THE SCIENTIFIC REVOLUTION

THE SCIENTIFIC REVOLUTION

The Renaissance inspired a spirit of curiosity in many fields. In science, as in the arts and humanities, people began to question ideas that had been accepted for hundreds of years. New scientific theories and discoveries led to changes so great that historians speak of a Scientific Revolution during the 1500´s and 1600´s.

The Scientific Method

The many discoveries of the Scientific revolution were made possible by a new method of looking at nature. As early as 1200´s, the English thinker Roger Bacon had argued that scientist should use experiments to learn about the natural world. At the time, Bacon’s ideas fell on deaf ears. By the late 1500´s, however, many scientists were turning in that direction. They used what has come to be called the Scientific method – a logical procedure for gathering information and testing ideas.

The scientific method involves stating a problem or question, forming an hypotheses (an unproved theory), making observations and experiments, and drawing conclusions. Using the scientific method, scientists of the 1500´s and 1600´s revolutionized the way we think of the universe.

Changing views of the Universe

The Medieval view. In medieval times people believed that the sun the moon, and planets revolved around the earth. This idea had begun with the Greek philosopher Aristotle in the 4^th century B.C. It had been restated by the Greek astronomer Ptolemy in the 2^nd century A.D., and supported by the Christian Church during the Middle Ages. The Church had taught that God had designed the universe especially for human beings. He had place the earth at the center of the universe, ringed by the planets. Beyond the planets lay the stars, and beyond the stars was the dwelling place of God.

This earth- centered view of the universe, called the Geocentric theory, made sense to people of the Middle Ages. They observed the sun traveling across the sky every day, and they noted the changing patterns of stars at night. It seemed logical to think that the earth was the fixed center of the universe.

A new Scientific view. In the early 1500´s, the geocentric view of the universe was questioned by Nicolaus Copernicus, a Polish churchman, doctor and astronomer. Copernicus thought that the sun was in a fixed position at the center of the universe and that the earth was one of the planets circling around it.

Copernicus´ Heliocentric theory – the idea that the sun was the center of the universe – marked the beginnings of modern astronomy and modern scientific thinking. Copernicus knew, however, that most scholars and clergy of the time would reject his theory because it went against their religious views. Fearing persecution, he did not publish his work until 1543, the last year of his life. Not until the next century would his ideas become widely accepted.

 

THE ACHIEVEMENTS OF GALILEO

One of the first people to agree with Copernicus was Galileo Galilei (1564- 1642). An Italian scientist and mathematician, Galileo was a firm believer in the scientific method. Knowledge of nature, he thought, came from making “sensible experiments and necessary demonstrations”.

Early in his career, Galileo caused a great stir with an experiment on the laws of motion. Galileo is said to have climbed the Leaning Tower of Pisa and dropped objects of different weight to the ground. To the surprise of many people, he found that light objects fall at the same time as heavy objects. This discovery sparked controversy, as did Galileo’s later work in astronomy.

Galileo’s study of the skies. When Galileo heard about a recent Dutch invention – the telescope – he turned his attention to studying the stars. He made a telescope for himself, with which he could even see the moon’s craters. He described his discovery enthusiastically:

“It is a most beautiful and delightful sight to behold the moon. Anyone may know that the moon certainly does not possess a smooth and polished surface, but one that is rough and uneven, just like the face of earth itself, it is everywhere full of vast bulges and deep chasms”

Galileo’s observations seemed to disprove the medieval belief that objects in the heavens were smooth and perfectly shaped, and thus purer than the earth. Other scientists challenged his findings, but soon they used their own telescopes to confirm his reports. Galileo also discovered that Jupiter has moons circling around it. This challenged the view that all heavenly bodies move around the earth.

A clash with the Church. Early in the 1620´s Galileo asked the Pope’s permission to write a book comparing Ptolemy’s and Copernicus´ ideas. The Pope agreed because Galileo had promised to uphold the Church’s teachings. When the book was published in 1632, however, it shocked and angered the Pope. Galileo had kept his promise by making a final statement supporting Ptolemy’s views. Yet the rest of the book clearly showed that he agreed with Copernicus. In 1633 he was brought before the Inquisition and accused in these words:

“You, Galileo, were denounced to this Holy Office for holding as true the

false doctrine taught by some that the sun is the center of the world and

immovable and that the earth moves”

Threatened with torture, the 70- year old Galileo was forced to retract what he had said. In addition, he had to promise not to teach the heliocentric theory and had to remain under arrest in his own house, where he was closely watched. Still, these actions did not prevent the spread of Galileo’s ideas. He continued to write, and with the aid of friends, smuggled out a new manuscript.

FURTHER DISCOVERIES

Galileo was not alone in looking for new theories to explain what he saw in the skies. Other astronomers of the time included Tycho Brahe of Denmark and Johannes Kepler in Germany.

Brahe. Like Renaissance artists, scientists of the early 1500´s and 1600´s often depended on wealthy patrons. With money from the Danish king, Brahe built one of the earliest modern observatories. There he watched the stars for evidence to support his ideas. Brahe agreed with Copernicus that planets move around the sun, but he still thought the sun circled the earth once a year.

