These are all over the place in Norway (as are they everywhere else, presumably!)
When we moved to the island we currently live on, our address was in a road called 'Solsteinen' (The Sun Stone), but I didn't think anything of it until I realized that the roughly hewn stone serving as the property limit marker was juuu-uuust touched by the sun on Winter Solstice. Aha.
A quick call to the local archaeologist confirmed my suspicion - 'Oh, so you're the new resident there, I'd planned on being in touch - that stone monument has been there for more than 2000 years, is A-listed and please, whatever you do, don't do anything with it. Seriously.'
Oh, he works for the county, but happened to live just up the hill from us.
There's so much old stuff around here that he is basically being called out to perform an assessment every time anyone wishes to build anything.
Where we live now, for instance, there are a handful of burial mounds from God knows when (all plundered long ago), lots of old charcoal pits, a couple of late stone age fish traps in the lake in a corner of our farm.
To exaggerate just a little - where we could build our home was basically dictated by where we could find a spot noone had claimed thousands of years ago...
it seems like you moved to property on "a road called 'Solsteinen' " .. did it occur to anyone that many special local things might be built close to the stable sun stone? I would even guess that no one built a home or horse barn there because they were not allowed to by the community.. this is modern development.. using up the ancient old area for a new sale. That is the appearance from the description above.
(Nothing quite like watching an archeologist go 'Oooh, that's interesting!' during a dig to establish whether you can go ahead building on your chosen spot...)
Isn't that solved by rescue archaeology ? Here in the Czech Republic everything has been settled for many thousands of years - so you basically automatically call the archeologists for any construction, they will check the area, record any interesting findings and retrieve artifacts of interest. Then the are is free to be used for the construction project.
Something like that is happening right now here in Brno:
A massive construction project & equally massive archaeology operation - mapping the remains of old textile factories, an old channel and rail line, fish storage tanks, a mill, a villa and even a cemetery or two.
The archaeology work is wrapping up in a month or two & then the construction crews will take over the site (they already work in the areas that have been fully searched) to finish the construction project (which includes a 13 meter deep water tight "tub" due to a very shallow water table for the basement levels or 200 meter deep geothermal energy piles, etc.).
I suspect most local councils in the UK have an archaeology team and failing that there are a lot of professional consulting archaeologists - a lot (all?) large scale building works often include the need for archaeological surveys and/or remediation.
e.g. Work for what is now the Queensferry Crossing bridge uncovered a 10,000 year old home:
We also have these in Germany, in the region where I live it which is North Rhein Westfalis they are quite a common thing actually. Strongly recomment people check it out if they pass by here some time
They aren't "all over the place" in the US, and I certainly don't have a local archaeologist that I can just call up.
FWIW: The Northeastern US is quite recent with human presence. It wasn't settled until after the last ice age. Pretty much anything old is celebrated because there is so little of anything old.
> They aren't "all over the place" in the US, and I certainly don't have a local archaeologist that I can just call up… The Northeastern US is quite recent with human presence
Fun fact, New England has at least 71 different stonework “prayer sites” that are all astrologically aligned.
Two of the most notable are King Philip’s Cave (Sharon, MA) with a stone aperture through which a "dagger of light" appears specifically during the winter solstice, and Pole Hill (Gloucester, MA) which has fixed boulders that align with the summer solstice sunrise/sunset and the winter solstice sunrise.
When they built the new High School in my old home town in western CT one of the local archaeologists (day job: science teacher) did some exploration on site and discovered all sorts of stuff - no funding for a proper dig so they capped it and put up a plaque about it (ISTR they put the tennis courts on top since that disturbed it least?)
So, yeah, there's lots of archaeology in New England, it's just that a lot of it is literally buried or otherwise not called out. (And "in the US, 100 years is a long time; in the UK, 100 miles is a long distance" is also Just How It Is...)
Norway also wasn't populated until after the last ice age. As an American archaeologist, old stuff is also quite common here. The fun examples I like to use are the structures in Tucson older than Rome.
Your "local archeologist" is one of the staff at the state historic preservation society [0], though you'll likely have more luck contacting a local university archeologist if you find anything.
Ohio was populated with numerous earthworks, the Hopewell Earthworks finally being recognized as a UNESCO world heritage spot after being preserved for years by being used as a golf course. Unfortunately many of these have been lost as European settlers destroyed many of them. This continues to this day as Google is building a data center in central Ohio a top of land that was home to numerous native american burial mounds - https://www.datacenterdynamics.com/en/news/google-breaks-gro...
”You moved the cemetery, but you left the bodies, didn't you? You son of a bitch, you left the bodies and you only moved the headstones! Why? Why?” </Poltergeist>
As the other replies note, there are things. Many were destroyed though and so there is nothing to preserve. However much of North America lacks ready access to building materials that will last and so many of the natives built with organic goods that rotted away in a few decades and so there isn't much to find. You can find many flint arrowheads - but that only tells us when (about) it was made and since there are millions of them there isn't much to learn anymore.
