LA-UR Updated 2025-07-16
Publicly released documents from the Los Alamos National Laboratory are marked with this identifier. This is for example the case of each video on ther YouTube channel: www.youtube.com/@LosAlamosNationalLab. E.g. Video "Historic, unique Manhattan Project footage from Los Alamos by Los Alamos National Lab" is marked with "LA-UR 11-4449".
www.osti.gov/biblio/1372821 contains "How to Get an LA-UR: Using RASSTI to Release Your Work" which is of interest: permalink.lanl.gov/object/tr?what=info:lanl-repo/lareport/LA-UR-17-26023. That document documents the acronym's expansion, plus it leaks some internal-only URLs such as lasearch.lanl.gov/oppie/service.
TODO is there somewhere you can search for the document for a given identifier? Some PDFs are listed at: sgp.fas.org/othergov/doe/lanl/index2b.html
Black Hat Briefings Updated 2025-07-16
LC circuit Updated 2025-07-16
When Ciro Santilli was studying electronics at the University of São Paulo, the courses, which were heavily inspired from the USA 50's were obsessed by this one! Thinking about it, it is kind of a cool thing though.
That Wikipedia page is the epitome of Wikipedia failure to explain things in a way that is of any interest to any learner. Video 1. "Tutorial on LC resonant circuits by w2aew (2012)" is the opposite.
Tutorial on LC resonant circuits by w2aew (2012)
Source. - youtu.be/hqhV50852jA?t=239 series LC circuit on a breadboard driven by an AC source. Shows behaviour on oscilloscope as source frequency is modified. We clearly see voltage going to zero at resonance. This is why thie circuit can be seen as a filter.
- youtu.be/hqhV50852jA?t=489 shows the parallel LC circuit. We clearly see current reaching a maximum on resonance.
Introduction to LC Oscillators by USAF (1974)
Source. - youtu.be/W31CCN_ZF34?t=740 mentions that LC circuit formation is the root cause for Audio feedback with a quick demo. Not very scientific, but cool.
LC circuit by Eugene Khutoryansky (2016)
Source. Exactly what you would expect from an Eugene Khutoryansky video. The key insight is that the inductor resists to changes in current. So when current is zero, it slows down the current. And when current is high, it tries to keep it going, which recharges the other side of the capacitor. Blade server Updated 2025-07-16
HP Blade Server by Brian Kirsch (2013)
Source. Featuring an HP DL380 blade server, presumably an older model of this series: buy.hpe.com/uk/en/servers/proliant-dl-servers/proliant-dl300-servers/proliant-dl380-server/hpe-proliant-dl380-gen10-server/p/1010026818.
In the video we can see that it contains RAM, disk storage, we are told about two CPUs, and networking interfaces, so it is a complete computer on its own. He also explains that unlike typical rack servers, each blade unit does not have its own coolers and power supply related hardware, which goes instead on the chassis.
Lean (proof assistant) Updated 2025-10-14
Source code:
- github.com/leanprover/lean4 why a separate repo per version... but it is what it is.
- github.com/leanprover/lean
They are huge fans of Unicode characters! Check this out from a formal proof of the prime number theorem: github.com/AlexKontorovich/PrimeNumberTheoremAnd/blob/fbdbb5310d036d33b9797b35f3b04b08f2447a6e/PrimeNumberTheoremAnd/ZetaBounds.lean
Their dependency graph thingy is just beautiful however: alexkontorovich.github.io/PrimeNumberTheoremAnd/web/dep_graph_document.html
Leanpub Updated 2025-07-16
Founder: Peter Armstrong
ruboss.com/ documents their stack, a somewhat similar choice to OurBigBook.com as of 2021, notably Next.js. But backend in Ruby on Rails. They actually managed Apollo/GraphQL, which Ciro Santilli would have liked, but din't have the patience for.
The founder/CEO Peter Armstrong www.linkedin.com/in/peterburtonarmstrong/ He looks like a nice guy.
Learn in public Updated 2025-07-16
This is the most extreme and final form of peer tutoring, it's natural final consequence given the Internet Age.
