Johannes Kepler

Date of Birth-Death : 1571 - 1630 Country of Birth : Holy Roman Empire (now in Germany) Major Discoveries : Laws of Planetary Motion Writing by the Scientist : Epitome Astronomiae in 1621 in seven volumes Born in the small town in the then Roman empire, Johannes Kepler was the son of a mercenary soldier. Even as a young student, Kepler excelled in mathematics. His intelligence and hard work, earned young Kepler a special place in the hearts of his teachers. It was on the recommendation of one of his teachers that Kepler got an opportunity to work with the renowned Danish astronomer, Tycho Brahe. These were times when it was believed that the Earth was the center of the Universe, and seven planets- Moon, Mercury, Venus, Sun, Mars, Jupiter and Saturn - moved round the Earth. Already several scientists were disputing this theory. Copernicus had put forth his "heliocentric theory" where he stated that the Sun was the center of the Universe, with planets moving around it. Kepler got his chance to not only prove this through mathematical calculations, but also define specific elliptical orbits for the planets' paths around the sun. Kepler worked with Tycho Brahe and after his death, took over the mantle of Imperial Mathematician. Drawing data from Tycho Brahes observations and his own, Kepler formulated the three laws of planetary motion, which established the current theory that planets move in elliptical orbits around the sun. Despite a number of personal tragedies, Kepler's involvement in his work did not wane. As one of the most respected and admired mathematicians of his time, Kepler had many "firsts " to his credit. He was the first to correctly explain planetary motion. Keenly interested in optics, he was one of the first to investigate the formation of pictures with a pin hole camera and the first to explain the principles of how a telescope works.

Stephen Hawking

Date of Birth : 1942 Country of Birth : UK Major Discoveries : Theories on the origin of the Universe Writing by the Scientist : A brief history of time : From the Big Bang to Black Holes (1995) Stephen Hawking decided to become a scientist when he was 8 or 9 years old. By the time he was 14, he had narrowed down his field of interest to mathematics and physics. After obtaining a first class honours degree from Oxford University, he decided to do his Ph.D. study at Cambridge. It was at Cambridge that the disease that was to make him a physical wreck first manifested itself. He began bumping into things. His hands trembled and he found it difficult to tie his shoelaces. His parents took him to a specialist who, after subjecting him to a battery of tests, announced that he had a rare ailment known as motor neuron disease. Victims of the disease usually do not live very long and Hawking, who was 21 years old at the time, was told that he might not live to see his 25th birthday. He was plunged into despair and lost interest in his work. His despondency lasted two years. Then he realised that death was not imminent and he began to fight back the crippling ailment. He obtained his Ph.D. in 1966, married, had children, and slowly began to make a name for himself in his chosen field of study, Cosmology, the study of the Universe. In 1988, he wrote a book in which he put down some of his ideas about the formation and ultimate destiny of the universe. It was titled 'A Brief History of Time'. It became a best-seller, and brought him fame and fortune. Today Hawking is confined to a wheelchair and he cannot even speak without a synthesizer, but his mind remains unaffected. To doctors, he is a medical curiosity; to scientists, he is a pathbreaker in the study of the universe — some have even described him the 'world's greatest living physicist'.

Charles Darwin

Date of Birth-Death : 1809-1882 Country of Birth : UK Major Discoveries : The theory of natural selection Writing by the Scientist : Origin of species by means of natural selection(1859); Descent of man (1871)

Born into a wealthy family, Darwin grew up amidst a life of wealth and comfort . His father was a doctor and had similar aspirations for him. It was no surprise therefore that Darwin first studied medicine at Edinburgh. However, it soon became clear to the family, and particularly to young Charles, that he was not cut out for a medical career. He then went to Cambridge to train to become a clergyman . While at Cambridge, Darwin befriended a biology professor John Stevens Henslow, and his interest in zoology and geography grew. An unforeseen opportunity precluded Darwin's plan of becoming a clergyman. He was invited on board the ship, H.M.S. Beagle as a gentleman companion to the captain. 

The round-the-world journey on H.M.S.Beagle lasted almost five years. Darwin spent most of these years investigating the geology and life of the lands he visited, especially South America, the Galapagos islands, and Pacific coral reefs. This journey triggered in him, an interest in evolution of life on earth, the diversity in plant and animal life, and how they survived.
Upon his return to England in 1836, Darwin tried to solve the riddles of these observations and the puzzle of how species evolve. He began to develop the theory of evolution that was to make him famous. 