Don't take the above as a sign that the natives were uninteresting or stupid. Just that they didn't leave much for us to learn from, both because they couldn't and because what they did was destroyed.
What I find cute is that every year on the 21st of december a small number of modern day pagans and nature lovers gather at Ales Stenar here in southern Sweden and watch the sun rise over the center stone of the "ship".
We bring thermos bottles, some bring kids, pets, and we just stand there in silence watching the sun.
Afaik it's not coordinated, it's just a bunch of people having the same idea every year.
That's.. neat. I guess lots more people show up for summer solstice though? Or are they occupied with the mainstream-pagan Midsummer celebrations then?
This reminded me of The Anasazi Sun Temple that catches the first light of the Summer Solstice in a specific point in the temple. I first discovered this watching Carl Sagan's Cosmos early this year (which I'd highly recommend, BTW)
The street I live on also has a "henge," and it's annoying as all get-out because I have to drive up a big hill with the setting sun in my face to get home.
I had tickmarks for stuff (when to go to bed to sleep for 7.5h and wake up near sunrise, things like that). I was working on adding a config file format.
Sunrise and sunset aren't in phase (or exactly out of phase). The latest sunrise and the earliest sunset don't happen on the same day and neither happens on the solstice. Not at this northern latitude anyway.
There is a temple in India called “Konark Sun Temple”, meant to be worship place of sun god.
It is built east-west to signify sun’s journey. The temple has a wheel sort of structure which kinda acts as sundial with minute level accuracy.
In India, difference in day time between winter and summer solstices is minimal ( 3.5 hours ), I guess it doesn’t signify anything major close to equator.
Depends on where in India you are from. Winter solstice times with chillai kalan [0] which is treated as a headache. Everything basically shuts down in the Western Himalayan regions of India around this time - from Ladakh to Kashmir to Upper Himachal and Uttarakhand [1], though it has gotten much drier/warmer compared to the stories my parents or grandparents told.
How did ancient cultures know when the solstice was? If you didn't tell me it was the 21st, I don't know how I'd be able to tell you other than by carefully measuring the sunrise and sunset times
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.
I have read that the auspicious date of December 25th may have been intended to be the Solstice but that the degree of error for "making a note on a fence" is why we have the 25th.
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.
Also because today we have accurate clocks and most of us don't depend on seasons for anything. Farmers care about when to plant, and a few gardeners pay attention, but for most of us nothing changes in life. (I'm carefully not counting the traditional vacations that most of us have around this time - though that is important to us and historically related, we could move the date and it wouldn't affect anything else).
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.
> 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.
They didn't like go out on Dec 21st, and look where the sun was and mark it. They didn't even have calendars like that. They watched the sun every day, and waited until it stopped being lower in the sky at it's highest point in the day (or whatever other sign of the solstice they wanted to use), and marked that angle and built whatever viewport they wanted (a door, tunnel, etc).
Then they could just go wherever they built the thing that pointed at that point in the sky, and go, oh, okay, the solstice is soon, or just happened, or whatever and plan accordingly.
It actually wasn't really accurate to the day, anyway. There are a few days on either side of the solstice where the effect is basically the same for the viewer.
Something to keep in mind is that this isn't only useful for determining the exact date of the winter solstice, which they may not have even cared that much about. You can see roughly where you are in the year on either side of the solstice by looking at how far out of alignment the sun is on a given day. So it could be useful throughout the fall and even well into the winter for gauging the passing of time. People didn't need to plan day by day or even week by week, but they did need to do things in roughly the right part of the year.
People act like this is some unexplainable advanced technology, and anybody can just do this with a stick and some rocks.
Pre technology, the sky was very central to life. Sunlight, rain and snow dictated much of your life (and death), and you probably considered the sun, moon and five planets as gods.
You and I personally may not have kept track, but our local religious leader did, and maybe the even staged a ceremony at the winter solstice to ask the sun to make the days longer.
>and you probably considered the sun, moon and five planets as gods.
I find it strange that today knowing much more about sun and moon we don't consider them as gods. Today we know for sure they are the origin of all life on this planet and yet many cultures decided to go for an abstract intangeable entities instead of what is directly in front of us and can't be debated.
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.
For very ancient people, it's the longest/shortest day.
After you notice that, if you want more precision, it's the day the Sun rises and sets most on the North/South. It's also the day things cast the largest shadow at noon. You will need some special device to get very precise on the sun raising position (like a pair of stones or something with a hole), and you won't be able to get precision on the shadow thing.
For more modern people, starting about only half a dozen millennia ago, it's the hour the Sun stops moving North/South within the stars and starts moving the other way around. You will need to look at it and take notes many times, and average things out to get any precision. Even more because you can't see the Sun and the stars at the same time, so you have to model them.
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.
