Rene Descartes Rene Descartes was a French philosopher who was initially preoccupied with doubt and uncertainty. The one thing he found beyond doubt was his own experience. Emphasizing the importance of the mind, he asserted I think, therefore I am. He argued that because the mind cannot be doubted but the body and material world can, the two must be radically different. From this came the principle of mind and matter; meaning, matter was detached and could be investigated independently through reason. Descartes came to be known as the father of modern rationalism. This system of thought is based on the belief that reason is the chief source of knowledge. Descartes laid the basis for deductive reasoning by emphasizing the importance of questioning all established knowledge and the importance of solid evidence.
Galileo Galilei Galileo Galilei was an Italian mathematician and scientist who built on the theories of Copernicus. In 1609 Galileo built his own telescope and used it to study the heavens. In 1610, Galileo published a small book called Starry Messenger, which described his astonishing observations. Galileo announced that Jupiter had four moons and that the sun had a dark spot. He also noted that the Earth s moon had a rough, uneven surface made of composed of material substances. These discoveries shattered Aristotle s theory that the moon and stars were made of pure, perfect substance. Galileo s conclusions caused an uproar and frightened both the Catholic and Protestant Churches. Galileo s findings contradicted Church teachings about the world and their authority. In 1632, Galileo published Dialogue Concerning the Two Chief World Systems, in which he presented and supported Copernicus s theories. The Catholic Church put Galileo on trial and under the threat of torture and death, agreed that the ideas of Copernicus were false. Regardless his books and ideas still spread across Europe. In 1992 (yes, like 23 years ago) the Catholic Church officially acknowledged that Galileo had been right. Trial of Galileo before the papal court
Nicholas Copernicus In the mid 1500s, Polish scholar Nicholas Copernicus challenged the belief that the earth was the center of the universe. In his published work On the Revolutions of the Heavenly Spheres, Copernicus using mathematical formulas suggested that the universe was heliocentric, or sun centered. He said that the planets revolved around the sun and the moon revolved around the Earth. Copernicus also explained that the apparent movement of the sun around the Earth was actually caused by the daily rotation of the Earth on its axis as well as the Earth s yearly revolution around the sun. Most scholars of the day rejected Copernicus s theory. Johannes Kepler a German mathematician, later confirmed Copernicus s heliocentric theory and also showed that the orbits were not circular but elliptical, with the sun towards the end of the ellipse instead of the center. Copernicus s Heliocentric Model
Al-Khwarizmi (c. 780 c. 850) Muslim Mathematician born in Baghdad Arabic numerals, including the zero, were developed in India. They were introduced to the Muslim world in the ninth century CE by al-khwarizmi s book The Hindu Art of Reckoning, which explained how to use them for calculating without an abacus. Translated into Latin in the early twelfth century, the numbering system was introduced to Italy by a trader s son who had been sent to North Africa to learn mathematics around 1200. Zero did not come into widespread use in Europe until the seventeenth century.
Isaac Newton In the mid 1600s, Isaac Newton, a great English scientist brought together the breakthroughs of Copernicus, Kepler, and Galileo and put them into a single theory of motion. Newton who studied mathematics and physics at Cambridge University, at the age of 26 was certain that all physical objects were affected equally by the same forces. Newton s greatest discovery was that the same force ruled motion of the planets and all matter on earth and space. The key idea that linked motion in the heavens to motion on earth was the law of universal gravitation (gravity). According to this law, every object in the universe attracts every other object. The degree of attraction depends on the mass of the object and the distance between them. In 1687, Newton published his ideas in a work called The Mathematical Principles of Natural Philosophy. It was one of the most important scientific books ever written. The universe he discirbed was like a giant clock. Its parts all worked together perfectly in ways that could be expressed mathematically. Newton believed that God was the creator of this orderly universe, the clockmaker who set everything in motion. Replica of Newton s Telescope