Legend says that Rome was founded by Romulus and Remus, twin brothers who after being abandoned as infants, suckled a she-wolf to survive. The image of the young boys at the wolf’s teat has been recreated in countless artworks over thousands of years, but few are as famous as ‘La Lupa Capitolina’, the Capitoline Wolf.
Cast in bronze, the 75-centimetre statue was discovered in the 15th century and was at the time believed to be over one thousand years old. It wasn’t until the 2000s that analysis using a nuclear technique – radiocarbon dating – stunned the world by shattering that belief and firmly dating the statue to just the 12th century.
How could a single scientific technique so quickly and robustly overturn the understanding held for centuries of such an important cultural artefact? A new, freely available IAEA e-learning course on accelerator mass spectrometry (AMS) dating reveals the power of radiocarbon dating, its fundamentals and how to process and interpret its data. The course also expounds upon case studies, including the Capitoline Wolf, and presents an overview of other dating methods and forensic AMS applications.
“Radiocarbon dating has been absolutely transformative in the field of archaeology, and now with the growing proliferation of accelerators, there’s an opportunity to use it more widely also for authentication and provenance,” said Aliz Simon, an IAEA nuclear physicist who specialises in accelerator applications. She and her team developed the e-learning course, funded through the IAEA’s technical cooperation programme, to improve knowledge on radiocarbon dating and AMS techniques. “It’s important that we train those who can be end-users of AMS techniques to improve our understanding of the past or even solve crimes and combat the illicit trade of art, food, medicine and ivory,” Simon said.
AMS dating is a technique for measuring long-lived isotopes, primarily carbon-14, with a mass spectrometer and a particle accelerator. Carbon-14 is a radioactive isotope present in all living organisms. It decays at a steady rate, so by measuring the amount of carbon-14 present in a sample, researchers can determine its age. While measuring carbon-14 as a technique was originally conceived in the late 1940s with the use of liquid scintillation counters and gas proportional counters, today AMS dating is more popular, having proven to be more sensitive, less time consuming and requiring fewer samples.
Radiocarbon dating has been absolutely transformative in the field of archaeology, and now with the growing proliferation of accelerators, there’s an opportunity to use it more widely also for authentication and provenance.
A revealing nuclear science course
Spread over six modules, the IAEA’s online course rewards participants with a certificate on completion. Modules take between 45 and 60 minutes to complete and students are assessed in each with a test – a passing grade of 60 per cent is required to receive the certificate.
“To develop this course we worked closely with our partners – globally respected institutions such as the University Paris-Saclay, an IAEA Collaborating Centre – to ensure that content is interesting and relevant to those that may be new to AMS applications, such as archaeologists, museum curators and forensic scientists from humanities backgrounds,” said Lena Bassel, an associate project officer for heritage science at the IAEA. Another partner in the course is the Australian Nuclear Science and Technology Organisation (ANSTO), an IAEA Collaborating Centre whose innovative use of AMS has shone light on Australia’s remarkable and long history.
Among the many rock shelters found in the Kimberley region of Western Australia are an estimated 100,000 artistic images. The ochre-coloured rocks of this area of the Outback are decorated with depictions of animals, people and abstract concepts, telling the stories and history of the region’s indigenous people. In a project described as a case study in the e-learning course, researchers from the University of Melbourne and ANSTO developed a method to extract datable carbon from ancient wasp nests lying above and below some of Kimberley’s rock art paintings. The researchers also developed tests to determine the reliability of these age estimates, which placed one rock art at over 17,000 years old – among the oldest radiometrically dated rock art in Australia.
“The cultures of First Australians are the oldest continuous cultures in the world, and the Kimberley is rich in paintings of different styles and motifs,” said Geraldine Jacobsen a Principal Research Scientist at ANSTO. “While it was always clear these paintings are ancient, determining how old they are was difficult because of the type of pigments used and the condition of the rock art. However, using innovative AMS approaches we’ve managed to date some of them and will continue to use AMS to better explore Australia’s past.”
To learn more about the rock art at Kimberley, the Capitoline Wolf, or other examples and innovative methods of radiocarbon dating, enrol in the IAEA’s AMS radiocarbon e-Learning Course.