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Demons Don't Die

Topic: Demons Don’t Die

Speaker: K. P. N. Murthy, School of Physics, University of Hyderabad, Hyderabad 500046, India

Date & Time: Monday, June 13, 2011, 2:00 PM

Place: Room 140 VMC (Chambers Hall)

I am going to talk about one of Maxwell’s mischiefs. In the year 1857Maxwell proposed an entity that violates the second law of thermodynamics. Ever since the entity is christened Maxwell’s demon. In this talk I shall tell you of the origin of the second law of thermody-namics, various ways of stating it and what it implies. It is one law that hasnot yet been proved; nor is their any experiment in which it is violated.

A consequence of the second law is that it is impossible to extract work from an isolated equilibrium system. Maxwell considered a box full of equi-librium gas with a partition in the middle. There is a hole in the partition guarded by a demon. The demon opens the door only when a fast moving molecule tries to go from right to left and a slow moving molecule from left to right. In this way it manages to create a temperature gradient. A Carnot’s engine operating between hot left partition and cold right partition would extract work. The demon can thus defeat the second law. Ever since, Maxwell’s demon has been haunting the physics community. Several attempts have been made to vanquish the demon. In fact at least on two occasions the demon was pronounced dead. But then the demon didn’t die. In this talk I shall tell you of the story of the demon and its various disguises. In particular I shall tell you of some very recent developments that relate equilibrium free energies to non equilibrium work fluctuations.


K. P. N. Murthy is a professor at the School of Physics, University of Hyderabad. He is also the coordinator of the academic a_airs of the Centre for Modeling, Simulation and Design (CMSD). His research interests include Monte Carlo methods in statistical physics and in radiation transport; random walks and _rst passage time problems in regular and disordered lattices; self avoiding walks; stochastic processes;nonlinear dynamics and chaos etc. K.P.N.Murthy did his doctoral work at University of Hyderabad on uctuation phenomena in model non-equilibrium systems. He has carried out post-doctoral research at the Juelich Research Centre on random walks in regular and disordered lattices. He was at the Indira Gandhi Centre for Atomic Research in the theoretical studies section of the Materials Science Division. In the year 2006 he shifted to the University of Hyderabad. His principal research contributions include work on exponential biasing in Monte Carlo simulation of radiation transport; analytical expression for the mean _rst passage time of random walks on lattices with quenched disorder; phenomenological model for studying phase transition in liquid crystals con_ned to the pores in a random network; interacting growth walk model for generating compact self avoiding walks; non-Boltzmann Monte Carlo simulation; and at histogram algorithm in the context of interacting self avoiding walks. Prof. K.P.N.Murthy has published over two hundred papers in journals and conferences.

Refreshments will be served at 1:45 PM