// HACKER NEWS — CYBERSECURITY
The startling 1960s theory that Stonehenge was a prehistoric computer
In August 1966, a US astronomy professor shared his astonishing findings with the BBC. He believed that the Neolithic stone circle was built to predict eclipses.
Experts have long debated the meaning of Stonehenge, the prehistoric stone circle in the south-west of England. They have speculated that the mysterious monument might have been a place to commemorate the dead, a sacrificial altar, or a site of other religious ceremonies. But in August 1966, a Boston astronomy professor, Gerald Hawkins, told the BBC's Chronicle programme that he'd solved the puzzle thanks to a peculiar configuration of numbers – and an early IBM computer.
Hawkins' theory formed the basis of his popular and influential 1965 book Stonehenge Decoded. The British-born scientist suggested to the BBC that alignments of the huge slabs and archways meant that "circles at Stonehenge could have been used as a computer to follow the Moon, and predict eclipses". Eclipses, such as those witnessed around the world this month, could have been accurately foretold by ancient Britons – more than 4,500 years ago.
In the BBC footage, Hawkins gestured to an exact scale model of Stonehenge, showing how in the biggest circle, marking the circumference of the site, there are 56 holes. "Fifty-six was the only number that would fit a certain pattern of the Moon," he claimed, suggesting that the holes "make a simple counting device for predicting eclipses".
The meaning for those who built Stonehenge was, he believed, significant. "Eclipses are spectacular events that surely aroused the deepest emotions of our primitive ancestors," said Hawkins. "The light of the Moon, which is, of course, borrowed from the Sun, is cut off. It passes into the Earth's shadow. The Moon turns from silvery white to red. The ancients regarded it as blood red and attributed ominous meanings to it."
Stonehenge Decoded had "the surprising effect of silencing speculation for several decades", said a 2007 article in the British magazine Current Archaeology.
According to Hawkins, it was "the first theory concerning the purpose of Stonehenge that has been academically accepted and published in the scientific journals". Although the connection between the site and summer solstice had been recognised since the 18th Century, the professor took the idea further, proposing that what had been seen as a temple of Sun-worship could have been a sophisticated "astronomical observatory".
In 1961, he had visited Stonehenge to try and understand "how the monument was supposed to mark the sunrise". As he told the BBC five years later, "I looked around in the dawn light at Stonehenge… between the great stone archways. I felt that my view was controlled, confined. The archways seemed to force me to look at certain points on the horizon. What was I supposed to see?"
Struck by the way ancient architects had framed his sightline, Hawkins returned to the US with charts of the site, plotting the positions of its centre point and each stone, archway, hole and mound.
In History is a series which uses the BBC's unique audio and video archive to explore historical events that still resonate today. Sign up to the accompanying weekly newsletter.