In the last issue Lewis Dartnell explained how chaos on the brain is not only unavoidable but also beneficial. Now he tells us why the same is true for our solar system and sends us on a journey that has been travelled by comets and spacecraft.
More than a century ago, an American astronomer named Seth Carlo Chandler discovered that, as the earth spun on its axis, it also wobbled. This wobble, now known as the Chandler wobble in honour of its discoverer, didn't disappear over time, as would have been expected if no further force reactivated it. The source of the continuing activating force has remained a mystery ever since - until now.
Johannes Kepler (1571-1630) is now chiefly remembered as a mathematical astronomer who discovered three laws that describe the motion of the planets. J.V. Field continues our series on the origins of proof with an examination of Kepler's astronomy.