[/caption]Sir Issac Newton, who discovered gravity, was a mathematician physicist nearly three centuries ago. Many people have the image that he was sitting under an apple tree when an apple fell and hit him on the head, thus giving him the idea for gravity. In reality what he discovered was that there existed a force that is required to change the speed or direction of a moving object. After much further experimentation he wrote his theories of gravity. They have been the basic mathematical solutions for the way that things attract and repel for hundreds of years now.
Sir Isaac Newton was born in England in 1643. He was a man of many talents including: astronomy, mathematics, physics, and alchemy. In 1687 he published the Philosophiae Naturalis Principia Mathematica. This work is considered to be among the most influential books in the history of science because it laid the groundwork for most of classical mechanics. In this work, Newton described universal gravitation and the three laws of motion. These theories dominated the scientific view of the universe for three centuries. He showed that the motions of objects on Earth and in the heavens are governed by the same set of natural laws, thus removing the last doubts about heliocentrism and advancing the scientific revolution.
Gravity is affected by a few different things. Among those factors are mass, distance, and placement. The amount of gravity here on Earth varies from point to point. Gravity seems to vary the most in the Northern Hemisphere of our planet. The mass of an object also helps to determine the overall gravity of the object. In general, the more massive an object the gravity it displays. Finally, gravity is affected by the distance between two objects. The closer they are the stronger the gravitational pull will be. Gravity is all around us. It pulls the snow and rain down to the Earth’s surface. It holds everything to the surface. It also keeps our planet in its orbit around the Sun.
Here on Universe Today we have a couple of great articles related to gravity. One is about Sir Isaac Newton and the other is about the forces of gravity between celestial bodies. We are always looking for new ways to defy gravity. Astronomy Cast offers two good episodes on that topic. One is about interstellar travel and the other is about space elevators. Here is a map of the different gravities on Earth.