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Anarchaeologist t1_ja9j59e wrote

Pick a spot and watch the sun rise. Now put a post in the ground in between the spot you are standing and the point on the horizon the sun rose above.

Now stand on that spot day after day (some days will be too cloudy to see the sun, but keep it up and you'll see a trend.) At first, depending on the season and the hemisphere you're in, you'll see the point on the horizon the sun's rising above move in one direction. But one day it will reverse. Put a post between your standing spot and the farthest in that direction the sun rose above the horizon. This may take a few years to see because of cloudy days, but eventually you'll have it nailed down.

This extreme is called the solstice. There are two of them in a year, and they mark the start of summer or winter. They have either the shortest or longest period of daylight depending on the season.

Now watch for about 6 months more from your spot, and you'll find another extreme point on the other side of your first post. This is the other solstice. Put a post there.

You'll find that it takes 365 sunrises to make the complete cycle through both solstices.

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Lower_Departure_8485 t1_ja9s7a6 wrote

There's a mound builder site near Saint Louis where they used that exact method. There is a central observation point then posts laid in circles around it. Some of the posts align perfectly with the solstices others with planting times.

Even without the sticks in the ground most people who spend a lot of time outdoors would notice the pattern of the sun shifting across the sky and daylight changes.

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Nwcray t1_ja9xpcf wrote

Cahokia. It’s one hell of an interesting place. I used to go on elementary school field trips every year, so didn’t realize how special it was until I went back as an adult. But wow, it’s a cool place.

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