In our time, few branches of science have taken as much public abuse as quantum physics, the study of how things behave at the atomic scale. It's not so much that people dislike the subject as they see fit to draft it in support of any given notion: quantum physics, one hears, proves that we have free will, or that Buddhist wisdom is true, or that there is an afterlife, or that nothing really exists. Those claims may or may not be true, but they do not help us at all to understand what quantum physics actually is. For that we'll want to turn to Dominic Walliman, a Youtuber whose channel Domain of Science features clear visual explanations of scientific fields including physics, chemistry, mathematics, as well as the whole domain of science itself — and who also, as luck would have it, is a quantum physics PhD.
With his knowledge of the field, and his modesty as far as what can be definitively said about it, Wallman has designed a map of quantum physics, available for purchase at his web site. In the video above he takes us on a guided tour through the realms into which he has divided up and arranged his subject, beginning with the "pre-quantum mysteries," inquiries into which led to its foundation.
From there he continues on to the foundations of quantum physics, a territory that includes such potentially familiar landmarks as particle-wave duality, Heisenberg's uncertainty principle, and the Schrödinger equation — though not yet his cat, another favorite quantum-physics reference among those who don't know much about quantum physics.
Alas, as c explains in the subsequent "quantum phenomena" section, Schrödinger's cat is "not very helpful, because it was originally designed to show how absurd quantum mechanics seems, as cats can't be alive and dead at the same time." But then, this is a field that proceeds from absurdity, or at least from the fact that its observations at first made no sense by the traditional laws of physics. There follow forays into quantum technology (lasers, solar panels, MRI machines), quantum information (computing, cryptography, the prospect teleportation), and a variety of subfields including condensed matter physics, quantum biology, and quantum chemistry. Though detailed enough to require more than one viewing, Walliman's map also makes clear how much of quantum physics remains unexplored — and most encouragingly of all, leaves off its supposed philosophical, or existential implications. You can watch Walliman's other introduction to Quantum Physics below.
Based in Seoul, Colin Marshall writes and broadcasts on cities, language, and culture. His projects include the book The Stateless City: a Walk through 21st-Century Los Angeles and the video series The City in Cinema. Follow him on Twitter at @colinmarshall, on Facebook, or on Instagram.