Friday, March 27, 2015

Finding meteorite impacts in Aboriginal oral tradition


Imagine going about your normal day when a brilliant light races across the sky. It explodes, showering the ground with small stones and sending a shock wave across the land. The accompanying boom is deafening and leaves people running and screaming.
This was the description of an incident that occurred over the skies of Chelyabinsk, Russia on February 15, 2013, one of the best recorded meteoritic events in history. This airburst was photographed and videoed by many people so we have a good record of what occurred, which helped explain the nature of the event.


But how do we find out about much older events when modern recordings were not available?
A century before Chelyabinsk, a similar event occurred on July 30, 1908, over the remote Siberian forest near Tunguska.
That explosion was even more powerful, flattening 80 million trees over an area of 2,000 square kilometres and sending a shock wave around the Earth – twice. It was 19 years before scientists reached the Tunguska site to study the effects of the blast.

Effects of the Tunguska blast 19 years after the event. Some of the trees flattened by the airburst can still be seen to this day. Leonid Kulik
Click to enlarge

The apparent lack of a meteorite fuelled speculation about how it formed, from sober suggestions of an exploding comet to more outlandish claims of mini-black holes and crashed alien spacecraft (research confirms it was an exploding meteorite).

Meteoric events in Indigenous oral tradition

In 1926, the ethnographer Innokenty Suslov interviewed the local Indigenous Evenk people, who still vividly remembered the Tunguska airburst.
At the time, a great feud persisted among Evenki clans. One clan called upon a shaman named Magankan to destroy their enemy. On the morning of July 30th, 1908, Magankan sent Agdy, the god of thunder, to demonstrate his power.

A carving of the thunder god Agdy at Tunguska. University of Bologna, Department of Physics.
Click to enlarge

Many Indigenous cultures attribute meteoritic events to the power of sky beings. The Wardaman people of northern Australia tell of Utdjungon, a being who lives in the Coalsack nebula by the Southern Cross.
He will cast a fiery star to the Earth if laws and traditions are not followed. The falling star will cause the earth to shake and the trees to topple.
Like the Evenki, it seems the Wardaman have faced Utdjungon’s wrath before.
The Luritja people of Central Australia also tell of an object that fell to Earth as punishment for breaking sacred law. And we can still see the scars of this event today.

A surviving meteorite impact legend

Around 4,700 years ago, a large nickel-iron meteoroid came blazing across the Central Australian sky. It broke apart before striking the ground 145km south of what is now Alice Springs.
The fragments carved out more than a dozen craters up to 180 meters across with the energy of a small nuclear explosion.
Today, we call this place the Henbury Meteorites Conservation Reserve.

A cluster of the largest craters at Henbury, as seen from the nearby Bacon Range. Duane Hamacher
Click to enlarge

Aboriginal people have inhabited the region for tens-of-thousands of years, and it’s almost certain they witnessed this dramatic event. But did an oral record of this event survive to modern times?
When scientists first visited Henbury in 1931, they brought with them an Aboriginal guide. When they ventured near the site, the guide would go no further.
He said his people were forbidden from going near the craters, as that was where the fire-devil ran down from the sun and set the land ablaze, killing people and forming the giant holes.
They were also forbidden from collecting water that pooled in the craters, as they feared the fire-devil would fill them with a piece of iron.
The following year, a local resident asked Luritja elders about the craters. The elders provided the same answer and said the fire-devil “will burn and eat” anyone who breaks sacred law, as he had done long ago.

The longevity and benefits of oral tradition

The story of Henbury indicates a living memory of an event that occurred a few thousands of years ago. Might then we find accounts of events from tens of thousands of years ago?
Yes, it seems so.
Recent studies show that Aboriginal traditions accurately record sea level changes over the past 10,000 years.
Other studies suggest the volcanic eruptions that formed the Eacham, Euramo and Barrine crater lakes in northern Queensland more than 10,000 years ago are recorded in oral tradition.
In addition to demonstrating the longevity of Indigenous oral traditions, emerging research shows that these stories can lead to new scientific discoveries. Aboriginal stories about objects falling from the sky have led scientists to meteorite finds they would not have known about otherwise.
In New Zealand, geologists are also using Maori oral traditions to study earthquakes and tsunamis. New Zealand has a much more recent human history – compared to Australia – with the first Maori ancestors thought to have arrived around the 13th Century.
The arrival of the first Australians goes back at least 50,000 years. There is still much to learn, as Australia’s ancient landscape has been exposed to meteorite strikes that we don’t know about, some of which have probably occurred since humans arrived.
But given that Australia is home to the oldest continuing cultures on Earth, we are only just scratching the surface of the vast scientific knowledge contained in Indigenous oral traditions.
We anticipate that our work with Aboriginal elders to learn about Indigenous astronomy will lead to new knowledge and cultural insights about natural events and meteorite impacts in Australia.
This article was originally published in The Conversation.

