Emergence of simple laws

In statistical physics it is seen that universal and fairly simple overall laws often emerge even in systems whose underlying molecular or other structure can be quite complicated. The basic origin of this phenomenon is the averaging effect of randomness discussed in Chapter 7 (technically, it is the survival only of leading operators at renormalization group fixed points). The same phenomenon is also seen in quantum field theory, where it is essentially a consequence of the averaging effect of quantum fluctuations, which have a direct mathematical analog to statistical physics.