|Section 1: What is Science?|
History From the Beginning
The Definition of Science
In the foregoing history of the early development of science a number of elements of science have been mentioned. You may remember some of them. They are elements of ordinary human experience and mental activities, but directed systematically toward chosen goals. They include human experience, observation of things in the natural world, comparison, contrast, classification, naming, trial and error, measurement, instruments like the telescope, scientific theories, and philosophies of science. One famous disagreement or debate in science at the time of Galileo was discussed briefly. And we considered at some length a great scientific discovery made possible by the application of the scientific method. How, then, should science be defined. Here is a concise definition:
Science is human experience systematically planned and extended(by intent, method, and instruments) for the purpose of learning more about the natural world, and for critically testing all hypotheses about the natural world.
Remember that just in the experience of living and growing up we each learn many scientific facts about the world in which we live. But this is ordinary human experience, not science. Science is a special kind of human experience, for there is an intent to learn more about the world. There is an intention to answer a particular question, solve a particular problem, or meet a particular human need. That need may simply be the need of the scientist to satisfy his curiosity. Sometimes, too, serendipity enters into science, for a scientist may stumble into a great new discovery more or less by accident. Of course, he must be acute enough to recognize the significance of what he has tripped on. But, in any event, intent directs or channels human experience toward the end of increasing knowledge. A scientist may have a limited or extensive knowledge about some type of object or activity in nature. He becomes familiar with the subject of interest, alertly observing and recording facts about the subject of interest. He then plans a systematic program of investigation aimed at achieving the intended increase in knowledge which will answer the particular question or solve the problem he has in mind. However, once this process begins, there is no way to predict the outcome, what new knowledge may finally be gained.
In addition to intent, in scientific research a method of research is applied which provides certain rules which the scientist is to follow. Furthermore, in each investigation a set of procedures is planned which makes the research orderly and efficient. The scientific method with its rules, with procedures carefully designed for each research project, refines and extends the effectiveness of ordinary human experience for the purpose of increasing valid knowledge about the natural world.
In his experimentation the scientist may be able to make all of the necessary observations by means of his natural senses--sight, sound, touch, etc. Or he may have to use suitable instruments which extend the powers of his natural senses--a microscope, sensitive balance for weighing, an electric voltmeter, etc. It is necessary to observe as many pertinent facts as possible and as accurately as possible. Quantitative measurements are vital in modern science. Instruments greatly increase the scientist's power to do these things. They extend the scope of ordinary human experience.
The next element in our definition of science is hypotheses and the testing of hypotheses. Scientists generally carry on their research projects with some idea of what they expect to find. They usually ask many questions and then, on the basis of what they already know, plus creative speculation about what they do not yet know, they attempt to devise explanations for what they have observed or to answer their questions. These explanations are called hypotheses. A scientific hypothesis is an educated guess framed to answer a question or to explain a set of observed facts. Sometimes the scientist reasons logically to form a hypothesis. At other times a scientist may arrive at a hypothesis by intuition or by an act of pure creative imagination.
What does a scientist do with a hypothesis which may or may not be correct? First, he studies his hypothesis to see if it is internally consistent, not self-contradictory. Second, he analyzes logically the connection of the hypothesis with accepted scientific theories and laws, noting any apparent contradictions or problems. Third, he reasons logically to deduce the consequences of the hypothesis. If the hypothesis is correct, what particular results does it demand or predict under certain controlled conditions? Fourth, he attempts to test the hypothesis by new experiments. If he is able to set up the right controlled conditions in a new experiment, the scientist will then be able to observe whether or not predictions which follow logically from the hypothesis actually agree with reality in the observable world. If this is the case, the experiment supports or corroborates the new hypothesis. If the observed results do not agree with the prediction, the experimental results may serve to prove that the hypothesis is false or needs to be revised.
The process just described is the experimental testing of a scientific hypothesis. The more such tests a new hypothesis survives, the better established it becomes as a scientific theory. However, even a theory which has survived many tests and becomes widely accepted by the scientific community, may finally be rejected. It may in the end fail to survive the discovery of new evidence or a crucial new experimental test. That hypothesis will then have to be either modified or replaced by a new hypothesis.