philosophy-of-science

"The old cosmological constant problem is to understand why the is so small; the new problem is to understand why it is comparable to the present mass density. ... does not help with either; anthropic considerations offer a possibility of solving both. In theories with a that takes random initial values, the anthropic principle may apply to the cosmological constant, but probably to nothing else."

"Once one starts to admit anthropic interpretations of fine-tuning problems like the cosmological constant, it is clear that such a proposal might be made for other fine-tuning problems, such as the problem of the Higgs boson mass. Certainly, we would not be here if the Higgs boson mass, and hence also the and and and masses, were greatly bigger. If they were near the , for example, any collection of more than a few elementary particles would collapse into a Black Hole. More generally, if the elementary particle masses were scaled up by a factor N, the number of elementary particles in a star or planet would scale down like N–3, and for very modest N the stars would stop shining."

"There seems to be a vast landscape of possible universes. ... We live in one in which life is possible, but if the universe were only slightly different, beings like us could not exist. What are we to make of this fine-tuning? Is it evident that the universe, after all, was designed by a benevolent creator? Or does science offer a different explanation?"

"δῶς μοι πᾶ στῶ καὶ τὰν γᾶν κινάσω."

"Soweit es sich hier um „Paria"-Intellektualismus handelt, ... beruht dessen Intensität darauf, daß die außerhalb oder am unteren Ende der sozialen Hierarchie stehenden Schichten gewissermaßen auf dem archimedischen Punkt gegenüber den gesellschaftlichen Konventionen, sowohl was die äußere Ordnung wie was die üblichen Meinungen angeht, stehen. Sie sind daher einer durch jene Konvention nicht gebundenen originären Stellungnahme zum „Sinn" des Kosmos und eines starken, durch materielle Rücksicht nicht gehemmten, ethischen und religiösen Pathos fähig."

"Make Christianity your own, and it will show you a point outside the world, and by means of this you will move heaven and earth."

"One needs occasionally to stand aside from the hum and rush of human interests and passions to hear the voices of God. And it not unfrequently happens that the All-loving gives a great push to certain souls to thrust them out, as it were, from the distracting current for awhile to promote their discipline and growth, or to enrich them by communion and reflection. And similarly it may be woman's privilege from her peculiar coigne of vantage as a quiet observer, to whisper just the needed suggestion or the almost forgotten truth. The colored woman, then, should not be ignored because her bark is resting in the silent waters of the sheltered cove. She is watching the movements of the contestants none the less and is all the better qualified, perhaps, to weigh and judge and advise because not herself in the excitement of the race."

"It is important to keep straight what does and what does not change in scientific revolutions, a distinction that is not made in Structure. There is a "hard" part of modern physical theories ("hard" meaning not difficult, but durable, like bones in paleontology or potsherds in archeology) that usually consists of the equations themselves, together with some understandings about what the symbols mean operationally and about the sorts of phenomena to which they apply. Then there is a "soft" part; it is the vision of reality that we use to explain to ourselves why the equations work. The soft part does change; we no longer believe in Maxwell's ether, and we know that there is more to nature than Newton's particles and forces. The changes in the soft part of scientific theories also produce changes in our understanding of the conditions under which the hard part is a good approximation. But after our theories reach their mature forms, their hard parts represent permanent accomplishments. If you have bought one of those T-shirts with Maxwell's equations on the front, you may have to worry about its going out of style, but not about its becoming false. We will go on teaching Maxwellian electrodynamics as long as there are scientists. I can't see any sense in which the increase in scope and accuracy of the hard parts of our theories is not a cumulative approach to truth."

"This reality crisis has grown so dire that Stephen Hawking has called for a kind of philosophical surrender, a white flag he terms "model-dependent realism", which basically says that while our theoretical models offer possible descriptions of the world, we'll simply never know the true reality that lies beneath. Perhaps there is no reality at all. But structural realism offers a way out. An explanation. A reality. The only catch is that it's not made of physical objects. Then again, our theories never said it was. Electrons aren't real, but the mathematical structure of quantum field theory is. Gauge forces aren't real, but the symmetry groups that describe them are. The dimensions, geometries and even strings described by any given string theory aren't real—what's real are the mathematical maps that transform one string theory into another."

"Structural realism—in its metaphysical version, championed by the philosopher of science James Ladyman—is the deepest explanation I know, because it serves as a kind of meta-explanation, one that explains the nature of reality and the nature of scientific explanations."

