Australia: The Land Where Time Began

Australian Aboriginal Astronomy – Wurdi Youang – a Stone Arrangement with Possible Solar Indications

Wurdi Youang is an Aboriginal stone arrangement in Victoria, Australia, that is in the shape of an egg. This paper presents the results of a new survey of the site which show that the major axis aligns to within a few degrees of east-west. The survey confirms a previous hypothesis that it aligns with the position of the setting Sun on the horizon at the equinox and the solstices, and also shows that 2 independent sets of indicators align with these directions. It is shown that these alignments are not likely to have arisen by chance, and that the stone arrangement builders appear to have deliberately aligned the site on positions that are astronomically significant.

Aboriginal Astronomy

It has been well established that in many Australian Aboriginal cultures the night sky plays an important role (Stanbridge, 1861; Mountford, 1956; Haynes, 1992; Johnson, 1998; Cairns & Harney, 2003; Norris & Norris, 2009; Norris & Hamacher, 2009, 2011). The sky is used to regulate calendars, and mark the time of year when particular foods become available, as well as being associated with traditional songs and ceremonies. There were also practical applications of the sky in navigation and time keeping (Cairns & Harney, 2003; Clarke, 1997), and there is also some evidence for meaning in astronomical phenomena, e.g. eclipses, the motion of the planets and tides (Norris & Hamacher, 2009). In ceremonies and artefacts, such as the Morning Star pole used in Yolngu ceremony (Norris & Norris, 2009; Allen, 1975), and in depictions in bark paintings of constellations such as Scorpius (ibid.), astronomical themes are also widespread. It is not well-established if any measurements were ever made of the positions of the celestial bodies, also if there is any reference in the ethnographic literature to the solstices or equinoxes.

Norris et al. suggest it is not wise to assume similarities between the approximately 400 different Aboriginal cultures in Australia, though it is important to acknowledge that there are some similarities in some cases. E.g. the association of Orion and a young man, or a group of males, and the association of the Pleiades with a group of girls, are present in many Aboriginal cultures across Australia. In this paper the focus is entirely on the Wurdi Youang Stone Arrangement, the Wathaurong people, and similarities with any other Aboriginal cultures are not assumed, though we refer to them to set the context.

Stone Arrangements

Several Aboriginal cultures across Australia constructed stone circles that were of many different morphologies, such as circles, lines, pathways, standing stones, and cairns (Enright, 1937; Towle, 1939; Palmer, 1977; Lane & Fullagar, 1980; Frankel, 1982; Attenbrow, 2002). Some of the arrangements are believed to have had practical purposes; such as fish traps, land boundaries, while others had ceremonial purposes, such as initiation, or burial. Stone artefacts are often found associated with stone arrangements, such as rock engravings, scarred trees, and axe grinding grooves (e.g. Lane & Fullagar, 1980; Lane, 2009).

Stone arrangements vary in size from 1 m to 100 m, and local rocks are typically used in their construction, and are small enough to be carried by 1 or 2 people, though larger rocks are occasionally found that weigh up to 500 kg (Lane & Fullagar, 1980; Long & Schell, 1999). Ceremonial stone arrangements are commonly located on ridges and hill tops that have a panoramic view of the surrounding landscape (Hamacher et al., 2012). It has been suggested (McCarthy, 1940) that the surrounding landscapes were incorporated into the stone arrangements that were used for ceremonial purposes, and that they may indicate the direction of a landmark, or mimic a land feature.

According to Norris et al. there are 30 stone arrangements that have been recorded in Victoria (Marshall & Webb, 1999), though more are known to Norris et al. and it is claimed (Lane, 2009) that there are actually hundreds in western Victoria. There are no known ethnographic records or oral histories about these arrangements, and Norris et al. suggest this may be because they are considered to be sacred and secret to Aboriginal communities.

Wurdi Youang

The Wurdi Youang stone arrangement is also known as the Mount Rothwell Archaeological Site. It is located between Melbourne and Geelong, near the small town of Little River, and in 1977 it was declared a protected site by the Victorian Archaeological Survey (AAV Site No. 7922-001). The Wathaurong people, known also as the Wada Wurrung, are the traditional owners, their land extending to the west from the Werribee River to Fiery Creek beyond Shipton, and northwards from the south coast to the watershed of the Great Dividing Range north of Ballarat. The precise location is not given in this paper to protect the site, though access may be granted after gaining the permission from the traditional owners via Aboriginal Affairs Victoria.

