Ciro Santilli @cirosantilli 37

It is hard to overstate how low the level of this conference seems to be at first sight. Truly sad.

Nice looking and expensive operating system by Apple. Ciro Santilli believes that:

The story of how OS X was ported to x86 from PowerPC with large initial work up to boot by a single man in the year 2000, John Kullmann, is really worth reading: www.quora.com/Apple-company/How-does-Apple-keep-secrets-so-well/answer/Kim-Scheinberg on Quora, see also:

An algebra over a field where division exists.

Shows up when trying to solve 2D wave equation on a circular domain in polar coordinates with separation of variables, where we have to decompose the initial condition in termes of a fourier-Bessel series, exactly like the Fourier series appears when solving the wave equation in linear coordinates.

For the same fundamental reasons, also appears when calculating the Schrödinger equation solution for the hydrogen atom.

Biography of Enrico Fermi by fellow physicist, free rent on the on the Internet Archive: archive.org/details/enricofermiphysi0000segr

Examples:

This section talks about solvers/simulators dedicated solving the wave equation. Of course, any serious solver will likely be able to solve a wider range of PDE, so this section contains mostly fun toys. For more serious stuff see: Section "PDE solver".

JavaScript toy solvers:

Related:

Start with: Section "String polarization".

Then go to: Section "Polarization of light".