Circles and PiNewton

A few decades later, Isaac Newton was able to prove Kepler’s observations, using his newly developed laws of gravity. Newton realised that there is a force between any two masses in the universe – similar to the attraction between two magnets.

Gravity is what makes everything fall to the ground and gravity is also what makes the planets move around the sun. It is only the great speed at which planets move, that prevents them from falling directly into the sun.

Frits Ahlefeldt

Using Newton’s laws, you can derive the path that objects take when moving under the force of gravity. It turns out that planets move on ellipses, but other objects like comets can travel on parabolic or hyperbolic paths: they fly close to the sun before turning around and shooting off into the universe, never to come back.

According to legend, a falling apple inspired Newton to think about gravity. He was one of the most influential scientists of all time, and his ideas shaped our understanding of the world for nearly 300 years – until Albert Einstein discovered relativity in 1905.

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Circles and PiNewton