Physics

Prof. Ram Ramaswamy
Jawaharlal Nehru University, New Delhi

Abstract :
Chance is crucial in a diverse range of situations. To paraphrase
Monod (1971), nature relies on chance and not on destiny. Depending on the context, chance can mean different things to different people.A chance event may either be a consequence of
intrinsic fluctuations, or may be due to incomplete or imprecise
knowledge. The notion of contingency is closely tied into that of
chance, and thus uncovering the underpinnings - whether this is due to underlying stochastic phenomena or underlying chaotic dynamics - is of great interest.

Using examples from dynamical systems theory, I will discuss the role of chance when there are several coexisting dynamical attractors, with attractor basins that are intermingled in a complex manner. Small uncertainties in determining the initial state can lead to very large uncertainties in the outcomes. Intrinsic noise, on the other hand,plays a major role in small systems where the dynamics is stochastic.

Both phenomena occur in biological systems and are exploited, at a systems level, in different ways. On the one hand, chance provides the possibility of complex dynamical states such as chimeras, and on the other, chance allows for stochastic switching both in the realm of dynamics within a cell or within a population.