The 2013 Nobel Prize in Chemistry has gone to three pioneers of molecular dynamics – Martin Karplus (Harvard/Strasbourg), Michael Levitt (Stanford), and Arieh Warshel (Southern California) – “for the development of multiscale models for complex chemical systems.”
This is the kind of thing their work made possible:
In particular, multi-level simulation is needed to simulate this kind of behaviour. Quantum theory has the finest resolution, but is computationally intractable. Classical models are more computationally tractable, but inaccurate. The solution is to combine the two approaches, working at two different levels.
Similar challenges occur in other areas, such as in the tension between micro and macro models of economics. For example, agent-based models of individual purchasing decisions can predict changes in prices. However, quite different models predict the behaviour of national economies as a whole. Adequately marrying the two levels is still an unsolved problem, but simulation scientists in all fields of endeavour can take heart from the successes of chemical simulation.
See Scientific American for more on this prize.