Ciro Santilli once talked to a man who had been working on high-frequency trading for the last six years.
He was quite nice.
Ciro asked him in what way did he feel his job contributed to the benefit of society.
He replied that it didn't contribute at all. It was completely useless. More than that, it so completely useless, that it was even pure. A bit like advanced mathematics, but not even providing beauty for anybody outside of the company, since everything is a closely guarded trade secret, unlike mathematics which is normally published for the vanity recognition.
And so, Ciro was enlightened.
Not the same as Hermite polynomials.
Why do multiple electrons occupy the same orbital if electrons repel each other? by
Ciro Santilli 40 Updated 2025-07-16
As shown at Schrödinger equation solution for the helium atom, they do repel each other, and that affects their measurable energy.
This changes however at higher orbitals, notably as approximately described by the aufbau principle.
Boring rule that says that less energetic atomic orbitals are filled first.
Much more interesting is actually determining that order, which the Madelung energy ordering rule is a reasonable approximation to.
Equation "Hydrogen spectral series mnemonic" gives for example from principal quantum number 1 to 2 a difference:which with Planck-Einstein relation gives about 121.6 nm ( Hz), which is a reasonable match with the value of 121.567... from the NIST Atomic Spectra Database.
Setups we've tried:
- backend:
- randyscotsmithey/feathers-realworld-example-app worked with React and Vue.js
- the React setup failed as shown at: github.com/gothinkster/react-redux-realworld-example-app/issues/187
- gothinkster/django-realworld-example-app
- the Nest.js failed on Ubuntu 20.10 as per github.com/lujakob/nestjs-realworld-example-app/issues/19
- frontend:
The first chapter of the New Testament.
The cheapest and most resilient way to publish text content humanity has achieved so far.
Some tests:
- github.com/cirosantilli/jekyll-cheat: cirosantilli.com/jekyll-cheat
- github.com/cirosantilli/test-gh-pages-min: cirosantilli.com/test-gh-pages-min. Minimal version of the above.
The heart/main innovation of GitHub!
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