Wurdi Youang consists of about 100 basalt stones that are roughly egg-shaped, about 50 m across along the major axis, which is aligned east-west. The stones are of a range of sizes from small rocks about 0.2 m in diameter to standing stones up to 0.75 m high, some of which appear to be supported by trigger stones. It has been estimated (Lane & Fullagar) the combined mass of the stones to be about 23 tonnes. They don’t appear to be part of the bedrock, so potentially moveable.

A group of 3 large stones, about 0.6m high, are particularly prominent at the western end of the stone arrangement. These stones are at the highest point of the stone arrangement, the land on which it is built sloping downwards from the western end to the eastern end, a total fall across the arrangement of about 4 m.

There are no known eyewitness record of the construction of the stone arrangement or use by the Wathaurong people, the site is considered to have been constructed by Aboriginal people for the following reasons (Aboriginal Affairs Victoria 2003):

· There are similar stone arrangements that are known of in Victoria, though none are known that resemble exactly Wurdi Youang (e.g. Massola, 1963);

· The arrangement is on a property owned by a single family since the area was first settled, and a European origin of the arrangement is ruled out by family tradition (Lane & Fullagar (Fullagar?, 1980);

· There are no known counterparts of the arrangements among colonial structures: it is located on rocky ground of no known agricultural or commercial value, it would not have been suitable for defining the boundaries of a sheep dip, sheep pen, or cattle dip, and evidence does not exist that it ever formed part of a fence or building (Lane & Fullagar, 1980);

· Among the Wathaurong owners there is traditional knowledge regarding the sanctuary of the site (Marshall & Webb, 1999).

Also, the Wathaurong owners have found aboriginal artefacts on the site.

It is not known when it was constructed. It is believed the Aboriginal people have occupied the area from about 25,000 BCE (Clark, 1990) to 1835 when they were displaced by European settlers (Clark, 1995). The name “Wurdi” has been suggested (Morieson, 1994) to mean “plenty of people”, and Youang means “bald” or “mountain”, which has been presumed to relate to the nearby mountain range that was called “You Yangs”. It has been suggested (Morieson, 2003) that the name “Wurdi” may be related to a word from the Woiwurrung “Wurding” which means abalone, which refers to the shape of the stone arrangement possibly being in the shape of a abalone shell, or possibly another mollusc, in which case the site may possibly have been used for increase rituals. These suggestions may, however, be weighed against the distance of 18 km between the site and Port Phillip Bay, where abalone could be found, the nearest major body of salt water.

Around the Wurdi Youang the vegetation is low and scrubby at the present, though it may have been much higher prior to European occupation, possibly even obscuring the view of the setting Sun. Norris et al. also note the common practice among Aboriginal people around the continent of clearing the land by fire periodically when necessary, as part of the standard Aboriginal land management practices (Clark, 2007; Gammage, 2011), so Norris et al. say it is equally possible that the vegetation was removed. They also suggest any such growth would need to have been cleared in those directions if this site was used to observe the position of the setting Sun.

The Morieson Hypothesis

It was suggested (Morieson, 2003) that 3 small outlying stones, the “outliers”, indicated the position of the setting Sun at solstices and equinoxes when they were viewed from 3 prominent stones at the western apex. The Morieson hypothesis is specifically that the outliers were placed deliberately in their locations to indicate the position on the horizon of the Setting Sun at the equinoxes and solstices. The primary aim of this paper is to test the Morieson hypothesis.

There are significant differences between the results of the only 2 surveys of this site that were available, which suggests that at least 1 of them was seriously flawed, in spite of the potential importance of this site to knowledge of pre-contact Aboriginal culture. Also, the outliers that were proposed by Morieson were not included in either survey, so a new survey was required to test the Morieson hypothesis. There is also a previous survey that Norris et al. were made aware of after the new survey was completed.

Secular Changes in the Sky

Relative to the stars, the Earth’s axis of rotation processes in a complete circle of 23.5^o radius over a period of about 26,000 years. This motion, the ‘precession of the equinoxes’ causes the apparent position of the stars to move by 1^o every 72 years from the viewpoint of the observer. The position of the stars would be significantly different from the present if the site had been used thousands of years ago. Therefore the position of the setting of a star on the horizon changes relatively rapidly over time, and a stellar alignment from 2,000 years ago could differ from that of the present by almost 30^o.

Also, stars move relative to their neighbours as they are not stationary. This effect, ‘stellar proper motion’, results in the apparent position of the stars shifting relative to each other over time. An example is the Southern Cross, which would have looked significantly different 10,000 years ago.

