Natural units Updated 2025-07-16
A series of systems usually derived from the International System of Units that are more convenient for certain applications.
Named small order polynomial Updated 2025-07-16
Named algebraic equation Updated 2025-07-16
Naive Lie theory by John Stillwell (2008) Updated 2025-07-16
Nabla symbol Updated 2025-07-16
As if Greek letters weren't enough, physicists and mathematicians also like to make up tons of symbols, some of which look like the could actually be Greek letters!
Music teenager Ciro Santilli liked to listen to Updated 2025-07-16
Lower teens, before discovering more hardcore stuff that is more genial and adult-venerable:So a base mix of what you migth expect from a regular male teenager born in 1989 Brazil.
The following are also adult venerable though :-)
And no, the opening sentence "Some of those that work forces" is not understandable: ell.stackexchange.com/questions/262444/what-is-the-meaning-of-the-phrase-that-work-forces-in-rage-against-the-machine
Musician Updated 2025-07-16
Music by country Updated 2025-07-16
Municipal Market of São Paulo Updated 2025-07-16
But as of 2020, it is completely surrounded by extremely poor people, to the point that it makes you scared if you stand out in any way by showing any kind of middle/upper class wealth, or being a foreigner.
The market is basically a touristic spot that no person in Sao Paulo will ever go to (unless they are young, single, and can just walk in there by themselves) in the middle of this surreal environment.
In 2020 Ciro was there with his wife on a touristic visit. Living in Europe at the time, he felt even more privileged. So they went to a fruit stand, and the man started giving his wife amazing free samples of very exotic fruit, some of which Ciro had never tasted himself, without saying the price. It did feel like he was giving out too much for free. Then Ciro decided of course to buy some more fruits to pay for the show, which was a nice show. Then while buying, it came out a bit more expensive than would have been reasonable, but Ciro was too dazzled by the speed and noises, and he paid for it. Later on, he told his wife about it, and how he felt that they had added some ultra-expensive bulk fruits that were of a clearly lower level than the gold nuggets of the free samples (especially for Brazil's cost standards). The presenter was an extremely crafty con artist, and Ciro felt like they had specifically preyed on Ciro Santilli's self perceived compassionate personality, because it was apparent that those men were underprivileged and fighting for their living day by day with those over-expensive fruits. This was an extremely valuable lesson, Ciro was glad that it was learnt at a relatively low cost on that occasion.
Nested set model Updated 2025-07-16
This is particularly important in SQL: Nested set model in SQL, as it is an efficient way to transverse trees there, since querying parents every time would require multiple disk accesses.
The ASCII art visualizations from stackoverflow.com/questions/192220/what-is-the-most-efficient-elegant-way-to-parse-a-flat-table-into-a-tree/194031#194031 are worth reproducing.
As the sets:
__________________________________________________________________________
| Root 1 |
| ________________________________ ________________________________ |
| | Child 1.1 | | Child 1.2 | |
| | ___________ ___________ | | ___________ ___________ | |
| | | C 1.1.1 | | C 1.1.2 | | | | C 1.2.1 | | C 1.2.2 | | |
1 2 3___________4 5___________6 7 8 9___________10 11__________12 13 14
| |________________________________| |________________________________| |
|__________________________________________________________________________|Consider the following nested set:
0, 8, root
1, 7, mathematics
2, 3, geometry
3, 6, calculus
4, 5, derivative
5, 6, integral
6, 7, algebra
7, 8, physics Multi-Omics Model and Analytics Updated 2025-07-16
By Tagkopoulos lab at University of California, Davies.
- www.nature.com/articles/ncomms13090 Multi-omics integration accurately predicts cellular state in unexplored conditions for Escherichia coli (2016)
- www.sciencedaily.com/releases/2016/10/161027173552.htm
Multimedia software Updated 2025-07-16
Multicellular organism Updated 2025-07-16
MuJoCo getting started Updated 2025-07-16
Tested on Ubuntu 23.10;
git clone https://github.com/google-deepmind/mujoco
cd mujoco
git checkout 5d46c39529819d1b31249e249ca399f306a108ac
mkdir -p build
cd build
cmake ..
make -jNow let's play. Minimal interactive UI simulation of a simple MJCF scene with one falling cube:Test soure code: github.com/google-deepmind/mujoco/blob/5d46c39529819d1b31249e249ca399f306a108ac/sample/basic.cc. The only thing you can do is rotate the scene with the computer mouse it seems. Mentioned at: mujoco.readthedocs.io/en/2.2.2/programming.html#sabasic
bin/basic ../doc/_static/hello.xmlSome more interesting models can be found under the
model/ directory: github.com/google-deepmind/mujoco/tree/5d46c39529819d1b31249e249ca399f306a108ac/model E.g. the imaginary humanoid robot DeepMind used in many demos can be seen with:bin/basic ../model/humanoid/humanoid.xmlA more advanced UI with a few controls:Test soure code: github.com/google-deepmind/mujoco/tree/5d46c39529819d1b31249e249ca399f306a108ac/simulate. Mentioned at: mujoco.readthedocs.io/en/2.2.2/programming.html#sasimulate
bin/simulate ../doc/_static/hello.xmlA very cool thing about that UI is that you can manually control joints. There are no joints in the hello.xml, but e.g. with the humanoid model:under "Control" you move each joint of the robot separately which is quite cool.
bin/simulate ../model/humanoid/humanoid.xmlThere's also a Mentioned at: mujoco.readthedocs.io/en/2.2.2/programming.html#sarecord but TODO that produced a broken video, related issues:
bin/record test executable that presumably renders the simulation directly to a file:bin/record ../doc/_static/hello.xml 5 60 rgb.out
ffmpeg -f rawvideo -pixel_format rgb24 -video_size 800x800 -framerate 60 -i rgb.out -vf "vflip" video.mp4 Muhammad Ali Updated 2025-07-16
MUD (game genre) Updated 2025-07-16
Proxima Centauri Updated 2025-07-16
It is so close that we can notice its proper motion, and its distance to us will vary significantly across a few tens of thousands of years!
Projective elliptic geometry Updated 2025-07-16
Each elliptic space can be modelled with a real projective space. The best thing is to just start thinking about the real projective plane.
Projective plane Updated 2025-07-16
Projective space Updated 2025-07-16
The definition is to take the vector space, remove the zero element, and identify all elements that lie on the same line, i.e.
The most important initial example to study is the real projective plane.
There are unlisted articles, also show them or only show them.