29 Scientific method Quotes

Perfect as the wing of a bird may be, it will never enable the bird to fly if unsupported by the air. Facts are the air of science. Without them a man of science can never rise.

If we are uncritical we shall always find what we want: we shall look for, and find, confirmations, and we shall look away from, and not see, whatever might be dangerous to our pet theories. In this way it is only too easy to obtain what appears to be overwhelming evidence in favor of a theory which, if approached critically, would have been refuted.

In desperation I asked Fermi whether he was not impressed by the agreement between our calculated numbers and his measured numbers. He replied, 'How many arbitrary parameters did you use for your calculations?' I thought for a moment about our cut-off procedures and said, 'Four.' He said, 'I remember my friend Johnny von Neumann used to say, with four parameters I can fit an elephant, and with five I can make him wiggle his trunk.' With that, the conversation was over.

The confidence in the unlimited power of science is only too often based on a false belief that the scientific method consists in the application of a ready-made technique, or in imitating the form rather than the substance of scientific procedure, as if one needed only to follow some cooking recipes to solve all social problems. It sometimes almost seems as if the techniques of science were more easily learnt than the thinking that shows us what the problems are and how to approach them.

If I am not mistaken, psychology, psychiatry and some branches of sociology, not to speak about the so-called philosophy of history, are even more affected by what I have called the scientistic prejudice, and by specious claims of what science can achieve.

'Since religion intrinsically rejects empirical methods, there should never be any attempt to reconcile scientific theories with religion. An infinitely old universe, always evolving, may not be compatible with the Book of Genesis. However, religions such as Buddhism get along without having any explicit creation mythology and are in no way contradicted by a universe without a beginning or end. Creatio ex nihilo, even as religious doctrine, only dates to around AD 200. The key is not to confuse myth and empirical results, or religion and science.'

'To try to write a grand cosmical drama leads necessarily to myth. To try to let knowledge substitute ignorance in increasingly larger regions of space and time is science.'

[H]istorical science is not worse, more restricted, or less capable of achieving firm conclusions because experiment, prediction, and subsumption under invariant laws of nature do not represent its usual working methods. The sciences of history use a different mode of explanation, rooted in the comparative and observational richness in our data. We cannot see a past event directly, but science is usually based on inference, not unvarnished observation (you don't see electrons, gravity, or black holes either).

When we seek a textbook case for the proper operation of science, the correction of certain error offers far more promise than the establishment of probable truth. Confirmed hunches, of course, are more upbeat than discredited hypotheses. Since the worst traditions of 'popular' writing falsely equate instruction with sweetness and light, our promotional literature abounds with insipid tales in the heroic mode, although tough stories of disappointment and loss give deeper insight into a methodology that the celebrated philosopher Karl Popper once labeled as 'conjecture and refutation.'

When you make the finding yourself - even if you're the last person on Earth to see the light - you never forget it.

'Have the climate models been successful in predicting anything? They, of course, predict substantial global warming. This is not surprising given the expressed belief of some of the model builders in the global warming hypothesis and the many parameters in the model that need to be introduced. However, the models also predict unambiguously that the atmosphere is warming faster than the surface of the earth; but all the available observational data unambiguously shows the opposite! Truth in science is always determined from observational facts. One finds the truth by making a hypothesis and comparing observations with the hypothesis. It is absolutely essential that one should be neutral and not fall in love with the hypothesis. If the facts are contrary to any predictions, then the hypothesis is wrong no matter how appealing. 'Truth by Assertion' is not science.' [1]

Science is a method for testing claims about the natural world, not an immutable compendium of absolute truths. The fundamentalists, by 'knowing' the answers before they start, and then forcing nature into the straitjacket of their discredited preconceptions, lie outside the domain of science-or of any honest intellectual inquiry.

Thus science may implement the ways in which man produces, stores, and consults the record of the race. It might be striking to outline the instrumentalities of the future more spectacularly, rather than to stick closely to the methods and elements now known and undergoing rapid development, as has been done here. Technical difficulties of all sorts have been ignored, certainly, but also ignored are means as yet unknown which may come any day to accelerate technical progress as violently as did the advent of the thermionic tube.

The scientist has a lot of experience with ignorance and doubt and uncertainty, and this experience is of very great importance, I think. When a scientist doesn't know the answer to a problem, he is ignorant. When he has a hunch as to what the result is, he is uncertain. And when he is pretty damn sure of what the result is going to be, he is still in some doubt. We have found it of paramount importance that in order to progress, we must recognize our ignorance and leave room for doubt. Scientific knowledge is a body of statements of varying degrees of certainty - some most unsure, some nearly sure, but none absolutely certain. Now, we scientists are used to this, and we take it for granted that it is perfectly consistent to be unsure, that it is possible to live and not know. But I don't know whether everyone realizes this is true. Our freedom to doubt was born out of a struggle against authority in the early days of science. It was a very deep and strong struggle: permit us to question - to doubt - to not be sure. I think that it is important that we do not forget this struggle and thus perhaps lose what we have gained.

