental data for the ascertaining of principles and examples for their application."
"[O]f that scientifically practical skill which produces the greatest effect with the least possible expenditure of material and work, the instances are comparatively rare. In too many cases we see the strength and the stability which ought to be given by the skilful arrangement of the parts of a structure supplied by means of clumsy massiveness, and of lavish expenditure of material, labour, and money; and the evil is increased by a perversion of the public taste, which causes works to be admired, not in proportion to their fitness for their purposes, or to the skill evinced in attaining that fitness, but in proportion to their size and cost."
"A physical theory, like an abstract science, consists of definitions and axioms as first principles, and of propositions, their consequences; but with these differences:—first, That in an abstract science, a definition assigns a name to a class of notions derived originally from observation, but not necessarily corresponding to any existing objects of real phenomena, and an axiom states a mutual relation amongst such notions, or the names denoting them; while in a physical science, a definition states properties common to a class of existing objects, or real phenomena, and a physical axiom states a general law as to the relations of phenomena; and, secondly,—That in an abstract science, the propositions first discovered are the most simple; whilst in a physical theory, the propositions first discovered are in general numerous and complex, being formal laws, the immediate results of observation and experiment, from which the definitions and axioms are subsequently arrived at by a process of reasoning differing from that whereby one proposition is deduced from another in an abstract science, partly in being more complex and difficult, and partly in being to a certain extent tentative, that is to say, involving the trial of conjectural principles, and their acceptance or rejection according as their consequences are found to agree or disagree with the formal laws deduced immediately from observation and experiment."
"With respect to those works which, from unscientific design, give way during or immediately after their erection, I shall say little; for with all their evils, they add to our experimental knowledge, and convey a lesson, though a costly one."
"The hypothesis of molecular vortices is defined to be that which assumes — that each atom of matter consists of a nucleus or central point enveloped by an elastic atmosphere, which is retained in its position by attractive forces, and that the elasticity due to heat arises from the centrifugal force of those atmospheres revolving or oscillating about their nuclei or central points. According to this hypothesis, quantity of heat is the vis viva of the molecular revolutions or oscillations."
"Discrepancy between theory and practice, which in sound physical and mechanical science is a delusion, has a real existence in the minds of men; and that fallacy, through rejected by their judgments, continues to exert and influence over their acts."
"This law (regarding the theoretical efficiency of heat engines by Mr. Joule), and the law of the maximum efficiency of heat engines, are particular cases of a general law which regulates all transformation of energy, and is the basis of the Science of Energetics."
"An essential distinction exists between two stages in the process of advancing our knowledge of the laws of physical phenomena; the first stage consists in observing the relations of phenomena, whether of such as occur in the ordinary course of nature, or of such as are artificially produced in experimental investigations, and in expressing the relations so observed by propositions called formal laws. The second stage consists in reducing the formal laws of an entire class of phenomena to the form of a science; that is to say, in discovering the most simple system of principles, from which all the formal laws of the class of phenomena can be deduced as consequences."
"There can be no doubt that our descendants will learn to exploit the energy of fusion for peaceful purposes even before its use becomes necessary for the preservation of human civilization."
"Our relationships as experimentalists with theoretical physicists should be like those with a beautiful woman – we should accept with gratitude any favours she offers, but we should not expect too much nor believe all that is said."
"Science is a way to pursue one's sense of inquiry at the expense of the State."
"If the Steam Engine be the most powerful instrument in the hands of man, to alter the face of the physical world, it operates, at the same time, as a powerful moral lever in forwarding the great cause of civilization. ...If ...we are now met to consider of placing a monument to the memory of Mr. Watt beside the monuments of those who fell in the splendid victories of the last war, let it not be said that there is no connexion between the services of this modest and unobtrusive benefactor of his country, and the triumphs of the heroes which those monuments are destined to commemorate. ...It has been often said, that many of the great discoveries in science are due to accident; but it was well remarked by [Humphry Davy]... that this cannot be the case with the principal discovery of Mr. Watt. ... Again, it has frequently happened that those philosophers, who have made brilliant and useful discoveries... have only been able to turn their discoveries to the purpose of averting evils threatening, and often destroying, the precarious tenure of human existence. Thus Franklin disarmed the thunderbolt, and conducted it innocuous through our buildings, and close to our fire-sides—thus Jenner stripped a loathsome and destructive disease of its virulence, and rendered it harmless of devastation—thus [Davy]... sent the safety lamp into our mines to save... their useful inhabitants from the awful explosion of the fire damp. But the discovery of Mr. Watt went further: he subdued and regulated the most terrific power in the universe,—that power which, by the joint operation of pressure and heat, probably produces those tremendous convulsions of the earth, which in a moment subvert whole cities, and almost change the face of the inhabited globe. This apparently ungovernable power Mr. Watt reduced to a state of such perfect organization and discipline... that it may now be safely manœuvred and brought into irresistible action—irresistible, but still regulated, measured, and ascertained—or lulled into the most complete and secure repose, at the will of man, and under the guidance of his feeble hand. Thus one man directs it into the bowels of the earth, to tear asunder its very elements, and bring to light its hidden treasures; another places it upon the surface of the waters, to control the winds of heaven, to stem the tides, to check the currents, and defy the waves of the ocean; a third, perhaps and a fourth, are destined to apply this mighty power to other purposes, still unthought of and unsuspected, but leading to consequences, possibly not less important than those which it has already produced. ... those benefits, conferred by Mr. Watt on the whole civilized world, have been most experienced by his own country, which owes a tribute of national gratitude to a man, who has thus honoured her by his genius, and promoted her well being by his discoveries."