Wednesday, December 24, 2014

"Speaking with": Duane Hamacher on Indigenous astronomy

Duane Hamacher interviewed by Tamson Pietsch. Originally published on The Conversation on 19 December 2014, 11.35am AEDT.


Aboriginal and Torres Strait islander people have between 40,000 and 60,000 years of pre-colonial history that includes stories of constellations they observed in the night sky and traditions that align with the stars and the moon. But until recently, these stories were largely dismissed by the scientific community.
Researchers are now finding that Indigenous oral traditions contain vast environmental and scientific knowledge. These complex knowledge systems have helped Indigenous people survive Australia for tens of thousands of years.
Tamson Pietsch speaks with cultural astronomer Duane Hamacher about Indigenous astronomy and its complex relationship to history, culture and applied scientific knowledge.

Thursday, December 11, 2014

Studying Cultural Astronomy for a Career - a Guide

By Duane Hamacher

I am frequently asked how to go about studying cultural astronomy and pursuing a career in the field. Due to its interdisciplinary nature, knowing what to study and how to build a foundation in this area is not as straightforward as one might think.

This blog post will serve as a guide to studying cultural astronomy at the university level, from undergrad to PhD. I will also list some of the career options for graduates in this field. This is based on my knowledge and experience.

What is Cultural Astronomy?

Cultural astronomy is the academic study of the ways in which various cultures understood and utilized the celestial realm. It is a social science informed by the physical sciences. Since it involves human perception of the natural world, it is grounded in the social sciences. But as it utilises information and knowledge about the natural world, it is informed by the physical and natural sciences.

Cultural astronomy is generally divided into two sub-disciplines: archaeoastronomy and ethnoastronomy.

Archaeoastronomy is the study of the astronomical practices and beliefs of past cultures. It relies heavily on the archaeological record and has traditionally focused on alignments in monuments, structures, and stone arrangements. This approach relies heavily on archaeological surveys, precision measurements, and statistical analysis.


                    Archaeoastronomical studies at Chankillo in Peru.

Ethnoastronomy is the study of the astronomical practices and beliefs of contemporary cultures, with a focus on Indigenous peoples. It relies heavily on the the ethnographic and historical records and involves learning about human understanding of the sky directly from the people themselves, particularly Indigenous elders.



   Ethnoastronomical work with Aboriginal elder Bill Yidumduma Harney.


The study of astronomy in culture is a growing field of interest, and an increasing number of masters and doctoral degrees are being awarded with theses and dissertations in the field. The graph below shows the increase trend in graduate degrees with theses/dissertations in cultural astronomy being awarded between 1965 and 2004 (McCluskey, 2004).

Dissertations and Theses in Cultural Astronomy (1965-2004)

Cultural astronomy is highly interdisciplinary, so could consider a number of different majors and degree programs, depending on your personal interests. If you want to learn about astronomical alignments in temples, megalithic structures, or ancient cities, archaeoastronomy is your area and archaeology and classics are suitable fields of study. If you are interested in learning about contemporary Indigenous cultures, anthropology and sociology are a better option. If your interest lies in interpreting ancient texts, linguistics and languages would be a suitable option.

Very few universities have any structured programs in cultural astronomy, and only a handful offer courses on the subject (a list of such courses will be the focus of a future post). So do not expect to find a university where you can complete a full program in cultural astronomy... you'll have to build your own.

What should I study at the Undergraduate Level?

Regardless of which area of cultural astronomy you choose to pursue, you need a grounding in the social sciences, and a working knowledge of astronomy. Basic knowledge in other sciences, such as geology, ecology, and biology, are also useful. Skills such as surveying, computer programming, and statistics are also highly valuable. Majors or fields of study for each sub-discipline are given below. This is not an exhaustive list. It only serves as a general guide.

