Bouncing from project to project, I’m trying to figure out how a time traveler could derive standards of time, distance, and mass accurate enough that common physics and engineering formulas (G = 9.8m/s², for example) would be accurate and reproducible.

I like the idea of publishing the exact length of Cheops’ sarcophagus, so a time traveler could use that to derive a meter, but I’m sure there’s a simpler way.