AGI-complete Updated +Created
Term invented by Ciro Santilli to refer to problems that can only be solved once we have AGI.
It is somewhat of a flawed analogy to NP-complete.
Exponential function differential equation Updated +Created
The differential equation that is solved by the exponential function:
with initial condition:
TODO find better name for it, "linear homogenous differential equation of degree one" almost fully constrainst it except for the exponent constant and initial value.
Gaussian function Updated +Created
Kibble balance Updated +Created
The Kibble balance is so precise and reproducible that it was responsible for the 2019 redefinition of the Kilogram.
Figure 1.
NIST-4 Kibble balance
. Source.
It relies rely on not one, but three macroscopic quantum mechanical effects:
How cool is that! As usual, the advantage of those effects is that they are discrete, and have very fixed values that don't depend either:
  • on the physical dimensions of any apparatus (otherwise fabrication precision would be an issue)
  • small variations of temperature, magnetic field and so on
One downside of using some quantum mechanical effects is that you have to cool everything down to 5K. But that's OK, we've got liquid helium!
The operating principle is something along:
Then, based on all this, you can determine how much the object weights.
Video 1.
How We're Redefining the kg by Veritasium
. Source.
Video 2.
The Kibble Balance, realizing the Kilogram from fundamental constants of nature by Richard Green
. Source. Presented in 2022 for a CENAM seminar, the Mexican metrology institute. The speaker is from the Canadian metrology institute
Video 3.
The Watt balance and redefining the kilogram by National Physical Laboratory
. Source. Nothing much, but fun to hear Kibble talking about his balance in beautiful English before he passed.
Matrix exponential Updated +Created
Is the solution to a system of linear ordinary differential equations, the exponential function is just a 1-dimensional subcase.
Note that more generally, the matrix exponential can be defined on any ring.
The matrix exponential is of particular interest in the study of Lie groups, because in the case of the Lie algebra of a matrix Lie group, it provides the correct exponential map.
Video 1.
How (and why) to raise e to the power of a matrix by 3Blue1Brown (2021)
Source.
ffplay multiple input files Updated +Created
For synthesized streams like sine we can do it e.g.
ffplay -autoexit -nodisp -f lavfi -i '
sine=frequency=500[a];
sine=frequency=1000[b];
[a][b]amerge, atrim=end=2
'
but it does not seem to accept multiple -i for some reason. So is there a way to open a file from some filter? E.g.:
ffplay -i tmp.wav -i tmp.mkv -filter_complex "[0:a]atrim=end=2[a];[1:v]trim=end=2[v]" -map '[a]' -map '[v]'
fails with:
Argument 'tmp.mkv' provided as input filename, but 'tmp.wav' was already specified.
Fractional quantum Hall effect for Updated +Created
Fractional quantum Hall effect for Updated +Created
AI game with natural language Updated +Created
We define this category as AI games in which agents are able to produce or consume natural language.
It dawned on Ciro Santilli that it would be very difficult to classify an agent as an AGI if tthat agent can't speak to take orders, read existing human generated documentation, explain what it is doing, or ask for clarification.
Video 1.
Human player test of DMLab-30 Select Described Object task by DeepMind (2018)
Source. This is one of the games from DeepMind Lab.
Video 2.
WorldGPT by Nhan Tran (2023)
Source. Not the most amazing demo, but it is a start.
Ain't Nobody Got Time For That Updated +Created
Video 1.
Ain't Nobody Got Time For That
. Source.
Algebraic equation Updated +Created
Algebraic number Updated +Created
Raga by time of the day Updated +Created
Indian classical musician Updated +Created
Indian classical musician by instrument Updated +Created
Cycling landscape of Cambridge's surroundings Updated +Created
Anywhere north, including NE and NW: fenlands, i.e. marshes. Quite a few quarries as well. Extremely flat, very uniform, towns often have to be on top of small hills to escape the incessant flooding. Norfolk Coast AONB is beautiful if you take a train ride first, the beaches are very wide and many of them have few people if you avoid a few very busy spots.
East and SE: rolling hills towards Suffolk and the coast. Beautiful county, both Dedham Vale AONB and Suffolk Coast AONB.
South: first one of the hilliest nearby areas around Elmdon and Arkesden, then gently going down to the lush Lee River valley.
Southwest: larger and larger cities as you move towards London. From a train starting point, you can reach the Northen Chilterns, for some serious hills.
West: mostly flat farmland until you hit the River Great Ousse.

Unlisted articles are being shown, click here to show only listed articles.