Understanding QFT - Episode 1: How spin was discovered
Channel: Highly Entropic Mind
Date: 2023-06-21

JJJreact

The history of Quantum Field Theory started with the discovery of spin

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Special thanks to all my patreons, but specially to:

OtiumOtiosum, Valerie Hyde, T Highfill, Ryan Roberts, Carlo Fazioli and Cookie_T and Azure Azalia

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Credits:

Script, Host, Filming, Directing, Flaying, Editing, Production: Fernando Franco Félix

Animations and graphics: Oscar Flores and Fernando Franco Félix

Special thanks to Michael Dayah for letting me use his animations from ptable.com

Special thanks to arkiv.dk for letting me use the picture of Bohr, Harald, and their mother Ellen

The song used at 50:15 is "Emotional Epic Choir" by Allen Grey and I paid for the license to use it

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Sources:

Most of the research for this video came from:

Mehra, Jagdish, and Helmut Rechenberg. The historical development of quantum theory. Vol. 1. Springer Science & Business Media, 2000.

Details about Bohr's life came from:

Pais, Abraham. Niels Bohr's times: In physics, philosophy, and polity. Oxford University Press, 1991.

Details about Bohr's work came from his essays:

Bohr, Niels. The theory of spectra and atomic constitution. CUP Archive, 1924.

I also used Griffith's book as a guide:

Griffiths, David J., and Darrell F. Schroeter. Introduction to quantum mechanics. Cambridge university press, 2018.

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Chapters:

00:00 - Intro
02:05 - Presenting: Niels Bohr
04:51 - Thomson discovers the electrons
06:47 - Why do hot things glow?
09:57 - Planck proposes the photon
13:03 - Einstein discovers the photon
16:18 - Rutherford discovers the nucleus
19:55 - Why don't electrons spiral down towards the nucleus?
22:02 - Patreon stuff
23:37 - Bohr discovers the orbits are quantized
25:41 - Spectrum saga
30:04 - Light is quantized because the orbits are quantized
34:45 - Bohr defends his model from the haters
37:01 - The answer
39:42 - Angular momentum is quantized
41:57 - Why aren't all electrons in the first orbit?
45:32 - Orientations are discovered
48:15 - Atomic structure is discovered
51:03 - Bohr almost discovers spins
52:39 - Why 8 is important in chemistry
54:23 - Bohr explains nearly all spectra
56:18 - Stern-Gerlacht experiment
01:01:24 - Anomalous Zeeman Effect
01:03:31 - Pauli proposes spin
01:04:44 - Ralph Kronig discovers spin
01:06:10 - Spin is discovered, again
01:07:18 - Outro

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Attributions for graphical resources not stated in the video itself: 

Sspeech bubbles: Image by coolvector on Freepik

https://www.freepik.com/free-vector/comic-chat-bubbles-collection_16395946.htm#query=comic%20book%20bubbles&position=2&from_view=keyword&track=ais

Science center set:  Image by pikisuperstar on Freepik 

https://www.freepik.com/free-vector/realistic-news-studio-background_35105920.htm#query=news%20studio%20background&position=1&from_view=keyword&track=ais

University classroom: Image by tohamina on Freepik 

https://www.freepik.com/free-photo/empty-conference-hall-interior-with-stage-ready-lecture-generative-ai_43297848.htm#query=university%20lecture%20realistic%20background&position=9&from_view=search&track=ais

Kid's room: Image by macrovector on Freepik

https://www.freepik.com/free-vector/teen-boy-room-interior-design-with-trendy-workspace-homework-cupboard_4015430.htm#query=kid%20s%20room%20realistic%20background&position=18&from_view=search&track=ais

Graduation cap: Image by macrovector on Freepik

https://www.freepik.com/free-vector/realistic-vector-education-cup-white_10601469.htm#query=graduation%20cap&position=6&from_view=search&track=ais

Water droplet: Image by Petar Milošević, used under cc-sa-4.0

If you are weird enough to have read this far, you may be interested to read about how Rydberg was shafted by corruption at his university:
https://mathshistory.st-andrews.ac.uk/Biographies/Rydberg/
https://mathshistory.st-andrews.ac.uk/Extras/Rydberg_application/