Bromine Updated 2025-07-16
Brooks's law Updated 2025-07-16
Video 1.
The Misty Mountains Cold Scene from The Hobbit: An Unexpected Journey (2012)
Source.
I will take each and every one of these dwarves over an army from the Iron Hills. For when I called upon them they answered. Loayalty. Honour. And willing heart. I can ask no more than that.
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:
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.
The first suggestions of atomic theory were from the 1860s.
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.
Video 1.
Observing Brownian motion of micro beads by Forrest Charnock (2016)
Source.
Browser game Updated 2025-07-16
There's a beauty in the portability of browser games.
The fact that the browser is not the main gaming platform as of 2020 shows how crappy web tech is. There is no fundamental reason why it shouldn't be so.
Browser platform game Updated 2025-07-16
gobattle.io/#! 2D top down dungeon crawler/brawler, controls feel good.
bsub get job stdout and stderr Updated 2025-07-16
By default, LSF only sends you an email with the stdout and stderr included in it, and does not show or store anything locally.
One option to store things locally is to use:
bsub -oo stdout.log -eo stderr.log 'echo myout; echo myerr 1>&2'
as documented at:Or to use files with the job id in them:
bsub -oo %J.out -eo %J.err 'echo myout; echo myerr 1>&2'
By default bsub -oo:
  • also contains the LSF metadata in addition to the actual submitted process stdout
  • prevents the completion email from being sent
To get just the stdout to the file, use bsub -N -oo which:
  • stores only stdout on the file
  • re-enables the completion email
as mentioned at:
Another option is to run with the bsub -I option:
bsub -I 'echo a;sleep 1;echo b;sleep 1;echo c'
This immediately prints stdout and stderr to the terminal.
btcdeb Updated 2025-07-16
Tested on Ubuntu 23.10:
sudo apt install libtool
git clone https://github.com/bitcoin-core/btcdeb
cd btcdeb
git checkout 4fd007e57b79cba9b5ffdf5ffe599778c0d63b88
./autogen.sh
./configure
make -j
Patch submited at: github.com/bitcoin-core/btcdeb/pull/143
Then we use it;
./btcdeb '[OP_1 OP_2 OP_ADD]'
and inside the shell:
btcdeb 5.0.24 -- type `./btcdeb -h` for start up options
LOG: signing segwit taproot
notice: btcdeb has gotten quieter; use --verbose if necessary (this message is temporary)
3 op script loaded. type `help` for usage information
script  |  stack 
--------+--------
1       | 
2       | 
OP_ADD  | 
#0000 1
btcdeb> step
                <> PUSH stack 01
script  |  stack 
--------+--------
2       |      01
OP_ADD  | 
#0001 2
btcdeb> step
                <> PUSH stack 02
script  |  stack 
--------+--------
OP_ADD  |      02
        |      01
#0002 OP_ADD
btcdeb> step
                <> POP  stack
                <> POP  stack
                <> PUSH stack 03
script  |  stack 
--------+--------
        |      03
btcdeb> step
script  |  stack 
--------+--------
        |      03
btcdeb> step
at end of script
btcdeb>
Bullshit Updated 2025-07-16
Business film Updated 2025-07-16
Ciro Santilli defines a "business film" as a film about business, enterprises or entrepreneurship. Political thrillers are closed related as well.
This is one of his favorite film genres!
Some lists:
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.:
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!
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.'
B vitamin Updated 2025-07-16

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