Lebesgue integral of is complete but Riemann isn't Updated 2025-07-16
is:
- complete under the Lebesgue integral, this result is may be called the Riesz-Fischer theorem
- not complete under the Riemann integral: math.stackexchange.com/questions/397369/space-of-riemann-integrable-functions-not-complete
And then this is why quantum mechanics basically lives in : not being complete makes no sense physically, it would mean that you can get closer and closer to states that don't exist!
Bloons Tower Defense 5 Updated 2025-07-16
One of Ciro Santilli's favorites.
Blue (university sport) Updated 2025-07-16
Bohr-Sommerfeld model Updated 2025-07-16
Refinement of the Bohr model that starts to take quantum angular momentum into account in order to explain missing lines that would have been otherwise observed TODO specific example of such line.
They are not observe because they would violate the conservation of angular momentum.
Introduces the azimuthal quantum number and magnetic quantum number.
Browser MMORPG Updated 2025-07-16
Browse S3 bucket on web browser Updated 2025-07-16
They can't even make this basic stuff just work!
Lawrence Livermore National Laboratory Updated 2025-07-16
Founded partly due to the influence of Edward Teller who thought Los Alamos National Laboratory was not making good progress on thermonuclear weapons, large part of which was developed there.
Butterfly dream Updated 2025-07-16
Chapter 2 paragraph 14:
Formerly, I, Zhuang Zhou, dreamt that I was a butterfly, a butterfly flying about, feeling that it was enjoying itself. I did not know that it was Zhou. Suddenly I awoke, and was myself again, the veritable Zhou. I did not know whether it had formerly been Zhou dreaming that he was a butterfly, or it was now a butterfly dreaming that it was Zhou. But between Zhou and a butterfly there must be a difference. This is a case of what is called the Transformation of Things.'
C3 Oxford physics course Updated 2025-07-16
- web.archive.org/web/20170907092044/http://www2.physics.ox.ac.uk/students/course-materials/c3-condensed-matter-major-option it wasn't paywalled in the past up to 2017, but later became. Bastards.
- www2.physics.ox.ac.uk/sites/default/files/page/2011/10/04/c3-intro-vacprobs17-41753.pdf gives the 2016 structure:
- Crystal Structure & Dynamics 10 lectures Dr Roger Johnston
- Band Theory 10 lectures Prof Michael Johnston
- Magnetism 7 lectures Prof Radu Coldea
- Optical Properties 6 lectures Prof Laura Herz
- Superconductivity 7 lectures Dr Peter Leek and Dr Amalia Coldea. web.archive.org/web/20170912021658/http://www2.physics.ox.ac.uk/sites/default/files/page/2011/10/04/cmpsc-handout-2017-41006.pdf
Cabbage (Csound) Updated 2025-07-16
Caenorhabditis elegans Updated 2025-07-16
- www.cell.com/cell-systems/fulltext/S2405-4712(16)30120-X
- www.cell.com/cell-systems/fulltext/S2405-4712(16)30151-X A Genome-Scale Database and Reconstruction of Caenorhabditis elegans Metabolism Gebauer, Juliane et al. Cell Systems , Volume 2 , Issue 5 , 312 - 322
Caesium standard Updated 2025-07-16
Uses the frequency of the hyperfine structure of caesium-133 ground state, i.e spin up vs spin down of its valence electron , to define the second.
International System of Units definition of the second since 1967, because this is what atomic clocks use.
TODO why does this have more energy than the hyperfine split of the hydrogen line given that it is further from the nucleus?
Cambridge Updated 2025-07-16
The city appear to exist there because it was a convenient crossing of the Cam. It also lies near the start of the ancient navigable section TODO towards north or south? Castle hill also offered a convenient fortification location near the river, and is part of the reason for the early Roman settlement. The original bridge was presumably in the current Magnalene bridge, just under the castle hill.
TODO why did the University of Oxford scholars flee to after the The hanging of the clerks in 1209? Why not anywhere else?
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