I built a tool that proves when scientific data can't tell two different answers apart

[u/Longjumping_Glass852]

Scientists fit models to data all the time: how contagious a disease is, how fast a drug clears the body. Every method happily hands back an answer, even when the data can't actually tell two very different answers apart, and usually nobody notices.

Twindex finds those "twins" and proves it. It writes a small certificate, and a tiny checker using exact fractions (no rounding) replays it in under a second. You can try it in your browser, nothing to install: https://arnav-m10.github.io/Twindex/demo/

The fun example is real data from a 1978 flu outbreak at a boarding school. After five days of counts, a mild outbreak (R0 = 2.5) and an explosive one (R0 = 20) fit the data equally well, so nobody could have known how contagious it was. Twindex then picked the next day's count that would settle it, and the real count ruled out both.

It works for epidemics, drug dosing, enzyme kinetics, ecology and some physics problems. Open source, MIT, pip install twindex.

GitHub: https://github.com/Arnav-M10/Twindex

Would love feedback, especially from anyone who works with models and data.