Ciro Santilli @cirosantilli 37

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Mantou Updated 2025-07-16

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Quantum field theory lecture by Tobias Osborne (2017) / Lecture 3 Updated 2025-07-16

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www.youtube.com/watch?v=cj-QpsZsDDY&list=PLDfPUNusx1EpRs-wku83aqYSKfR5fFmfS&index=3

symmetry in classical field theory
from Lagrangian density we can algorithmically get equations of motion, but the Lagrangian density is a more compact way of representing the equations of motion
definition of symmetry in context: keeps Lagrangian unchanged up to a total derivative
Noether's theorem
youtu.be/cj-QpsZsDDY?list=PLDfPUNusx1EpRs-wku83aqYSKfR5fFmfS&t=3062 Lagrangian and conservation example under translations
youtu.be/cj-QpsZsDDY?list=PLDfPUNusx1EpRs-wku83aqYSKfR5fFmfS&t=3394 same but for Poincaré transformations But now things are harder, because it is harder to describe general infinitesimal Poincare transforms than it was to describe the translations. Using constraints/definition of Lorentz transforms, also constricts the allowed infinitesimal symmetries to 6 independent parameters
youtu.be/cj-QpsZsDDY?list=PLDfPUNusx1EpRs-wku83aqYSKfR5fFmfS&t=4525 brings out Poisson brackets, and concludes that each conserved current maps to a generator of the Lie algebra
This allows you to build the symmetry back from the conserved charges, just as you can determine conserved charges starting from the symmetry.

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Audio file format Updated 2025-07-16

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Data file format Updated 2025-07-16

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Git tips / gitk Updated 2025-07-16

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For the newbs.

Slick? No. But gitk does the job, like any one of the other 100 billion free Git UI viewers out there

gitk master HEAD

https://raw.githubusercontent.com/cirosantilli/media/master/gitk.png

Many IDEs are also implementing this now (e.g. VS Code, Eclipse. Most free IDE GIt implementations are still crap, but that is the future, because you want to edit, view history, edit, view history, commit, edit.

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Japanese film Updated 2025-07-16

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markdownlint/markdownlint Updated 2025-07-16

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github.com/markdownlint/markdownlint

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Mars exploration Updated 2025-07-16

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Model organism Updated 2025-07-16

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prokaryote models:
- E. Coli: the most well studied
- mycoplasma: a very minimal genus, notable species: Mycoplasma genitalium
eukaryote
- S. cerevisiae: simplest eukaryote model. Unicellular.
- C. elegans: simplest multicellular organism model
- vertebrate:
  - Zebrafish: simplest vertebrate model
  - mammal:
    Mus musculus: simplest mammal model

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Protein of unknown function Updated 2025-07-16

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Video file format Updated 2025-07-16

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Climatology Updated 2025-07-16

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Harry Potter Updated 2025-07-16

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List of file formats Updated 2025-07-16

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Mars sample-return mission Updated 2025-07-16

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Not done yet as of 2020! Will be done one day for sure.

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Massachusetts Institute of Technology Updated 2025-07-16

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Prussian Academy of Sciences Updated 2025-07-16

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Published as session reports of the Royal Prussian Academy of Sciences at Berlin.

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Qsynth Updated 2025-07-16

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Qt front-end for FluidSynth.

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Mate choice Updated 2025-07-16

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MathBook XML Updated 2025-07-16

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github.com/rbeezer/mathbook

XML, ain't nobody ever going to write that manually.

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