Linda Kohner, Age 11, Of St, Catharines, Ont., Canada, for her question:
What is the science of physics?
The word physics sets us thinking of atomic energy and other wonders of our modern world. But the first book entitled "physics" was written by the great thinker aristotle in the year 330 b.c. About 100 years later, Archimedes used certain laws of physics to invent the lever and the pulley and to discover the principles of specific gravity.
To the ancient greeks., the word physics meant nature, in our modern world.. The science of physics deals with matter and energy and the natural laws which govern them. Early in this century., the physicist albert einstein suggested that matter is a form of energy and that a certain amount of matter can be converted into a certain amount of energy. This led to our experiments in atomic energy,
Nuclear physics, which unleashes the energy of the atom, is, however., only one branch of the science of physics. Energy and matter are involved when heat changes ice into water and water into steam. Abridge builder must figure the interaction between his steel girders and the force of gravity. The laws of physics operate in a pump and a light bulb, in tv and astronomy.
Every speck of matter in the world is governed by forms of energy. These silent invisible powerhouses include heat and light, gravity and magnetism. The science of physics, then., reaches into other sciences, into mechanics and machinery. No one can be expert in all the branches this master science reaches.
Dynamics is the branch of physics which deals with matter and movement. Wells and water pumps are built by experts in hydrodynamics. Planes are designed by experts in aerodynamics. The laws of physics operate in a generator to give us electric current and the dramatic science of electronics. The astronomer studies the laws of motion as they relate to the distant stars. We enjoy the benefits of radio and tv, radar and telephone because physicists have learned the interactions between
Electromagnetic energy and various instruments made of matter.
Energy is involved when substances form :chemical compounds, when sodium and chlorine form salt. This activity comes from electrons. The chemist uses physics when he studies the behavior of the atoms of different elements. The nuclear physicist studies the particles in the core or nucleus of the atom and the energy which binds them together.
Until recently the science of physics seemed to concern only non living things. But since the master science underlies the whole of nature, we are not surprised to see it applied to the study of biology. Living cells are made of molecules, molecules are chemicals and chemistry depends upon physics. A brand new study called molecular biology takes the laws of physics into the very processes of life itself