Teacher background information

Over millennia, periodic events and periodic motion have been used as measures of time, such as the motion of the sun across the sky and the phases of the moon. In its simplest form, time is often counted in days, months and years based on the Earth’s rotation and orbit around the sun. Time is important across all facets of life, including when to travel, in music, scheduling and attending events, quantifying rates of change and knowing when to harvest. Globally and historically there are many different systems that record the passage of time and mark significant events. This elaboration provides students with the opportunity to learn how Aboriginal and Torres Strait Islander Peoples developed timekeeping systems based on astronomical observations of the night sky, including the moon, stars, planets and appearance of the sun, and that these ways of monitoring and communicating significant times continue to be used today. Students will have the opportunity to research Aboriginal and Torres Strait Islander Peoples’ systems for monitoring and communicating time, including the use of oral records, stone arrangements, paintings and petroglyphs.

In the development of time keeping methods Aboriginal and Torres Strait Islander Peoples observed the patterns of the motions of celestial bodies in the night sky for many thousands of years. The recurring patterns were, and continue to be, used as a system to track time and signify important events. For many First Nations Peoples, the moment a certain planet, star or constellation is first visible on the horizon (heliacal rising) indicates an important time, such as the beginning of a season, ceremony or the time for travel. Aboriginal and Torres Strait Islander Peoples track time using the complex patterns of the moon, stars, planets and sun and record and communicate methods of timekeeping through oral language, paintings, petroglyphs and stone arrangements. Such records are important within a community. However, the cultural diversity of Aboriginal and Torres Strait Islander Peoples, encompassing a diverse range of languages and dialects, necessitated a means of communication by which to synchronise time across communities and Nations.

Aboriginal and Torres Strait Islander Peoples’ observations of the recurrent patterns of celestial bodies in the sky have long been used as markers of time and as indicators of certain events. The Ngarrindjeri Peoples of southern South Australia explain the patterns of the moon and the sun in oral records that have been sustained through generations. The oral records include knowledge of the phases of the lunar month, understood through unbroken astronomical observations of the night sky over millennia. The records also detail knowledge of the timing of the appearance of the sun as a way of monitoring the coming or passing of days. In the Southern Coorong district of South Australia, the Ngarrindjeri Peoples used the number of full moons to record the age of children under the age of one, while in the Hahndorf area of South Australia, the Peramangk Peoples marked the appearance of each new moon on an object, such as a digging stick, to record their own age. The patterns of the stars have also long been used as indicators of time, particularly in relation to the life cycles of organisms within their Country/Place to indicate a particular season, time for travel, or availability of a certain resource. For example, the appearance of Dhinawan (the emu) in the Milky Way indicates to the Ngemba, Kamilaroi and Euahlayi Peoples of north western New South Wales that it is time to harvest emu eggs.

Aboriginal and Torres Strait Islander Peoples distinguish planets visible to the naked eye in the night sky from other celestial objects such as stars. The planets of Earth’s solar system are distinguishable from stars as they move in complex paths across the sky, whereas stars appear in fixed positions with respect to each other. The peoples of the Tiwi Islands, 80 kilometres to the north of Darwin where the Arafura Sea joins the Timor Sea, have long known that the planets are different from stars and they exist in a connected system, and this knowledge is passed down in oral records through generations. The Tiwi Peoples describe the planets as wives of the moon, as they follow the same path across the sky, in what astronomers now call a planetary parade. On the island of Mer in the Torres Strait, the planet Venus is differentiated from surrounding stars by the fact that the planet does not twinkle like a star, and it can be seen moving in relation to the stars as it orbits around the sun. Such observations inform the Meriam people of Mer Island in the Torres Strait of changes in the season and weather that are used to time planting and harvesting.

Knowledge of the planet Venus can be found in many Aboriginal and Torres Strait Islander Peoples’ cultural records. Venus is in closer proximity to the sun than Earth and orbits the sun inside the orbit of Earth. When Venus trails the sun in the sky, it appears in the night sky just after the sun sets (Evening Star), and when it is on the other side of the sun it is visible in the early dawn before the sun rises (Morning Star). In an event that occurs every 548 days, the Yolngu People of north eastern Arnhem Land use Venus to time the commencement of a special ceremony to celebrate the first rising of Venus, the Morning Star, as it transitions from the Evening Star. The detailed scientific knowledge of the orbital pattern of Venus, developed from monitoring the night sky for millennia, demonstrates one method of astronomical observation that the Yolgnu Peoples use to monitor time and is told in story and song within the Yolgnu community. The movement of other planets visible to the naked eye, Mercury, Mars, Jupiter and Saturn, has also been documented in the oral records from Aboriginal Language Groups across Australia, and has significance in the timing of events, such as harvests and important meetings.

Aboriginal and Torres Strait Islander Peoples’ observations of the night sky also include astronomical features outside Earth’s solar system, such as constellations that appear at certain times of the day or year, due to the rotation of the Earth on its axis and its orbit around the sun. The Pitjantjatjara Peoples of the central Australian desert know that the appearance of the constellation Pleiades in the dawn sky indicates the beginning of the cold season. For the Yirrkala Peoples of east Arnhem Land in the Northern Territory the visibility of Scorpius in the morning sky indicates the beginning of the beche de mer (sea cucumber) trading season. The Boorong Peoples of north western Victoria observe that when Neilloan, the mallee fowl constellation (Lyra), appears in the night sky the birds build their nests, and when the constellation disappears approximately six months later, mallee fowl eggs have been laid and can be collected. On the western islands of the Torres Strait, the first appearance of Baidam (the Shark constellation) on the horizon indicates that yams are ready for harvesting and the start of the turtle mating season. The people of Mabuiag Island in the Torres Strait time important ceremonies by the appearance of the star Kek (known as Arcturus in western cultures), as it coincides with a plentiful supply of resources. The significance of this timing is encoded in the songs and dances of some of the islands in the Torres Strait, which serve as an important transgenerational system of transferring and maintaining knowledge.