Archaeoastronomy: Archaeology, Anthropology, Ancient History, Classics, History & Philosophy of Science, Cultural Heritage Management. Noteknowledge of statistics and surveying are essential.

Ethnoastronomy: Anthropology, Sociology, Indigenous Studies, History & Philosophy of Science, Environmental Humanities, Religious Studies.

You would be best suited to take either a Major in a social science and a Minor in astronomy/physics, or double Major in both social science and astronomy/physics. A single major in the social sciences will not generally provide you with the scientific foundation necessary to work in the field, and vice versa for a major in the sciences. A dual Major or double degree will be very intensive but is the best overall option. A dual BA would be easiest (e.g. BA Anthropology/BA Astronomy). However, a BA/BS provides the widest breadth and opens up the most opportunities (e.g. BA Anthropology/BS Astronomy).

[A colleague at Macquarie University in Sydney completed a dual degree to pursue his interests in Egyptian astronomy. He completed a BA in Ancient History and a BS in Astrophysics, with an Honours year studying Egyptology. It was hard work, but he's glad he did it!]

What should I study at the Graduate/Postgraduate Level?

If you want to pursue a career in cultural astronomy, you will need to complete a PhD.

You will be best suited in a social science or humanities program. It is very important to carefully choose a university and department that will support the research, and a knowledgeable, able, and supportive supervisor. You also much carefully choose the field of study in which the degree will be awarded. "Studies" programs tend to be more broad, while "traditional" programs (e.g. anthropology, archaeology) are more narrowly focused.

PhDs in the sciences with a cultural astronomy thesis topic are rare. A study in 2004 showed that of 79 masters and doctoral degrees awarded with theses in some area of cultural astronomy, only 3 were awarded through physics/astronomy departments. This means you will be far more likely to be accepted into a PhD program through the social sciences than the physical sciences.

Graduate degrees awarded with theses in cultural astronomy, divided into disciplines (1965-2004).

Career Opportunities

It should be made very clear that cultural astronomy is a tiny academic field - only a handful of people in the world have managed to carve out a career in this discipline - and the chances of getting a job in that area are incredibly slim. That is the advice my supervisors gave me. But it is possible to study cultural astronomy and make a career out of it… I did. You simply have to carve a niche, strategise your career, and maximize your opportunities. Just remember that nothing is guaranteed and academia is brutally competitive.

There are numerous employment opportunities that will utilize your skills and knowledge set, although the job may not entail further cultural astronomy research. These include:

  • Research and/or Teaching Academic
  • TAFE/Community College Instructor
  • Cultural Heritage Management
  • Archaeological and Anthropological Consultant
  • Education and Curriculum Developer
  • Museum or Gallery Curator
  • Outreach Officer
  • Astronomy Educator
  • Tour Guide
  • Tourism Consultant
  • Media and Communication
  • Journalism
  • Policy Development
  • Journal/Magazine Editor
  • School Teacher
  • Administration
  • Park Ranger
  • Technical Writer
  • Analyst (for those with high maths/stats skills)

So if this is a subject you wish to pursue... go for it. But be warned that the chances of landing a career in the discipline are very small. But it is a very exciting field in which to work and provides you with broad skills that can be used in a number of careers.

Monday, December 8, 2014

Stories from the sky: astronomy in Indigenous knowledge

by Duane Hamacher (University of New South Wales)
Indigenous Australian practices, developed and honed over thousands of years, weave science with storytelling. In this Indigenous science series, we’ll look at different aspects of First Australians' traditional life and uncover the knowledge behind them – starting today with astronomy.

This article contains the names of Aboriginal people who have passed away.
Night sky over Lake Tyrrel in Western Victoria – home of the Wergaia people. Alex CherneyCC BY-NC-ND

