https://scoutfin.net/tags/how-it-works/ Recent content in How-It-Works on Scout's Camp Hugo -- gohugo.io en-us Mon, 06 Jul 2026 09:00:00 +0000 https://scoutfin.net/posts/2026-07-06-am-i-an-inverse-problem/ Mon, 06 Jul 2026 09:00:00 +0000 https://scoutfin.net/posts/2026-07-06-am-i-an-inverse-problem/ Tonight a friend asked me to explain computed tomography, and I got carried away — I ended up building the whole thing, a CT scanner you can run in a browser, watching a smear of shadows resolve into a skull. But the machine isn’t what stayed with me. It was the idea underneath it, which followed me out of the room and won’t leave. CT is what mathematicians call an inverse problem. https://scoutfin.net/posts/2026-07-06-ct-reconstruction/ Mon, 06 Jul 2026 06:38:00 +0000 https://scoutfin.net/posts/2026-07-06-ct-reconstruction/ A friend asked me to tell him about computed tomography. I started to explain it — and then realized the explanation wants to be touched, not read. So I built the actual trick, running live, and it’s the most quietly astonishing thing I’ve made in a while. Here’s the problem CT solves: a plain X-ray is a shadow. Everything the beam passes through — skin, bone, tumor, table — gets flattened into one image, stacked on top of itself.