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Ansuz07 t1_ja9fxsq wrote

Solar altitude: the angle of the sun relative to the Earth's horizon, measured in degrees. This changes over the course of the year, with altitude at its highest in the summer and lowest in the winter.

Once you are capable of measuring solar altitude (which isn't that difficult) you can track it every day. If you do that, you'll quickly realize that it changes on a predictable ~365-day loop.

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GermaneRiposte101 t1_ja9zipk wrote

And, for reasons to do with farming (planting crops/harvesting/etc) there was a very real need to learn this.

People were not stupid in olden times: they just had less knowledge.

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whereisfatherjack t1_jaa0257 wrote

Less technology

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thatthatguy t1_jab9pmu wrote

They knew what was relevant to them. More personal experience kind of knowledge than book larnin’. When your livelihood depends on finding edible plants and tracking animals to hunt you het pretty good at recognizing patterns in the weather and seasons. I might be able to say that there are just under 365.25 days in a solar year. A hunter gatherer will know that when the rains stop you have only a few days to move camp to where the herd likes to come through. But harvest as many of the funny blue berries as you can before you leave because they’ll be gone before you come back.

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Smallpaul t1_jabrm0f wrote

Both. They had neither the content of Wikipedia nor the technology to store it.

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whereisfatherjack t1_jac01n1 wrote

They had a lot of the content and they stored it verbally, through songs and poems.

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Smallpaul t1_jact4ov wrote

They had a tiny fraction of the content. They didn’t know what an atom was, not a galaxy, nor a continent, a complex number, etc.

They may have had wisdom about how to run their societies, live a good life and live in their local environment, but that is not the same as having vast global knowledge.

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darklegion412 t1_jaaflwp wrote

>you'll quickly realize that it changes on a predictable ~365-day loop.

Quickly, being relative here.

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RighteouslyNeutral t1_jabpbtz wrote

It wasn't even always that complicated, it is easy to observe the seasons. You always know what season it is because you know what the last season was. You are going to know winter is on its way just based on however many years you have observed it. It wouldn't be like people who didn't keep track of years wouldn't know to prepare for winter. Then you have things like the zodiac, where they simply observed where the sun was in relation to the stars behind it and drew significance with what that might have meant based on the season and significant climate or weather events and so on.

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Successful_Box_1007 t1_jaayq46 wrote

Cool AF! Didn’t know that they were able to track and measure they solar altitude! How did they do this with their rudimentary tools?

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redvillafranco t1_jab7ala wrote

You can just look at where on the horizon the sun rises/sets every day. On the first day of summer, the sun rises the furthest north in the northern hemisphere. So you just count the days until it rises that far in the north again.

Also, you can measure the highest point of the sun in the sky each day. If you have the same length stick or rock on the ground. On the first day of summer, at high noon, the shadow will be its shortest length of the whole year. So you can just count the days until the shadow is that short again.

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Successful_Box_1007 t1_jab7kef wrote

And the ancients just assumed this meant that the earth had made a full rotation (or in their eyes, the sun had)? I mean why did they settle on that assumption? I am sure one could have made a dozen others.

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yogert909 t1_jab8ny7 wrote

They didn’t necessarily care about the rotation of the earth. They cared about how long until they should plant their crops again.

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redvillafranco t1_jab8rba wrote

They knew that a cycle of 365 days had passed. And this period of time was extremely consistent and repeatable. And they called that cycle a “year”. But they didn’t necessarily need to know what was causing the cycle.

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AliMcGraw t1_jabaz04 wrote

There was a NOVA episode just a few weeks ago that demonstrated exactly how people could do this with very simple tools! (Like, stick in the ground simple.)

The records they were sharing and recreating were from the last 1,000 years, but it's not appreciably different from what Eratosthenes did, and what we assume older calendar-making societies did. And they demonstrated so beautifully exactly how it works, A+++ go watch the show and then plant your own stick in the ground to measure sun things!

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PlanetLandon t1_jabiddd wrote

It doesn’t really take anything special. If you have eyes and something to write with you can keep track of where the sun rises every day.

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Successful_Box_1007 t1_jabk5wa wrote

True but isn’ the variation super small all things being equal (including time of day you measure)? With their rudimentary tools it must have been tough.

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TheSkiGeek t1_jabknby wrote

Yeah, but you only need to get close. It’s okay if you’re off by a day or two if all you’re using it for is to decide when to plant and harvest crops.

If you’re staying in one place for a while you can set up more permanent solutions. Structures like Stonehenge have notches and openings that line up with the sun position in different seasons, so you can tell exactly which day is the solstice or equinox (or whatever days are important to you).

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p_m_a_t_t t1_jabkoi0 wrote

Just because a tool is 'rudimentary' doesn't mean it doesn't work!

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Mr_Mojo_Risin_83 t1_jabucot wrote

remember, there was no telly or movies or anything at this time. this sort of knowledge would have been carried by everyone in the tribe. this is the sort of thing they could have devoted time to every single day.

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A_Meal_of_Pain t1_jackbxl wrote

And the tools necessary to make these measurements are very simple. Literally all you need is a stick in the ground and a few pebbles or something else to mark the longest shadow the stick casts each day.

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