FREE ESSAY ON HISTORY OF PHYSICS

HISTORY OF PHYSICS

Physics began when man first started to study his surroundings. Early applications of
physics include the invention of the wheel and of primitive weapons. The people who built
Stone Henge had knowledge of physical mechanics in order to move the rocks and place them
on top of each other. It was not until during the period of Greek culture that the first
systematic treatment of physics started with the use of mechanics.
Thales is often said to have been the first scientist, and the first Greek philosopher.
He was an astronomer, merchant and mathematician, and after visiting Egypt he is said to
have originated the science of deductive geometry. He also discovered theorems of
elementary geometry and is said to have correctly predicted an eclipse of the sun. Many
of his studies were in astronomy but he also observed static electricity.
Phythogoras was a Greek philosopher. He discovered simple numerical ratios relating the
musical tones of major consonances, to the length of the strings used in sounding them.
The Pythagorean theorem was named after him, although this fundamental statements of
deductive geometry was most likely first an idea from Egyptian methods of measurements.
With the help of his followers he discovered that the earth was a sphere, but he did not
believe it revolved around the sun.
Democritus was the leader of a group called Atomists. Although they were unable to prove
that matter was made up of small particles, they were the first to come up with the idea.
Democritus believed that atoms differed in size, shape, and movement but were all made of
the same substances.
Aristotle was the most important scientific philosopher in Greece. He believed that all
matter on earth consisted of four pure substances or elements, which were earth, air,
fire, and water. He also believed that the earth was the centre of the universe, and that
anything beyond the earth consisted of a fifth pure substance called quintessence. 
Archimedes was an inventor and mathematician, who discovered several basic scientific
principles and developed a number of measuring techniques.
Ptolemy was an Egyptian astronomer. He developed a model for predicting the positions of
the sun, moon, stars, and planets. Like Aristotle, he believed that the earth was the
center of the universe. Between 400 AD. and 1000 AD. Most educated people in Western
Europe looked to religion rather than scientific investigation to answer their questions
about the laws of nature. At the same time Arabic scholars were correcting Ptolemy system
of astronomy and performing experiments in optics and mechanics. As trade increased
between Arab countries and western countries, their work and Greek scientific documents
became available to western culture. During the 1200's St. Thomas Aquinas reconciled
Aristotle's beliefs with church principles. During this time Roger Bacon an English
scholar conducted studies in optics.
During the Renaissance there were many social, economic and political changes that
produced new approaches to science. The famous Italian painter Leonardo da Vinci
conducted studies in motion and hydraulics. The polish astronomer Nicolaus Copernicus
proposed a system in which the sun was placed at the centre of the universe and the earth
was one of the planets orbiting the sun. In the 1600's Johannes Kepler, a German
astronomer constructed a new and accurate model of the solar system. Rene Descartes, a
French philosopher and mathematician developed the concept of inertia ( that objects
maintain their state of motion unless disturbed ). At this time people began to realise
that the physical world was governed by natural laws and that it was possible to discover
those laws through careful measurement under controlled conditions. Galileo, an Italian
physicist developed a number of telescopes to study the heavens, and performed laboratory
experiments on the motion of falling bodies. 
In the 1600's there was a great deal of scientific activity. Sir Isaac Newton, an English
scientist, published his Mathematical Principle of Natural Philosophy. He developed three
laws of motion and a law of universal gravitation based on the work of Galileo and
Descartes. He also invented a new form of mathematics called Calculus. 
During the Industrial Revolution scientific instruments were produced which were more
accurate and enabled scientists to perform more complicated experiments. People began
specializing in specific areas such as: Heat and Energy, Light, and Electricity and
Magnetism. Scientists began to learn that heat was able to do work. James Joule, and
English physicist, devised a way to calculate how much work a give quantity of heat could
do. Later a number of Physicists proposed the Law of Conservation of Energy (energy can
neither be created nor destroyed, only transformed from one form to another). In the
early 1800's the theory was developed that light existed in the form of waves. Physicists
believed that all space was filled with ether and that light energy was the vibration of
the ether. There were other development in the study of electricity and magnetism, for
example Count Alessandro Volta of Italy invented the electric battery; Andre Marie Ampere
and Hans Christian showed that electricity and magnetism were related, and Michael
Faraday and Joseph Henry showed how mechanical energy could be converted into electrical
energy. At the end of the 1800's many physicists believed that all the laws concerning
the universe had been discovered. 
The first Physicists in Canada taught at universities and did very little research. When
Ernest Rutherford studied radioactivity at McGill University, he inspired other
Physicists to do more research. In 1930 James Hillier helped to build the first electron
microscope while he was a student at the University of Toronto. With financial help from
the National Research Council scientists have developed the CANDU nuclear power reactor.
Gerhard Herzberg received a Nobel Prize for his studies of the ways atoms and molecules
give off and absorb light. The Alouette satellites, which were launched in the 1960's,
have helped Physicists to study matter high above the earth's surface. 
At the turn of the twentieth century the understanding of the physical universe changed
completely when Antoine Henri Becquerel and Wilhelm Roentgen discovered radioactivity and
x-rays. A general, theoretical picture for the generation of x-rays emerged after Niels
Bohr developed the first atomic theory. At this time Physicists realized that they had to
reexamine the philosophical foundations of their work. In doing so, the public saw them
as intellectuals who probed the dark mysteries of the universe. Physical knowledge was
reorganized and the theories of quantum mechanics were formulated.
Up until this time most Physicists worked at universities mainly in German-speaking
Europe. Then research moved to new countries where it was supported by industry, National
Research Council, or private foundations. 
Max Planck, a German physicist, published his Quantum Theory of Energy Transfer. Later,
Erwin Schrodinger and Werner Heisenberg initiated the development of the field of quantum
mechanics. Albert Einstein showed how mass and energy are related in his famous equation
E = mc2. 
Research in physics has led to important advances in technology, for example: in 1947
American physicists invented the Transistor which revolutionized the electronics
industry, and in the early 1960's physicists produced lasers which are light amplifying
devices and are valuable tools in areas such as communications, industry, and medicine. 
Governments have become interested in promoting scientific investigation. The United
States and the Soviet Union have carried out extensive research on thermonuclear weapons
and started a space program.
Physics has evolved greatly from when primitive man devised ways to move heavy objects to
the complex scientific research that is being done today. Physics has also moved from
being a branch of Philosophy in Aristotle's day to being a very exact science today.
Physicists are still seeking knowledge concerning the laws of nature and the universe and
are involved in many diverse areas of research, such as, biophysics, astrophysics,
solid-state physics, and genetic engineering. Physicists no longer believe, as they once
did, that everything is now known concerning the universe and are constantly searching
for new truths.