Indigenous Australians have been developing complex knowledge systems for tens of thousands of years. These knowledge systems - which seek to understand, explain, and predict nature - are passed to successive generations through oral tradition.
As Ngarinyin elder David Bungal Mowaljarlai explains: “Everything under creation […] is represented in the ground and in the sky.” For this reason, astronomy plays a significant role in these traditions.
Western science and Indigenous knowledge systems both try to make sense of the world around us but tend to be conceptualised rather differently. The origin of a natural feature may be explained the same in Indigenous knowledge systems and Western science, but are couched in very different languages.
A story recounted by Aunty Mavis Malbunka, a custodian of the Western Arrernte people of the Central Desert, tells how long ago in the Dreaming, a group of women took the form of stars and danced a corroboree (ceremony) in the Milky Way.
One of the women put her baby in a wooden basket (coolamon) and placed him on the edge of the Milky Way. As the women danced, the baby slipped off and came tumbling to Earth. When the baby and coolamon fell, they hit the ground, driving the rocks upward. The coolamon covered the baby, hiding him forever, and the baby’s parents – the Morning and Evening Stars – continue to search for their lost child today.
If you look at the evening winter sky, you will see the falling coolamon in the sky, below the Milky Way, as the arch of stars in the Western constellation Corona Australis – the Southern Crown.
The place where the baby fell is a ring-shaped mountain range 5km wide and 150m high. The Arrernte people call it Tnorala. It is the remnant of a giant crater that formed 142 million years ago, when a comet or asteroid struck the Earth, driving the rocks upward.
Tnorala (Gosses Bluff crater). Dementia/FlickrCC BY-SA
Click to enlarge

Predicting seasonal change

When the Pleiades star cluster rises just before the morning sun, it signifies the start of winter to the Pitjantjatjara people of the Central Desert and tells them that dingoes are breeding and will soon be giving birth to pups.
The evening appearance of the celestial shark, Baidam traced out by the stars of the Big Dipper (in Ursa Major) tells Torres Strait Islanders that they need to plant their gardens with sugarcane, sweet potato and banana.
When the nose of Baidam touches the horizon just after sunset, the shark breeding season has begun and people should stay out of the water as it is very dangerous!
Torres Strait Islanders use constellations, such as the shark ‘Baidam’ pictured here, for practical purposes. Brian Robinson
Torres Strait Islanders' close attention to the night sky is further demonstrated in their use of stellar scintillation (twinkling), which enables them to determine the amount of moisture and turbulence in the atmosphere. This allows them to predict weather patterns and seasonal change. Islanders distinguish planets from stars because planets do not twinkle.
In Wergaia traditions of western Victoria, the people once faced a drought and food was scarce. Facing starvation, a woman named Marpeankurric set out in search of tucker for the group. After searching high and low, she found an ant nest and dug up thousands of nutritious ant larvae, called bittur.
This sustained the people through the winter drought. When she passed away, she ascended to the heavens and became the star Arcturus. When Marpeankurric rises in the evening, she tells the people when to harvest the ant larvae.
Arcturus (Marpeankurric – on the lower left) and the Milky Way over Lake Hart. Alex Cherney
Click to enlarge
In each case, Indigenous astronomical knowledge was used to predict changing seasons and the availability of food sources. Behind each of these brief accounts is a complex oral tradition that denotes a moral charter and informs sacred law.
An important thing to consider is that small changes in star positions due to stellar proper motion(rate of angular change in position over time) and precession (change in the orientation of Earth’s rotational axis) means that a few thousand years ago, these sky/season relationships would have been out of sync.
This means knowledge systems had to evolve over time to accommodate a changing sky. This shows us that what we know about Indigenous astronomical knowledge today is only a tiny fraction of the total knowledge developed in Australia over the past 50,000-plus years.

Moving forward

As we increase our understanding of Indigenous knowledge systems, we see that Indigenous people did develop a form of science, which is used by Indigenous and non-Indigenous people today.
Students in Albury/Wodonga learning about Indigenous astronomy through the Charcoal Nights initiative. Murray Arts
Traditional fire practices are used across the country, bush medicines are being used to treat disease, and astronomical knowledge is revealing an intellectual complexity in Indigenous traditions that has gone largely unrecognised.
It is time we show our appreciation for Indigenous knowledge and celebrate the many ways we can all learn from this vast accumulation of traditional wisdom.

Duane is speaking at The Edges of Astronomy symposiumat the Australian Academy of Science in Canberra on December 4, 2014.

Thursday, September 11, 2014

Are supernovae recorded in Indigenous astronomical traditions?

New research by Dr Duane Hamacher at the University of New South Wales explores Indigenous traditions that may describe supernovae, and sets criteria for confirming supernovae in oral tradition and material culture (e.g. artefacts, rock art, etc).

Journal of Astronomical History & Heritage, Vol. 17(2), pp. 161-170.

