Devlog #4 — Heavy Elements Cut, Liquid Hydrogen Locked In

Lead and titanium were off by 50%. I didn’t hide it.

My model tracks how particles slow down inside matter. For heavy elements like lead and titanium, you need a correction for the atom’s electron shells — skip it, and your numbers drift by half the actual value. I haven’t built that correction yet. Faking the results to look clean would gut the whole point of the model. So heavy elements are out for now.

Liquid hydrogen sits at the opposite extreme. One electron, no shell complexity — the model handles it without shortcuts. I checked against NIST’s official proton data: 0.14% deviation across the full energy range. In physics terms, that’s a bullseye.

Five Materials, One Hierarchy

I ran five materials together — liquid hydrogen, methane, polyethylene, water, and aluminum — and tested them as a chain. Two things had to hold: thicker shielding means lower dose, and going from hydrogen to aluminum, dose has to climb, because light elements stop protons better.

Both held, with no exceptions. Polyethylene and water differ by just 3% in electrons per gram — the model caught even that gap correctly.

The sharpest result: at 40 g/cm², liquid hydrogen cuts dose by 44% compared to aluminum. That’s why some spacecraft designs wrap the crew compartment in hydrogen tanks — fuel and radiation shield in one.

All five materials are now locked into regression tests. Total: 103 green tests in CI.

One Function, One Truth

The dashboard and the generated reports used to calculate their numbers separately. Two parallel code paths mean two places for drift to appear. Now both pull from a single shared function. The number on screen and the number in the report are physically incapable of disagreeing.