Documentary film Updated +Created
Double-slit experiment Updated +Created
Amazingly confirms the wave particle duality of quantum mechanics.
The effect is even more remarkable when done with individual particles such individual photons or electrons.
Richard Feynman liked to stress how this experiment can illustrate the core ideas of quantum mechanics. Notably, he night have created the infinitely many slits thought experiment which illustrates the path integral formulation.
Dojo learning model Updated +Created
k-nearest neighbors algorithm Updated +Created
One of the most simply classification algorithm one can think of: just see whatever kind of point your new point seems to be closer to, and say it is also of that type! Then it is just a question of defining "close".
Ampere in the 2019 redefinition of the SI base units Updated +Created
Starting in the 2019 redefinition of the SI base units, the elementary charge is assigned a fixed number, and the Ampere is based on it and on the second, which is beautiful.
This choice is not because we attempt to count individual electrons going through a wire, as it would be far too many to count!
Rather, it is because because there are two crazy quantum mechanical effects that give us macroscopic measures that are directly related to the electron charge. www.nist.gov/si-redefinition/ampere/ampere-quantum-metrology-triangle by the NIST explains that the two effects are:
Those effect work because they also involve dividing by the Planck constant, the fundamental constant of quantum mechanics, which is also tiny, and thus brings values into a much more measurable order of size.
Don't repeat yourself Updated +Created
Klein-Gordon equation in Einstein notation Updated +Created
The Klein-Gordon equation can be written in terms of the D'alembert operator as:
so we can expand the D'alembert operator in Einstein notation to:
Cowan-Reines neutrino experiment Updated +Created
Gas chromatography Updated +Created
This technique is crazy! It allows to both:
  • separate gaseous mixtures
  • identify gaseous compounds
You actually see discrete peaks at different minute counts on the other end.
It is based on how much the gas interacts with the column.
Detection is usually done burning the sample to ionize it when it comes out, and then you measure the current produced.
The procedure remind you a bit of gel electrophoresis, except that it is in gaseous phase.
Video 1.
Gas chromatography by Quick Biochemistry Basics (2019)
Source.
Video 2.
How I invented the electron capture detector interview with James Lovelock by Web of Stories (2001)
Source. He mentions how scientists had to make their own tools during the 40s/60s. Then how gas chromatography was invented at the National Institute for Medical Research and gained a Nobel Prize. Lovelock came in improving the detection part of things.
Kondo effect Updated +Created
If you adda bit of impurities to certain materials, at low temperatures of a few Kelvin their resistivity actually starts increasing if you go below a certain critical temperature.
Figure 1.
Kondo effect graph for gold with added impurities
. Source.
Knowledge graph as a component of AGI Updated +Created
Related:
E. Coli genome starting point Updated +Created
The conventional starting point is not at the E. Coli K-12 MG1655 origin of replication.
biocyc.org/ECOLI/NEW-IMAGE?type=EXTRAGENIC-SITE&object=G0-10506 explains:
This site is the origin of replication of the E. coli chromosome. It contains the binding sites for DnaA, which is critical for initiation of replication. Replication proceeds bidirectionally. For historical reasons, the numbering of E. coli's circular chromosome does not start at the origin of replication, but at the origin of transfer during conjugation.
If it is a bit hard to understand what they mean by "origin of transfer" though, as that term is usually associated with the origin of transfer of bacterial conjugation.
E. Coli K-12 Updated +Created
E. Coli K-12 MG1655 gene of unknown function Updated +Created
UniProt for example describes YaaX as "Uncharacterized protein YaaX".
As function is discovered, they then change it to a better name, e.g. to names such as the E. Coli K-12 MG1655 transcription unit thrLABC proteins all of which have a clear name due to threonine.
There are many other y??? as of 2021! Though they do tend to be smaller molecules.
Kosovo War Updated +Created
Korean drama Updated +Created
www.nytimes.com/2023/07/09/world/asia/north-korea-china-defectors.html
North Korea keeps itself cut off from the internet and sends these highly trained specialists to do work in China, Southeast Asia and elsewhere to avoid international sanctions imposed on the country for its nuclear weapons program. The specialists usually live together in dormitory apartments, where they are instructed to spy on each other. Their North Korean minders look for signs of disloyalty - like watching K-dramas.
K-drama, the ultimate symbol of resistance. Epic.
Eigenvalues and eigenvectors Updated +Created
Kudos Updated +Created
Ahh, Ciro Santilli was certain this was some slang neologism, but it is actually Greek! So funny. Introduced into English in the 19th century according to: www.merriam-webster.com/dictionary/kudo.
Ł Updated +Created
Video 1.
Exploring! the Special Letters of the Polish Alphabet: Ls by Polish Girl Next Door (2021)
Source.

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