Category Archives: mathematics

Adventures in JavaScript: Number Bases

Here’s just a quick lit­tle JavaScript that will con­vert num­bers between dif­fer­ent bases. It grew out of the idea that num­bers in a sys­tem based on π would be much more use­ful in engi­neer­ing that the reg­u­lar old ones. Well, just because one can do it doesn’t mean it’s a good idea, but it was […]

the Gaussian beam (interactive)

The Gauss­ian beam “is a con­ve­nient, wide­spread mod­el in laser optics.” [1] It is indeed con­ve­nient that such a math­e­mat­i­cal­ly rel­a­tive­ly sim­ple mod­el can describe the evo­lu­tion of laser light in free space so well. Giv­en the wave­length of the laser, it can be described by a sin­gle para­me­ter. This can be either the beam […]

The Coupon (Sticker) Collector

Super­mar­ket chain Ede­ka cur­rent­ly runs this stick­er col­lect­ing rack­et – which used to be smurf col­lect­ing – where you get four stick­ers with ani­mal pic­tures for every €10 spent. The kids are col­lect­ing like crazy, I am told, even though the pic­tures are mediocre at best. Any­way, as geeks we don’t care much about the […]

Series Expansions

Some­thing I made back in July. Since then it shows up at the bot­tom of these here pages in the menu rib­bon, but I nev­er wrote a prop­er post about it. I guess it deserves a lit­tle more pub­lic­i­ty since I do use it quite reg­u­lar­ly. So here is my orig­i­nal descrip­tion for the cheat […]