The science of the material world

Physics is the science studying various phenomena in nature, mostly the phenomena of nonliving matter. Using mathematics as a tool, it is an exact science of the material world and forms the basis of many other studies. The astronomer, the chemist, the geologist, the engineer – all need some knowledge of physics to progress better in their respective spheres of work.

Physics is generally divided into a number of branches. At an elementary level these are mechanics, heat, sound, optics, electricity, and magnetism. As we go deeper and deeper into the structure of matter we have to introduce more divisions. But it must be remembered that there is a unity in nature and these divisions are man-made for his own convenience in studying nature. The object of physics is to determine exact relations between physical phenomena.

Physics is also divided into two great branches, experimental and theoretical physics. The task of experimental physics is to make observations and carry out experiments. On the basis of experimental facts theoretical physics is to formulate laws and predict the behavior of natural phenomena. Every law is based on experiments, therefore it is important that experiments be done very accurately. It was the study of the natural phenomena that made it possible to formulate various laws.

Although physics is an exact science it is also an activity exercising imagination. As we have progressed from mechanics to nuclear physics, physics has become more and more difficult to understand. The deeper we go into subject, the more we have to use our imagination. Our ideas, however, are colored by our experience in mechanics which has supplied us with the most fundamental concepts. Perhaps the most important one is energy as it is to concern of every physicist whatever his field may be. It should be right to say that physics is the science of matter and energy.

There are still a lot of problems to be solved. Scientists all over the world are doing their best to find answer to numerous yet unknown phenomena.

The words of science

There are many words which the scientists have been using since long ago. Sometimes the meaning of these scientific terms may not be the same as that of the words used in everyday life. Let’s consider some of them. Physics adopted the word “current” to describe the changed properties of a wire connected to a voltaic battery between electromotive force and current and gave the ratio the name of “resistance”.

Sometimes, scientist will take an ordinary word to expand or widen its meaning, so that a single thing gives its name to a group or category. “Salt”, for example, is a material that is essential for human beings and animals, and has a long association with social history. Its name appears in the English language in such a word as “salary” meaning that the money one earn is meant, in the first turn, for buying what is most necessary for human existence. The chemist, however, use the word to denote a class of compounds, which he defines as the product of replacing the hydrogen of an acid, wholly or in part, by a metal or metallic radicle. Common salt is a compound, which comes only to a limited extent within the terms of this definition and only to this limited extent do these two salts mean the same thing.

Sometime a scientist will take a word and force it to do work for which it has no qualification.

Such is the case of family of related words – “force”, “work”, “power” and “weight” . In mechanics force does not mean strength. It means that force is a push or a pull, and since in physics all things must be measured, it acquires from newton’s law of motion a quantitative sense, which makes it the product

Of mass and acceleration. This , of course, is quite different from anything that word force implies in everyday use.

A weight is not only familiar block of metal with a ring on top, but a force. This is logical, because things fall under their own weight with an acceleration (due to gravity), so that the weight of a thing has to be the force with which the earth attracts it.

As to “work”, the physicist has decided that a force works or does not work, only when it moves something. I may push and pull in vain at some immovable obstacle, and find that, nevertheless, mathematically I have done the work. After this it is quite easy to accept the idea that power has come to mean the rate at which work is done.

Scientific words do not change their basic meanings in the course of centuries, as many ordinary words do. This singleness of meaning, this constancy in form and function give to scientific words a character, which distinguishes them from other words, but relates them to the symbols of mathematics.