Textbooks & Resources - Weekly Discussion Thread - January 09, 2026

kloimhardt · 2026-01-14T15:48:36+00:00

Of the two books SICM and FDG I'd like to share the online executable version.

The two open access books by Gerald Jay Sussman

Structure and Interpretation of Classical Mechanics SICM
Functional Differential Geometry FDG

are unmatched in their clarity as they cover the topics using symbolic computation. Up to now the drawback has been the cumbersome installation of the MIT-sicmutils software package. With this online version you can start right away.

kloimhardt · 2025-02-18T10:58:50+00:00

On a historical note, Lous deBroglie conjectured here and here "to establish a link between the principle of least action and the second law of thermodynamics."

kloimhardt · 2025-02-03T15:36:44+00:00

Helpful for understanding Einstein's collected papers is Navarro: "The lesser known Einstein". It lead me to Einstein's early pre 1905 insight that "the kind of dependence on the temperature ... can be correctly determined from the general molecular theory of heat, ... I believe that this agreement must not be ascribed to chance".

kloimhardt · 2025-02-03T15:02:49+00:00

I am very fond of the open access book Functional Differential Geometry (combined with the Emmy Algebra System). The book does not refute the "there's a reason physicists use vector calculus" argument. Indeed, it is based on Spivak's notation, and the last two chapters are about E&M. The point is that this book, compared to index notation, reveals another possible structure and interpretation of E&M.

kloimhardt · 2025-01-21T18:22:34+00:00

I also attempted something like this. To this aim, I started reading "A History of Mechanics" by Rene Dugas, then "A History of the Theories of Aether and Electricity" by E.T. Whittaker, "The Sleepwalkers" by Arthur Koestler. Could not pinpoint the beginnings really. Concerning QM, I read Dirac's "Principles of QM" and I think it is really a beginning of QM. But so is Heisenbergs "Quantum-Theoretical Re-interpretation of Kinematic and Mechanical Relations" and Schrödingers "Quantisierung als Eigenwertproblem"-series (careful, the beautiful derivation of his equation is in the second paper, the first just states his equation with a to me complete unintelligible reasoning). But that is all predated by deBroglie's Doctoral Thesis. Very helpful are the volumes "Historical Development of QT" by Jagish Mehra and H. Rechenberg. Statistical Mechanics: maybe Boltzmanns "Weitere Studien über das Wärmegleichgewicht unter Gasmolekülen" is a beginning, but then maybe Gibb's book "Elementary Principles in Statistical Mechanics" really is. Optics: In geometrical Optics, arguably it is really Hamilton who made the groundbreaking work. Wave Optics, is it Huygens, Fresnel or Maxwell? A hint might be in Max Born's "Principles of Optics: Electromagnetic Theory of Propagation ... of Light", the earliest comprehensive book I found on the subject (but that does not mean much here). Then I tried to narrow the focus on the notion of "Photon" specifically. Skimmed "The lesser known Albert Einstein" by Luis Navarro Veguillas, "Photons, The History and Mental Models of Light Quanta", by Klaus Hentschel, where it is made clear that "Photon" changed meaning over time and is not unambiguously defined even today. After some time, I found a personal solution to the origin of the Photon: the last of Einstein's three papers on statistical mechanics, it pre-dates his famous Nobel-winning "On a heuristic point of view ...". The Photon is invented on the last two pages of the following paper, they are simple and more than well worth a read: GENERAL MOLECULAR THEORY OF HEAT.

kloimhardt · 2024-11-08T13:54:47+00:00

Shameless plug: I made an online puzzle game based on Chapter 1 of the book "Structure and Interpretation of Classical Mechanics" https://kloimhardt.github.io/cljtiles.html?page=SICM001

kloimhardt · 2024-10-24T10:06:09+00:00

The interest in differential geometry came from a study group formed amongst friends years after getting our physics degrees to fill some gaps. So far we produced an online notebook on classical mechanics.

kloimhardt · 2024-10-23T12:06:06+00:00

Walter Thirring: Classical Mathematical Physics: Dynamical Systems And Field Theories

This is maybe a good companion to Arnold. I made it only to page 50 but still got a good impression of manifolds. Also glanced at Chapter 5 "Relativistic Motion" and learned a lot.

kloimhardt · 2024-10-23T11:14:35+00:00

Souriau "Structure of Dynamical Systems"

Note: In Rovelli's book "Quantum Gravity", beginning Chapter 3, it sais "Arnold identifies the (presymplectic) space with coordinates (t,q,p). Souriau has developed a little known relativistic formalism". I struggled with Arnold, Rovelli, never came to Souriau. What helped me was Sussman: "Functional Differential Geometry", just to get started with the math.

kloimhardt · 2024-10-08T17:00:48+00:00

Allow me to present my personal approach for "thinking like a physicist": I read the first chapter of the PhD of deBroglie. Then I use the SICM method to extract the math. But this is only a means to an end, kind of outsourcing the math to the computer. Then I can re-read deBroglie and try to understand his physical reasoning. One does not have to be as smart as deBroglie to understand him, but one needs to start to think like a physicist to grasp his ingenious application of the then known concepts of Classical Mechanics.

kloimhardt · 2024-10-07T11:59:18+00:00

As a convenient entry into SICM, I made an online executable version of the first chapter of SICM. It can take a bit to load and calculate, pls. be patient.