"Weirdly, although the beauty of physical theories is embodied in rigid mathematical structures based on simple underlying principles, the structures that have this sort of beauty tend to survive even when the underlying principles are found to be wrong. A good example is Dirac’s theory of the electron. Dirac in 1928 was trying to rework Schrödinger’s version of quantum mechanics in terms of particle waves so that it would be consistent with the special theory of relativity. This effort led Dirac to the conclusions that the electron must have a certain spin, and that the universe is filled with unobservable electrons of negative energy, whose absence at a particular point would be seen in the laboratory as the presence of an electron with the opposite charge, that is, an antiparticle of the electron. His theory gained an enormous prestige from the 1932 discovery in cosmic rays of precisely such an antiparticle of the electron, the particle now called the positron. Dirac’s theory was a key ingredient in the version of quantum electrodynamics that was developed and applied with great success in the 1930s and 1940s. But we know today that Dirac’s point of view was largely wrong. […] Yet the mathematics of Dirac’s theory has survived as an essential part of quantum field theory; it must be taught in every graduate course in advanced quantum mechanics. The formal structure of Dirac’s theory has thus survived the death of the principles of relativistic wave mechanics that Dirac followed in being led to his theory. So the mathematical structures that physicists develop in obedience to physical principles have an odd kind of portability. They can be carried over from one conceptual environment to another and serve many different purposes, like the clever bones in your shoulders that in another animal would be the joint between the wing and the body of a bird or the flipper and body of a dolphin. We are led to these beautiful structures by physical principles, but the beauty sometimes survives when the principles themselves do not."

"The principle of simplicity is the central theme of Ockham’s approach, so much so that this principle has come to be known as “Ockham’s Razor.” Ockham uses the razor to eliminate unnecessary hypotheses."

"A theory is the more impressive the greater the simplicity of its premises is, the more different kinds of things it relates, and the more extended its area of applicability."

"What is found in biology is mechanisms, mechanisms built with chemical components and that are often modified by other, later, mechanisms added to the earlier ones. While is a useful tool in the physical sciences, it can be a very dangerous implement in biology."

"There never was a sounder logical maxim of scientific procedure than Ockham's razor: Entia non sunt multiplicanda praeter necessitatem. That is to say; before you try a complicated hypothesis, you should make quite sure that no simplification of it will explain the facts equally well. No matter if it takes fifty generations of arduous experimentation to explode the simpler hypothesis, and no matter how incredible it may seem that that simpler hypothesis should suffice, still fifty generations are nothing in the life of science, which has all time before it; and in the long run, say in some thousands of generations, time will be economized by proceeding in an orderly manner, and by making it an invariable rule to try the simpler hypothesis first. Indeed, one can never be sure that the simpler hypothesis is not the true one, after all, until its cause has been fought out to the bitter end. But you will mark the limitation of my approval of Ockham's razor. It is a sound maxim of scientific procedure. If the question be what one ought to believe, the logic of the situation must take other factors into account. Speaking strictly, belief is out of place in pure theoretical science, which has nothing nearer to it than the establishment of doctrines, and only the provisional establishment of them, at that. Compared with living belief it is nothing but a ghost. If the captain of a vessel on a lee shore in a terrific storm finds himself in a critical position in which he must instantly either put his wheel to port acting on one hypothesis, or put his wheel to starboard acting on the contrary hypothesis, and his vessel will infallibly be dashed to pieces if he decides the question wrongly, Ockham's razor is not worth the stout belief of any common seaman. For stout belief may happen to save the ship, while Entia non sunt multiplicanda praeter necessitatem would be only a stupid way of spelling Shipwreck. Now in matters of real practical concern we are all in something like the situation of that sea-captain."

"Numquam ponenda est pluralitas sine necessitate."

"Men see with arrogant eyes which organize everything seen with reference to themselves and their own interests. ...Western philosophy and science have for the most part been committed to the Simplicity Theory of Truth: the simplest theory that accounts for the data is the true theory. (Theories are simplest which postulate the fewest entities, require the fewest hypotheses, generate predictions by the fewest calculations, etc.) ...If someone believes that the world is made for him to have dominion over and he is made to exploit it, he must believe that he and the world are so made that he can, at least in principle, achieve and maintain dominion over everything. But you can’t put things to use if you don’t know how they work. So he must believe that he can, at least in principle, understand everything. If the world exists for man, it must be usably intelligible, which means it must be simple enough for him to understand. A usable universe is an intelligible universe is a simple universe. ...And so it goes with the philosophy and the science of The Arrogant Eye."

