Science and Scientific Method PDF

Science and Scientific Method Jerrold J. Garcia I n the intellectual theory of humankind, two defining moments stand out in stark relief. The first was the rise of...

Science and Scientific Method Jerrold J. Garcia I n the intellectual theory of humankind, two defining moments stand out in stark relief. The first was the rise of Greek philosophy, which Russell (1961) dated to Thales (ca585 BC). The second rise was the rise of modern science, which encompassed the period from Galileo to Newton (ca. 1600). Both Greek philosophy and modern science have become anchors of Western civilization and culture, which, through past colonization and present globalization, suffuse almost the entire globa. In non-Western societies where Western civilization has made deep inroads—such as Philippine society—there is hardly an institution that has not been influence directly or indirectly by both. Despite the influence of science in our society, it is not always accompanied by a clear understanding of its method. It may not even be clear at all what science is—and what it is not. For our purpose and for brevity, we may define science as “rational inquiry into Nature”. By rational we mean that such inquiry must be within some logical structure, and not some haphazard inquisition. At the same time, this definition attributes an objective existence to Nature, which is the object of the inquiry. In short there are two entities: the object of the inquiry and the (mind of the) inquirer. The object of inquiry is assumed to have an objective existence independent of the inquirer’s. The inquirer is assumed to have an objective existence independent of the inquirer’s. The inquirer is assumed to be capable of rational inquisition. We are, for the moment, assuming that we can set the observer/inquirer apart from Nature and that the boundary between them can be delineated clearly. Science as body of knowledge  As commonly understood, the purpose of this rational inquiry is to gain knowledge about Nature. Knowledge, as idea, resides in the mind. Thus, “scientific knowledge” can be taken as a mental picture of what Nature is. In our mind, there exists some sort of a model, which we believe represent the physical Nature found “out there”. The faithfulness with which our mental model represents the real world reflects the degree of our understanding of that real world. It varies with time, and with discipline. For example, we say that our knowledge of physics has improved over time. What this means is that over the centuries from the time of Newton’s Principle, the fidelity with which our mental model corresponds to the real world has improved. On the other hand, the fidelity of our model for biology is nowhere close to that of our model for physics. But it is safe to say that, at all times, our mental models are not perfect representations of the various aspects of Nature. But, neither are they static or stagnant. They continually undergo change and improvement. Any bit of scientific knowledge is a declarative statement about the real world. It is an empirical statement, the validity of which is eventually decided through observation and experimentation. If there happens to be two competing theories, two conflicting interpretations or two contending points of view, the conflict cannot be resolved by mere debates, argumentation, or ratiocination. At some point the contending parties must resort to experimentation and observation to resolve the conflict. For example, the question of whether there is a top quark or not (there is), or the question of whether polywater exists or not (it does not) could never be settled through argumentation and debate. On the other hand, scientific knowledge is much more than just a mere collection of empirical statements. For a collection of empirical statements to constitute scientific knowledge, it must satisfy at least the following requirements: a) the collection must be internally consistent; b) there must be a logical interrelationship between the statements that organizes them into a coherent whole c) we should be able to deduce a prediction, which can then be tested by an experiment or observation  In other words, it is not the individual statements alone, but also the logical interrelationship between them that defines the system of scientific knowledge. Ideally, one cannot detach even the tiniest part of the system without causing the entire complex to unravel. However, due to imperfections in our information and knowledge, the interconnections could be very tight and rigid in some areas, while very tenuous in other areas. Roughly speaking, these empirical statements could be arranged in some sort of hierarchy. At the lowest level are the primitive statements of direct observation—e.g., the moon is spherical in shape; ice melts at zero degree Celsius under standard conditions; the electron has an electrical charge with negative polarity by convention. At the next level are statements that are not of direct observation, but instead express some common features of or relationship between the entities. Here, for example, you would find Newton’s famous second law of motion; a body, acted by a net force, accelerates in the direction of the force, and the magnitude of the acceleration is proportional to the magnitude of the force and inversely proportional to the body’s mass. Newton’s law, thus, gets these three concepts (force, mass, and acceleration) together and expresses a relationship among them. These general statements, or natural law, together with their logical