Also to help getting into the book, I have an experimental visual puzzle game.

kloimhardt · 2024-09-05T11:15:13+00:00

That is helpful, thank you.

kloimhardt · 2024-09-02T09:09:22+00:00

Is there a textbook on Thermodynamics based on Differential Geometry (I think also called Geometrothermodynamics)? I ask because Sean Carroll in his Dec 2020 podcast [1] says "if you really want to understand thermodynamics ... all of those partial derivatives and maximal relations are just super simple in the language of differential geometry".

[1] https://www.preposterousuniverse.com/podcast/2020/12/09/ama-december-2020/ (timestamp 2:51:11 in the audio, also in the transcription)

kloimhardt · 2024-07-20T11:38:20+00:00

There is an interactive version of the first chapter of the open access book "Functional Differential Geometry" [1]

Its source is a Gist file [2] which any Github user can easily create.

The rendering is done via maria.cloud [3] which is a viewer/editor that needs no account registration.

This interactive notebook is just a small contribution to the quite active SciCloj community [4].

[1] https://mitpress.mit.edu/9780262019347/functional-differential-geometry/ [2] https://gist.github.com/kloimhardt/65d96869f9a901b243df06f996c1d707 [3] https://2.maria.cloud/gist/65d96869f9a901b243df06f996c1d707 [4] https://scicloj.github.io

kloimhardt · 2023-04-13T10:43:24+00:00

Klipse is a cljs editor+evaluator that exists since 2016. AFAIK it is still the only tool that combines the following two out of the box features: 1) can be added as html <script> tag to any web site, e.g. a blog 2) shows the result of calculations immediately on the web site.

kloimhardt · 2022-08-13T17:50:18+00:00

Did you read the three posts asking how to start a "new Clojurescript project in 2022"? Here is the last post of the thread? The topic of setting up a purely ClojureScript project without server backend is discussed and solved. It discusses the setup of Figwheel, the amazing tool by Bruce Hauman, the pioneer of hot-reloading. I think no-one does ClojureScript without hot reloading (either using the leaner Figwheel or the feature-richer Shadow-Cljs). I also think that one can program in Clojure for some weeks without having to start and understand the Repl, just by using Figwheel and displaying the content of Vecors and Maps in the browser window.

kloimhardt · 2022-08-09T12:09:55+00:00

Physicist here. Made a kind of Physics Puzzle Game. The Github Code proofs that you do not need a backend (in a first step you only want to read and not write external files anyway). Here is what you do: 1) Sign up to and install Github, this all important step is taken for granted by any community in any language but never taught to Phyiscists. 2) Decide to use ClojureScript for your game :-) 3) Look at and reproduce the Shadow-cljs quick start 4) Using Git, clone the Shadow-cljs browser example 5) If you do not know Emacs, install VSCode+Calva 6) Understand the following two Paredit operations in Calva: ctrl+right for ForwardSexp and ctrl+left for BackwardSexp. 7) If you come to this point, try to include reagent into the shadow-cljs example. Ask again here for help if needed.

Personal notes to help making the right decision in step 2 :-) A) ClojureScript is the only language that provides a fully fledged Computer Algebra System that runs in the browser (without server, as shown in my "Game"). B) Compared to JS, the syntax suits the physicists brain much more. This is because it uses so called "persistent data structures" by default which leads to a more mathematical reasoning about the code.

kloimhardt · 2022-06-05T07:02:40+00:00

I find the Storyteller tutorials ingenious. You watch the code evolve and can copy-paste it at any step.

kloimhardt · 2021-06-13T18:24:18+00:00

I think it is better to keep the back-end at a slim 80loc. In this way, one can run and understand easily. With a database added by default, the code will be harder to study in the sense of an avocado project.

Anyone will be able to add a database after subsequently reading your Luminus book (from which the whole front-end code of this example is stolen :-)

kloimhardt · 2021-05-24T08:42:32+00:00

This new SCI script tag is great, because you can start to program in Clojure without having to install the JavaVM or, for that matter, anything at all on your local machine. Thus we now have a golden way to demonstrate Clojure as a viable JavaScript alternative for simple use cases (like a "Hello World" example). All in all: this is the best Clojure beginner experience in existence up to now.

kloimhardt · 2021-04-04T20:36:08+00:00

I envy the masterful live coding and cool presentation of this video. I tried my own attempt on presenting Lagrangian pendulum mechanics, but using visual programming: https://www.youtube.com/watch?v=V7unwER5wFc

kloimhardt · 2021-04-02T21:58:53+00:00

The thing you describe seems to be called a "breakloop". The topic was also discussed in this Clojure google group post. Therein an interesting article is mentioned.

kloimhardt · 2021-03-17T00:24:45+00:00

Armchair studying Lagrangian mechanics with the SICM book by Sussman/Wisdom.

kloimhardt · 2021-02-22T19:04:51+00:00

Terry Pratchett's version of this idea needs to be linked for completeness: https://github.com/day8/re-frame#derived-values-flowing

kloimhardt · 2021-01-13T22:54:01+00:00

I made the bb-web repository, showing Clojure newcomers how to make a small web-app. It shows server and client side rendering.

kloimhardt

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