Quantum weirdness: How real is reality? Matt!!! (Introduction)

by David Turell , Monday, January 11, 2016, 19:49 (3027 days ago) @ David Turell

This article discusses the philosophic ontological and epistemological approaches to quantum mechanics:-http://www.npr.org/sections/13.7/2016/01/05/462010293/how-real-is-reality-"But when physicists began probing the realm of the atom, the behavior they found was very weird and very different from what's observed for macro-scale objects like billiard balls and planets. In response to this dilemma, the founders of quantum created a new kind of mathematical physics that could describe what was seen in experiments. More importantly, this mathematics predicted the outcome of experiments with astonishing accuracy — basically the equivalent to firing a rifle bullet from New York City at a target in Los Angeles and nailing the bull's eye to within the width of a dime. It was that good.-"The only problem was that no one knew how to interpret the mathematics.-"This meant there was no simple way for understanding what the mathematics was describing. It couldn't tell us what, for example, an electron was — in-and-of-itself. And if we couldn't picture the stuff making up reality (like electrons) then we must still be in the dark about reality itself.-***-"For the first camp, the mathematics directly describes a reality that is independent and objective. In this view, quantum mechanics is an ontological theory (ontology is the branch of philosophy dealing with what truly exists). For the second camp, however, the mathematics of quantum mechanics describes only our knowledge of the world. For these folks, quantum physics is an epistemological theory (epistemology is the branch of philosophy dealing with what human beings know and how they know it).-"Ontology vs. Epistemology: the world in-and-of-itself vs. just our knowledge about the world. The split between these camps can get pretty contentious. That's because most physicists start off as ontologists. When we're young we get excited about our equations. We think they are so powerful they seem to be like "thoughts in the mind of God," pointing to a truth that lies beyond the daily concerns and limitations of human life.-***-"The problem with all these interpretations is that, in general, there remains no way to distinguish between them experimentally. All anyone can do is argue philosophical positions based on, well, philosophy.-"In a few cases, however, so-called "no-go" theorems have been proven — turning out to be enormously powerful. A no-go theorem tells scientists when certain kinds of physical situations are fundamentally impossible to achieve given the laws we understand. For example, in 1964 John Bell derived a set of relations (the Bell Inequalities) that could distinguish between true quantum weirdness and the possibility of a more classical "normal" reality hidden beneath what was seen in experiments. Experiments using Bell's no-go theorem eventually showed that quantum weirdness ruled.-"More recently there has been so-called PBR theorem (which has nothing to do with hipster beer but, instead, was named after its creators Matthew Pusey, Jonathan Barrett and Terry Rudolph). PBR is also a no-go theorem that appeared to eliminate an entire class of epistemological interpretations for quantum physics. It was a very big deal — and its meaning is still being debated. But the PBR theorem didn't eliminate the most epistemological of epistemological interpretations. This is the so-called Copenhagen view that claims there is no way to talk about the world having any properties in-and-of-itself. In the Copenhagen interpretation, electrons don't have intrinsic properties like position or spin. It's only the act of measurement that makes the electrons take on specific values of these properties.-"So which is it? Does the world have an intrinsic ontology? Is there something out there independent of us that has specific properties in-and-of-it? Or is it all a mush of potential and possibility about which only our knowledge takes on a stable form?-"The fundamental question remains. How real is reality?"-Comment: Any thoughts?