1. Go out every morning to work in your field. 2. When the Sun rises, make a note on the same fixed piece of wood, e.g., a fence. 3. Observe the leftmost and rightmost positions, these are your solstices. 4 You can now use your fence to identify and predict solstices.

Honestly I bet you would have at least a reasonable intuition about it if you were among them. It's pretty remarkable how much our distractions and 'being indoors' all the time dulls our senses to nature.

I started doing astrophotography about three years ago. I'd always been interested in 'space' but never really spent hours upon hours out at night over the course of months actually just studying the night sky. I remember wondering as a kid how people even thought about planets or came up with these wild stories with the constellations...to me it just kind of looked like a bright field of randomly twinkling lights.

Well, when you're out every night from 10pm to 2am looking up, it all just kind of comes alive. You see everything. The motion of the planets, the elliptic upon which they travel, the gradual shift of the entire field as the seasons change, the undulations of the moon and it's varied trajectory across the sky. The shifting of the sun's set and rise and the ebb and flow of day vs night. Everything. Your mind just starts to harmonize with the rhythm of it all. It's pretty wonderful.

They could reason about the Pythagorean theorem in 2000 BC. It's not a surprise they could figure out when the sun set in 2800 BC.

It seems unintuitive today because people living in cities and towns don’t usually see sunrises and sunsets from where they live. If you had a way to easily reference the sunrise and sunset points against known horizon, it’d be very easy to tell.

> How did ancient cultures know when the solstice was

Solstice is a small thing they figured long ago, there are things they managed that are much more complex than that. In India there are whole temples dedicated to astronomy and built to align with different celestial geometries.

Probably easier to measure the location of sunsets and sunrises rather than the time?

Edit: Obviously somewhere like here in Scotland observing the sunrise is easier said than done - particularly at this time of year!

To tell it accurately of course takes work.

However if you live in the open, or have daily access to the open sky, after a while you are bound to notice.

We are so used to having a ceiling above us, so used to constructions blocking our view of the sky that this seems a feat.

I was the same till I got access to the sky. Then ... oh wait ... the sunset is shifting towards those landmarks every day. Oh wait, now its turning around to go the other way.

The total span of movement is so large, that its hard to miss unless you are on a featureless landscape or in the open sea.

I am super impressed by humans noticing and separating the planet's from the stars. Look at those stars they don't twinkle and they move funny. I guess the planets drew attention because of their brightness and by their lack of twinkle.

I’m sure you’d know that this was winter. If you line 2 sticks up with sunrise, and keep adjusting them every morning, eventually you’ll see that the sun stops rising further south and starts moving north again. You don’t need complex mathematics to work it out.