Isaac Newton (1642-1727)

Sir Isaac Newton was an English scientist, mathematician and astronomer.

He was not a particularly strong student, but did go to college. When the university shut down because of the plague, he went home and continued to study on his own. He had a notebook with 140 blank pages and he began to fill them with notes as he read and experimented. He is known for three important discoveries that he made in a one and a half year period.

One day when he was drinking tea in the garden, he saw an apple fall to the ground. He start ed thinking about why it fell, and finally concluded that the same force which caused the apple to fall also kept the moon in orbit around the earth. This same force, gravity, also kept the planets in orbit around the sun.

The apple incident led to his three basic laws of motion: An object in motion tends to remain in motion unless an external force stops it; an object moves in a straight line unless some force diverts it; and for every action, there is an equal and opposite reaction. His second discovery was about light and the properties of light. He spent months in a darkened room doing experiments. He passed a beam of sunlight through a prism and discovered that the beam of light was broken down into different colors. His conclusion: something that appears green, such as grass, looks green because it reflects the green light in the sun and absorbs most of the other colors.

He also made a reflecting telescope to use in his studies.

Newton's third great discovery was in the field of math when he developed a kind of math we call calculus. He was just 24 years old at the time. However, he did not publish his findings for about 20 years, and by then someone else had figured out the same thing. Newton said the man had stolen his idea. There was a bitter debate over which man made the discovery.

By the time he was in his mid 50's he had worn himself out and suffered from exhaustion. Some were even afraid he might have mercury poisoning caused by his experiments.

Sir Isaac Newton never married. It is said he was very generous with his nieces and nephews and with the scientists who helped him in his work. GALILEO

Galileo Galilei was born in Pisa, Italy on February 15, 1564. He is called the Father of Modern Science. He was the first to develop a scientific theory in which he would observe an event, develop a theory and then experiment to test his theory.

Before Galileo's time many people believed the earth was the center of the universe and the sun and the planets moved in an orbit around the earth. This theory was described by a Roman astronomer named Ptolemy (TAH luh me) and was called the Ptolemaic (tah luh MA ik) Theory. Aristotle also believed the sun moved around the earth. To believe otherwise was considered heresy by the Roman Catholic Church, and people were persecuted who believed the earth was not central.

He studied motion and performed experiments by dropping objects from heights such as the Leaning Tower of Pisa. He wanted to disprove Aristotle's idea that heavier objects fall faster than lighter ones. According to legend he dropped two objects of different weights and proved that two falling objects of different weights reach the ground at the same time.

Nicolaus Copernicus (nik uh LA us ko PUR nih kus) about twenty years before Galileo was born published a theory that the earth revolved around the sun. It was called the Copernican (ko PER nih kuhn) Theory, but he died before he could prove it.

Galileo decided he would either prove Copernicus' theory or else show it was false. In 1609 he heard about an invention which enabled people to see things far away. It was the telescope . He reproduced it and studied the moon and the planets. He discovered four bright "stars" revolving around Jupiter and concluded they must be planets near Jupiter. He called them Medician (med uh CHEE un) Stars to honor his patron in the influential Medici (MED ih chee) family. These moons of Jupiter are now named Io, Europa, Ganymede, and Callisto. Shortly after his discovery he was appointed Chief Mathematician of the University of Pisa. He would hold the title for life. Galileo went to Rome and appeared before the Roman Church to defend his views, but the Church considered them heresy* since his ideas were contrary to the Ptolemaic view that the sun revolved around the earth, which they considered the Biblical view. He was forbidden to discuss or write about his theory.

When a new pope was appointed Galileo had new hope that he would be heard. In April 1624 he traveled to Rome and had six audiences with Pope Urban VIII. As a result of his visit he was permitted to discuss his theory as long as he treated it as a mathematical hypothesis .

However, after the printing of Galileo's book Dialogue he was summoned to appear before the Inquisition. Galileo replied that he was too ill to go to Rome. He was told he would be arrested and brought in chains if he did not come. He went to Rome where he was questioned for 18 days.

At an Inquisition the accused person had to testify, but could not ask questions nor be represented by counsel. Sometimes a person was tortured to get them to "confess", and the sentence could not be appealed.

They condemned him for heresy and put him under house arrest. He was released for a while, but there would be further hearings and he would remain under arrest the remainder of his life. Five years after his sentencing he became totally blind. He asked to be released from his imprisonment, but his plea was denied.

Galileo died on January 8, 1642 while still under house arrest at his home in Arcetri near Florence.

