There is a common popular perception that people people in the Neolithic and Bronze Age spent a good deal of time trying to make sense of the movement and position in the sky of the sun, moon and stars, and building monument to capture this knowledge. However, despite this, archaeologists have paid ‘archaeoastronomy’ scant attention as a serious line of enquiry until relatively recently. However, proposing connections between monuments and the sky have a long tradition in Scotland. (NB Alignments associated with recumbent stone circles, multiple stone rows and Clava cairns will be dealt with in the Chalcolithic and Bronze Age document.)
Interest in the cosmological significance of the design and use of Scottish Neolithic monuments began with the work of Sir Norman Lockyer (1909) who, fresh for his work at Stonehenge, sought to extend his observations to the avenues and circles of Calanais, Isle of Lewis, and the recumbent stone circles. As well as identifying specific alignments on the sky, Lockyer conceived the idea that if astronomical alignments could be tied to the observation of particular celestial bodies, then the movement of those bodies over time would allow calculations to be made that would reveal the date of construction of the monument. So for instance he concluded, “that the Aberdeen circles are more than a thousand years younger than those of Cornwall and the West coast” (1909, 408). (Bradley (2005) has demonstrated, this was a good estimate, albeit arrived at erroneously.) Lockyer’s work at Calanais was quickly followed by additional surveys by Captain (later Admiral) H. Boyle Somerville. His survey of Calanais is the first accurate plan of the monument to be produced; he noted the main stone avenue here aligned true north, and he was the first to observe the lunar alignments at this site (Somerville 1912, 1923).
Calanais subsequently inspired another non-archaeologist-surveyor, the engineering Professor Alexander Thom (who had first encountered Calanais, and the Pole star, on a sailing holiday (Thom 1996)). From the 1930s to 1980s, Thom carried out surveys of hundreds of megaliths in Scotland (as well as elsewhere in Britain and in Brittany); he actively published his results from the 1950s onwards with a generally negative reception from the archaeological establishment (his key works being Thom 1967, 1871, Thom & Thom 1978). Thom had a very high opinion of the technical, scientific and astronomical skills of prehistoric people (unlike many of his contemporaries) and established some classic, if flawed, ideas pertaining to the construction and organisation of megalithic monuments. These included the concept of a standardised unit of measurement used in the European Bronze Age (the ‘megalithic yard’, 2.72 feet), an idea which has largely been dismissed (cf. Heggie, 1981, Ruggles 1999, 83, Burl 1991, 125-6). More pertinently, Thom believed that the layout of megaliths revealed the alignment of elements of the structure that in association with prominent/distinctive features of natural or man-made origin on a skyline at some distance enabled the recognition or the forecasting of particular solar, lunar or even stellar events that were of crucial calendrical significance. Often these relationships were incredibly accurate, and would have depended on occupants of Neolithic and Bronze Age Scotland to have been aware of at least the rudiments of Pythagorean mathematics and capable of carrying out and recording observations over cycles sometimes running for many years.
Thom’s work was largely sidelined (or ignored) by mainstream archaeologists, with concerns raised about issues such as the methods and accuracy of Thom’s work, and the lack of context of the sites with which he worked. (For a full summary of the pros and cons of Thom’s work, see Heggie 1981; Ruggles 1999.) Thom’s super-accurate alignments and calculations came under further scrutiny in light of the work of Aubrey Burl (1976, 1976a, 1981, 2006) and Clive Ruggles (1998, 1999, Ruggles & Barclay 2000) in the 1970s and 1980s. Burl for instance noted for recumbent stone circles that the coincidence of lunar movement with the recumbent placements meant that it would have been possible to determine the arrival of a period of full moon and its monthly risings and settings using rather rough and ready markers. Burl and Ruggles were the advance guard of what one could term the ‘non-precisionist school’. Their contention was that the precise, observational hypothesis of Thom that sought evidence for an advanced mathematical, Pythagorean capacity in early farming culture, was not well-founded.