Darwin proposed that all life on earth developed gradually over millions of years from a few common ancestors. In other words, the numerous species alive today arose from a single original life form. They developed new characteristics to adjust to different conditions and environments. Those that could not survive perished. 

He called this process of evolution - natural selection. All life, he said, is a continuous struggle in which only the fittest can survive. In other words, in the struggle for survival, the fittest win out at the expense of their rivals because they succeed in adapting themselves best to their environment. 

Darwin was the first of the evolutionary biologists. Until then, people believed that the world they lived in, was the same as what God had created thousands of years ago. Darwin’s theories met with fierce opposition, and even though his theories have been questioned and debated upon, “Darwinism” as his theories are called, remain the first ever documentation on how such a variety of species of plants and animals evolved. 

Darwin continued to write and publish his works on biology throughout his life. He lived with his wife and children at their home in the village of Downe, fifteen miles from London. In the later years, Darwin was plagued by fatigue and intestinal sickness. He died on 19 April, 1882, and lies buried in Westminster Abbey.

Hippocrates

This was an era when people believed that humans suffered from diseases because of supernatural causes such as the action of unfriendly spirits, ghosts, and demons, or from witchcraft. There was no science of medicine. Superstition was very deep rooted in the society. 

It was during these times that Hippocrates was born on the Aegean island of Cos, in Greece. What is known of Hippocrates is from the writings by famous scientists of those times, including those of Hippocrates himself. His teachers in medicine are said to have been his father, Heracleides, and Herodicos of Selymbria.

Hippocrates was the first to understand the workings of the human body through scientific experiments. He did not believe in any of the superstitious explanations given for the ailments of the human body, nor did he believe in miraculous cures. His extensive research in the field of medicine and disease earned him the name of Hippocrates Asclepiades, or "descendant of (the doctor-god) Asclepios." 

Hippocrates’ observations of the human body, have been brought together in the form of a ten volume encyclopedia of medicine and surgery as known in his day. Hippocrates was the first to scientifically explain how the human body works, on the importance of good nutrition for a healthy mind and body, and that disease occurs when something goes wrong with the normal functioning of our body systems. These were revolutionary thoughts. His work not only gained undisputed popularity during his times, but have been accepted as the first step towards the Science of Medicine. 

The contributions of Hippocrates to the field of medicine have stood the test of time. Even today when doctors graduate out of medical school they take an oath, called the Hippocratic oath, which has remained the universal standard for patient care down the years. In the oath, the physician pledges to work for the good of the patient, and to do him no harm.

Thomas Alva Edison

Thomas Alva Edison (February 11, 1847 – October 18, 1931) was an American inventor and businessman. He developed many devices that greatly influenced life around the world, including the phonograph, the motion picture camera, and a long-lasting, practical electric light bulb. Dubbed "The Wizard of Menlo Park” by a newspaper reporter, he was one of the first inventors to apply the principles of mass production and large teamwork to the process of invention, and therefore is often credited with the creation of the first industrial research laboratory.

Edison is the fourth most prolific inventor in history, holding 1,093 US patents in his name, as well as many patents in the United Kingdom, France, and Germany. He is credited with numerous inventions that contributed to mass communication and, in particular, telecommunications. These included a stock ticker, a mechanical vote recorder, a battery for an electric car, electrical power, recorded music and motion pictures.

His advanced work in these fields was an outgrowth of his early career as a telegraph operator. Edison originated the concept and implementation of electric-power generation and distribution to homes, businesses, and factories – a crucial development in the modern industrialized world. His first power station was on Manhattan Island, New York.


Main Invention

Electric light

Building on the contributions of other developers over the previous three quarters of a century, Edison made improvements to the idea of incandescent light, and entered the public consciousness as "the inventor" of the light bulb, and a prime mover in developing the necessary infrastructure for electric power.

After many experiments with platinum and other metal filaments, Edison returned to a carbon filament. The first successful test was on October 22, 1879; it lasted 13.5 hours. Edison continued to improve this design and by November 4, 1879, filed for U.S. patent 223,898 (granted on January 27, 1880) for an electric lamp using "a carbon filament or strip coiled and connected to platina contact wires".

Although the patent described several ways of creating the carbon filament including "cotton and linen thread, wood splints, papers coiled in various ways”, it was not until several months after the patent was granted that Edison and his team discovered a carbonized bamboo filament that could last over 1,200 hours. The idea of using this particular raw material originated from Edison's recalling his examination of a few threads from a bamboo fishing pole while relaxing on the shore of Battle Lake in the present-day state of Wyoming, where he and other members of a scientific team had traveled so that they could clearly observe a total eclipse of the sun on July 29, 1878, from the Continental Divide.

