Submitted by Slokkkk t3_11dm4k6 in explainlikeimfive
jowie7979 t1_ja9j4de wrote
People in ancient times used observation of the moon's cycles and the sun's position to estimate the length of a year. However, it wasn't until the development of sophisticated astronomical observations that the length of a year could be determined accurately, leading to the Gregorian calendar with a year length of 365 days and a leap year of 366 days every four years.
furrykef t1_jab9rvo wrote
A year of 365 days plus a leap day every four years is actually the Julian calendar. The Gregorian calendar adds an extra rule: there is no leap day on years divisible by 100 unless it's also divisible by 400.
DressCritical t1_ja9o0yb wrote
You can measure the length of the year to within the correct number of days with a stick, the ground, a way to mark the ground, the ability to count, and patience. It does not take anything sophisticated.
incizion t1_ja9pff5 wrote
>and patience
you lost me
DressCritical t1_ja9thlm wrote
Patience is required for two things.
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You must check repeatedly during the shortest days of the year to find out on which one the shadow of the stick is the the longest at noon.
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You must keep track day after day for a year until the shortest day returns again. Until the shortest days return, however, all you need to do is to add a day to your tally.
icelandichorsey t1_ja9ph4l wrote
Except the time to do and the means to do it and have the patience and the scientific method which is not actually that old.
DressCritical t1_jaa8p1a wrote
Wanna bet?
Karahan Tepe, Turkey, the oldest known ancient site accurately aligned to the winter solstice is over 11,000 years old.
There is a site in Aberdeenshire, Scotland, with a lunar calendar that used the solstice to keep on track that is about 10,000 years old, though it is not nearly so sophisticated.
There are a number of sites in Great Britain, Mesopotamia, and at least one in Germany aligned with the solstice which are as old or older than the pyramids.
The ancient Egyptians tracked more than 4,000 astronomical events. There are a number of examples of ancient calendars and structures that were aligned with the solstice created by the Egyptians, such as the Sphinx.
Heard of Stonehenge? Tracked quite a bit more than the winter solstice. Not that old considering it appears to be 7,000 years younger than the oldest known example.
If going by technology rather than age, then in the New World, we have Machu Picchu, Chichen Itza, Chaco Canyon, and quite a few others.
Scientific method? Not required. Not even close. Not even Neolithic. Mesolithic. Some of these structures were built prior to the most recent period of the Stone Age.
icelandichorsey t1_jabmyvt wrote
Fair enough, thanks
Your original comment sounded like taking our current world (or even the world of the last 500 years) for granted. A world where enough people have the time to sit around and measure things like this and make accurate enough conclusions and then also be able to influence the hierarchy enough to make it into a "calendar".
Also they would have had to stay in one place rather than migrate long enough, again, we're talking this for granted. That's no small thing although I didn't consider organised religion who of course tick all of these boxes and have been around for thousands of years.
Anyway, your subsequent response clarified that you weren't thinking like this. Thanks
annomandaris t1_jaarnci wrote
lol, you don't need the scientific method to count 13 lunar months, 28 days, 364 days in a year. and then after a few years you would realize that your days are off a little. After a few resets, it wouldn't be hard to realize that 1 day every 4 years keeps it on track.
This would have been known and kept track of so long ago, 50K? maybe 100K years ago. They didn't have writing tools but they had pretty sophisticated markings on sticks and stuff.
AliMcGraw t1_jabbit3 wrote
Also deadass giveaway that someone is a man who doesn't know much about women and generally lacks curiosity about the world when it doesn't occur to them that a lunar cycle would be of INTENSE INTEREST and OBVIOUS USE to the 50% of humans who menstruate on roughly a lunar cycle.
"Well, I don't need to know the lunar cycle, so I don't see why ANYONE would," u/icelandichorsey harrumpfs to himself, before explaining to the woman unfortunate enough to sit next to him on public transit how science works, actually.
im_the_real_dad t1_jaciaaf wrote
So you're saying that the lunar cycle appears to be 23 days long to some women and it appears to be 33 days long to other women and to still other women the moon goes through the lunar cycle in some number of days in between?
icelandichorsey t1_jabmwj2 wrote
I'm sorry, what the actual fuck? How did you get there from my 2 lines about the scientific method? You know literally nothing abjht me. Projecting much?
Erablian t1_jabcrc5 wrote
The synodic month averages 29.53 days, quite a bit different from your 28-day month. After 13 of those, your calendar would be 9.6 days out of sync with the actual phase of the moon.
13 synodic months is about 384 days, not 364.
annomandaris t1_jaar5mo wrote
>However, it wasn't until the development of sophisticated astronomical observations that the length of a year could be determined accurately, leading to the Gregorian calendar with a year length of 365 days and a leap year of 366 days every four years
people in the Stone age would have had a lunar calendar which was 13 months of 28 days, totaling 364, and they would have realized it was offset every few years and adjusted it accordingly.
This would have been known a LONG, LONG time ago, long before writing, maybe as much as 100,000 years ago
I mean Stonehenge was made around 5000 years ago near the end of the stone age, and that was a masterpiece showing knowledge of leap days and such, and this was before any of the more advanced techniques of the bronze age like water clocks, hour glasses, and more precise sundials that showed up around 3500BC.
foolishle t1_jabqt1g wrote
The lunar month is a little over 29 days so a 13 month count is going to get out of sync with the moon phase super fast.
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