It would, however, be wrong to think of an electron as a bullet-like structure with tentacles sticking out from its surface. We can calculate the mass of the bullet, and also the mass of the tentacles. The two masses are found to be identical, each agreeing with the known mass of the electron. Thus we cannot take the electron to be bullet plus tentacles... The two pictures do not depict two different parts of the electron, but two different aspects of the electron. They are not additive but alternative; as one comes into play, the other must disappear.

Before the quantum theory appeared, the principle of the uniformity of nature - that like causes produce like effects - had been accepted as a universal and indisputable fact of science. As soon as the atomicity of radiation became established, this principle had to be discarded.

A similar situation occurred in astronomy, where the Newtonian law of gravitation had been found to predict the orbits of the outer planets with great accuracy, but had failed with the orbits of Mercury and Venus. The relativity theory of gravitation had provided the necessary modification of Newton's law, and in working out the details of the new theory, Einstein had utilized the fact that Newtonian law gave the right result at great distances from the sun. Heisenberg, confronted with a similar problem, was able to avail himself of the fact that the classical mechanics gave the right result at great distances from the atomic nucleus. Here, and here alone Heisenberg's theory made contact with the world of the older physics.

When two hypotheses are possible, we provisionally choose that which our minds adjudge to be simpler, on the supposition that this is the more likely to lead in the direction of truth. It includes as a special case the principle of Occam's razor-entia non multiplicana praeter necessitatem.

Linus Pauling was not always right in his ideas. But my belief is that, in most cases, if somebody is always right in his ideas you find that he does not have much to say. It is an expression of somebody's fertility that he does produce quite a number of ideas, and I think Linus Pauling's score is pretty high... I do not think, as I said earlier, that it is right to discuss the impact of Linus Pauling on molecular biology. Rather, he was one of the founders of molecular biology. It was not that it existed in some way, and he simply made a contribution. He was one of the founders who got the whole discipline going.

Bohr's investigation had typified what had become a standard procedure in problems of theoretical physics. The first step was to discover the mathematical laws governing certain groups of phenomena; the second was to devise hypothetical models or pictures to interpret these laws in terms of motion or mechanism; the third was to examine in what way these models would behave in other respects, and this would lead to prediction of other phenomena-predictions which might or might not be confirmed when put to the test of experiment. For instance, Newton had explained the phenomena of gravitation in terms of a force of gravitation; a later age had seen the luminiferous ether introduced to explain the propagation of light and, subsequently, the general phenomena of electricity and magnetism; finally Bohr had introduced electronic jumps in an attempt to explain atomic spectra. In each case the models had fulfilled their primary purpose, but had failed to predict further phenomena with accuracy.

All experiments in psychology are not of this [cargo cult] type, however. For example there have been many experiments running rats through all kinds of mazes, and so on - with little clear result. But in 1937 a man named Young did a very interesting one. He had a long corridor with doors all along one side where the rats came in, and doors along the other side where the food was. He wanted to see if he could train rats to go to the third door down from wherever he started them off. No. The rats went immediately to the door where the food had been the time before. The question was, how did the rats know, because the corridor was so beautifully built and so uniform, that this was the same door as before? Obviously there was something about the door that was different from the other doors. So he painted the doors very carefully, arranging the textures on the faces of the doors exactly the same. Still the rats could tell. Then he thought maybe they were smelling the food, so he used chemicals to change the smell after each run. Still the rats could tell. Then he realized the rats might be able to tell by seeing the lights and the arrangement in the laboratory like any commonsense person. So he covered the corridor, and still the rats could tell He finally found that they could tell by the way the floor sounded when they ran over it. And he could only fix that by putting his corridor in sand. So he covered one after another of all possible clues and finally was able to fool the rats so that they had to learn to go to the third door. If he relaxed any of his conditions, the rats could tell. Now, from a scientific standpoint, that is an A-number-one experiment. That is the experiment that makes rat-running experiments sensible, because it uncovers the clues that the rat is really using - not what you think it's using. And that is the experiment that tells exactly what conditions you have to use in order to be careful and control everything in an experiment with rat-running. I looked into the subsequent history of this research. The next experiment, and the one after that, never referred to Mr. Young. They never used any of his criteria of putting the corridor on sand, or of being very careful. They just went right on running rats in the same old way, and paid no attention to the great discoveries of Mr. Young, and his papers are not referred to, because he didn't discover anything about rats. In fact, he discovered all the things you have to do to discover something about rats. But not paying attention to experiments like that is a characteristic of cargo cult science.

