Isaac Newton

Isaac Newton
Credit: G Kneller

Occupation: Mathematician, Astronomer, and Physicist

Year born: 1643

Research Areas: Optics, maths, motion, gravity


"If I have seen further it is by standing on the shoulders of giants."

Source: Letter from Isaac Newton to Robert Hooke, 5 February 1676.


Early Life

Isaac was born in Woolsthorpe, England. For most of this childhood he was raised by his grandmother and went to a grammar school. At school, he learned Latin, Ancient Greek, and some maths. His mother wanted him to be a farmer, but Isaac hated farming. At the age of 18, Isaac went to the University of Cambridge. His uncle had previously studied there and recommended him to the university. 

Isaac worked as a servant to pay his way at college for a few years until he won a scholarship. When he was 22, Isaac’s college closed because of the Great Plague. He spent 2 years back at his mother’s home and continued to work on his ideas about maths and the world around him.

Career Highlights

Isaac did important work in the area of optics, the science of light. By using a prism, he discovered that white light is made up of all the colours in the spectrum. From this, he worked out that this would cause a problem for refracting telescopes. The white light would separate slightly into its spectrum of colours and blur. To solve the problem, Isaac designed the first reflecting telescope. Today this is known as a Newtonian telescope.

According to the legend, Isaac was at home during the Great Plague, sitting under a tree when an apple fell and hit him on the head. It may be more true that Isaac only saw an apple fall. In any case, the event led him to think about why the apple fell straight down, and not at an angle. He developed a theory of gravity based on maths. Isaac built his ideas on the work of Galileo. Isaac's work explained everything from apples falling to the Earth's orbit around the Sun. 

In 1687, aged 44, he published his work in his most famous piece of writing: the 'Philosophiæ Naturalis Principia Mathematica’ (Mathematical Principles of Natural Philosophy). This is still thought to be one of the most important events in the history of science. The Principia contain the 3 Laws of Motion:

1)    A stationary body will stay stationary unless an external force is applied to it. 
2)    Force is equal to mass times acceleration. And a change in motion (change in speed) is proportional to the force applied. 
3)    For every action, there is an equal and opposite reaction.

Following the publication of Principia, Isaac became famous. In 1705, aged 62, he was knighted by Queen Anne and became Sir Isaac Newton. 


Today, Isaac is still thought of as one of the leading scientists of all time. The Institute of Physics awards the 'Isaac Newton Medal and Prize' to a physicist each year. Three telescopes on La Palma, are called the 'Isaac Newton Group of Telescopes' in his honour.

Other Interests

As well as options and gravity, Newton developed a maths theory that later became calculus! He also worked for the Royal Mint and worked hard to stop criminals counterfeiting coins.