Milutin Milankovitch: Seeking the Cause of the Ice Ages

This article, from Earth: Inside and Out, reports on how mathematician Milutin Milankovitch developed a complete astronomical theory of glaciers. It discusses his work charting the ice ages of the Pleistocene, which incorporated new information about how the gravitational tug of other planets causes small variations in the tilt of the Earth's axis. His conclusion was that Earth's orbit alternates between three cycles of different lengths, causing variations of more than 20 percent in the amount of sunshine reaching the northern latitudes. The site also notes that recent technical advances show variations that correlate with his figures. Educational levels: High school, Undergraduate lower division