I understand," says Schwinger, "and I admit that QFT has not solved the causality problem. But at least it has localized the probability aspect to a single event called field collapse-an event that is not covered by the equations of QFT. That is to say {Schwinger's favorite expression}, QFT itself is causal, but it only takes us so far. At some point a discontinuous event takes place that is not covered by the theory. It is possible that at some time a theory will be developed for field collapse and it may turn out to be causal after all. On the other hand, it may be that it is a truly probabilistic process, and perhaps God does play dice with the world. Either way, it doesn't detract from what QFT has accomplished.
( Rodney A. Brooks )
[ Fields of Color: The theory ]
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