The fog that was not

In macroscopic systems, we can use classical mechanics to describe an object's motion with precise knowledge of where the object is and where it is going. But the microscopic world is governed by the laws of quantum mechanics, which rob us of this precision. We can no longer simultaneously predict the object's position and momentum, or its energy measured over a finite period of time. We accommodate this by recognizing two of the most powerful and yet indigestible concepts: the uncertainty principle and the particle–wave duality of matter.