"Nobody knows how many universes there are. Theory places no limit: any and all possibilities in unlimited number of combinations of "natural" laws, each sheaf appropriate to its own universe. But this is just theory and Occam's Razor is much too dull."

"Not merely trainee and professional members of the medical profession commit the base-rate fallacy. Even very eminent scientists do, as we have seen. And all the philosophers who use the No-Miracles argument do so as well."

"The riddle of induction can be put thus: What rational basis is there for any of our beliefs about the unobserved? The theory of personal probability touches on the domain of the riddle and can even be construed as giving a partial answer. The theory prescribes, presumably compellingly, exactly how a set of beliefs should change in the light of what is observed. It can help you say, "My opinions today are the rational consequence of what they were yesterday and of what I have seen since yesterday." In principle, yesterday's opinions can be traced to the day before, but even given a coherent demigod able to trace his present opinions back to those with which he was born and to what he has experienced since, the theory of personal probability does not pretend to say with what system of opinions he ought to have been born. It leaves him, just as Hume would say, without rational foundation for his beliefs of today. Can there be any such foundation? The theory as such is silent, but I am led by study of it to doubt that there is a rational basis for what we believe about the unobserved. In fact, Hume's arguments, and modern variants of them such as Goodman's discussion of 'bleen' and 'grue', appeal to me as correct and realistic. That all my beliefs are but my personal opinions, no matter how well some of them may coincide with opinions of others, seems to me not a paradox but a truism. The grandiose image of a demigod tracing his beliefs back to the cradle only to find an impasse there seems a valid metaphor. If there is rational basis for beliefs going beyond mere coherency, then there are some specific opinions that a rational baby demigod must have. Put that way, the notion of any such basis seems to me quite counterintuitive."

"The positive argument for realism is that it is the only philosophy that doesn't make the success of science a miracle."

"Domestic animals expect food when they see the person who usually feeds them. We know that all these rather crude expectations of uniformity are liable to be misleading. The man who has fed the chicken every day throughout its life at last wrings its neck instead, showing that more refined views as to the uniformity of nature would have been useful to the chicken."

"The borderlines between genuine science and pseudoscience may be fuzzy, but this should be even more of a call for careful distinctions, based on systematic facts and sound reasoning. To try a modicum of turtle blood here and a little aspirin there is not the hallmark of wisdom and even-mindedness. It is a dangerous gateway to superstition and irrationality."

"The main reason for believing scientific theories (at least the bestverified ones) is that they explain the coherence of our experience. Let us be precise: here ‘experience’ refers to all our observations, including the results of laboratory experiments whose goal is to test quantitatively (sometimes to incredible precision) the predictions of scientific theories. … This agreement between theory and experiment, when combined with thousands of other similar though less spectacular ones, would be a miracle if science said nothing true – or at least approximately true – about the world. The experimental confirmations of the best-established scientific theories, taken together, are evidence that we really have acquired an objective (albeit approximate and incomplete) knowledge of the natural world."

"I claim that the success of current scientific theories is no miracle. It is not even surprising to the scientific (Darwinist) mind. For any scientific theory is born into a life of fierce competition, a jungle red in tooth and claw. Only the successful theories survive—the ones which in fact latched onto the actual regularities in nature."

"The fantastic 12-digit agreement between the theoretical predictions of QED and the experimental results is a miracle. It would be good for physicists to acknowledge the unsatisfactory mathematical structure of this prediction. It starts from a mathematically undefined Feynman Integral, proceeds by making many very complicated manipulations, and ends up with a formal series that Dyson showed to be divergent! Physicists think of it as an asymptotic expansion, but they have no mathematical proof of this. I often joke that this agreement of theory and experiment is a new proof of the existence of God and that she loves physicists!"

"Realism is not a dirty word. If you wonder why all scientists, philosophers, and ordinary people, with rare exceptions, have been and are unabashed realists, let me tell you why. No scientific conjecture has been more overwhelmingly confirmed. No hypothesis offers a simpler explanation of why the Andromeda galaxy spirals in every photograph, why all electrons are identical, why the laws of physics are the same in Tokyo as in London or on Mars, why they were there before life evolved and will be there if all life perishes, why all persons can close their eyes and feel eight corners, six faces and twelve edges on a cube, and why your bedroom looks the same when you wake up in the morning."

