Barbarian Mathematicians

It had long been assumed that barbarians had inhabited western europe in prehistoric times and that civilization had begun in the middle east. This was known as the theory of diffusionism suggesting that civilization had spread slowly westward from Mesopotamia and Egypt. For example the practice of burial in chambered tombs could be traced from the Aegean via Malta, Portugal and France to Britain and Scandinavia.
          In 1949 Willard Libby discovered away of dating prehistoric relics by measuring the amount of radioactive carbon 14 they contained. But it was not until 1967 that Dr Hans Suess perfected the reliability of the radio carbon dating technique beyond dispute. This proved that the western megalithic sites were considerably older than the eastern civilizations they were supposed to have derived from.

Also in 1967 Professor Alexander Thom published his book "Megalithic sites in Britain" for the previous 30 years Thom had surveyed over 450 sites in the British Isles, and his research showed that the sites had been chosen and the stones erected by people with a great knowledge of astronomy, geometry and mathematics. Thom's main discovery was the megalithic yard, the unit of measurement used by the prehistoric builders. This unit was equivalent of 2.75 feet and together with another unit which he called the megalithic rod 2.5 times the megalithic yard, Thom found to be a constant feature of all the sites he surveyed. From Brittany to islands off the coast of Scotland. Thom concluded that there must have been a civilization of considerable sophistication in western europe with a central administration. Because if the measuring instruments had not been officially standardized and issued there would have been a great degree of local error and variation if the communities had been copying from their neighbors. Thom also showed that the megalithic builders had understood the principal of Euclidean geometry 2000 years before Euclid, and that they had a full knowledge and understanding of Pythagorean triangles long before Pythagoras.

Astronomers

It was known that Stonehenge and other monuments were aligned on many stars as well as the sun. But the full extent of their builders astronomical knowledge was not known. Thom himself was astonished when he found real evidence of it. The cycle of the Suns positions throughout the year are simple and constant, but the moon is a different story. It's cyclic pattern cannot be understood without taking into account a period of 18.6 years. Over this period it first rises and sets in extreme northerly and southerly positions. Then it moves inward from these extreme positions for a period of 9.3 years and outward towards them again for a second 9.3 year period. Astronomers call the extreme positions reached by the moon every 9.3 years it's Major and Minor standstills, and for a few days either side of these stands it is possible to observe what is known as the moons perturbation or wobble, which is caused by the gravitational pull off the Sun. This would have given them the power to predict eclipses, for it is when the moons perturbation is at it's greatest that eclipses occur. The size and location of the Grand Menhir Brise in Brittany had always been a mystery but Thom's survey of the region showed that it's purpose was to pin point to within a fraction of a degree the moons major and minor standstills and the exact amount of perturbation. The megalith would have been used as a foresight for the rising and setting of the moon at its extremes. The observer would have used 8 different points to observe from, one of them as far away as 10 miles.
          Thom was not alone, many others were investigating the astronomical theory and at  Stonehenge the 56 Aubrey holes were analysed to show they may have been used to study the complicated movement cycles of the moon. It may even have been in this observatory built of stone and wood that mankind first worked out the moons patterns, through continuous observations.  If the discovery had been made at Stonehenge it may account for it's later glorification with standing stones.
          But who were the people that devised these wonders, it was not the ordinary farmers and even today most people would not be capable. There must have been an intellectual elite, that was respected enough to command large labor forces to build it's projects. They must have coordinated their efforts over many centuries to achieve the knowledge and establish the traditions that they did. Radio carbon dating has shown that burials in the great chambered tombs in certain places, was spread out throughout hundreds of years. Could those people have members of that elite class, we will probably never know.

The end of the megaliths

Between 1500-1400bc, the weather pattern in europe changed from the dry warmth and clear sky's of the Sub-Boreal period, to the cool and rainy climate of the Sub-Atlantic period which is still with us. This change was disastrous to the farmers that had built the megaliths. The high and open areas such as Salsbury plain and Bodmin moor, which had been pleasant regions were now exposed to wind and rain, and a blanket of peat moss began to grow over them. The once clear sky's which had allowed  observations of the sun, moon and the stars was now clouded over much of the time. By 1400bc megalith building had stopped. For the people and their leaders it was a terrible time, the order and stability that had been built up over thousands of years was crumbling around them. Whatever hold the elite had over the people was now gone, as desperate farmers left their now useless land to live in lower areas more suited to the times. Leaving behind them their stone circles and chambered mounds deserted on the moors.