 

Kepler. After Brahe’s death in 1601, Johannes Kepler continued Brahe’s work. Using Brahe’s observations and measurements, Kepler showed that a mathematical order exists in the planetary system. More important, he took Copernicus´ ideas from theory to fact: he proved mathematically that the planets revolve around the sun. Kepler’s work made an enormous contribution to astronomy.

 

THE GENIUS OF NEWTON

The ideas of Copernicus, Galileo, Brahe and Kepler changed the way people looked at the world. Isaac Newton (1642- 1727), an English mathematician and scientist, came up with even more startling ideas.

Newton showed that all objects in the universe – things on earth, as well as moons and planets – obey the same laws of motion. He explained this by demonstrating the actions of gravity and inertia. Gravity is the attraction that draws all objects toward each other. This force, Newton found, increases qith the mass of the objects.

Inertia is resistance to change. According to the law of inertia, an object at rest will remain at rest unless a force causes it to move. Similarly, a moving object will keep moving in a straight line unless another force causes it to halt or change direction.

Newton’s discoveries made it possible to explain the movements of planets. According to the law of inertia, the planets would move in a straight line endlessly into space. however, the gravitational pull from the sun forces the planets into oval- shaped orbits. With the same reasoning, Newton could explain the movement of objects on earth. Apples, for example, fall to the ground instead of flying upward because of gravity.

Newton’s achievement was remarkable. Building on earlier discoveries, he had explained laws that operate everywhere in nature. In 1687, he published his ideas in a work known as the Principia. The universe Newton describe was like a giant clock, whose parts all worked together perfectly according to strict scientific laws. Newton, however, believed that God was the creator of this orderly universe, the clockmaker who had set everything in motion.

THE STUDY OF LIVING THINGS

Careful observation and use of the scientific method became important in many different fields. At the same time that astronomers began to explore the secrets of the universe, other scientists began to study the nature of living things.

Vesalius. In 1543, the year Copernicus published his theories, a Flemish doctor Andreas Vesalius, published a beautifully illustrated textbook on anatomy. Recognized as a pioneer in the field, Vesalius is often considered the father of modern anatomy.

As a child, Vesalius was so curious about the structure of living things that he dissected the bodies of mice, rats, dogs and cats. As he grew older, he studied the writings of ancient doctors such as Galen. However, Vesalius did not accept many of the long- held ideas about human anatomy because they were based on studies of animals. He would therefore begin to dissect human corpses, despite widespread disapproval of this practice. To find bodies, Vesalius searched cemetaries in the middle of the night.

Although his work caused great controversy, Vesalius knew more about anatomy than any other doctor in Europe. Teaching at the University of Padua in Italy, Vesalius urged his students no to rely on the theories of earlier scientists but to learn by investigating for themselves.

Harvey. One of the graduates of the University of Padua, an English doctor named William Harvey (1578- 1657), discovered that blood circulates in the body and is pumped through vessels by the heart. As part of his research, Harvey examined the hearts of many animals. “I found the task so full of difficulties”, he wrote, “that I was almost tempted to think that the motion of the heart was only to be understood by God”. Harvey’s careful work was another triumph for the experimental method.

Leeuwenhoek. Scientist’s investigations in many fields were made easier by the invention of the microscope. Anton van Leeuwenhoek, a Dutch shopkeeper and amateur scientist who lived from 1632 to 1723, was one of the first people to build and use a microscope. With this instrument, Leeuwenhoek studied the eye of the ox, the brain of a fly, wool fibers and the seed of plants. He even watched the blood racing through a tadpole’s body.

One day Leeuwenhoek put some water under the lens of his microscope and saw “living creatures, little animals”, swimming quickly about. Soon he was looking with “wonder at a thousand living creatures in one drop of water”. Leeuwenhoek was peering into a mysterious new world – the world of one- celled living things.

Linnaeus. One of the aims of early scientists was to find laws or systems that would reveal a logical order in nature. The Swedish biologist Carolus Linnaeus came up with such a system in the 1700´s. Linnaeus started his work by studying plants and animals and writing careful descriptions of them. Linnaeus walked nearly 1000 miles through the lonely, freezing areas of northern Europe to collect samples. From his observations, Linnaeus developed a system for naming and classifying plants, and he published his research in 1753. five years later, he published a system for classifying more than 4000 animals.

Linnaeus system, which gave a two- word Latin name to each kind of living thing, put similar animals into groups. For example, the group Felis (cat) included both Felis domesticus (the house cat) and Felis leo (the lion). Today’s system of classifying living things is based on Linnaeus model.

PHILOSOPHERS OF SCIENCE

A number of thinkers who were not working scientists played important roles in the Scientific Revolution. Sir Francis Bacon, an English politician and writer of the early 1600´s. believed that science could help people live more comfortable lives and better understand the world around them. Bacon urged scientists to free themselves from the cobwebs of the past – from ignorance and prejudice – to make new discoveries.

 

In France at about the same time, René Descartes took a keen interest in science. However, his approach to gaining knowledge was different from Bacon’s. Rater than using observation and experimentation, Descartes relied on mathematics and logic. For Descartes, the only clear truth was his own mind and ability to reason. He expressed this idea in a few words: “I think, therefore I am”.

Modern scientific methods are based on the ideas of Bacon and Descartes. Scientists has shown that observation and experimentation, together with general laws that can be expressed mathematically. Can lead us to a better understanding of the natural world.

~ by HistoryRocks.com on March 29, 2008.