Monte Carlo method has been of increasingly importance in modern science, incluing geophysics.Inverse problems are the most important issue in geophysics, which tend to have a great number of local minimums/maximums and thus require global optimization methods. Monte Carle method, which represents a variety of methods come out under the similiar idea arised in gambling.

Today we saw another approach to utilize Monte Carlo method in geophysics in forward modeling rather than inverse problems. Peter Shearer, one of the famous geophysicists in tomography, showed us how to modeling heterogenity of scale much smaller than the shortestseismic wavelength existed in practice by "phonon" method (The idea comes from forward method used to modeling photon by physicists).

As time goes, researchers in geophysics, maybe as well as other areas, attack problems with much more smaller(or larger） scale, much more complex structure. It really challenges the classic method we used to adpot perviously. The quantum mechanics implies every thing is a particle and its motion can be only be described by probability theory. Additionally, for complex structure, using statistical characteristics is a eaiser way to describe it. Therefore, Monte Carlo method and other methods based on probability and statistical theory are expected to play more important role in future.