Hundreds and thousands of theories

Antoinette Tordesillas, Associate Professor and Reader, Mathematics and Statistics and Associate Dean (International), Faculty of Science, shows her visitors a simple mixing bowl containing fine grain white sugar and the slightly larger balls of multi-coloured hundreds and thousands – all sloshing around in random disorder.

But pour the mix into a cylinder and rotate it horizontally and precise order begins to assert itself.

Pointing to a slide of the end result whereby the sugar gathers to form a core surrounded by the hundreds and thousands with not a grain in the wrong place.

“How does the sugar know how to move like that ?” asks Associate Professor Tordesillas.

“We know that we get order out of disorder and that it has nothing to do with the cylinder so like so many spectacular patterns occurring in nature there is no mathematical explanation and so it remains an unsolved problem.”

But a solution to this seemingly harmless little kitchen conundrum can be unravelled using Graph Theory and Complex Networks and used to extract profound insights to explain and predict the patterns of movement of the very much larger grains that form the surface of the earth and cause such damage when they shift violently in the form of earthquakes.

“To better understand the physics behind earthquakes as part of my project with the Melbourne Energy Institute, I am going to analyse two data sets using techniques never used before,” she tells the students.

“First we will analyse results from experiments on a small scale comprising 1000 or so particles such as the scale of the hundreds and thousands ‘system’ and compare them with data from actual seismic events,  from as recent as the Japan and Christchurch earthquakes.”

Mathematicians Associate Professor Tordesillas and Dr David Walker plan to analyse two unique data sets: one from seismologist Gary Gibson from Melbourne University (Earth Science), the other from physicist Prof Robert Behringer of Duke University. Gary Gibson has compiled a unique catalogue of earthquake data, that is one of a kind in the world. Associate Professor Tordesillas’ group intends to compare the dynamics of natural seismic events to the dynamics extracted from high-resolution “laboratory faults” from the experiments of Behringer which has information down to the individual grains.

“Today’s just the start of a project that will take a number of years to report its findings,” she says.

The Groningen students who enjoyed this unique insight into pioneering research are mostly master students, representing a variety of studies, including the fields of (Applied) Maths, (Applied) Physics, Computing Science and Astronomy.

“The purpose of this trip is to get to know a little bit about the science and the culture in Australia,” says Kim van Oost, a member of the committee of the study tour Cookaburra ‘11 which took the party to Melbourne from the 20 to 30 April followed by a stay in Sydney until departing Australia on 10 May.

“During our day at Melbourne University we visited four departments: Mathematics, Chemistry, Physics and Geology,” says Ms van Oost.

“The students really liked the Maths presentation because it showed a real world application for a mathematical model. The part that made it more interesting was the fact that it was applied to an Australian problem.

“And even though chemistry isn’t really our field, the fact that we got to blow up a balloon full of hydrogen awoke the inner child in us.

“The physicists showed us around the lab, where some of us really felt at home, because of the coffee machines and spare parts of hardware.

“And the Geology presentation opened our eyes to a field of science which we didn’t know much about yet. Also the human skulls which we could pick up and play with were a great added bonus to the presentation.

“In the afternoon the students of Melbourne University Maths Society showed us some typical Australian pas-times including a barbecue and cricket. As a thank you we introduced them into the wonderful world of juggling.”

Associate Professor Tordesillas says that the Faculty of Science plays host to many academic and cultural visits from university students and staff worldwide and from a wide range of disciplines.

“These visits are a testament to the breadth and depth of the Melbourne science program and its influence on the international landscape of science today, from the three fronts of research, teaching and learning, and engagement,” she says.

“Yesterday’s visit was a particularly delightful treat!  It was exciting for me to see the students display such an intense level of interest in our research within only a matter of minutes of having met them.   The astute questions fired at us in rapid succession, along with the requests for more information and ‘leads’ on the scientific challenges I raised yesterday were seemingly endless.  I felt almost guilty to walk away from them.

“I look forward to hosting many more such visits as Associate Dean for International programs in Science.”

http://www.ms.unimelb.edu.au/