scaffolding, their tacit assumptions and philosophical underpinning would make up what we commonly call scientific theory. Thus, we have the theories of classical mechanics, thermodynamics, general relativity, etc. Finally, at the highest level are the overarching fundamental principles that encompass the entire range of the Natural Sciences. These could be conservation principles such as the principles of conservation of energy, or they could be symmetry principles such as the Galilean principle of relativity. Unlike those theories that are limited only to within their specific topics and regions of validity, these principles allow no exception and cut across all disciplines. Thus, all our theories in physics, chemistry, and biology must, at all times, submit to the principle of conservation of energy. The philosophical underpinning  This entire structure of scientific knowledge rests on its philosophical underpinning, on the philosophical assumptions that are necessary to play this game. One such assumption is what we had earlier mentioned: that Nature is regarded to have an objective existence independent of that of the scientist and of his mind. In science, we seek the so-called laws of nature; which are general statements about the behavior of Nature: the more general the statements, the better. But, this quest depends on two crucial assumptions: 1) there is regularity in Nature that is expressed by these laws, and 2) the human mind can “know” these laws. Remove these assumptions and the scientific structure crumbles. In physics and chemistry (and increasingly so in biology), this regularity in Nature is often expressed in the language of mathematics. This again points to another assumption: that the regularity in Nature has the same logical structure as mathematics. Moreover, the laws of Nature, as we express them, do not carry any time stamp that indicates when and where they were discovered, or where they are applicable. This implies that we assume that the laws of Nature are the same everywhere and remain so for all the time—again, a philosophical assumption. Needless to say, these assumptions are not subject to empirical proof, but we need them for science to exist at all. Once can say that these are the articles of faith of science. This majestic edifice of scientific observations, laws, theories, and principles, together with all the (explicit or tacit) philosophical assumptions necessary to hold them together, constitute what we call the scientific Weltanschauung, or the scientific worldview. The affirmation of the Weltanschauung is what differentiates the mind of a scientist from a non-scientist’s. This scientific worldview is closely related to what Thomas Kuhn (1962) referred to as the scientific paradigm, in his analysis of how science progresses. In a nutshell, scientists all subscribe to the existing paradigm (or model) of their discipline. This paradigm claims to be an interpretation of the physical world, not just empirically, but even philosophically. Thus the physicists, chemists, and biologists have their respective paradigms. The paradigm is necessary if scientists are to work cooperatively. Without this paradigm, the scientific community would disintegrate into an incoherent Babel because each scientist would have his own interpretation of the world. Ordinarily, scientists do what Kuhn calls “normal science”. This consists of elucidating the paradigm, i.e, making small discoveries here and there and verifying the predictions of the paradigm. These discoveries and observations are explained and understood within the context of the paradigm. Such normal science activities strengthen the intellectual hold of the paradigm on the scientific community. But, since our knowledge is not perfect—and, therefore, the paradigm is not perfect representation of the real world—there are discoveries and observation made every now and then that do not quite fit into the paradigm. These are called anomalies. Over time, these unexplainable anomalies accumulate, creating an intellectual tension within the community. A point may finally be reached when the validity of the paradigm itself may be called into question. But for as long as the paradigm is the only viable one, it is maintained as such notwithstanding its shortcomings and the anomalies. Events, however, take a different turn if there is a competing paradigm that is equally viable and, in addition, can explain the anomalies. When this is the case, then the existing paradigm is overthrown and a new one is established. After the smoke has cleared in this “scientific revolution,” as Kuhn calls sit, the scientific community goes back into doing normal science, this time elucidating the new paradigm—and accumulating anomalies all over again. The periods of scientific revolution are also the times when fundamental changes in our scientific knowledge occur ad fundamental discoveries are made. This is no doubt stimulated by the liberation of the mind from the limiting constraint of the obsolete paradigm, and this enables us to look at the world from new perspectives. The twentieth century saw two scientific revolutions in physics: Einstein’s Theory of Relativity and the rise of Quantum Physics. Scientists, on the whole, are loath to replace the existing paradigm. There has to be extremely compelling reasons before a paradigm is replaced. Generally, scientists can be markedly conservative, but, once the community feels that the existing paradigm must go, it is replaced without any qualm whatsoever. However, the old paradigm may not completely disappear. In many cases it is retained—though— dethroned—because, in practical terms, it is still useful.  