PHYS 400















Supervisor: Assoc. Prof. Dr. Çaðlar Tuncay











November, 1998




1. INTRODUCTION .......................................................



2.1. About Science ........................................................


2.2. A Definition of Science ..........................................




3.1. Scientific Method ....................................................


3.1.1. Characteristics of Scientific Method ................


3.1.2. Induction and Deduction ..................................


3.2. Facts and Scientific Method ....................................




4.1. Definition of Methodology......................................


4.2. Methodology as the "Science" of Methods .............


4.3. Michelson’s Mirror Experiment .............................


4.3.1. The Problem .....................................................


4.3.2 The Experiment .................................................


4.3.3 The Conclusion of the Experiment ...................



5.1. A Standard Language ..............................................


5.2. Why Measure? ........................................................


5.3. Types of Measurements ..........................................


5.4. Error of Measurement .............................................


6. CONCLUSION ............................................................


REFERENCES .................................................................




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.















2.1. 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.


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:

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."



3.1. 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:


    1. Observation,
    2. Generalization,
    3. 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.



4.1. 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." . 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:

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.

Michelson performed his experiment in various conditions: The whole apparatus was mounted on a revolvable platform. This enabled him carrying out the experiment for several times, in different directions. However, the most famous part of the experiment was its result: It was negative; there was no effect!

4.3.3. The Conclusion of the Experiment

The conclusion drawn from the result had an important consequence: The fact that the interference pattern does not change if the measurement is done when the Earth's position is altered with respect to the Sun was manifested that the speed of light is the same for all observers.

Indeed the cycle was started anew: each conclusion was based on new postulates whose consequences were again subject to test, and so dozens of subsequent experiments were designed in order to settle the questions raised by the first.

Michelson, insisted to believe in ether, however. He thought that the ether, like the atmosphere, could be carried along on the Earth's surface. Thereafter, he repeated the experiment at high altitudes. Yet, the ether might be stationary at this altitudes, he thought. Therefore, he never gave up his belief that under proper conditions the existence of ether can be shown. Here we have the situation in which a theory, originally useful and convenient in overcoming major conceptual difficulties, causes even greater difficulties in attempting to prove itself in the face of experimental counterproof, until finally it must be abandoned.

Albert Einstein saw that Michelson's results demanded critical evaluation, not of the answer but rather of the question contained in the experiment. He argued: Is it really possible to postulate a system at rest, let alone a quiescent ether, with reference to which any motion such as earth's can be measured in absolute fashion? The theory of relativity came out upon the basis of Einstein's conclusion on this ether drift experiment. According to this theory, there cannot be a physical law enabling us distinguish between moving systems, regarding their absolute velocity or their absolute rest. This led to many further re-analyses of concepts such as time, simultaneity, and also the developments of other theories.

Scientists saw that it was not meaningful to try to define a coordinate system at absolute rest. It was recognized that all measurements between moving systems have only a relative meaning, which is part of the discussion of methodology.

It should now be apparent that why we chose Michelson's experiment and Einstein's theory of relativity for discussion. Here are the steps of scientific work: The question arising from a theoretical picture; the experimental test; the conclusion giving rise to new questions, so that the process of obtaining the results of research, knowledge, and insight moves not in circles but in a path of expanding spirals. This, eventually, also forms an example to the scientific method. Finding the correct answer is not always more difficult than asking the right question.



5.1. A Standard Language

Like all observation types, measurement has fundamental limitations of reliability. This is of central interest for such limitations reveal important aspects of nature. Hence, the accuracy of measurement ought to be examined. In addition, the criteria of reliability should be studied throughout some statistical analyses. Measurement is based on a comparison with some certain conventionally chosen standards and units. Howbeit, these can be linked to physical parameters.

Without the communication of ideas, it is impossible to expect any progress in science. The barking of a dog, the song of a bird, the roar of a lion, for instance, are different means of communication. As far as we know, man has the most sophisticated way of communication through the use of symbols.

The existence of many different languages makes it more difficult to communicate. However, this is not the sole problem: In science, we have a problem of expressing measurements. The act of making a measurement implies making a comparison. It is impossible to measure without comparing the results with something else. The statement "Today is hot" implies that today is hotter than some other days. "She is eight years old", requires a comparison of the length of time the person has lived with the number of times the Earth has rotated around the Sun. This last statement introduces another aspect of the difficulty of measurement: The term "eight years old" means one thing to a European and something quite different to a Chinese, for example, since the birth of day corresponds to different things in these countries.

5.2. Why Measure?

Measurements allow us to compare the same properties of different things, and the same property of the same thing at different times, and to describe how properties of the same or different things are related to each other. Therefore, in general terms, measurement can be defined in terms of its function: It is a way of obtaining symbols to represent the properties of objects, events, or states, which symbols have the same relevant relationship to each other as do the things which are represented.

