PHYS 400
SPECIAL PROBLEMS IN PHYSICS
METHODOLOGY IN SCIENCE
by
Mutlu DOĞRUEL
100630-3
Supervisor: Assoc. Prof. Dr. Çağlar Tuncay
November, 1998
CONTENTS
1. INTRODUCTION ...... / 22. SCIENCE
2.1. About Science ...... / 4
2.2. A Definition of Science ...... / 5
3. METHODS OF SCIENCE
3.1. Scientific Method ...... / 6
3.1.1. Characteristics of Scientific Method ...... / 8
3.1.2. Induction and Deduction ...... / 9
3.2. Facts and Scientific Method ...... / 10
4. "SCIENCE" OF METHODS
4.1. Definition of Methodology...... / 11
4.2. Methodology as the "Science" of Methods ...... / 12
4.3. Michelson’s Mirror Experiment ...... / 13
4.3.1. The Problem ...... / 13
4.3.2 The Experiment ...... / 14
4.3.3 The Conclusion of the Experiment ...... / 15
5. MEASUREMENT
5.1. A Standard Language ...... / 17
5.2. Why Measure? ...... / 18
5.3. Types of Measurements ...... / 19
5.4. Error of Measurement ...... / 20
6. CONCLUSION ...... / 21
REFERENCES ...... / 23
1. INTRODUCTION
The accelerating pace of this century's research activity and technology that followed from it, is perhaps the sole candidate to characterize the present century best among the many other historical events. Yet, this scientific work have become obscured rather than illuminated by the sheer mass and complexity of its own results. Hence, there is a growing need for a study of science as a whole, as a "science" behind all sciences. To be sure, this is not an entirely new discipline. Its roots are elongated to the ancient field of epistemology, the theory of knowledge and the methods by which it is apperceived.
In recent times, however, scientific introspection has taken a different and more creative form that by itself presents the key to important discoveries. The emphasis has shifted from abstract philosophy to the test of experience. The new aspects of scientific method, its objectives, and limitations represent the subject of the project. Therefore, our aim is also, to demonstrate how a scientific inquiry is accomplished and how the improvement of the methods may be useful for the exploration of other facts.
Science can be considered as a body of knowledge. We shall focus, however, on the process, which generates this knowledge, rather than on the knowledge itself. In this regard, methodology forms the crux of this work.
The project starts with a general discussion on science, and the definition of science follows. The next parts have the titles "The Methods of science" and "The "Science" of methods". These two concepts must be distinguished as this forms the crucial point. In this project we are not interested in methods employed by different branches of science, however, this is an analysis of the methods. In other words, the question "How can we manipulate the methods in order to get better results" will be answered.
The analysis of method is important as we may deal with many other questions by using the same method. But there is another good reason why method interests us: The history of science is full of examples of inconsistencies that made scientists re-examine the employed method which yielded contradicting results. It is then that most of the revolutionary discoveries are made. Perhaps the most crucial reason for a critical study of methods is that it can reveal new views and directions of science.
In the next meeting, in order to demonstrate the scientific process with its all steps, as an example, Michelson's mirror experiment will be discussed from the methodological point of view. Additionally, measurement, one of the major steps of the scientific method, will be covered in detail.
2. SCIENCE
2.1. About Science
“We are living in an age of science.” is not always a reasonable argument: Without any doubt, the current science and technology would astonish our predecessors. Yet, the present situation would not be seemed to the next generations as "too scientific".
The concept “Science is an essential part of the human life” is quite new. We understand from cave paintings that art has been performed sophistically for a very long time. Religion, too, can be said to date back to at least fifty thousand years. On the contrary, science as an effectual element of the human life has just set out to spread into the minds; changing the thoughts and behaviors strongly. Only for the last two hundred years it became an important factor of our daily life. Compared to how it influenced people in the ancient times, the present science yielded most of the fundamental changes improving the human life, only within this short period of time.
It would be nonsense to presume that the revolutionary power of science is over or is in its maximum level. In fact, the possibility that science is going to be more powerful in the next centuries is much greater. For example, in 1928, Max Born told a group of visitors, "Physics, as we know it, will be over in six months." His confidence was based on the discovery by Dirac of the equation that governed the electron. It was thought that a similar equation would govern the proton, which was the only other particle known at that time and that would be the end of theoretical physics. However, the discovery of the neutron and of nuclear forces knocked that one on the head, too.[1]
Despite of this kind of speculations, what we infer from the history is that the effects of science on thoughts, hopes, habits, life styles become more and more powerful and will keep on increasing for ages: Science is not going to die out unless the human race is threatened with complete extinction!
