Isaac Newton discovered many things. He is best remembered for discovering the principle of gravity, calculus, and the three laws of motion. He began discovering these things in his early twenties. His ability to think and concentrate helped him stick to a problem until he solved it.

Young Life

Isaac Newton was born on Christmas Day in 1642 in Woolsthorpe Manor, England. When Isaac was three years old, his mother married and Isaac was left behind to live with his grandmother. One thing Isaac Newton liked to do was to be alone to read. He read books about Descartes, Aristotle, Galileo, Copernicus, Kepler, and many more great scientists and mathematicians of the past. Reading books about Galileo and the other great scientists of the past inspired him. They inspired him with their ideas and inventions. From the readings about Galileo, Newton was inspired to improve the telescope. Aristotle’s theory that the earth was round inspired Isaac Newton to prove that the earth really was round.

Principle of Gravity

One of the things Isaac Newton discovered was the principle of gravity. One day in 1665 while reading under a tree in his garden, an apple fell off the tree and hit Newton on the head. He saw that a force pulled the apple down to earth instead of going sideways or up, and he called that force gravity. Another example of the law of gravity would be when you throw a ball up into the air, the ball is always pulled back down to earth by the force of gravity. All bodies on earth are affected by this force of gravity.

Fluxions

Also in 1665, Isaac Newton invented fluxions. You are probably asking yourself right now what are fluxions? Fluxions comes from the word "flux" which means constantly changing. Newton’s idea of fluxions is now called calculus. Calculus is the branch of mathematics that studies the way things change over time. Isaac Newton is known as the father of calculus.

Newton’s First Law of Motion

Isaac Newton’s first law of motion says that if an object isn’t moving then it won’t start to move on its own. It also means that if an object is moving then it won’t stop or change direction unless an outside force pushes against it or friction and gravity act upon it to stop it. An example would be if there is a soccer ball sitting on the ground not moving then it won’t move until a force of some kind pushes it (for example, someone kicks it). Once the ball is kicked, it will continue in a straight line until someone else kicks it. If no one else kicks the ball, it will eventually stop because of the effect of friction and gravity on it. If you kicked the ball in outer space it would keep going and never stop unless it comes to another object in space because there isn’t any gravity or friction to stop it.

Newton’s Second Law of Motion

Isaac Newton’s second law of motion says that if a force pushes on an object the object moves the way it is being pushed. For example, if you hit a baseball with a bat and swing the bat towards first base, then the ball will go towards first base. If you did the same thing in outer space, the ball would never stop because there isn’t any gravity or friction to stop it. Here’s another example. If you kick a light soccer ball lightly and then kick a heavy bowling ball hard they could go the same distance just because of their weight and the force you use to kick it. Since the soccer ball weighs less than the bowling ball it takes less force to move it. It takes more force to make the bowling ball move because it weighs more and that’s how they could be kicked the same distance.

Newton’s Third Law of Motion

Isaac Newton’s third and final law of motion says that for every action there is an equal and opposite reaction. An example would be when a rocket is about to be launched into outer space, the rocket fuel shoots out and begins to burn. The explosion is directed toward earth. The rocket reacts by being pushed in the opposite direction into outer space. Another example of this third law of motion is swimming in a pool. The swimmer reaches out in front of his body and pulls his arm through the water. The opposite reaction to the water being pulled behind him is the swimmer moving forward through the water.

A book he wrote on his laws of motion was published in 1687 called the Principia. Isaac Newton died in 1727 at the age of 85. He is still known as one of the greatest scientists of all time and one of the smartest people of all time. Isaac Newton’s discoveries continue to inspire mathematicians and scientists after him to learn more about gravity, calculus, and motion.