Galileo concluded that if "planets", as he called them, could revolve around another planet, then the planets could also revolve around another body such as the sun. His view of the cosmos* is known as heliocentrism * . This model is shown at the bottom of the illustration with the sun in the center. The upper part of the illustration shows a geocentric * model with the earth at the center.

Andreas Vesalius and Human Anatomy At the dawn of the sixteenth century, European scholars could gain only a crude understanding of the anatomy of humans and animals. At the handful of universities where students trained in medicine—such as Bologna or Paris—professors read from the books of the Greek physician Galen. Galen had combined the philosophical work of Aristotle and other Greeks with his own lifetime of dissections, creating a system that explained not just the structure of the human body, but how the body worked.

After the fall of Rome, Galen’s legacy lived on in Arab cities like Baghdad. In the 1100s, Europeans began to translate Galen from Arabic and made his work the basis of medical training. But in the many steps of translation, much of the spirit of Galen’s work —especially his emphasis on observing for oneself rather than relying on authority— was lost. A tradition had emerged in which professors read Galen to their students, while a surgeon dissected an executed criminal to show the relevant parts of the body. There was no point in the professor looking for himself at the body, since everything worth learning could be found in Galen’s books.

A young Flemish anatomist changed all that when he realized that Galen was dramaticaly wrong. Andreas Vesalius (1514-1564) started out his career as a defender of “Galenism” at the University of Paris. But when he moved to the University of Padua, he began dissecting corpses for himself to show his students the fine details of anatomy. He drew charts for the students to study, and the exquisite quality of the charts made Vesalius famous—so famous that the criminal court judge of Padua made sure he had a steady supply of cadavers from the gallows.

As he grew more familiar with the human body, Vesalius began to notice that here and there, Galen had made mistakes. The human breastbone is made of three segments; Galen said seven. Galen claimed that the humerus (the upper arm bone) was the longest bone in the body, save only the femur; Vesalius saw that the tibia and fibula of the shin pushed the humerus to fourth. Over the centuries, anatomists someti mes had minor quibbles with Galen, but Vesalius began to suspect that there was something seriously wrong with his work. Vesalius widened his scope, dissecting animals, and reading over his Galen more carefully. The source of the mistake dawned on him. Galen had never dissected a human. The traditions of Rome did not allow such a practice, and so Galen had had to make do with dissecting animals and examining his patients during surgery. Instead of humans, Galen was often writing about oxen or Barbary macaques.

GUTENBERG AND THE PRINTING PRESS

The spread of literacy and the development of universities meant that by the 15th century, despite an assembly line approach to the production of books, supply was no longer able to meet demand. As a result there was widespread interest in finding an alternative means of producing books.

In the mid-15th century Johannes Gutenberg invented a mechanical way of making books. This was the first example of mass book production. Before the invention of printing, multiple copies of a manuscript had to be made by hand, a laborious task that could take many years.

In the Far East, movable type and printing presses were known but did not replace printing from individually carved wooden blocks, from movable clay type, processes much more efficient than hand copying. The use of movable type in printing was invented in 1041 AD by Bi Sheng in China. Since there are thousands of Chinese characters, the benefit of the technique is not as obvious as in European languages.

It is not clear whether Gutenberg knew of these existing techniques or invented them independently, though the former is considered unlikely because of the substantial differences in technique.

When Johannes Gutenberg began building his press in 1436, he was unlikely to have realised that he was giving birth to an art form which would take center stage in the social and industrial revolutions which followed. He was German, his press was wooden, and the most important aspect of his invention was that it was the first form of printing to use movable type.

His initial efforts enabled him in 1440 to mass-produce indulgences -- printed slips of paper sold by the Catholic Church to remit temporal punishments in purgatory for sins committed in this life, for those wealthy enough to afford indulgences. Although Laurence Koster (Coster) of Haarlem, Netherlands also laid claim to the invention, scholars have generally accepted Gutenberg as the father of modern printing.

Legal documents indicate that Gutenberg probably began printing the Bible around 1450. It was in this year that Gutenberg entered into a partnership with Johann Fust who lent him money to finance the production of a Bible. Gutenberg certainly introduced efficient methods into book production, leading to a boom in the production of texts in Europe -- in large part, owing to the popularity of the Gutenberg Bibles, the first mass-produced work, starting in 1452. Even so, Gutenberg was a poor businessman, and made little money from his printing system.

Gutenberg' s invention spread rapidly after his death in 1468. It met in general with a ready, and an enthusiastic reception in the centers of culture. The names of more than 1000 printers, mostly of German origin, have come down to us from the fifteenth century. In Italy we find well over 100 German printers, in France 30, in Spain 26. Many of the earliest printers outside of Germany had learned their art in Mainz, where they were known as "goldsmiths".