By Global Challenges Travel Scholar, Mariana Sontag Gonzalez
Earlier this year, I had an amazing opportunity of visit a lab in Freiburg, Germany, after receiving a grant from UOW’s Global Challenges. This visit was crucial for my PhD project, in which I focus on dating archaeological sites in Indonesia.
Tens of thousands of years ago, modern humans reached the exotic places I am researching on their migrations across the globe. But before they got there, other kinds of humans had already called these islands home. On the Indonesian island Flores, the short human-like Homo floresiensis (aka the Hobbit) was already inhabiting the cave of Liang Bua (which means Cool Cave, see picture below) 50 thousand years ago. We don’t yet know so much about the species living on the Indonesian island of Sulawesi, because no fossil remains have been found, only stone tools. But these tools are distinctly different from the stone tools used by modern humans later on.
Such archaeological sites are really exciting (well, I think so, at least!) because they are all that remains of past peoples and studying them gives us a unique window into what life was like 50 or one hundred thousand years ago. Archaeological scientists are able to tell us what kind of foods they ate and whether or not they were newly arrived at the location where the remains were found. In contrast, my research revolves around providing the chronological framework through which their story can be told. I work with optically stimulated luminescence (OSL) dating, where we obtain a physical signal from sand grains which lets us determine when a layer of sediment was buried, and that gives us an age for archaeological sites. More specifically, we use machines that shoot lasers onto grains of sand and record the light that is emitted back because of electrons being repositioned within the mineral. These machines also need to hold the samples at the right temperature (between 200 and 300°C), so that we only receive the special signal we are interested in.
Work trips for archaeological scientists like myself usually involve going straight to the excavation to collect samples (this is where we put on our hats and play Indiana Jones for a few days). This can be a lot of fun, even though there are no guarantees of luxuries like showers or hot water! During my latest trip, however, I visited a German lab in Freiburg where I did important work on the reproducibility of my results, specifically at the temperature used by different machines. While the location is less exotic than on fieldwork, this kind of lab exchange is really vital to give credibility to my measurements. The years’ worth of results of my PhD project would be meaningless if other researchers at different institutions were not able to reproduce my findings.
At Freiburg, I spent of lot of re-screwing and repositioning various attachments to the luminescence reader (see picture above) together with my host, UOW-alumna Dr. Daniela Mueller. This didn’t always lead to the results we wanted, but always led to our learning something new! And of course the weekends provided enough relaxation through sightseeing of the beautiful old town (see below) and of nearby places. I had a great trip where I learned a lot and I hope to be able to return there (either for business or for pleasure)! So that’s it from me, because I have to go back to analysing the data I measured so that you can all (hopefully soon) read about the work we are doing on when human-like people roamed the Earth and what they did or ate and how they interacted with their environment, thus elucidating our shared human past.