A Working Library
Applied Mathematics
The handful of plain ideas that quietly run the world — taken one at a time, from the first principle all the way out to the machine it ends up inside.
Here's a funny thing about the mathematics that actually gets used: it's really a small handful of ideas, each one wearing a dozen different costumes. So that's what we'll do here — take them one at a time. Build each one up from nothing, find the single move that makes it useful, and then chase it out into the wild, into the places it earns its keep: money, signals, learning machines, falling balls, networks straining under load. And we won't just talk about it — every section is yours to poke at. Read the idea, then grab a slider and watch the whole thing move.
Contents
-
Geometric Series
Take a number and shave it by the same fraction, over and over — that's the whole idea. And yet it prices a bond that pays you forever, smooths the jitter out of a noisy sensor, discounts tomorrow's rewards, and tells you whether a viral loop will catch fire or quietly run out of breath — and, when you're not careful, exactly how it lies to you.
-
More ideas on the way — one costume at a time.