It's the old chicken vs. egg dilemma
“If the “carefully placed” towers enabled this ancient civilization to predict the time of year within two or three days, how did they previously predict the time of year accurately within two or three days to know where to carefully place and build the towers that would enable them to predict the time of year within two or three days?”
Near to these are a couple natural straight ridges with outcroppings sticking up and similarly arranged and aligned. I would theorize that previous solar observations of these natural ridges and outcroppings inspired the more accurate man made structure to be built closer to the main complex.
“how did they previously predict the time of year accurately within two or three days to know where to carefully place and build the towers that would enable them to predict the time of year within two or three days?”
You ask such embarrassing questions!
But it’s a good question. If you knew there was a periodic event how would you go about determing more accurately and repeatedly the point in time of the maximun and minimum of the event?
Well, I imagine you start out just putting a stick in the ground or something each day lined up with the sunrise. Then after 365 days you notice that the sun is rising in the same place you put the first stick. After that the rest is easy.
Probably starts with natural objects. Folks noticing that when you stand here the sun rises behind that tree on a day when this other stuff happens. Then eventually they start working things out probably with sticks, or piles of small stones. Get it worked out and make the more permanent towers. This kind of stuff was the work of years. But the tribes who pulled it off knew stuff, like when the migratory birds were coming, the right time to plant, and thrived.
The statement isn't very accurate. I live in a house that has a view of the sunsets from my porch. After just one or two years It was easy to find where the end towers would be placed by just watching the sunsets from my porch. Since the towers seem to be evenly spaced, it would then be just a matter of spacing them between the end points.
However, the sun doesn't move across the horizon at an even pace. The distance changes very slowly at each end point, and most quickly at the solstices in the middle. The towers would have to be spaced accordingly to make up for this. That would make the tower spacing very complicated without algebra and geometry.
Trial and error no doubt. I can’t imagine conducting a “scientific” experiment that would take numerous years to figure out. I was going to say “I hope they used sticks or something” - but over the course of a year the sticks would have blown away, been damaged, etc. So I suppose they did use large rocks or something.
Interesting that there are 13 towers. 12 spaces (months!?) between each tower.
Maybe all they did was have a few large rocks near the ends of the sun’s travel and noted where it stopped, and then divided the time up accordingly? With another special rock when the sun was at its highest point??