"From causes which appear similar we expect similar effects. This is the sum of all our experimental conclusions. Now it seems evident that, if this conclusion were formed by reason, it would be as perfect at first, and upon one instance, as after ever so long a course of experience. But the case is far otherwise. Nothing so like as eggs; yet no one, on account of this appearing similarity, expects the same taste and relish in all of them. It is only after a long course of uniform experiments in any kind, that we attain a firm reliance and security with regard to a particular event. Now where is that process of reasoning which, from one instance, draws a conclusion, so different from that which it infers from a hundred instances that are nowise different from that single one? This question I propose as much for the sake of information, as with an intention of raising difficulties. I cannot find, I cannot imagine any such reasoning."

"Even though Mendeleev always denied that electrons exist, they later turned out to be vital for ordering the elements in his table."

"By convention (νόμῳ) sweet is sweet, by convention bitter is bitter, by convention hot is hot, by convention cold is cold, by convention color is color. But in reality there are atoms and the void. That is, the objects of sense are supposed to be real and it is customary to regard them as such, but in truth they are not. Only the atoms and the void are real."

"I need only remind you of Davy's great researches: nitrous oxide; electric conduction and decomposition—resulting, on the one hand, in the separation of potassium and sodium, the decomposition of the earths following as a necessary consequence, and on the other in the electro-chemical theory; iodine and chlorine—resulting in the extension and confirmation of the word element, the discovery of the so-called hydrogen acids, and the important modification of the French theory of the constitution of acids; the investigation of gaseous explosion and of flame, and the invention of the safety lamp. These are the contributions to science which stand out more prominently in connection with Davy. But over and above all this is the peculiar manner of his discoveries. He was no patient plodder. He did not elaborate his work in minute detail. He dashed it off in broad masses; but just on that account there has never been anyone to follow up his investigations. Davy's mantle fell on no one, not even on Faraday."

"Chemistry as an earnest and respectable science is often said to date from 1661, when Robert Boyle of Oxford published The Sceptical Chymist — the first work to distinguish between chemists and alchemists — but it was a slow and often erratic transition. Into the eighteenth century scholars could feel oddly comfortable in both camps — like the German Johann Becher, who produced sober and unexceptionable work on mineralogy called Physica Subterranea, but who also was certain that, given the right materials, he could make himself invisible."

"The word chemistry, in Greek should be wrote χημια, and in Latin and English chemia and chemistry; not as usual, chymia and chymistry. The first author in whom the word is found is Plutarch, who lived under the Emperors ', ', and '. That philosopher, in his treatise of ' and ', takes occasion to observe that Egypt, in the sacred dialect of the country, was called by the same name as the black of the eye viz., χημια—by which he seems to intimate that the word chemia in the Egyptian language signified black, and that the country, Egypt, might take its denomination from the blackness of the soil. ...Instead of black, some will have it originally denote secret, or occult; and hence derive it from the Hebrew chaman, or '—a mystery, whose radix is cham. And, accordingly, Plutarch observes that Egypt, in the same sacred dialect, is sometimes wrote in Greek χαμια—chamia; whence the word is easily deduced further from Cham, eldest son of Noah, by whom Egypt was first peopled after the deluge, and from whom, in the Scripture style, it is called the land of Cham, or Chem. Now, that chaman, or haman, properly signifies secret appears from the same Plutarch, who, mentioning an ancient author named Menethes Sibonita, who had asserted that Amman and Hammon were used to denote the god of Egypt, Plutarch takes this occasion to observe that in the Egyptian language anything secret or occult was called by the same name, αμμον—Hammon... Lastly, the learned Bochart, keeping to the same sense of the word, chooses to derive it from the Arabic chema, or kema—to hide; adding that there is an Arabic book of secrets called by the same name Kemi."

"We must not forget that when was discovered no one knew that it would prove useful in hospitals. The work was one of pure science. And this is a proof that scientific work must not be considered from the point of view of the direct usefulness of it. It must be done for itself, for the beauty of science, and then there is always the chance that a scientific discovery may become like the radium a benefit for humanity."

