Newgrange and the Boyne Valley monuments – advanced lunar calculations and observation of the effects of precession of equinoxes in Neolithic Ireland - Part 1
Near the east coast of Drogheda, about 30 miles north of the Irish capital city, Dublin, lie the remains of a vast prehistoric monumental landscape. Newgrange and its sister sites at the Brú na Bóinne complex were built more than 5,000 years ago. These giant stone edifices survive today, along with a smattering of other smaller archaeological monuments.
Archaeologists say Newgrange, Knowth and Dowth were tombs, built in ancient times to provide somewhere to bury the dead. And yet, the passage and chamber of Newgrange are aligned so that the beams of the winter solstice sun enter into the deepest part of the chamber at dawn on the shortest days of the year. This is accepted as a key aspect of the design of Newgrange, and is not something that happens by chance.
In addition, the number of bone fragments found inside Newgrange hardly constitutes evidence of a communal burial chamber. In total, the bones of only five individuals were found inside the monument during excavations in the 1960s. Admittedly, some bones could have been taken away after the rediscovery of the entrance to the passage and chamber in 1699. But at over 85 metres in diameter, and containing over a quarter of a million tonnes of stone and earth, this monument would seem such a lavish and grandiose tomb for a few mere mortals, if that were indeed its sole purpose.
In addition to the fact that the chamber of Newgrange accepts sunlight at dawn on winter solstice, there are several other aspects of its design, its alignments, its cosmology and its mythology that command the attention of those exploring its true functions. And there are several aspects of Newgrange that remain a puzzle to archaeologists.
Up until 1967, after archaeological excavation, conservation and restoration work, it was not possible for the light of the sun to illuminate the interior. This was due to slow subsidence of the roofing stones of the passage, which had slowly sunk as the supporting orthostats leaned inwards over the long centuries. Before 1967, when archaeologist Professor Michael O’Kelly became the first person to witness the solstice event in modern times, nobody could have witnessed this phenomenon. And yet, local folklore held that the sun shone into Newgrange on the shortest day of the year. O’Kelly points to this as being one of the reasons for his visit to the chamber in December 1967 when he became the first person to witness the alignment in the modern era.
In addition to the local folklore describing the solstice alignment, several authors had previously suggested its passage was aligned towards winter solstice sunrise. General Charles Vallancey had hinted at it in the eighteenth century. In 1909, astronomer and Solar Physics Observatory director, Sir Norman Lockyer, stated that Newgrange was orientated towards winter solstice sunrise. In 1911, W.Y. Evans-Wentz implied the same thing.
But the astronomical mysteries of Newgrange run much deeper than all this. In 1958, in his book about primitive mythology, Joseph Campbell recounted a folk tale from the Boyne Valley in which a local had told him the light of the Morning Star, Venus, shone into the chamber of Newgrange at dawn on one day every eight years and cast a beam upon a stone on the floor of the chamber containing two worn sockets. This might seem like an incredible suggestion, except for the fact that it is astronomically accurate. Venus follows an eight-year cycle and on one year out of every eight, it rises in the pre-dawn sky of winter solstice and its light would be able to be seen from within the chamber.
Christopher Knight and Robert Lomas, authors of Uriel’s Machine, suggest that a series of eight x-shaped markings on the lintel stone of the aperture above the entrance of Newgrange – the so-called ‘roof box’ which allows light into the chamber – represent the eight-year cycle of Venus. However, they were not aware when writing their wonderful book of the story that had been told to Joseph Campbell about the Morning Star shining into the chamber.
How did local people living in the Boyne Valley in the 1950s come into the possession of knowledge describing an astronomical phenomenon that was likely to have taken place at Newgrange in the ancient past? This is a question not easily answered by archaeologists. No-one could have witnessed Venus in the chamber of Newgrange in the middle of the twentieth century because not only had the passage roof subsided, but the whole roof box aperture was completely blocked up with soil and grass, as is evidenced from photographs of the time. Indeed, it is unlikely that anybody had seen light from either the sun or Venus shining into the chamber of Newgrange since entrance was rediscovered in 1699. It would have been impossible, given the structural condition of the monument, to view such an occurrence.
So how far back did this folklore go, if the penetration of light from the sun or Venus was not observable in the three centuries after the 1699 rediscovery? When Newgrange was excavated in the twentieth century, it was found that a great amount of the cairn had “slipped” over the retaining kerbstones at some remote epoch. All of the great kerbstones – there are 97 in total, each weighing an average of three tonnes, or the weight of an Asian elephant – had been covered when this collapse occurred, as indeed had been the entrance and the roofbox. Astonishingly, archaeologists tell us the cairn slip happened around 500 years after the monument was built. Given the estimated construction date of approximately 3,150BC, this means the cairn had slipped around 2,650BC, at that period in time marking the end of the Neolithic and the beginning of the Bronze Age. According to the archaeologists, Newgrange lay hidden for four thousand years. Its appearance was that of a miniature tree-covered hill, with just a few of the outer Great Circle of stones visible.
In his 1911 book about Fairy-Faith in the Celtic countries, W.Y. Evans-Wentz said: “But when we hear legendary tales which have never been recorded save in the minds of unnumbered generations of men, we ought not on that account to undervalue them; for often they are better authorities and more trustworthy than many an ancient and carefully inscribed manuscript in the British Museum; and they are probably far older than the oldest book in the world.”
We might agree. In the twentieth century, folk memory had preserved knowledge of astronomical occurrences at Newgrange that could not have been witnessed at the time. Given the archaeological evidence – firstly that the passage stones had subsided, and secondly that the cairn slippage had concealed the passage and chamber since the late Neolithic – it seemed that this knowledge might go right back towards the time when Newgrange had been built.