| Not to tut-tut too much, because it is interesting the extent to which a lot of science is older than any of us tend to think[1], but this isn't so hard. You need two measurements: 1. A count of days. Have your acyolytes put a rock in a jar every morning, whatever. Tedious, but easy. 2. A measurement of the sun's highest[2] angle each day. Harder, but not that hard. Put a stick in the ground and have the acolytes spend their lunch carefully moving a pebble to see how close the shadow gets to the base of the stick, then carefully paint the ground to show where the pebbles have been. Change the color each year. If it's cloudy, paint a line between the dots to interpolate. Do this for four years. You'll note that the highest point of the fourth year is 4x365+1 days, give or take. Do it for a decade or two and you'll see that 365.25 isn't quite right either because you're still a little off. It requires patience and rigor, but those aren't modern inventions. [1] While a lot of it, including most of medicine, is much younger than we'd expect. [2] Or lowest. But acolytes prefer to do their tedious stuff in the summer, lest they start engaging in idolatry and moon worship or whatever. |