Some years ago I had a conversation with a layman about flying saucers - because I am scientific I know all about flying saucers! I said 'I don't think there are flying saucers'. So my antagonist said, 'Is it impossible that there are flying saucers? Can you prove that it's impossible?' 'No', I said, 'I can't prove it's impossible. It's just very unlikely'. At that he said, 'You are very unscientific. If you can't prove it impossible then how can you say that it's unlikely?' But that is the way that is scientific. It is scientific only to say what is more likely and what less likely, and not to be proving all the time the possible and impossible. To define what I mean, I might have said to him, 'Listen, I mean that from my knowledge of the world that I see around me, I think that it is much more likely that the reports of flying saucers are the results of the known irrational characteristics of terrestrial intelligence than of the unknown rational efforts of extra-terrestrial intelligence.' It is just more likely. That is all.

I have for many years been a partisan of the Copernican view because it reveals to me the causes of many natural phenomena that are entirely incomprehensible in the light of the generally accepted hypothesis. To refute the latter I have collected many proofs, but I do not publish them, because I am deterred by the fate of our teacher Copernicus who, although he had won immortal fame with a few, was ridiculed and condemned by countless people (for very great is the number of the stupid). (Quoted in Hermann Kesten, Copernicus and His World, trans. by E.b. Aston and Norbert Gutterman, NY, Roy Publishers, 1945, p.349, emphasis added)

My dear Kepler, what would you say of the learned here, who, replete with the pertinacity of the asp, have steadfastly refused to cast a glance through the telescope? What shall we make of this? Shall we laugh, or shall we cry?

I have not been able to discover the cause of those properties of gravity from phenomena, and I frame no hypotheses;' for whatever is not deduced from the phenomena is to be called a hypothesis, and hypotheses, whether metaphysical or physical, whether of occult qualities or mechanical, have no place in experimental philosophy.

Yet scientists are required to back up their claims not with private feelings but with publicly checkable evidence. Their experiments must have rigorous controls to eliminate spurious effects. And statistical analysis eliminates the suspicion (or at least measures the likelihood) that the apparent effect might have happened by chance alone.

During all those years of experimentation and research, I never once made a discovery. All my work was deductive, and the results I achieved were those of invention, pure and simple. I would construct a theory and work on its lines until I found it was untenable. Then it would be discarded at once and another theory evolved. This was the only possible way for me to work out the problem. ... I speak without exaggeration when I say that I have constructed 3,000 different theories in connection with the electric light, each one of them reasonable and apparently likely to be true. Yet only in two cases did my experiments prove the truth of my theory. My chief difficulty was in constructing the carbon filament. . . . Every quarter of the globe was ransacked by my agents, and all sorts of the queerest materials used, until finally the shred of bamboo, now utilized by us, was settled upon.

It now remains that we find the amount of time of descent through the channel. This we shall obtain from the marvelous property of the pendulum, which is that it makes all its vibrations, large or small, in equal times. This requires, once and for all, that two or three or four patient and curious friends, having noted a fixed star that stands against some fixed marker, taking a pendulum of any length, shall go counting its vibrations during the whole time of return of the fixed star to its original point, and this will be the number of vibrations in 24 hours. From the number of these we can find the number of vibrations of any other pendulums, longer or shorter, at will, so that if for example those counted by us in 24 hours were 234,567, then taking another shorter pendulum with which one counts 800 vibrations while another counts 150 of the longer pendulum, we already have, by the golden rule, the number of vibrations for the whole time of 24 hours; and if we want to know the time of descent through the channel, we can easily find not only the minutes, seconds, and sixtieths of seconds, but beyond that as we please. It is true that we can pass a more exact measure by having observed the flow of water through a thin passage, for by collecting this and having weighed what passes in one minute, for example, then by weighing what passes in the time of descent through the channel we can find the most exact measure and quantity of this time, especially by making use of a balance so precise as to weigh one sixtieth of a grain.

'The issue of 'science' does not intrude itself directly upon the occasion of the performance of a musical work, at least a non-electronically produced work, since-as has been said-there is at least a question as to whether the question as to whether musical composition is to be regarded as a science or not is indeed really a question; but there is no doubt that the question as to whether musical discourse or-more precisely-the theory of music should be subject to the methodological criteria of scientific method and the attendant scientific language is a question, except that the question is really not the normative one of whether it 'should be' or 'must be,' but the factual one that it is, not because of the nature of musical theory, but because of the nature and scope of scientific method and language, whose domain of application is such that if it is not extensible to musical theory, then musical theory is not a theory in any sense in which the term ever has been employed. This should sound neither contentious nor portentous, rather it should be obvious to the point of virtual tautology.' From Milton Babbitt, 'The Structure and Function of Musical Theory', College Music Symposium, Vol. 5 (Fall 1965), pp. 49-60; reprinted in Perspectives on Contemporary Music Theory, ed. Benjamin Boretz and Edward T. Cone (New York: Norton, 1972), pp. 10-21, ISBN 0393005488, and in Milton Babbitt, The Collected Essays of Milton Babbitt, ed. Stephen Peles, with Stephen Dembski, Andrew Mead, and Joseph N. Straus (Princeton: Princeton University Press, 2003), pp. 191-201, ISBN 0691089663.