2.2. The Definition of Science
Above all, science is a set of information; but one that connects some certain facts under some more general laws. Nevertheless, science gives us the chance of operating on the nature. That is why the social importance of science is much more than that of art, for example. This does not necessarily mean that science is superior to art in investigating the truths; but the idea is that when viewed as a technique, science has a much more practical meaning that art can never reach at.
Attaining an adequate definition to science is not easy. Because, the meaning of science is not fixed, but is dynamic. As science has evolved, so has its meaning; with successive ages its significance changes and thereby it gets new meanings. So, we should not expect to have the most ultimate definition of science, however, some common understanding of the concept can be mentioned for the sake of that it is only necessary to agree on a few of its essential characteristics.
Science is a process of inquiry: In this regard, it is a procedure of answering questions, solving problems, and finally, developing more effective procedures for answering questions and solving problems.
Beyond having the pursuit of solving problems, all research efforts in science have the aim of testing, evaluating and improving the research procedures employed.
Scientific progress has two dimensions: First, the range of questions and problems to which science has been applied has been continuously extended. Second, science has continuously increased the efficiency with which inquiry can be conducted. The products of scientific inquiry then are:[2]
- A body of information and knowledge which enables us better to control the environment which we live,
- A body of procedures that enables us to add to this body of information and knowledge better.
Parallel to the developments in science, especially in physics and chemistry, the collapse of the then-predominant Aristotelian school and thoughts was indispensable: new methods, techniques were improved and these replaced the former ones. Upon such a basis there emerged the so-called "scientific method."
3. THE METHODS OF SCIENCE
3.1. Scientific Method
Scientific method is a set of principles and procedures for the systematic pursuit of knowledge involving the recognition and formulation of a problem, the collection of data through observation and experiment, and the formulation and testing of hypotheses.
The scientific method, even it may be seen as too complex in its advanced forms, indeed is very simple: While analyzing a subject, a researcher should make observations that would allow the discoveries of general laws on the subject matter. It consists of two steps: First, observation; and second, concluding a law. Both are of equal importance, they are open to an infinite development.
There are many examples of the scientific method: As a matter of fact, the person who said “fire pains” for the first time in his life, and then if he did this for several times, can be considered as being followed a scientific method. This person has undergone both the observation and generalization phenomena. Nevertheless, he was lacking the tools that scientific technique requires. These are fastidiously chosen significant tools and on the other hand, some methods -other than the generalization- that are essential to reach at “laws”. Someone who says “Objects which do not base on anything will fall down immediately” makes just a generalization; however, there is a possibility that he would face with the difficulty of being blamed as a liar by the balloons, butterflies, airplanes... Whereas, someone grasping the theory of falling bodies well, will certainly know how some irregular objects not obeying the laws will not fall down.
Actually, the so simple scientific method has not been developed so easily, with the fact that only a few people apply it on only a little number of problems they are dealing with. It is not really difficult to see a scientist who is capable of applying the scientific method extensively in laboratories, is not so talent to do so in his daily life for ordinary events. This example demonstrates that the “scientific behavior” is not that much natural for human being as one might expect. Because, our most of opinions are those that we suppose them to be real as we wanted them to be real, as Freud suggested for the explanation of dreams.
3.1.1. Characteristics of scientific method
The scientific method itself has been described so many times that today it is perhaps impossible to say something new on it. However, we have to define it for we may someday question if there exists a better way of obtaining information.
There are three basic steps to reach at scientific laws: First of all is to place some significant facts under observation; the second one, if it is appropriate, to get a hypothesis that explains these facts; and finally to extract conclusions whose worth is fixed by analyses and experiments. If the results are to be correct, even though they may need some manipulations in the future after some other findings have been revealed, they may be assumed as truth for a time. So, the phases of research can traditionally be identified as:[3]
- Observation,
- Generalization,
- Experimentation
3.1.2. Induction and Deduction
The two tools of the scientific method; induction and deduction
Science, even it starts from the observation and the analyses of the “details”, is itself about the “whole”. Science, in its final aim, is a series of steps of propositions whose bottom contacts with special facts or "details", and whose uppermost level is made up of the most general law governing everything in the universe. In this many-step series two arrows one being up and the other down carry out the logical relations between any different levels.
The up-directed arrow is called as “induction” and the downward as “deduction”. Induction is an inference of a generalized conclusion from particular instances while deduction is an inference in which the conclusion about particulars follows necessarily from general or universal premises. For example, the deductive system can be utilized in the textbooks, and inductive relations can be obtained as conclusions of experiments carried out in the laboratories.
3.2. Facts and Scientific Method
In modern science, the facts and the hypotheses coexist within the common structure of science. In science a fact is meaningful, that is, it can be used either to establish or to refute a claim. Moreover, a fact, in science, is not just a fact but is a sample, an instance. It may give way to some other findings, exploration of other facts.
