Physics is often portrayed with the falling of an apple from a tree. According to the popular anecdote, Newton was hit by an apple, but the impact of his ideas goes beyond gravity. Turning Aristotle on his head, Newton argued that objects had inertia - an object at rest stays at rest; an object in motion stays in motion. He also introduced the notion of the invisible force of gravity, an attraction between all matter, and proved that objects fell in parabolas, arcs, at a geometric rate. To do this, he created a new mathematical language, calculus, which allowed scientists to study the rate of change for the first time. The impact of the new Physics spread quickly to economics, politics, and engineering.