In 1878, Edison formed the Edison Electric Light Company in New York City with several financiers. Edison made the first public demonstration of his incandescent light bulb on December 31, 1879, in Menlo Park. It was during this time that he said: "We will make electricity so cheap that only the rich will burn candles."

Other Major Activities

Electric power distribution
Carbon Telephone Transmitter Development

Isaac Newton

Isaac Newton was born in 1642 in a manor house in Lincolnshire, England. His father had died two months before his birth. When Isaac was three his mother remarried, and Isaac remained with his grandmother. He was not interested in the family farm, so he was sent to Cambridge University to study.

Isaac was born just a short time after the death of Galileo, one of the greatest scientists of all time. Galileo had proved that the planets revolve around the sun, not the earth as people thought at the time. Isaac Newton was very interested in the discoveries of Galileo and others. Isaac thought the universe worked like a machine and that a few simple laws governed it. Like Galileo, he realized that mathematics was the way to explain and prove those laws. Isaac Newton was one of the world’s great scientists because he took his ideas, and the ideas of earlier scientists, and combined them into a unified picture of how the universe works.

Isaac Newton explained the workings of the universe through mathematics. He formulated laws of motion and gravitation. These laws are math formulas that explain how objects move when a force acts on them. Isaac published his most famous book, Principia, in 1687 while he was a mathematics professor at Trinity College, Cambridge. In the Principia, Isaac explained three basic laws that govern the way objects move. He then described his idea, or theory, about gravity. Gravity is the force that causes things to fall down. If a pencil falls off a desk, it will land on the floor, not the ceiling. In his book Isaac also used his laws to show that the planets revolve around the suns in orbits that are oval, not round.


Isaac Newton used three laws to explain the way objects move. They are often call Newton’s Laws. The First Law states that an object that is not being pushed or pulled by some force will stay still, or will keep moving in a straight line at a steady speed. It is easy to understand that a bike will not move unless something pushes or pulls it. It is harder to understand that an object will continue to move without help. Think of the bike again. If someone is riding a bike and jumps off before the bike is stopped what happens? The bike continues on until it falls over. The tendency of an object to remain still, or keep moving in a straight line at a steady speed is called inertia.

The Second Law explains how a force acts on an object. An object accelerates in the direction the force is moving it. If someone gets on a bike and pushes the pedals forward the bike will begin to move. If someone gives the bike a push from behind, the bike will speed up. If the rider pushes back on the pedals the bike will slow down. If the rider turns the handlebars, the bike will change direction.

The Third Law states that if an object is pushed or pulled, it will push or pull equally in the opposite direction. If someone lifts a heavy box, they use force to push it up. The box is heavy because it is producing an equal force downward on the lifter’s arms. The weight is transferred through the lifter’s legs to the floor. The floor presses upward with an equal force. If the floor pushed back with less force, the person lifting the box would fall through the floor. If it pushed back with more force the lifter would fly into the air.

When most people think of Isaac Newton, they think of him sitting under an apple tree observing an apple fall to the ground. When he saw the apple fall, Newton began to think about a specific kind of motion—gravity. Newton understood that gravity was the force of attraction between two objects. He also understood that an object with more matter –mass- exerted the greater force, or pulled smaller object toward it. That meant that the large mass of the earth pulled objects toward it. That is why the apple fell down instead of up, and why people don’t float in the air.

Isaac Newton thought about gravity and the apple. He thought that maybe gravity was not just limited to the earth and the objects on it. What if gravity extended to the moon and beyond? Isaac calculated the force needed to keep the moon moving around the earth. Then he compared it with the force the made the apple fall downward. After allowing for the fact that the moon is much farther from the earth, and has a much greater mass, he discovered that the forces were the same. The moon in held in an orbit around earth by the pull of earth’s gravity.

Isaac Newton’s calculations changed the way people understood the universe. No one had been able to explain why the planets stayed in their orbits. What held them up? Less than 50 years before Isaac Newton was born it was thought that the planets were held in place by an invisible shield. Isaac proved that they were held in place by the sun’s gravity. He also showed that the force of gravity was affected by distance and by mass. He was not the first to understand that the orbit of a planet was not circular, but more elongated, like an oval. What he did was to explain how it worked.