Today, we know that the (currently) correct theory that explains the phenomenon of gravitation is the theory of general relativity. This relativity paradigm replaced the Newtonian one around 1915. We still retain the old theory because it is mathematically simpler to work with and its predictions are generally correct (if you make allowances for its shortcomings), and let’s face it: how do you teach general relativity to general physics students? An illustrative example of the conservatisms of science involves the continental drift theory formally proposed in 1912 by Alfred Wegener, an astronomer and meteorologist. Briefly, the theory asserts that there is a large-scale horizontal motion of the continents relative to each other. When it was proposed, it went against the currently accepted world picture of geology. Though it attracted some interest, it was eventually abandoned and scorned by mainstream geology. But, by the 1960s, with compelling evidence and with the rise of the concept of plate tectonics, continental drift theory was revived and is now at the center of geology. The methods of science To repeat what we have said, science is empirical. Science is about the physical world. Therefore, its statements about the world must be validated by observation and experimentation. It is true that some logical inference or mathematical manipulation goes on all the time, but the final judge of acceptability is empirical observation. In the physical sciences, there is a division between the theorists and the experimentalists. The experimental side performs the experiments and makes the observations, while the theoretical side tries to deduce the predictions, given the assumptions and previous observations. However, the stylized ritual of problem-observation-hypothesis-confirmation-theory, as found in many school text books, is an almost comic distortion of the actual scientific method and, at most, shows only a very small facet of the whole scientific enterprise. For one, it misleads the reader into believing that the steps in scientific research are so well defined and that each step ineluctably leads to the next. For another, it leaves the impression that as long as one follows the steps, as you would a recipe, a worthwhile discovery at the end is unavoidable. Finally, such a description completely ignores the decisive role that serendipity, imagination, dreams, and simple luck sometimes play. The purpose of any scientific research is to arrive at a statement that describes an aspect of the physical world, whether it is one of simple observation, “the top quark exists with these properties…,” or a generalization, “particles confined in a box can only have discrete energy levels.” Before a scientist embarks on his research quest, he must already have an idea of what he is looking for. To decide what problem is worth investigating is, in itself, already a major effort. If the problem is too simple or insignificant, or if the problem turns out to be impossible, the investigator will have wasted time and effort. Once the problem has been defined, then, essentially, scientists are free to use whatever tools or devices, both physical and mental, that are at their disposal. It should also be pointed out that seldom is a scientist solving only one problem. It is usually a host of problems that is being solved. An experimentalist, for example, may be after the mass of the top quark, but in the process has to solve a myriad of problems connected with the design of highly sophisticated equipment—that may never have been designed and fabricated otherwise. Similarly, a theoretician who is out to find a solution to Einstein’s equations may need to develop some mathematical tools on differential equations along the way and end up making unintended discoveries in mathematics. The intellectual tools at the scientist’s disposal could be logical inference, inductive reasoning, analogy with past events, mathematics, imagination, lucky guesses, and even dreams. The chemist Friedrich August Kekule was led into the structure of the benzene ring by his dream of a snake swallowing its own tail. An apocryphal story was that the mathematician Stefan Banach hit upon the concept of a topological vector space while drunk in a saloon in Paris. Whether this story is true, it serves to illustrate our point. The philosopher of science, Paul Feyerabend (1993), in his book Against Method, even went so far as to declare that in science there is really no method. He was of the view that any prescribed “official” method would unduly hold back scientific progress. Marxists, on the other hand would insist that, regardless of the tool used in arriving at a theory of the physical world, the ultimate arbiter of the validity or truth of theories (insofar as a theory can be judged as true or false) is social practice, or what other would call practical or experimental verification (Lenin 1977).  