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.
Brownian motion Updated 2025-07-16
Small microscopic visible particles move randomly around in water.
If water were continuous, this shouldn't happen. Therefore this serves as one important evidence of atomic theory.
The amount it moves also quantitatively matches with the expected properties of water and the floating particles, was was settled in 1905 by Einstein at: investigations on the theory of the Brownian movement by Einstein (1905).
This suggestion that Brownian motion comes from the movement of atoms had been made much before Einstein however, and passed tortuous discussions. Subtle is the Lord by Abraham Pais (1982) page 93 explains it well. There had already been infinite discussion on possible causes of those movements besides atomic theory, and many ideas were rejected as incompatible with observations:The first suggestions of atomic theory were from the 1860s.
Further investigations eliminated such causes as temperature gradients, mechanical disturbances, capillary actions, irradiation of the liquid (as long as the resulting temperature increase can be neglected), and the presence of convection currents within the liquid.
Tiny uniform plastic beads called "microbeads" are the preferred 2019 modern method of doing this: en.wikipedia.org/wiki/Microbead
Original well known observation in 1827 by Brown, with further experiments and interpretation in 1908 by Jean Baptiste Perrin. Possible precursor observation in 1785 by Jan Ingenhousz, not sure why he wasn't credited better.
Observing Brownian motion of micro beads by Forrest Charnock (2016)
Source. 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!
BSHUNTER: Detecting and Tracing Defects of Bitcoin Scripts Updated 2025-07-16
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
Busy beaver Updated 2025-07-16
The busy beaver game consists in finding, for a given , the turing machine with states that writes the largest possible number of 1's on a tape initially filled with 0's. In other words, computing the busy beaver function for a given .
There are only finitely many Turing machines with states, so we are certain that there exists such a maximum. Computing the Busy beaver function for a given then comes down to solving the halting problem for every single machine with states.
Some variant definitions define it as the number of time steps taken by the machine instead. Wikipedia talks about their relationship, but no patience right now.
The Busy Beaver problem is cool because it puts the halting problem in a more precise numerical light, e.g.:
- the Busy beaver function is the most obvious uncomputable function one can come up with starting from the halting problem
- the Busy beaver scale allows us to gauge the difficulty of proving certain (yet unproven!) mathematical conjectures
Busy Beaver Challenge Updated 2025-07-16
Project trying to compute BB(5) once and for all. Notably it has better presentation and organization than any other previous effort, and appears to have grouped everyone who cares about the topic as of the early 2020s.
Very cool initiative!
By 2023, they had basically decided every machine: discuss.bbchallenge.org/t/the-30-to-34-ctl-holdouts-from-bb-5/141
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.
Linear differential equation Updated 2025-07-16
The name is a bit obscure if you don't think in very generalized terms right out of the gate. It refers to a linear polynomial of multiple variables, which by definition must have the super simple form of:and then we just put the unknown and each derivative into that simple polynomial:except that now the are not just constants, but they can also depend on the argument (but not on or its derivatives).
Explicit solutions exist for the very specific cases of:
- constant coefficients, any degree. These were known for a long time, and are were studied when Ciro was at university in the University of São Paulo.
- degree 1 and any coefficient
Poincaré sphere Updated 2025-07-16
In it, each of the six sides has a clear and simple to understand photon polarization state, either of:
The sphere clearly suggests for example that a rotational or diagonal polarizations are the combination of left/right with the correct phase. This is clearly explained at: Video "Quantum Mechanics 9b - Photon Spin and Schrodinger's Cat II by ViaScience (2013)".
MacOS Updated 2025-07-16
Nice looking and expensive operating system by Apple. Ciro Santilli believes that:
- if you want to be ripped off, just use Microsoft Windows which has more software available
- or if you want to attain Enlightenment, just use Linux, which is free and open source
Magic Aids Updated 2025-07-16
His combination of politically incorrect dirt talk with amazing quirky decks captures Ciro's imagination.
Anonymous no face-reveal.
The videos are heavily edited with all pauses cut out, which makes them very quick to watch and saves viewer time.
Modern focused, with some occasional newer formats mixed in.
When Wizards publishes several useless sets in a row without a single modern playable card, he's just forced into Standard.
Busy beaver scale Updated 2025-07-16
The Busy beaver scale allows us to gauge the difficulty of proving certain (yet unproven!) mathematical conjectures!
To to this, people have reduced certain mathematical problems to deciding the halting problem of a specific Turing machine.
A good example is perhaps the Goldbach's conjecture. We just make a Turing machine that successively checks for each even number of it is a sum of two primes by naively looping down and trying every possible pair. Let the machine halt if the check fails. So this machine halts iff the Goldbach's conjecture is false! See also Conjecture reduction to a halting problem.
Therefore, if we were able to compute , we would be able to prove those conjectures automatically, by letting the machine run up to , and if it hadn't halted by then, we would know that it would never halt.
Of course, in practice, is generally uncomputable, so we will never know it. And furthermore, even if it were computable, it would take a lot longer than the age of the universe to compute any of it, so it would be useless.
However, philosophically speaking at least, the number of states of the equivalent Turing machine gives us a philosophical idea of the complexity of the problem.
The busy beaver scale is likely mostly useless, since we are able to prove that many non-trivial Turing machines do halt, often by reducing problems to simpler known cases. But still, it is cute.
But maybe, just maybe, reduction to Turing machine form could be useful. E.g. The Busy Beaver Challenge and other attempts to solve BB(5) have come up with large number of automated (usually parametrized up to a certain threshold) Turing machine decider programs that automatically determine if certain (often large numbers of) Turing machines run forever.
So it it not impossible that after some reduction to a standard Turing machine form, some conjecture just gets automatically brute-forced by one of the deciders, this is a path to
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
C7.4 Oxford physics course Updated 2025-07-16
- qubit.guide/ HTML version od the book.
- github.com/thosgood/qubit.guide. Source code. Written in Bookdown.
- www.arturekert.org/iqis links to the lectures: www.youtube.com/@ArturEkert/playlists Well done in splitting those videos up!
- zhenyucai.com/post/intro_to_qi/
Interesting presentation cycle at Merton BTW: www.arturekert.org/teaching/merton
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