“In 1927, Werner Heisenberg showed that uncertainty is inherent in quantum mechanics. It is impossible to simultaneously measure certain properties of a particle—position and momentum. In the quantum world, matter can take the form of either particles or waves. Fundamental elements are neither particles nor waves but can behave as either and are merely different theoretical ways of picturing the quantum world. Inexactness marks an end to certainty. As we seek to measure one property more precisely, the ability to measure the other property is undermined. The act of measurement negates elements of our knowledge of the system. Inexactness undermines scientific determinism, implying that human knowledge about the world is always incomplete, uncertain, and highly contingent. Inexactness challenges causality. As Heisenberg observed: “Causality law has it that if we know the present, then we can predict the future. Be aware: In this formulation, it is not the consequence but the premise that is false. As a matter of principle, we cannot know all determining elements of the present.” Inexactness questions methodology. Experiments can prove only what they are designed to prove. Inexactness is a theory based on the practical constraints of measurement. Inexactness and quantum mechanics challenge faith as well as concepts of truth and order. They imply a probabilistic world of matter, where we cannot know anything with certainty but only as a possibility. It removes the Newtonian elements of space and time from any underlying reality. In the quantum world, mechanics are understood as a probability without any causal explanation. Albert Einstein refused to accept that positions in spacetime could never be completely known and quantum probabilities did not reflect any underlying causes. He did not reject the theory but the lack of reason for an event. Writing to Max Born, he famously stated, “I, at any rate, am convinced that He [God] does not throw dice.” But as Stephen Hawking later remarked, in terms that Heisenberg would have recognized, “Not only does God play dice, but … he sometimes throws them where they cannot be seen.” […] In his 1930 text The Principles of Quantum Mechanics, Paul Dirac contrasted the Newtonian world and the quantum one: “It has become increasingly evident … that nature works on a different plan. Her fundamental laws do not govern the world as it appears in our mental picture in any direct way, but instead they control a substratum of which we cannot form a mental picture without introducing irrelevancies.” There was a world before Heisenberg and his uncertainty principle. There is a world after Heisenberg. They are the same world, but they are different.”
— Satyajit Das, Impossible Inexactness (via ludimagister)