"These foundations decisively changed incentives for people and impelled the engines of prosperity, paving the way for the Industrial Revolution. First and foremost, the Industrial Revolution depended on major technological advances exploiting the knowledge base that had accumulated in Europe during the past centuries. It was a radical break from the past, made possible by scientific inquiry and the talents of a number of unique individuals. The full force of this revolution came from the market that created profitable opportunities for technologies to be developed and applied. It was the inclusive nature of markets that allowed people to allocate their talents to the right lines of business. It also relied on education and skills, for it was the relatively high levels of education, at least by the standards of the time, that enabled the emergence of entrepreneurs with the vision to employ new technologies for their businesses and to find workers with the skills to use them. It is not a coincidence that the Industrial Revolution started in England a few decades following the Glorious Revolution. The great inventors such as James Watt (perfecter of the steam engine), Richard Trevithick (the builder of the first steam locomotive), Richard Arkwright (the inventor of the spinning frame), and Isambard Kingdom Brunel (the creator of several revolutionary steamships) were able to take up the economic opportunities generated by their ideas, were confident that their property rights would be respected, and had access to markets where their innovations could be profitably sold and used."
"Almost everybody is sure... that it is proceeding with unprecedented speed; and... that its effects will be more radical than anything that has gone before. Wrong, and wrong again. Both in its speed and its impact, the information revolution uncannily resembles its two predecessors... The first industrial revolution, triggered by James Watt's improved steam engine in the mid-1770s... did not produce many social and economic changes until the invention of the railroad in 1829... Similarly, the invention of the computer in the mid-1940s... it was not until 40 years later, with the spread of the Internet in the 1990s, that the information revolution began to bring about big economic and social changes... the same emergence of the “super-rich” of their day, characterized both the first and the second industrial revolutions... These parallels are close and striking enough to make it almost certain that, as in the earlier industrial revolutions, the main effects of the information revolution on the next society still lie ahead."
"In science its main worth is temporary, as a stepping-stone to something beyond. Even the Principia, as Newton, with characteristic modesty entitled his great work, is truly but the beginning of a natural philosophy, and no more an ultimate work than Watt's steam-engine, or Arkwright's spinning-machine."
"I can think of nothing else than this machine."
"It is not worth my while to manufacture in three countries only; but I can find it very worthwhile to make it for the whole world."
"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?"
"Innovation is everything. When you're on the forefront, you can see what the next innovation needs to be. When you're behind, you have to spend your energy catching up."
"As the Knowledge of Nature tends to enlarge the human Mind, and give us more noble, more grand, and exalted Ideas of the AUTHOR of Nature, and if well pursu'd, seldom fails producing something useful to Man."
"I've reached the age where young people frequently ask for my advice. All I can really say is that electronics is a fascinating field that I continue to find fulfilling. The field is still growing rapidly, and the opportunities that are ahead are at least as great as they were when I graduated from college. My advice is to get involved and get started."
"It is electromagnetism (EM) in all its many forms that has been so basic, that haunts us and guides us."
"In the past century, and even nowadays, one could encounter the opinion that in physics nearly everything had been done. There allegedly are only dim 'cloudlets' in the sky or theory, which will soon be eliminated to give rise to the 'theory of everything'. I consider these views as some kind of blindness. The entire history of physics, as well as the state of present-day physics and, in particular, astrophysics, testifies to the opposite. In my view we are facing a boundless sea of unresolved problems."
"I am not a supporter of Marxism, but I fully agree with this formulation. Another thing is that opium can sometimes be useful, and its use justified. For example, I envy believers. Indeed, I am 86 years old, I understand that death is close. And it can turn out to be painful, and no less painful are thoughts about the fate of loved ones. How good it would be to believe in the existence of, say, an afterlife, etc. But the mind is given to man in order to control his emotions and not engage in self-deception, belief in miracles."