Abstract

Novae and supernovae are rare astronomical events that would have had an influence on the sky-watching peoples who witnessed them. Although several bright novae/supernovae have been visible during recorded human history, there are many proposed but no confirmed accounts of supernovae in indigenous oral traditions or material culture. Criteria are established for confirming novae/supernovae in oral traditions and material culture, and claims from around the world are discussed to determine if they meet these criteria. Aboriginal Australian traditions are explored for possible descriptions of novae/supernovae. Although representations of supernovae may exist in Aboriginal traditions, there are currently no confirmed accounts of supernovae in Indigenous Australian oral or material traditions.


Image from http://www.bosssupernova.com/whatisasupernova.htm



Wednesday, July 30, 2014

"Cultural Astronomy Channel" - YouTube

The Cultural Astronomy Channel is a YouTube channel moderated by Prof Jarita Holbrook from the University of the Western Cape in Cape Town, South Africa.

The channel features a number of videos on the subject of cultural astronomy. Most recently, Prof Holbrook uploaded talks from the recent conference of the International Society of Archaeoastronomy and Astronomy in Culture in Cape Town (aka "Oxford X"). The theme of the meeting was "Astronomy, Indigenous Knowledge, and Interpretation" and featured a number of talks on Indigenous astronomy from around the world.

You can view videos here, including those from Cape Town. Updated versions of the talks that incorporate lecture slides will be uploaded in the future. A talk on Australian Indigenous astronomy is given by Dr Duane Hamacher.


Monday, March 31, 2014

The Kamilaroi and Euahlayi Emu in the Sky


The concept of the Emu in the Sky exists in different Aboriginal groups across Australia. These stories have different meanings, from indicators of resources (when to collect emu eggs) to that of culture heroes. The Kamilaroi and Euahlayi peoples, who live in the north and northwest of New South Wales, also have traditions of an Emu in the Sky, which differed from many of the other accounts. For the Kamilaroi and Euahlayi, the celestial Emu represents different things at different times of the year. The Emu first becomes visible in March. When it is fully visible in the Milky Way during April and May, it assumes the form of a running emu (Figure 1). This represents a female emu chasing the males during the mating season. Because emus begin laying their eggs at this time, this appearance of the celestial Emu is a reminder that the emu eggs are available for collection.

Figure 1

In June and July, the appearance of the Emu changes, as the legs disappear. The Emu, which is now male, is sitting on its nest, incubating the eggs (Figure 2). The eggs are still available for collection as a resource at this time.

Figure 2

The Kamilaroi and the Euahlayi have in common their male initiation ceremony, called the bora. The preferred time for the bora ceremony is during the summer, but the planning for the ceremonies, and possibly the layout of the bora site, may take place in August and September. There is a strong connection between the bora ceremony and the Milky Way, where the culture hero Baiame lives, and to whom the ceremony is dedicated. There is also evidence that the Emu is connected to the ceremony: as male emus rear the young, so male Aboriginal elders nurture the young initiates into manhood.

The bora ceremonial site usually consists of two circles, one large, and one small, connected by a pathway. In August and September, the Emu once again changes appearance to that of two circles in the sky, vertically aligned above the south-southwest horizon (Figure 3). This is the direction to which most bora sites are aligned (from large circle to small circle).

Figure 3

Later in the year, around November, the Emu once again changes appearance and becomes Gawarrgay/Gawarghoo, a featherless Emu that travels to waterholes and looks after everything that lives there. The Emu is now low on the horizon in the evening, so it appears only as the “body” of the Emu. The Kamilaroi and Euahlayi say this is because the Emu is sitting in a waterhole (Figure 4). As a consequence, the waterholes in country are full (which is often the case in November).

Figure 4

Later in the summer, the Milky Way and the Emu dip below the horizon. This signifies that the Emu has left the waterholes, which dries up the waterholes.

The Kamilaroi and Euahlayi peoples have a complete story of the Emu in the Sky, and this reflects their belief that, at one time, the sky and everything in it was “down here”, and what is now “down here” was in the sky. This explains the connection between the Emu in the Sky, and the emu bird on the ground, and the connections to resource management and the ceremonial aspects of the male initiation ceremony.

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This post is based on research conducted by Robert Fuller, Michael Anderson, Ray Norris, and Michelle Trudgett with Kamilaroi and Euahlayi elders and custodians. Their paper, “The Emu SkyKnowledge of the Kamilaroi and Euahlayi Peoples will appear in the July 2014 issue of the Journal of Astronomical History and Heritage (Volume 17, Issue 2). You can read a preprint of the paper here.