Builders of Stonehenge 'were skilled astronomers'
The builders of ancient stone circles like Stonehenge were using Pythagoras's theorem 2,000 years before the Greek philosopher was born, experts claim.
A new book, 'Megalith', has re-examined the ancient geometry of Neolithic monuments and concluded they were constructed by sophisticated astronomers who understood lengthy lunar, solar and eclipse cycles and built huge stone calendars using complex geometry.
Pythagoras's discovery that the square of the hypotenuse in a right-angle triangle is equal to the sum of the squares of the other two sides has been used for millennia to help builders attain perfect corners.
The new book shows how within one of Stonehenge's earliest incarnations, dating from 2,750BC, there was a rectangle of four Sarsen stones which, when split in half diagonally, formed a perfect Pythagorean triangle. The eight lines which radiate from the rectangle and triangles also perfectly align to important dates in the Neolithic calendar, such as the summer and winter solstices and spring and autumn equinoxes.
They also mark Imbolc, the ancient date for the beginning of spring on February 1, Beltane, or May Day, Lammas, the start of the wheat harvest, and Samhain, October 31, which traditionally marked the time when cattle were brought down from summer pastures and slaughtered for the winter, which has become Halloween.
Contributor and editor John Matineau, said: "People often think of our ancestors as rough cavemen but they were also sophisticated astronomers."