What is Science?
For many thousands of years the earth was inhabited by creatures who lived and died without passing on their experiences to following generations. These early fish, reptiles, birds and mammals could only 'talk' to each other through the roars, calls and screams of the jungle. Yet, somehow, from these prehistoric beings a more intelligent animal evolved with a brain able to form the controlled sounds of speech.
At the same time, this human being began to use rocks and trees to fashion weapons to help him hunt for food.
Stones and spears were probably the first tools used by humans as extensions of their own bodies - the spear could travel faster in flight than man could run- and this ability to invent tools and pass on knowledge gave man a growing control of his surroundings.
His search for new ways to survive and improve his way of life continued through the ages and the story of this search is the story of man's world of science and invention.
As knowledge grew and the art of writing developed, parts of the story were recorded - some in one book, some in another. No man could remember all there was to know and writers found it useful to classify their knowledge under separate headings much like a library arranges its books in sections so that the reader will know where to look for each subject. Science became separated into various branches such as physics (the study of natural forces), chemistry (the study of materials), and biology (the study of living things). These various branches of science progressed at quite different rates. Biology, for example, was for many thousands of years simply the accumulation of man's experiences in the rearing of animals and the sowing and reaping of crops, while human biology was left to the ·witchdoctor, until the practice of medicine became well established.
Yet time after time one branch of science received new and exciting ideas from another which enabled it to make further progress. As knowledge in each subject grew, the subjects themselves began to overlap, producing new branches of science such as physical chemistry and bio-physics. Some men used this knowledge to build better machines and structures and later found it necessary to form special branches of what is called applied science. These engineers were the founders of civil, structural, mechanical and electrical engineering societies in many different countries.
Man's adventure into space is one example of the way in which scientists and engineers must today work in teams so that physicists, chemists, biologists, mathematicians, astronomers, doctors and engineers can all combine their own special knowledge of science to achieve a common aim.
Because the story of science and invention is so inter-related it is not told in the following pages under special headings like 'physics' or 'chemistry'.
Instead it is traced through some of the ways in which man has successfully found and used the laws of science to satisfy his physical needs as well as his curiosity.
Throughout history, man has thought about the nature of matter it is, after all, the 'stuff' from which he is made. Step by step he gained a deeper understanding of The microscopic world (the title of our next chapter) of simple particles and the behavior of atoms.
To know when to sow and when to reap his crops he learned how to measure Time. The control of moving bodies has been one of man's greatest achievements, first on earth and now in outer space. This science of dynamics, or the study of Motion, began with the first hunters as they watched their spears travel through the air. To build houses, towns, roads and bridges, man had to keep things still and make sure that what he built would remain standing: therefore, he developed the science of Equilibrium, which means maintaining even balance.
Only when man's curiosity and physical needs had led him to the discovery of the electron and the principles of electricity and magnetism, did he find the answers to many of the problems of science. The control of the electron, now the responsibility of the electrical and electronic engineer, opened up new means of communication such as the telephone, radio and television. The control of the nucleus followed, and knowledge of the atomic nucleus has led to the development of atomic energy, an achievement which has offered man life-giving energy independent of the sun's rays.
Though this may be the last chapter of our present story, it will certainly not be the final chapter of man's world of science and invention.
Scientific progress has been achieved in many ways. Early man learned by experience and tried to repeat from memory the best way to hunt, to build or to keep himself out of harm's way.
He was an inventor but had not yet become a scientist. Only when he began to search for natural laws and principles, and so produced theories, did he begin to use scientific method. The ability to use that part of his brain called imagination - to do this, was slow in developing. The first evidence of it can be seen in the cave paintings of primitive man. These paintings were all reproductions of the material world around him.
Much later, the Egyptians carved imaginative scenes of their sun gods on rock faces, but it was the Greeks who were the first to develop a scientific imagination. Greek philosophers, such as Plato (427-347 BC) and Aristotle (384-322 BC), created mental pictures of matter, while Archimedes (287-212 BC) used mathematical pictures to explain physical principles. The cave painters could not draw imaginative pictures of things they had never seen and many people today are in the same position, yet this is just what scientific invention is about. New ideas have often developed not only because an inventor had the ability to combine his knowledge with patient investigation, but because he could also use his imagination to make new and original scientific pictures and models.
Model building starts when we are very young with bricks and pieces of cardboard. A model plane can be built from two pieces of card or wood tied together with string. It is a very simple model but in imagination it can become the latest jet aircraft diving down through the clouds. With a construction kit and an elastic-powered engine, however, a real flying model is possibility. Not perhaps as realistic a craft as one of the more advanced radio-controlled models, which are so perfect in detail that from a photograph it is difficult to tell the difference between the model and the real thing. Scientists, too, like to build models and some of them appear in this book.
These scientific models are used to explain how and why things behave as they do. For example, in the following pages we will trace the development of atomic energy from the time when early scientists built their first model of an atom. Like the model plane made of pieces of wood, the model atom was a very simple toy - something like a small billiard ball.
But new facts about the behavior of atoms could not be explained by this means and so a more complicated atom model was constructed. This was a miniature solar system with a sun, or nucleus, at its center and planetary electrons rotating around it. This model worked extremely well, so well in fact that there was a danger of thinking that the atom was exactly like this.
As we have seen, models can easily be mistaken for the real thing.
During the 1920s, as a result of further research, an even more complicated atom model was constructed which could not be represented in terms of particles at all. This model, too, is likely to be replaced as scientists discover further facts about the behavior of the atom.
This is how science has progressed in many fields, and it is easy now to laugh at the earlier simple models and think how wrong they were. But like the crude model plane made from pieces of wood they did have something of the right shape and proved to be very useful in helping to develop many early inventions.
If you look at the number of important inventions and discoveries that have been made over the last 1,000 years you will find that most of them occurred in the last 300 years.
Why is this? What prevented progress being made in the previous 700 years?
One reason was the mistaken belief that once a scientific model had been built, it was a complete picture of the real thing. Anyone who doubted this ran the risk of being ridiculed by his fellow men and even in some cases of losing their lives by carrying on with their investigations.
Many of the scientists whose names appear in these pages were men and women who dared to doubt what seemed to others to be an obvious explanation of something. They helped to build the new models of the scientific age. It is no different today. Our models are not the real thing, and there are many new inventions and theories waiting to be developed. More names will be added to the growing list of scientists and inventors who have understood the need for simple models, but are prepared always to modify them when new facts demand a different explanation. Who knows? - perhaps in a few years' time one of these names may be yours.