Ciro Santilli @cirosantilli 37

Oh, and if it weren't enough, mathematicians have a separate name for the damned nabla symbol : "del" instead of "nabla".

TODO why is it called "Del"? Is is because it is an inverted uppercase delta?

Originally by Springer, but later moved to the European mathematical society.

A wiki that gathers mathematical proofs.

URL: proofwiki.org/wiki/Main_Page

MediaWiki-based.

This appears to be the creator: github.com/externl "Joe George".

A generalized definition of derivative that works on manifolds.

TODO: how does it maintain a single value even across different coordinate charts?

Harvard University + MIT combo.

As of 2022:Fuck that.

Also, they have an ICP.

November 2023 course search:

It is a shame that they refocused to more applied courses. This also highlights their highly "managed" approach to content creation. Their 2022 pitch on front page says it all:they are focused on the highly paid character of many software engineering jobs.

But one cool point of this website is how they hire tutors to help on the courses. This is a very good thing. It is a fair way of monetizing: e-learning websites must keep content free, only charge for certification.

We define it as a linear map where the domain is the same as the image, i.e. an endofunction.

Examples:

Solving differential equations was apparently Lie's original motivation for developing Lie groups. It is therefore likely one of the most understandable ways to approach it.

It appears that Lie's goal was to understand when can a differential equation have an explicitly written solution, much like Galois theory had done for algebraic equations. Both approaches use symmetry as the key tool.