Isaac Newton was one of the world's greatest scientists. He did research in mathematics, physics, astronomy and many other fields.

Newton was born in 1642. He worked on his family's farm but was not really interested in farming. His father died before Isaac was born. In his childhood he spent much time with his grandmother. Newton didn't have many friends and never married.

Newton did most of his scientific work at Cambridge, where he was a professor for many years. Although some other scientists criticized his work, he was admired throughout Europe. Queen Anne made Newton a knight. He died in 1727 and was buried at Westminster Abbey in London.

Isaac Newton was very ambitious young scientist who carried out his experiments very accurately. His main theory was that everything in nature could be explained through mathematics. Not all scientists had the same opinion.

Newton was an astronomer, who studied the Earth, the planets and stars. He became well-known for theories of gravity, in which he claimed that all objects of the universe have a gravitational force that pulled other objects towards them. An apple is pulled to the Earth's surface just like the Earth is being pulled towards the sun. He also showed that planets move around the sun in ellipses. His theory of gravity dominated physics for some time.

He also conducted experiments with light and found out that normal light is made up of many colors. He used prisms to break up light into a rainbow of colors. Newton invented a new kind of telescope that used lenses. It made objects look bigger.

In his book "The Mathematical Principles" Newton describes the three laws of motion:

- Every moving object keeps moving until something stops it. An object that lies on the ground continues to lie there until a force sets it in motion.

- Acceleration happens when a force acts on a mass. The greater the mass the more force must be applied to move the object. For example, you need more force to push a car than you need to push a bike.

- For every action there is an equal and opposite reaction. A rocket, for example, pushes down on the ground with its engines; the opposite action moves the rocket into the sky.

These principles were very difficult to understand at that time. Only few people really knew what Newton meant.

Newton also devoted a great deal of his life to alchemy. He studied it closely and believed that he was a special person who had magic powers and secret wisdom to change substances and objects. Newton wanted to keep these studies to himself; therefore he did not publish any of his alchemist works. At that time alchemy was a much-discussed topic that not everyone accepted.

Although Newton was one of the great scientists of his time, he based his work on the discoveries of Galileo and other scientists who lived before him. Scientists of following generations admired Newton's work. Albert Einstein, 20th century scientist, thought highly of Newton's work although his theory of general relativity moved away from his ideas.