The declinations of the Sun and Moon, and therefore their positions of rising and setting, are not affected by precession. The apparent declination of the Sun is, however, affected by a much smaller effect, the ‘nutation’ in the obliquity of the rotational axis of the Earth, which varies by about 2.4^o over a period of 41,000 years. Such variations will have no measureable effect on these alignments, because the alignments that are discussed in this paper are accurate to a few degrees.

The date of construction of the stone arrangement has no measurable effect on the rising and setting positions of the Sun.

The aim of this paper was to test the Morieson hypothesis.

A simulation was run 10,000 times and the results imply that the likelihood of the Wurdi Youang stone arrangement occurring by chance is 0.25 %. Norris et al. say they recognise that this is not a precise calculation, and that their simple approximation to the site geometry introduces the possibility of bias, though this process nevertheless provides a rough estimate of the likelihood that the alignments are produced by chance alone.

They concluded therefore that it is extremely unlikely that the outlier stones happen to indicate the astronomical alignments by chance, and that the alignments were almost certainly deliberate human constructions to indicate the equinoxes and solstices.

Newly Identified Alignments

Another prominent alignment, as well as the Morieson hypothesis, is the major axis of the stone arrangement, which lies roughly on the east-west axis. A prominent viewing position would be either the centre of the stone arrangement or the eastern apex, which is the lowest part of the arrangement. Roughly the same place on the horizon is indicated by both these viewing points, which is due west of the site, or the setting of the equinoctial Sun.

According to Norris et al. it is important to consider if there are any prominent alignments at the site. There are 2 straight sections to the east of the ring that are included in the egg-shape of the stone ring which also constitute prominent alignments. Norris et al. consider that these prominent alignments in the stone ring would also be chosen as the only prominent alignments by an unbiased observer, whether they look at the plan or visiting the actual site. Only the western-facing direction of the alignment is considered in each case, as the site was built on a slope rising to the west, so the westerly lines point to the horizon, while the easterly counterparts point down into the valley. There is a relatively straight section in each case, the precise direction being poorly defined, as it depends on the choice of stones to be included (e.g. in a least squares fit) and as a result of damaged stones. The direction of each straight section is, however, roughly parallel to the Morieson alignments, when the directions of the equinox and the solstices are superimposed on the ring and on the Morieson alignments.

The Gap is at an azimuth of 272^o and an elevation of 2^o, from a viewing height of 1.6 m, from the eastern vertex of the stone arrangement, as defined by the intersection of straight lines (Norris, Norris & Hamacher 2013, Fig. 8). There the Sun would set at equinox directly behind the 3 prominent stones at the western apex of the arrangement, when viewed from the vertex, and would be visible briefly through the Gap before setting, which would be dependant of the exact position and height of the viewer. Norris et al. point out that these directions are not adjusted to fit the ring, being defined astronomically. The diagram in (Norris, Norris & Hamacher 2013, Fig. 8) shows that the straight sections of the ring are well aligned to the astronomical directions as the Morieson alignments, though the straight lines are not well defined, and not exactly straight.

If the outliers are included as prominent alignments, and the viewing position is the same as Morieson, Norris et al. consider that there are 7 prominent alignments:

· The 3 noted by Morieson,

· A 4^th over the new outlier,

· The major axis of the ring, and

· The 2 sections of the ring that are almost straight.

Conclusion

The Morieson hypothesis that the position of the setting Sun at the solstices and equinoxes is supported by this detailed survey of Wurdi Youang. The likelihood of this occurring by chance was shown by statistical analysis to be extremely low. Also, the straight sides of the arrangement were found to indicate the solstices, and the point where the Sun sets at equinox is marked by the 3 prominent stones at the western apex of the arrangement, when viewed from the eastern apex.

In this paper there are no assumptions made concerning the viewing position, as the aim of the study is to test a specific hypothesis that has been made about viewing position. The many other possible sight-lines have been tested by Monte-Carlo analysis. It has been shown that the viewing position and the orientations suggested by Morieson are significant, and are not likely to have arisen by chance.

The age or purpose of the stone arrangement is not known, though it can be said with reasonable confidence that these alignments were intentional, while Norris et al. are careful not to claim that this is an “Aboriginal observatory”, as there are no known ethnographic or oral histories that explain the purpose or use of the sight. There are plans for further research to determine age of the site, as well as to search for similar sites elsewhere.

Sources & Further reading