(1642–1727). One of the great figures in the history of science, Isaac Newton laid the foundations for the study of physics. In the late 1600s and early 1700s, he explained the science of light and outlined the laws of gravity and motion. To carry out his studies, Newton invented the reflecting telescope and originated calculus, which is an advanced mathematical method.

Early life

Isaac Newton was born on December 25, 1642, in the village of Woolsthorpe, England. He attended grammar school in nearby Grantham. Beginning in 1653 he worked on the family farm but because he showed little interest in it, he was allowed to return to his studies.

In 1661 Newton enrolled at Trinity College, University of Cambridge. His coursework was based on the ideas of the ancient philosophers Plato and Aristotle. The scientific revolution was well under way in Europe. Great thinkers such as Nicolas Copernicus, Galileo, and Johannes Kepler had come up with new ideas about the universe. They proposed that the Earth and the other planets travel around the sun. This theory, called heliocentric (or sun-centered), challenged the long-held belief that the sun and planets travel around the Earth.

Other established ideas were being uprooted as well. The philosopher René Descartes thought that nature and the physical world were made up of tiny particles of matter (atoms). According to his theory, the wonders of nature are not wonders at all. Instead, they can be explained by the interaction of atoms. Newton was fascinated by such bold ideas, and he devoted many hours to studying them on his own.

Career

In 1665 Newton graduated from college and returned home. For the next two years he conducted experiments with light. He discovered that when white light passes through a prism, or crystal form, it breaks up into a wide band of colors, called a spectrum. He concluded that white light is a mixture of pure colors and that light is made up of tiny particles that travel in straight lines at great speeds.

Newton next wanted to find out what keeps the moon in its regular path around the Earth. He decided that only the attraction of the Earth and the moon, the pull of gravity, could account for it. This was an extension of the conclusion he arrived at after considering what force could cause an apple to fall from a tree to the Earth. He outlined his ideas about gravity in Mathematical Principles, published in 1687. There he also explained three basic laws of motion. These are: (1) a body in motion will stay in motion and a body at rest will stay at rest unless it is acted upon by a force, (2) acceleration is the result of a force acting on a body, and (3) to every force there is an equal and opposite force.

In 1669, Newton became a professor at Cambridge, teaching there until 1701. Widely recognized for advancing scientific knowledge, in 1703 he was elected president of the Royal Society (a major scientific group), a position he held until his death. He was also master of the mint. In that role he oversaw the standardization of Great Britain's coins. For his many achievements, Queen Anne made Newton a knight, which earned him the title “Sir.” He died in London on March 20, 1727.