The basic aim of science is to find out what the facts truly are. The application of the scientific method depends on the discovered facts. It is not possible to discover the facts without reflection: There is no way that we can know the facts only by our pure perceptions. If we touch at two objects with very high temperatures, it is inevitable that our instantaneous experiences would be much similar. On the other hand, it is impossible to conclude that they have exactly the same temperature, without any error.
A sensational experience can only introduce the problem, treating the findings as “knowledge” is possible only after such immediate experiences have undergone a detailed and complete reflective analysis.
All inquiries derive from a problem we face. Therefore, before starting to make inquiries, the issues to be studied must be selected and sifted. Such a sifting process requires some hypotheses, preconceptions, and even prejudices of the scientist. This, beyond limiting the subject matter issues which are studied elaborately, guides the researcher by helping to shape the inquiry. Every inquiry has its own characteristics as it raises a special problem and an appropriate solution to that problem. The inquiry is over if the solution is found. Unless there is a well-defined problem, it is not meaningful to try to collect “facts” from nature.
Developing and trying to solve problems which may help the researcher in finding the answers to somehow more difficult cases requires a great deal of intelligence and effort. The problems we face in daily life can be overcome, provided the application of the scientific method would make us able to solve the problem at all. Generally, this kind of problems -as a rule- do not bring some more complicated further issues: When they are solved, the problem disappears. Nevertheless, the most striking scientific method applications can be found in different branches of natural and social sciences.
4. THE "SCIENCE" OF METHODS
4.1. Definition of Methodology
Methodology, in its most compact form, can be defined as "the analysis of the principles or procedures of inquiry in a particular field."[4]. The objective of methodology is the improvement of the procedures and criteria employed in the conduct of scientific research. For this reason, methodology is often referred to as the logic of science.
The discussion and improvement of methodology is quite important: Scientific research requires the establishment of the highest possible standards of control. Measurement and methodology standards help providing a basis for adjusting results obtained under less than the best possible conditions. For example, if a scientist could not obtain a specific temperature at which the length of a metal bar to be measured, then he can adjust for the effect of the temperature by use of the linear coefficient of expansion of that metal. This will enable him to know the length of the metal bar at any temperature. This knowledge of the scientist, which is necessary to make such adjustments, is due to the existence of environmental, instrumental and operational specifications of the standard of measurement.
4.2. Methodology as the "Science" of Methods
Why do we study the method? The method we use to solve a given problem is indeed part of the problem itself. The analysis of method is important as we may deal with many other questions by using the same method. But there is another good reason why method interests us: The history of science is full of examples of inconsistencies that made scientists re-examine the employed method which yielded contradicting results. It is then that most of the revolutionary discoveries are made. Perhaps the most crucial reason for a critical study of methods is that it can reveal new views and directions of science. So, it can be considered a discipline of learning. In this sense our subject is the "science" of science. Any type of research can be shown to contain:
- Question
- Test
- Conclusion.
In order to illustrate this process, we will proceed with the famous example; the Michelson’s mirror experiment.
4.3. Michelson’s Mirror Experiment
4.3.1. The Problem
After the late 1800’s, it was thought that physics had solved most of its major problems. (See part 2.1) Moreover, the sole remaining tasks were only a little number of measurements: Finding out a few constants somewhat more accurately. At the time, for example, the question “What kind of mechanism makes it possible for a particular source to communicate with a target some distant away, by the means of electromagnetic waves or gravitational field etc.?” was represented by a mechanical model. How the Sun can know that the Earth is here and exerts a force on it was explained by an ever-present medium called “the ether”. The presumptions about ether were those that it is a special substance covering the whole universe, might be a matter, does not slow down the planets and should be motionless.
This last postulate was of primary significance, as it established a universal reference system of absolute rest upon which all motion could be defined. Could such motion be proven by measurement? This is the first step: We have a question to be answered.
4.3.2. The Experiment
Set-up of Michelson's mirror experiment
Michelson constructed an experimental setup to answer this question. This experiment and its consequences will be used later to demonstrate the general procedure of scientific method.
In Michelson’s experiment, if the question “How does the motion of the Earth affect the speed of light measured on its surface?” could be answered, then by a simple analogy one would be able to claim that if the Earth moves through an ether at rest, an observer should measure the speed of light other than c. Accordingly, an observer moving with a velocity v along the same direction that light travels through the motionless ether would measure the speed of light c-v, and an observer moving just in the opposite direction would measure it as c+v.
In this experiment, actually, the time difference between two light beams were measured. Any difference in the interference pattern would indirectly prove the existence of the ether. Because, if the assumptions about ether were correct then it would take a little more time to travel for one light ray than the other, hence an interference pattern is formed by the superposition of light waves.