Physics at the interface: Solving problems in biology and economics
2016 Nonlinear and Complex Physics Group Yuletide Lecture
Wednesday 7th December 2016; University of Machester
Dr Tobias Galla
Tobias Galla is a theoretical physicist in the Complex Systems and Statistical Physics Group at the University of Manchester. His research interests include statistical mechanics of complex systems, stochastic dynamics in biological systems and the application of game theory and mathematical modelling in health care.
The terms econophysics and sociophysics describe research in which physicists apply their ideas and methods to problems in economics and the social sciences. What do you have to know about the field to answer the question in the title? Similarly, what are the opportunities and dangers of working at the interface with the biological sciences? In this talk Dr Galla will give an assessment of what physicists can contribute to the field of economics, to biology and more generally to the science of complexity. He will discuss the main achievements of physicists in these fields as well as the things physicists have not achieved (despite occasional claims to the contrary). He will also discuss the potential hurdles young physicists may face moving into this area, and highlight the potentials and benefits of working in an interdisciplinary setting.
Event report by Matt Garrod:
This year’s Christmas lecture was given by Dr Tobias Galla from The University of Manchester’s Complex Systems and Statistical Physics Group. At the beginning of the talk Dr Galla posed the question “You are a young and aspiring Physicist. Is working at the interface with economics and biology a good idea?” Tobias is in a good position to answer this question; he wrote his PhD thesis on the application of path integral techniques from quantum mechanics to the study of the minority game from economics and has subsequently published research at the interface with both economics and biology.
The talk began with a brief introduction to how physicists became interested in tackling problems from other disciplines. Examples of physicists tackling problems related to economics go back decades. However, in recent decades, the number of physicists tackling interdisciplinary problems in fields such as economics and biology has increased dramatically. The 1990’s even saw the emergence of a discipline referred to as “econophysics.” Tobias, noted, however that “econophysics” is currently defined as the discipline where physicists work on problems in economics. This type of definition suggests that you can only do econophysics if you are a physicist!
After discussing the history of the field Tobias went on to discuss both the advantages and disadvantages of having physicists work at the interface with other disciplines. One thing he noted was that a great number of papers in the econophysics literature have a somewhat formulaic nature. For example, they often propose a slight alteration or addition to a Physics inspired model (perhaps related to the well studied Ising model). This is often followed by some numerical simulations, their results, and a claim that the results have relevance some given social or biological phenomena. However, the results of simulations like these, although they may show interesting behaviour from a physicist’s point of view, are not guaranteed to relate well to the intended physical application. (On the other hand, Tobias noted that, as a statistical physicist working close to economics, some of his own work be of a similar form to the above)
Another issue which appears when physicists work in the social sciences is that they are not typically used to dealing with data containing large amounts of noise. The result of this is that many physicists lack the statistical training required to properly analyse data of this type. As an example, most physicists (myself included) are unlikely to have been introduced to a p-value during the course of their undergraduate studies. The result of this is that physicists may do a poor job when interacting with real data in the field – this leads to a vast gap between theoretical models and data.
In contrast to the above, some physicists have had some great successes working in alongside the boundaries of physics and economics. For example, they have introduced the technique of agent-based modelling to the social sciences. Agent-based models are by no means predictive, however, they do allow researchers to career out sophisticated thought experiments which would usually be impossible for a single person. Another area that techniques inspired by physics have had some success is in nanoscale biology (reference this?), where techniques from nonequilibrium statistical mechanics have made some less unambiguous progress.
The lecture was concluded by attempting an answer to the question posed at the beginning: In general it is somewhat a matter of taste, however, if one is willing to properly get involved in understanding progress that has already been made in another discipline then your efforts may pay off. On the other hand, sometimes interesting results can come about when specialists in two disciplines come together and exchange ideas that neither of them would have come across independently.