Some support for Thom within the archaeological community was forthcoming however. Euan Mackie (1977) published his polemic ‘Science and Society in Prehistoric Britain’ in which he set out his experimental excavations at Kintraw, Argyll (illus), and observations at the site of Ballochroy, Kintyre and the reinterpretation of excavations at Cultoon on Islay which he felt were, in their different ways, ‘blind tests’ of Thom’s observational theories. He described Thom’s theories in far more accessible terms and attempted to place the expertise that Thom postulated within a feasible Neolithic society by creating the notion of astronomer priests, an exclusive group, highly privileged for which he garnered evidence and attempted to place this group and its cognate society on an ethnographically informed scale (but see Section 6.1). And any consideration of Thom’s legacy must include an appreciation of the immense body of survey material he collated throughout his career, still a valuable resource today. The subsequent work by Heggie, Ruggles, Burl and others was in no small part inspired by Thom, even if only by the desire to check the veracity of Thom’s work.
Heggie’s (1981) analysis of all of Thom’s observations allowed him to quite quickly dispose of the significance of complex geometry and mathematics that Thom hypothesised. In the same year Ian Thorpe (1981) examined the ethnographical record where he saw the almost universal interest in constellations and the lunar cycle among human societies. Where calendrical schemes have been created they are almost always uncomplicated. Such work re-enforced the idea that highly accurate alignments were neither likely, nor necessary, in prehistory. Therefore a less complex relationship with the sky has been postulated for the Neolithic, something archaeologists have become increasingly comfortable with.
There are a number of ‘classic’ examples of monumental associations with lunar or solar events that are by and large accepted by archaeologists as being part of the experience of those monuments. Perhaps the best documented example is the midwinter sunset alignment along the Maes Howe chambered tomb passage (illus), first reported by Magnus Spence, an Orcadian, in 1894. This remarkable phenomenon mirrors that at Newgrange. Importantly this phenomenon required some degree of monumental accuracy, but did not have to be millimetre perfect for the effect to work. And the lighting up of the back of the chamber for a short time each day for a week or so on either side of the solstice worked looking into, not away from, the monument (Burl 1981, 251; MacKie 1997; Richards 2005 and see www.maeshowe.co.uk). Loveday has argued that the cursus monuments at Holywood, with a near north-south axis, may have drawn on a general association with the constellation Orion, which would have been low in the southern sky in the Neolithic (2006, 139-42). Ruggles (1998, 1999) has suggested that general alignments such as this, which could be easily planned without a great deal of accuracy or specialist knowledge, should be viewed as part of the experience of monuments, but not the only reason for their construction. Alignments on, and drawing attention to, phenomenon in the skies was but one aspect of the world view of people in the Neolithic. And the ability to ‘stage-manage’ such other-wordly experiences may have been a source of power and legitimacy (Bradley in Barrett et al 1991, 56).
We know that people in the Neolithic must have had an interest in the sky. At a practical level knowledge of the position in the sky of the sun, moon and stars would have been invaluable for navigation and wayfinding, as well as managing the agricultural cycle, the seasonal round and ‘measuring’ time. Debate continues as to how precisely these heavenly bodies were understood, and to what extent the sky was a factor in the religious life of people in the Neolithic, as well in everyday tasks. Thom suggested: ‘We do not know the extent of Megalithic man’s knowledge of geometry and astronomy. Perhaps we never shall’ (Heggie / Thom 1981, 235).
Outstanding research questions
- What firm evidence do we have for people in the Neolithic monitoring and recording the position and movement of the moon, sun and stars? Did this change through time? (For instance, was there more of a focus on the sun in the later Neolithic?)
- Can we recognise significant astronomical alignments embedded in monuments? Is it possible to identify appropriate methodologies and datasets for establishing this? (For instance we need to evaluate the environmental context of monuments to establish how clearly horizons might have been visible.)