| − | Newton developed the [[Theory of Universal Gravitation]], more commonly known as gravity, when, according to legend, a falling apple struck him on the head. He realized that the same force that pulled the apple to the ground could be what keeps [[Jupiter]]'s moons in orbit. His theory stated that all matter is attracted to matter by a force, whose strength increases proportionally to the mass of the objects involved, and inverse proportionately to the distance between them. The theory's accuracy was later improved by the theory of [[relativity]]. | + | Newton developed the [[Theory of Universal Gravitation]], more commonly known as gravity, when, according to legend, a falling apple struck him on the head. He realized that the same force that pulled the apple to the ground could be what keeps [[Jupiter]]'s moons in orbit. His theory stated that all matter is attracted to matter by a force, whose strength increases proportionally to the mass of the objects involved, and inversely proportional to the squared distance between them. The theory's accuracy was later improved by the theory of [[relativity]], which replaces Newton's theory entirely at cosmological scales but gives similar results at small scales. |