Lord Kelvin, a physicist of the last century, expresses measurement as the necessary condition for any substantial scientific progress as follows:

When you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot express it in numbers, your knowledge is of a meager and unsatisfactory kind: it may be the beginning of knowledge, but you have scarcely, in your thoughts, advanced to the stage of science, whatever the matter may be.

Measurement is of special importance to science. First, measurement provides the basis on which more precise and accurate descriptions of data can be given. Secondly, measurement yields data amenable to mathematical treatment. One objective of measurement is to make communication possible. When a result can be expressed numerically, it can be transmitted to others. Another objective is to provide deeper understanding of the phenomena being measured.

To illustrate, consider one of many quantities which are being measured today by means of instruments that produce results of uncertain value. An intelligence test is an instrument that measures something and produces a number. Applied several times to the same subject, such tests produce results that are distressingly variable. There is also the big question as to what it is that is being measured. This question naturally leads us to wonder what intelligence is. Yet as "better" tests are devised, more will be learned about the subject, and there will be increasing agreement on the question of what the tests are measuring.


5.3. Types of Measurements

Measurement is the procedure of assigning numerals to objects or properties of objects according some rules. This definition, before mentioning these rules, requires the distinction of qualitative and quantitative descriptions: Qualitative descriptions are two types: classificatory and comparative.

A classificatory description places an object within a class. For example, "Whales are mammals", "Hydrogen is a gas" are each of classificatory type. On the other hand, descriptions such as "Physics is more interesting than chemistry", "Winter is colder than summer" are comparative. A comparative description is more precise and informative than a classificatory one.


Quantitative data, however, allow us to formulate more precise laws. Quantification involves three distinct uses:

  1. To label or identify the things;
  2. To show the positions or the rank order of the things in terms of a certain property or quality, and
  3. To indicate the quantity or the quantitative relations of objects or properties of objects.

Both the qualitative and the quantitative descriptions are characteristics that involve us: It is our language, not nature itself, which is qualitative or quantitative.

Quantitative descriptions provide answers to questions "how many?" and "how much?". The answer to the question "how many" involves counting; while "how much" involves measurement in its narrowest sense. This difference arises from the fact that counting applies when the object system consists of discrete elements. Measurement, on the other hand, is used when the object system involves continuos variables.

5.4. Error of Measurement

Any type of measurement, a classification, rank, or interval or ratio measurement has little significance without some knowledge of its accuracy. Not only does it affect the individual measurements of the person who is measuring, but it is also related to the philosophy of what he is trying to do and often to the real meaning of his work.


So, since "Measurement is never better than the empirical operations by which it is carried out, and operations range from bad to good.", no measurement is free from error. Beyond the possible instrumental errors, there are some other important factors of errors: The principle source of trouble is that when two measurements are made, they must occur at different times or at different places, or both. At these times or places,

  1. The "same thing" may not be quite the same, which is why the quotation marks are used.
  2. The instrument may undergo slight changes, or there may even be two instruments used.
  3. The user of the instrument may change, or the same person's use of the instrument may differ a bit from one measurement to the next.
  4. The circumstances surrounding the measurement may change.
  5. Formally, measurement errors are due to a) the observer, b) the instruments, c) environment, d) the observed, e) control of the experiment. In practical situations, error of measurement can be reduced by increasing the sensitivity of the instrument and improving the performance (perception, concentration, motivation, skill, etc.) of the human.


Methodology can be considered to be a special type of problem solving, one in which the problems to be solved are research problems. Any problem situation, and hence research problem situations, can be represented by the following equation:


V: The measure of performance or accomplishment that we seek to maximize or minimize.

Xi: The aspects of the situation we can control; the "decision" or "choice" or "control" variables.

Yj: The aspects of the situation (environment of the problem) over which we have no control.

Then solving a problem consists of finding those values of the decision variables Xi which maximize or minimize V. Theoretically, it is possible to formulate problems in research design in this way and to find "optimizing" solutions. The attainment of such optima is the objective of methodology. At the present time we can formulate only a few research problems in this way, but this achievement is the product of just a few years of such study of research procedures. Even where we cannot find such optima, however, we can learn a great deal about the relative effectiveness of different research procedures by attempting to formulate them in this way. Such an effort is the most efficient way we have of precisely defining problems in methodology and of directing scientific research to their solution.

Methodology evokes new thinking ways, or reveals new approaches to old problems. Such criticism has enormous potential as it gives unending tasks to the scientist. But then, we never reach finality. We begin with a question, and we end with a question.











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