Ciro Santilli @cirosantilli  40

The period does depend on the initial height/angle, except for the very small angle approximation:

youtu.be/Ca7c5B7Js18?t=803 compares Lagrangian mechanics equation vs the direct x/y coordinate equation.

Name origin: likely because it "determines" if a matrix is invertible or not, as a matrix is invertible iff determinant is not zero.

When it exists, which is not for all matrices, only invertible matrix, the inverse is denoted:

Ahh, this dude is just like Ciro Santilli, trying to create the ultimate natural sciences encyclopedia!

Paraprasing a friend of Ciro Santilli:

Luckily, early teens Ciro Santilli was partly protected from this by Ciro Santilli's cheapness.

But Ciro distinctly remembers one day in his early teens that he couldn't sleep very well, and he got up, and the was decided that he would become the greatest Magic: The Gathering player who ever lived. Can you imagine the incredible loss that this would have been to humankind? And talk about the incredible lack of development opportunity present in poor countries, related:

In 2019, a paper proved that MTG is Turing complete with a legacy legal deck. Live demo with some hand waving: Video "I Built a COMPUTER in Magic: The Gathering by Because Science (2019)". As Ciro Santilli comments at: github.com/cirosantilli/cirosantilli.github.io/issues/42 this was an interest addition to the previous "indefinite infinite loop" e.g. as found in a Four Horsemen combo deck