Isaac Newton: Who He Was, Why Apples Are Falling

Isaac Newton: Who He Was, Why Apples Are Falling

Sir Isaac Newton was born especially tiny but grew into a massive intellect and still looms large, thanks to his findings on gravity, light, motion, mathematics, and more.


4 - 12


Mathematics, Physics


Isaac Newton Kneller Painting

Far more than just discovering the laws of gravity, Sir Isaac Newton was also responsible for working out many of the principles of visible light and the laws of motion, and contributing to calculus.

Photograph of Sir Godfrey Kneller painting by Science Source
Far more than just discovering the laws of gravity, Sir Isaac Newton was also responsible for working out many of the principles of visible light and the laws of motion, and contributing to calculus.
Leveled by
Selected text level

Sir Isaac Newton was a tiny man in real life. But he was a giant in the world of science.

Newton created the theory of gravity around 1665 or 1666. He came up with the idea that every physical object, whether it's a person, an apple or a planet, exerts a force on other physical objects. A force is a push or pull in a certain direction. The bigger the body, the stronger the force. There are different types of forces, but this one is called gravitational.

Some say that Newton came up with his ideas about gravity after watching an apple fall. He wondered why the apple fell straight down. Why didn't it fall sideways, or even up toward the sky?

Gravity does not just make apples fall from trees. It also holds us on the ground. Newton showed that gravity even makes the moon circle around Earth, and Earth around the sun, Martin Rees says. He was president of Britain's Royal Society. The Royal Society is the United Kingdom's national academy of science.

Newton's Schooling

Newton was born on January 4, 1643, in Lincolnshire, England. As a kid, he liked building models. He once built a tiny mill. It could grind real flour. It was even powered by a mouse running in a wheel.

In 1661, Newton went to the University of Cambridge. At first, he did not stand out as a student. In 1665, the school closed for a time because of the bubonic plague. This deadly disease killed thousands of people.

Newton went home for two years. This is when he got his apple-falling idea. In 1667, he went back to Cambridge and became a math teacher until 1696.

Newton Changes Science Forever

The theory of gravity was just one of Newton's discoveries. He also loved calculus. This is a mathematical subject that studies rates. A rate is the measurement of how much something changes. Newton's ideas in calculus are still used today.

Newton also studied optics, the science of light. He found out that white light is not just white. It is actually a mix of all the colors of the rainbow. Newton used his knowledge of light to make better telescopes.

Following his apple idea, Newton wrote three laws of motion. These laws changed all of science, and are still used by scientists today.

First Law of Motion: Inertia

An object that sits still will remain still unless a force is applied to it. An object that is moving will keep moving along a straight line unless an outside force is applied to it.

Second Law of Motion: Acceleration

An object will accelerate if force is applied to it.

Acceleration is the change of an object's speed. The acceleration will happen in the same direction as the force.

This idea can also be written as force equals mass times acceleration, or F = ma.

Third Law of Motion: Action and Reaction

For every action there is always an equal and opposite reaction.

Newton's Published Work

Newton published his findings in 1687, in a book called Philosophiae Naturalis Principia Mathematica. Usually people just call it the Principia.

When it came out, not many people read or understood the book, mathematician Robert Wilson says. Still, "everyone knew that it was a great work."

Perceptions of Isaac Newton

Newton made many discoveries, but he wasn't well-liked. As a young man, Newton preferred being alone. When he was older, he was not kind to other scientists. He sometimes tried to ruin their work, Rees says.

When he was older, Newton worked in British government. At one point, he led the British Mint, which is the part of government that makes coins for the country. When someone was caught making fake coins, they were sometimes sentenced to death. Newton thought this was a good thing. He had no mercy, Sir David Wallace says. He was the head of the Isaac Newton Institute in Cambridge, England.

In 1727, at age 84, Sir Isaac Newton died in his sleep. He was buried in Westminster Abbey in London.

Media Credits

The audio, illustrations, photos, and videos are credited beneath the media asset, except for promotional images, which generally link to another page that contains the media credit. The Rights Holder for media is the person or group credited.

Last Updated

May 9, 2024

For information on user permissions, please read our Terms of Service. If you have questions about how to cite anything on our website in your project or classroom presentation, please contact your teacher. They will best know the preferred format. When you reach out to them, you will need the page title, URL, and the date you accessed the resource.


If a media asset is downloadable, a download button appears in the corner of the media viewer. If no button appears, you cannot download or save the media.


Text on this page is printable and can be used according to our Terms of Service.


Any interactives on this page can only be played while you are visiting our website. You cannot download interactives.

Related Resources