Aboriginal and Torres Strait Islander Peoples’ seasonal calendars are timed through complex combinations of astronomical and environmental interactions. Observations of weather, changes in climate, the flowering or fruiting of plants, the behaviour of animals within the environment, and the patterns of stars and constellations, all work in conjunction to indicate certain times in the cycle of seasons. The Arrernte Peoples whose lands encompass regions of the central desert of Australia surrounding Alice Springs, differentiate between the nightly movement of the stars from east to west, as well as the more gradual annual shift of the constellations. Notable events, such as the ripening of tubers and bulbs and the appearance of migratory birds and animals, are correlated with the positions of stars and constellations such as Orion, Pleiades and the Southern Cross. The timing of these events is detailed in cultural records, and the oral transmission of these knowledges to successive generations ensures the associations, with their significant connection to important resources, are remembered. Retelling such narratives through song and paintings ensured, and continues to ensure, the knowledges continue unbroken over millennia. The Wardaman Peoples of central north Australia created paintings to depict significant representations of such knowledges, including astronomical phenomena such as the Milky Way. The Anindilyakwa Peoples of Groote Eylandt created bark paintings to preserve knowledges about constellations, such as the Southern Cross and the Pointers, and their connection with important resources.

The abundance of important resources within a particular community has been an opportunity for seasonal gatherings and celebrations for thousands of years. Time, measured through a variety of means such as the constellations and seasonal indicators, is measured and recorded differently in the diverse Aboriginal and Torres Strait Islander Language Groups. Within Aboriginal and Torres Strait Islander languages and dialects there is much vocabulary relating to time, indicating the knowledge of timekeeping by Aboriginal and Torres Strait Islander Peoples and its importance for many purposes. Diversity of languages and dialects across Aboriginal and Torres Strait Islander Peoples means that oral language alone cannot be the only means of communication. Hence, the complexity of relaying the details of an important gathering, and finding ways to synchronise time across Language Groups, required innovative means of communication. This has long been the responsibility of messengers from the community, who were tasked with the responsibility of relaying important information about a gathering to invited guests that included: when the event was scheduled, the location and duration of the event, and who was invited to attend.

The use of a message stick was a common means of remembering and communicating such information. The Yidinji Peoples of far north Queensland developed a method of communicating time through a combination of message sticks, fern fronds and hand mnemonics. Notches carved into a message stick indicated the number of days, while the number of leaflets on the fern frond, folded over in half onto itself, indicated the number of interval days. Additionally, points on the palm of the hand indicated to a neighbouring community the number of days before they are expected to arrive for the gathering. Further notches on a message stick may have been used, if required, to communicate other important information. The Wotjobaluk Peoples of Victoria used the message stick to communicate the distance to the gathering place, what a community may be required to bring, and the number of people invited. Each community then used their own ways of monitoring time, including the tracking of constellations and the appearance of stars in the night sky, to synchronise their timing for the event. The Tarkiner Peoples of north west Tasmania applied the lunar phases of the moon to daily life and determined the timing of a gathering, for example, by the number of dark days after the moon had disappeared.

Petroglyphs, images engraved into a rock surface, provide evidence of Aboriginal Peoples’ understanding of the night sky and its connection with time. In Ngarrindjeri Country in South Australia, depictions of the sun and moon are engraved in a rock site called Ngaut Ngaut. The Traditional Owners of the site share the knowledge of a series of dots and lines carved into the rock to show the phases of the moon. The Guringai Peoples of the Sydney region recorded and communicated their observations and understandings of the phases of the moon in rock engravings at a site within what is now known as Ku-ring-gai Chase National Park, north of Sydney. A series of eight engravings of the phases of the moon portray the lunar calendar used by the peoples of this region. The Wathaurong Peoples of Victoria constructed a sophisticated stone arrangement, Wurdi Youang, in deliberate alignment with astronomically significant positions. The egg-shaped arrangement of over 50 basalt stones evidences and records the knowledge of the movement of the stars and sun. In a western context the arrangement is aligned in an east-west direction, with prominent stones on the western side indicating the position of the setting sun at the equinoxes (the times when day and night are of equal length) and solstices (the longest and shortest days of the year). The Wurdi Youang arrangement is believed to be the result of astronomical observations made by the Wathaurong Peoples over thousands of years, and that the recurrent patterns observed each year over time were used in its construction.

This elaboration provides students with the opportunity to research how Aboriginal and Torres Strait Islander Peoples understand the night sky and used observations of the recurrent astronomical patterns as a means of keeping time. The diversity of Aboriginal and Torres Strait Islander Peoples in Australia gives rise to equally diverse systems of keeping time, and recording and communicating the knowledges both intergenerationally among a community and across different language groups. Oral language records, stone arrangements, paintings and petroglyphs all contain evidence of Aboriginal and Torres Strait Islander Peoples’ astronomical knowledge and understanding relating to time. Through this elaboration students have the opportunity to learn how Aboriginal and Torres Strait Islander Peoples used the night sky to monitor time and the diverse ways that this knowledge has been preserved over millennia.