"The laws of thermodynamics, as empirically determined, express the approximate and probable behavior of systems of a great number of particles, or, more precisely, they express the laws of mechanics for such systems as they appear to beings who have not the fineness of perception to enable them to appreciate quantities of the order of magnitude of those which relate to single particles, and who cannot repeat their experiments often enough to obtain any but the most probable results."

"No original manuscript of the earliest writers on chemistry or alchemy has been discovered. Our knowledge must be gleaned from the pages of those writing upon other subjects, or must come from fragments handed down to us through several copyists."

"Two difficulties meet one in studying the early history of the science. One is... mysticism... and the other is the custom among the early writers of ascribing their discoveries, books, etc., to fabulous names or ancient heroes and gods. This latter had two objects, the first being to shield the true author in time of persecution, and the second to gain a certain amount of credit and reputation... by the use of the names of such celebrities as Moses, Solomon, Alexander, or Cleopatra. This tendency is especially noticeable among the writers of the Middle Ages, and also the early Greek authors, and is not peculiar to authors of alchemical treatises."

"The reason generally assigned for this absence of early records is that burned all writings of the Egyptians bearing upon alchemy, because, as he said, these taught the art of making gold and silver; and, by destroying them, he took away from the Egyptians the power of enriching themselves and rebelling against the Romans."

"The Coptic word khems or chems is closely related to this, and also signifies obscure, occult, and with this is connected the Arabic word chema, to hide."

"The word χημεία occurs first in the writings of , a Greek lexicographer of the eleventh century. It is there defined as the "preparing of gold and silver." This is manifestly a Greek rendering of the name Chema or Chemi, which is of Egyptian origin, and all attempts at deriving it from χεω, to fuse, or χνμα a liquid, are without import."

"It is therefore the occult or hidden science, the black art."

"[T]he Chinese... had... knowledge of metals, alloys, colors, and salts for a long time, and that they manufactured gun powder and porcelain before they were known in Europe."

"In... India... knowledge of the extraction of metals, the making of steel, the preparation of colors, and similar technical operations, dates back to the most remote antiquity. They also theorized as to the elements and their number. Their synonym for death was, "man returns to the five elements.""

"So great a result is not the work of one day or the conquest of a revolution; it is the result of slow and continued progress. But if we... carry our ideas back to the starting-point, we must avow that the progress is immense. Compared with the science of that time, the science of the present day appears to us not only enlarged, but transformed and regenerated."

"Is it... astonishing that theories suggested by the study of organic compounds, and at first restricted within [that] domain... have taken wing, and striven to clear the bounds which separate organic from mineral chemistry? ...[T]hey now embrace the whole field of the science; and, thanks to them... there is but one chemistry."

"Is it complete, as regards its doctrines; and are the new paths... made altogether plain? We do not think so. But the greatness of the advance permits us to affirm that the roads are good. We may then halt for a moment, and, casting our eyes over the distance already traversed, mark with certainty the point at which we have arrived."

"Alkimia Speculativa... treats of the generation of things from their elements, and of all inanimate things—as of the elements and liquids (humores) simple and compound; common stones, gems, and marbles; gold, and other metals; sulphur, salts, pigments, lapis lazuli, minium, and other colours; oils, bitumen, and very many other things—of which we find nothing in the books of Aristotle; nor are the natural philosophers or any of the Latins acquainted with these things. And being ignorant of them, they can know nothing of what follows in physics, that is, of the generation of animate things—as vegetables, animals, and man—because knowing not what is prior, they must remain ignorant of what is posterior. For the generation of men, and of brutes, and of plants, is from elemental and liquid substances, and is of like manner with the generation of inanimate things. Wherefore, through ignorance of this science, neither can natural philosophy... be known, nor the theory, and therefore neither the practice, of medicine; not merely because natural philosophy and theoretical medicine are necessary for the practice, but because all simple medicines are derived from inanimate things by this science."

"We avoid the gravest difficulties when, giving up the attempt to frame hypotheses concerning the constitution of matter, we pursue statistical inquiries as a branch of rational mechanics."

"Plutarch tells us that Chemia was a name given Egypt on account of the black soil, and that this term further meant the black of the eye, symbolizing that which was obscure and hidden."

"To discover the atomic constitution of organic compounds, and thereby to explain their properties, and establish their relations, is the object of Organic Chemistry... attained by determining the nature and number of the constituent atoms of organic compounds, and by studying their modes of formation and transformation. This great work was not really begun till about... 1830; but from that time it has been carried on with vigour and success."