You say that architecture CAD programs simulate things better than physical models with a lot of confidence, but I am not sure why. One way to think of this is

You say that architecture CAD programs simulate things better than physical models with a lot of confidence, but I am not sure why. One way to think of this is that the physical world is a vastly superior computer. We cannot make a fluid simulation that runs as precisely as an actual river, for example. Tribological models have to make tons of approximations since friction is insanely complicated - but the physical universe manages to calculate the real friction effect basically instantly!