Physics (English)

This video introduces my series "Understanding Quantum Mechanics". I say a few words about why I think this series is needed and what its intended scope is. In the second half, I recommend a few books to use along with my videos. Some important comments about materialism / realism versus the scientific worldview and about the meaning of "physical" conclude the introduction. Note: For our purposes, "materialism" and "realism" have the same meaning, which is specified in the working definition presented in this video. === LINKS === Support me on SubscribeStar: https://www.subscribestar.com/edwinsteiner My YouTube channel: https://www.youtube.com/c/EdwinSteiner Physics playlist: https://www.youtube.com/playlist?list=PLaMCxumvPhAFb6JEmIDQx3w7XaN0p_YJ2 Link to episode 1: https://youtu.be/85TUPcL7aWQ Link to episode 2: https://youtu.be/7C0ggtMLRFs Link to episode 3.1: https://youtu.be/S6Z4FILJVzM Link to the video "The Meaning of Plus in Quantum Mechanics": https://youtu.be/HOjM3t7HGIk Feynman Lectures online: https://www.feynmanlectures.caltech.edu/ 3Blue1Brown's "Essence of Linear Algebra": https://youtube.com/playlist?list=PLZHQObOWTQDPD3MizzM2xVFitgF8hE_ab Notes: https://github.com/edwinst/understanding_qm Some context on Einstein's "spooky action" quote: https://hsm.stackexchange.com/a/11319 === MUSIC CREDITS === "The Rocket" by Wintergatan This track can be downloaded for free at www.wintergatan.net Free License to use this track in your video can be downloaded at www.wintergatan.net === IMAGE CREDITS === Feynman diagrams image: Original diagrams were taken from FIG 1 in: Shouhua Zhu, Next-to-leading order QCD corrections to bg → tW− at the CERN Large Hadron Collider, http://arxiv.org/abs/hep-ph/0109269v5 Image modified (ES). Cosmic Microwave Background image: Original image in "Planck’s view of the cosmic microwave background": https://www.esa.int/ESA_Multimedia/Images/2018/07/Planck_s_view_of_the_cosmic_microwave_background ESA, Planck Collaboration Image modified (ES). Abell 370 cluster image: https://hubblesite.org/contents/media/images/2018/39/4229-Image.html?keyword=ultra%20deep&news=true NASA, ESA, A. Koekemoer (STScI), M. Jauzac (Durham University), C. Steinhardt (Niels Bohr Institute), and the BUFFALO team Library image: https://commons.wikimedia.org/wiki/File:13-11-02-olb-by-RalfR-03.jpg (C) Ralf Roletschek / Roletschek.at "Science library of Upper Lusatia in Görlitz, Germany." License: Creative Commons Attribution 3.0 Unported Image modified (ES). Krusty, the Clown as Pennywise image: Selene Malfavon Instagram: @art_of_selene Used per kind permission. https://www.instagram.com/art_of_selene/?hl=en Original downloaded from: https://i.pinimg.com/736x/32/9f/95/329f9511d1e5230f50e0088a082e8543.jpg Image modified (ES). "SUPERPOSITION" illustration: https://www.nist.gov/image/superpositiongif N. Hanacek, NIST Artist's concept of quantum entanglement image: Used many times, for example in: https://www.scientificamerican.com/article/chinese-researchers-achieve-stunning-quantum-entanglement-record/ Mark Garlick, GettyImages

Episode 3 establishes the principles of quantum mechanics. In this first part, we discuss the representation of knowledge. Topics we encounter include: the uncertainty principle, the choice of the observer, the wave function, compatible and complementary observables, Born's rule, the Hilbert space and its inner product, the physical interpretation of the wave function, and the so-called "collapse" of the wave function. --- The notes contain more detailed explanations of some of the points raised in the video and some technical details: See https://github.com/edwinst/understanding_qm/blob/main/ep03_principles.pdf --- Link to episode 1: https://utreon.com/v/bzDOBUO5WVo Link to episode 2: https://utreon.com/v/o3DaZqK6QTA Link to the video "The Meaning of Plus in Quantum Mechanics": https://utreon.com/v/cICxBF09AGE CREDITS Music: "The Rocket" by Wintergatan This track can be downloaded for free at www.wintergatan.net Free License to use this track in your video can be downloaded at www.wintergatan.net

In this episode, we first explore the concepts of uncertainty and probability as aspects of the common empirical basis of classical and quantum physics. Then we formulate the basic assumptions of classical physics and their consequences, in particular classical determinism. Finally, we discuss the weird but popular metaphysics suggested by (or at least compatible with) classical physics. The first episode of this series can be found here: https://utreon.com/v/bzDOBUO5WVo https://youtu.be/85TUPcL7aWQ CREDITS Music: "The Rocket" by Wintergatan This track can be downloaded for free at www.wintergatan.net Free License to use this track in your video can be downloaded at www.wintergatan.net NOTES ---------- Notes about the phase-space formalism used in the video: See https://github.com/edwinst/understanding_qm/blob/main/ep02_classical_mechanics.pdf ---------- Notes about the "mental process": The "mental process" I explain in the video is a pedagogic cartoon version of a psychological adaptation, the roots of which are certainly much older and more nebulous than the formulation of classical mechanics. The basis for this adaptation (or illusion, if you will) is the human tendency to confuse (1) the mental abstractions that our brains build in order to represent the world of our experience with (2) the world itself. Category (1) contains the "things" we think about and that are represented in our language and in our imagination. It is also the domain of mathematical objects. Making meaningful statements about category (2) is much more difficult and it is the purpose of physical theories to make such statements that are meaningful, quantitiative, and true. While the beginnings of said "mental process" are not as obvious in reality as I make them out to be in the video (for pedagogical reasons), we can certainly say that it reached its climax with the full formulation of classical mechanics and the quantitative determinism implied by this theory. What I called the "confusion" of categories (1) and (2) in the previous paragraph is herein promoted to a quantitative identification of the physical observables from category (2) with mathematical objects from category (1). Today we know that no such identification is compatible with experiment.

What is a physical theory? — The answer is crucial for anyone who wants to understand quantum mechanics. This video is the first in a series about quantum mechanics. In this episode, we discuss the general framework of a physical theory. In particular, we look at the mutual relationships of the physical and mathematical parts of such a theory and we begin to clearly separate the concepts of known and unknown quantities. Consistency of observations is emphasized as the measure of reality of physical concepts as opposed to the mathematical definitions and rigor applied in the mathematical part of the theory. CREDITS Music: "The Rocket" by Wintergatan This track can be downloaded for free at www.wintergatan.net Free License to use this track in your video can be downloaded at www.wintergatan.net