The conventional test of the acceptability of a theory is whether its prediction is verified by “experiment,” which actually means experimental measurement and observation under controlled conditions. In addition, there is also the requirement of reproducibility or repeatability. In other words, if chemist X says that he obtains a compound A from some ingredients under some stated conditions, then chemist Y, using the same ingredients and duplicating the same conditions, should be able to obtain the same compound A. This is one reason why publication in professional journals is of utmost importance in the sciences: to enable one’s colleagues to repeat the same experiments and reproduce the results. This reproducibility of results is what Marxists mean by the term “social”. Publication in a professional journal enables other scientists to scrutinize the entire exercise for possible error in method or in concept. This involves what we call peer review. A scientist sends his article to a journal, and the editor sends copies of it to a number of referees, who are considered experts on the topic. These referees review the article for suitability for publication. If the article passes muster, then it gets published. Otherwise, it is returned to the author for modifications, or is rejected outright. Upon publication, the article may turn out to be a) in consequential, in which case it is simply ignored; b) of such significance that it stimulates other researchers to extend research efforts and produce additional results; or c) erroneous, and the journal subsequently gets peppered with hostile reactions. Why are scientists so concerned about the veracity of reports and articles that appear in scientific journals? After all, not all news items in our newspapers are 100% correct, and yet everyday we manage to get on with our lives relatively intact. Why can’t the scientists take the same attitude? The answer is that scientists cannot afford it. Errors not caught in time and published in a journal can send countless scientists on a wild goose chase, and this can very expensive in terms of time, resources, and careers. If scientists do not exercise extreme caution in ensuring the credibility of journal articles, the profession may find itself drowning in a sea of spurious claims, and no one will be able to sort out credible claims from outright falsehood. It is for the same reasons that utmost honest is demanded of every scientists. A scientist is allowed by his peers to commit a mistake every now and then. That is why there is a pre-publication review: to catch the error before it gets printed. But, a scientist is never allowed to commit a dishonest act, such as deliberately fudging the data. A single instance of dishonesty is enough to ruin a scientist’s career forever. Does this make scientists scrupulously honest neighbors? Not necessarily so in daily life. But in the practice of their profession, their integrity must be as pure as driven snow. The value of science Where then lies the value of science? The value of science lies in its predictive power. We can anticipate events and effects because we can predict them. We can make use of natural laws for our benefit, or we can work our way around limitation imposed by them. Looking at our immediate surroundings, we see everyday tools and devices that science, through technology, has brought us: labor-saving tools, life- saving devices, educational equipment, etc. But, science also has a deeper value: it teaches us honesty, humility before facts, tolerance, and what the biologist J. Bronowski (1965) calls “the habit of truth”. It gives us lessons on boldness and courage, as Galileo, Newton, and Einstein were bold and courageous enough to advance ideas that broke the molds that they were in. While our society will probably never reach this ideal, science does offer us a s glimpse of a community where certain conflicts are not simply glossed over, but resolved decisively, not by physical force, intimidation, or even majority rule, but by force of reason. In the face of coercion and physical force, science falls silent. But for those who use force against science, the consequence has been always ruinous. An instructive example is the Lysenko doctrine that held sway in the Soviet Union from the 1930s to the 1960s. Trofim Lysenko was a biologist and agronomist who subscribed to Lamarck’s idea that acquired characteristics of an organism could be passed on to the offspring. We know now that this is not true. But, Lysenko managed to line up the Soviet leadership behind his idea and, as a highly placed bureaucrat in the Soviet Academy of Sciences, had almost total control over biological education and research in the USSR. Throughout his stay in power, all other views on genetics contrary to his were suppressed. The result, especially in agriculture, was disastrous. By the mid-1960s, he was removed from his position. It is estimated that Lysenkoism set back Soviet biology by a generation. The absolute certainty of dogmas is anathema to science. So is the idea of an absolute authority whose pronouncements cannot be questioned. If we look back at the history of science, we see that its development closely paralleled the growth and development of the democratic tradition. The constitutional protection of the right to free speech might as well have been lifted verbatim from the philosophy of science. As Bronowski (1979) aptly put it, “A man who looks for the truth must be independent, and a society which values the truth must safeguard his independence.” Science makes no claim that it holds the answer to all our problems. Necessarily, science is silent on questions of moral values and on moral dilemmas. Science may give us tools, but how we use the tools— that is beyond science. Richard Feynman (1958), in one of his essays, wrote of a proverb he learned in a Buddhist temple: “To man is given the key to the gates of heaven; the same key opens the gates of hell.” What science can do is to help us with the empirical parts of the problem so that when we make a decision, it will be an informed and rational decision made in a democratic environment that science has helped shape.