"A certain ounce of arrogance is not essential in carrying forward an idea. In talking about the device with others, surprising now number of people who either were quite negative and had reasons to suggest it would not function as described or claimed that it would be of little interest and no better than some already existing device."
"Every physicist (naturally, this equally applies to other specialities, but I restrict myself to physicists for definitiveness) should simultaneously know, apart from theoretical physics, a wealth of facts from different branches of physics and be familiar with the newest notable accomplishments."
"The Nobel Prize in Physics 2009 was divided, one half awarded to Charles Kuen Kao "for groundbreaking achievements concerning the transmission of light in fibers for optical communication", the other half jointly to Willard S. Boyle and George E. Smith "for the invention of an imaging semiconductor circuit - the CCD sensor". He had no friends, and he was a nerd in school."
"Cardano was a man of universal interests, and much of his ability must have been inherited from his father, Fazio Cardano... a lawyer... but also deeply steeped in the medical sciences, mathematics, and all kinds of occult lore... he had... a high reputation as a scholar in his native town; even Leonardo da Vinci notes several times that he consulted Messer Fazio on geometric questions... he was appointed as a public lecturer in geometry."
"When Cardano's Consolation or Comforte was translated into English in 1573... one of the readers is known to have been William Shakespeare. ...Hamlet's thoughts on death and slumber are believed to have been inspired by... passages in Comforte..."
"A great number of writers on the history of medicine have indicated important observations and suggestions which made their intitial appearance with Cardano."
"The law which asserts that the equation X = 0, complete or incomplete, can have no more real positive roots than it has changes of sign, and no more real negative roots than it has permanences of sign, was apparently known to Cardan; but a satisfactory statement is possibly due to Harriot (died 1621) and certainly to Descartes."
"The application of the theory [of probability] to mortality tables in any large way may be said to have started with John Graunt... The first tables of great importance, however, were those of Edmund Halley... however... Cardan seems to have been the first to have been the first to consider the problem in a printed work, although his treatment is very fanciful. He gives a brief table in his proposition "Spatium vitae naturalis per spatium vitae fortuitum declarare," this appearing in the De Proportionibus Libri V..."
"Cardano's entertaining books on science and curiosities were among the best read and most pirated works in the sixteenth century. ...his work on the "Great Art" has been characterized as the first that goes decisively beyond the attainments of classical Greek mathematics."
"The problem of the biquadratic equation was laid prominently before Italian mathematicians by Zuanne de Tonini da Coi, who in 1540 proposed the problem, "Divide 10 parts into three parts such that they shall be continued in proportion and that the product of the first two shall be 6." He gave this to Cardan with the statement that it could not be solved, but Cardan denied the assertion, although himself unable to solve it. He gave it to Ferrari, his pupil, and the latter, although then a mere youth, succeeded where the master had failed. ...This method soon became known to algebraists through Cardan's Ars Magna, and in 1567 we find it used by Nicolas Petri [of Deventer]."
"Most important for the history of science is the fact that Liber de Ludo Aleae, "The Book of Games of Chance," contains the first study of the principles of probability. ...it would seem much more just to date the beginnings of probability theory from Cardano's treatise rather than the customary reckoning from Pascal's discussions with his friend de Méré and the ensuing correspondence with Fermat... at least a century after Cardano..."
"He... gave thirteen forms of the cubic which have positive roots, these having already been given by Omar Kayyam."
"The Ars Magna is a great advance on any algebra previously published. Hitherto algebraists had confined their attention to those roots of equations which were positive. Cardan discussed negative and even complex roots, and proved that the latter would always occur in pairs, though he declined to commit himself to any explanation as to the meaning of these "sophistic" quantities which he said were ingenious though useless."
"Most of his analysis of cubic equations seems to have been original; he shewed that if the three roots were real, Tartaglia's solution gave them in a form which involved imaginary quantities. Except for the somewhat similar researches of Bombelli a few years later, the theory of imaginary quantities received little further attention from mathematicians until John Bernoulli and Euler took up the matter after the lapse of nearly two centuries. Gauss first put the subject on a systematic and scientific basis, introduced the notation of complex variables, and used the symbol i, which had been introduced by Euler in 1777, to denote the square root of (-1): the modern theory is chiefly based on his researches."
"The first epoch-making algebra to appear in print was the Ars Magna of Cardan (1545). This was devoted primarily to the solution of algebraic equations. It contained the solution of the cubic and biquadratic equations, made use of complex numbers, and in general may be said to have been the first step toward modern algebra."
"Cardan was the most distinguished astrologer of his time, and when he settled in Rome he received a pension in order to secure his services as astrologer to the papal court. This proved fatal to him for, having foretold that he should die on a particular date, he felt obliged to commit suicide in order to keep up his reputation—so at least the story runs."