Open measurements for geometricblackness.org — the research into surfaces that are black because of their shape, not their material. V-grooves, cavities, and pyramids that trap light by bouncing it until almost none escapes.
License: CC BY 4.0 — text, data, and protocols. Reuse freely with attribution. We're not patenting a shape.
data/
specimens.csv master registry — every reading points to a specimen here
runs.csv one row per measurement session (conditions, instruments)
stagnation/ Tier-0/Tier-1 no-flow temperature runs (the $65 afternoon up)
efficiency/ Tier-2 fluid-loop operating points (the collector curve)
reflectance/ optical (integrating-sphere) measurements
schemas/ column definitions for each table
protocols/ frozen copies of the build-and-test method
scripts/validate.py checks CSV headers against the schemas (run in CI)
File naming: YYYY-MM-DD_<contributor>_<tier>.csv, one run per file, append-only (don't rewrite history).
Confirmations and contradictions welcome — negatives are most of the signal.
- No git: open a Tier-0 results issue; we transcribe and credit you.
- Pull request: add
data/<tier>/YYYY-MM-DD_<handle>_<tier>.csvmatching the schema, add any new specimens todata/specimens.csvand your session todata/runs.csv. CI validates the header.
You record raw temperatures (and irradiance if you have it); the derived columns — delta_t_rise_c, efficiency, reduced_temp_km2w — and the go/no-go comparisons are computed, not submitted. Leave them blank.
Mount grooved and flat specimens of the same coating at the same aperture (projected footprint — the fairness rule), side by side in the sun, and read how hot each gets. Bare shiny metal folded into a groove should run dramatically hotter than flat bare metal (geometry traps light); a black groove beats a black flat by a smaller margin. Full method + parts list: protocols/ and geometricblackness.org.
See CITATION.cff.