Observation of complex behaviors in simple dissipative systems

Dr. Richard Julius Gotthard Löffler, StarPlan, Globe Institute, University of Copenhagen

Simple, far-from-equilibrium, dissipative systems involving droplets can express complex spatiotemporal patterns which result in behaviours that resemble those seen in living organisms such as chemotaxis or swarming. In this talk I will showcase a few examples of laboratory experiments with both soft and condensed matter systems that are self-propelled on aqueous surfaces. The driving force for these systems is based on the Marangoni effect where a concentration gradient of surface-active substances on a water surface or the interface between an oil-droplet and water induces a proportionate gradient in surface tension. This surface tension gradient induces a convective flow on the surface that drives the motion. Systems such as the ones presented here demonstrate that a rich reservoir of behavioural complexity can be the result of very simple physical and chemical processes. For instance, I will show how the addition of dyes to the system can modulate the interfaces and thereby also the behaviour, presenting a tool to programme behaviour to some degree. Furthermore, it is striking how easy it feels for the observer to assign imaginary non-trivial goals to these clearly non-living objects. This may indicate that these simple dissipative systems operate on the verge of goal-directed behaviour or display a primitive form of agency and could teach us about principal aspects of life and its origin.