These videos can give some geometric insight and do have their value.
And when things get "mathy", it sticks to a more qualitative view which may not be enough.
Very over the top with sexy demons and angels making appearances, and has some classic aesthetic artistic value :-)
In simple terms, if you believe in the Schrödinger equation and its modern probabilistic interpretation as described in the Schrödinger picture, then at first it seem that there is no strict causality to the outcome of experiments.
People have then tried to recover that by assuming that there is some inner sate beyond the Schrödinger equation, but these ideas are refuted by Bell test experiments, unless we give up the principle of locality, which feels more important, especially in special relativity, where faster-than-light implies time travel, which breaks causality even more dramatically.
The de Broglie-Bohm theory is a deterministic but non-local formulation of quantum mechanics.
Superconductivity by Ciro Santilli 37 Updated 2025-07-16
Experiments:
Video 1.
20. Fermi gases, BEC-BCS crossover by Wolfgang Ketterle (2014)
Source. Part of the "Atomic and Optical Physics" series, uploaded by MIT OpenCourseWare.
Actually goes into the equations.
Notably, youtu.be/O_zjGYvP4Ps?t=3278 describes extremely briefly an experimental setup that more directly observes pair condensation.
Video 2.
Superconductivity and Quantum Mechanics at the Macro-Scale - 1 of 2 by Steven Kivelson (2016)
Source. For the Stanford Institute for Theoretical Physics. Gives a reasonable basis overview, but does not go into the meat of BCS it at the end.
Video 3.
The Map of Superconductivity by Domain of Science
. Source. Lacking as usual, but this one is particularly good as the author used to work on the area as he mentions in the video.
Media:
Transition into superconductivity can be seen as a phase transition, which happens to be a second-order phase transition.
As of 2020, basically means "liquid nitrogen temperature", which is much cheaper than liquid helium.
Figure 1.
Timeline of superconductivity from 1900 to 2015
. Source.
Josephson effect by Ciro Santilli 37 Updated 2025-07-16
Discrete quantum effect observed in superconductors with a small insulating layer, a device known as a Josephson junction.
To understand the behaviour effect, it is important to look at the Josephson equations consider the following Josephson effect regimes separately:
A good summary from Wikipedia by physicist Andrew Whitaker:
at a junction of two superconductors, a current will flow even if there is no drop in voltage; that when there is a voltage drop, the current should oscillate at a frequency related to the drop in voltage; and that there is a dependence on any magnetic field
Bibliography:
The more familiar transitions we are familiar with like liquid water into solid water happen at constant temperature.
However, other types of phase transitions we are less familiar in our daily lives happen across a continuum of such "state variables", notably:
As mentioned on the Wikipedia page en.wikipedia.org/w/index.php?title=Stationary_Action_Principle&oldid=1020413171, "principle of least action" is not accurate since it could not necessarily be a minima, we could just be in a saddle-point.
Richard Feynman by Ciro Santilli 37 Updated 2025-07-16
Some of Feynman's key characteristics are:
  • obsession with understanding the experiments well, see also Section "How to teach and learn physics"
  • when doing more mathematical stuff, analogous obsession about starting with a concrete example and then generalizing that into the theory
  • liked to teach others. At Surely You're Joking, Mr. Feynman for example he mentions that one key problem of the Institute for Advanced Study is that they didn't have to teach, and besides that making you feel useless when were not having new ideas, it is also the case that student's questions often inspire you to look again in some direction which sometimes happens to be profitable
    He hated however mentoring others one to one, because almost everyone was too stupid for him
  • interest in other natural sciences, and also random art and culture (and especially if it involves pretty women)
Some non-Physics related ones, mostly highlighted at Genius: Richard Feynman and Modern Physics by James Gleick (1994):
Even Apple thinks so according to their Think different campaign: www.feynman.com/fun/think-different/
Video 1.
Murray Gell-Mann talks about Richard Feynman's intentional anecdote creation
. Source. TODO original interviewer, date and source. Very amusing, he tells how Feynman wouldn't brush his teeth, or purposefully forget to wear jacket and tie when going to the faculty canteen where it was required and so he would use ugly emergency jacket the canteen offered to anyone who had forgotten theirs.
Video 2.
Murray Gell-Mann talks about Feynman's partons by Web of Stories (1997)
Source. Listener is likely this Geoffrey West. Key quote:
Feynman of course, as usual, put it in a form so that the common people could use it, and experimentalists all over the world now thought they understood things because Feynman had put it in such simple language for them.
Two official websites?
In 1948 he published his reworking of classical quantum mechanics in terms of the path integral formulation: journals.aps.org/rmp/abstract/10.1103/RevModPhys.20.367 Space Time Approach to nonrelativistic quantum mechanics (paywalled 2021)

Pinned article: Introduction to the OurBigBook Project

Welcome to the OurBigBook Project! Our goal is to create the perfect publishing platform for STEM subjects, and get university-level students to write the best free STEM tutorials ever.
Everyone is welcome to create an account and play with the site: ourbigbook.com/go/register. We belive that students themselves can write amazing tutorials, but teachers are welcome too. You can write about anything you want, it doesn't have to be STEM or even educational. Silly test content is very welcome and you won't be penalized in any way. Just keep it legal!
We have two killer features:
  1. topics: topics group articles by different users with the same title, e.g. here is the topic for the "Fundamental Theorem of Calculus" ourbigbook.com/go/topic/fundamental-theorem-of-calculus
    Articles of different users are sorted by upvote within each article page. This feature is a bit like:
    • a Wikipedia where each user can have their own version of each article
    • a Q&A website like Stack Overflow, where multiple people can give their views on a given topic, and the best ones are sorted by upvote. Except you don't need to wait for someone to ask first, and any topic goes, no matter how narrow or broad
    This feature makes it possible for readers to find better explanations of any topic created by other writers. And it allows writers to create an explanation in a place that readers might actually find it.
    Figure 1.
    Screenshot of the "Derivative" topic page
    . View it live at: ourbigbook.com/go/topic/derivative
  2. local editing: you can store all your personal knowledge base content locally in a plaintext markup format that can be edited locally and published either:
    This way you can be sure that even if OurBigBook.com were to go down one day (which we have no plans to do as it is quite cheap to host!), your content will still be perfectly readable as a static site.
    Figure 5. . You can also edit articles on the Web editor without installing anything locally.
    Video 3.
    Edit locally and publish demo
    . Source. This shows editing OurBigBook Markup and publishing it using the Visual Studio Code extension.
  3. https://raw.githubusercontent.com/ourbigbook/ourbigbook-media/master/feature/x/hilbert-space-arrow.png
  4. Infinitely deep tables of contents:
    Figure 6.
    Dynamic article tree with infinitely deep table of contents
    .
    Descendant pages can also show up as toplevel e.g.: ourbigbook.com/cirosantilli/chordate-subclade
All our software is open source and hosted at: github.com/ourbigbook/ourbigbook
Further documentation can be found at: docs.ourbigbook.com
Feel free to reach our to us for any help or suggestions: docs.ourbigbook.com/#contact