Now if you disclose your local time offset from GMT, say, Palantir can send a drone carrying roses.
Of course this is meant as a joke, but wanted to emphasize how easy it is for location information to leak. And if one really doesn't care about collateral deaths how easy it is to exploit location data.
I lived briefly where the sun doesn't really shift that much in the sky. I didn't think about it at the time, but that constant noon day sun really messed with my sense of time passing. Weird.
That's regrettable yes, as any centrism. But people interested in epistemology certainly are aware of major contributions to sciences by Indian thinkers.
Biased coverage is unfortunately rather widespread in more general media. And rise of nationalisms don't help in the matter. Which is true for western and eastern countries by the way.
Regarding a case of several millennia of prior art, there is Pāṇini, who employed metalanguage long before the idea become of interest in western side.
Although western centrism is definitely a thing, the link you provided states that temple, for example, was started in the 16th century. The article link is about something from 2800BC
I don’t know if it’s related to Western-centrism or not, but I recall thinking it was weird that my English-speaking colleagues do not know the formula to solve second-degree polynomials as the “Bhaskara formula”, as we call it in Brazil.
By the way, Wolfram’s website has an interesting summary of the history of this formula.[0]
Depends on the details of how you define calculus. Archimedes was doing integration, Descartes was evaluating slopes and tangents of algebraic curves. Isaac Barrow had a good grasp of fundamental theorem of calculus -- that differentiation and integration are inverse operations. Brook Taylor did Taylor series before Newton.
Newton and Leibnitz get credit because they placed calculus as a general technique that is immensely broadly applicable not just for extrapolating the tangent function or the sin function as a series, but to any function that's smooth in some sense.
They worked out the details that do not depend on the specifics of the function and called them out as rules/results of broad applicability. Especially how to push the differential and integral operations through +,-,×,÷ and function composition sign. It did not matter what the function was as long as it was built up from those operations.
I am familiar with the work of Kerala school and also of Aryabhatta's work on using differential coefficients to extrapolate the sin function (this being much before Kerala school), his work on difference equations.
Rather than getting caught up with us versus them narratives , spend some time learning about the beauty of math and how different cultures have thought about them in such creative ways. Otherwise you risk sounding ignorant and rageful conspiracy monger.
The inaccuracies in the Hindu calendar is and was a lot more than the Julian calendar. The Julian calendar assumed that a year was 365 1/4 the day. This is slightly inaccurate and therefore there was a need to correct for the leap day that's added every 4 years by skipping it every 100 years, adding it back every 400 years. At time of Gregorian correction it was off by 10~11 days because of an error of 10 minutes in their estimate of the length of an year.
Hindu civilization's estimate of the length of an year, although remarkably accurate for its time, was less accurate than the estimate of 365 1/4th. Usually the length of an year has been overestimated, making the Hindu calendar lose accuracy quicker. These errors were order of a day per year versus off by about 10 minutes like the Julian calendar.
This was less of a problem historically because Ujjain observatory would correct the calendar time time using accurate observation of the Equinox. Since the fall of Ujjain observatory the Hindu calendar has been accumulating drift error for centuries.
The current state is such that we can, with great authority, give an exact measure of each "years" length, with every one bieng unique.
You touch on but dont quite state that math is a usefull game, but miss that reality does not use math consistantly, and we force arbitrary units and measures onto what we are trying to understand, but are still clueless as to what the nature of reality is, and how it works.
Testable theorys are thin on the ground now,Newton and his peers, past,present,here, and there, would be and are, unsatisfied with the meager conclusions we have, sure we can sincronise, and our tools and toys are wonderfull, but the universe remains,theoretical.
It takes my breath away how consistent the mean length of a day is and how accurately we can measure it. So accurately that if it deviates by mere tens of milliseconds, and it does, we can notice it.
It boggles my mind that a hunk of rock made up of differing densities, with so much of salty water sloshing around, Moon exerting her brakes, bombardments by extraterrestrial matter, Earth still remains so consistent. Of course, this is not surprising if one does the math.
Yes math and physics are different. It's the the fact that math can model the physics so accurately at all that it's breathtaking.
ha ha ha!, we state the same thing, I think, maybe, but it's the "10's of milliseconds" of inconsistancy that I am refering to, we can measure things in as you well state, a "breathtaking" way, but are then reduced to bieng reality's mad, overworkered, note keepers, and ALL of the clocks are still ALWAYS wrong, with the very definition of time becoming something that we must descibe as "realitys ongoing mistake, that we must correct for".
I will indulge myself and go a bit farther into woooooo, teritory, in that this new ability to keep time so accuratly is something that resists entropy by creating order, where there is none.
Even without venturing into the realms of Quantam Mechanics or Chaotic Dynamics, all measurements are, by physical definition, upto the resolution of the measuring instrument. So it always come with inherent +/- error bars. Sometimes these error bars are made explicit, at other times they are elided, often with the assumption that it's obvious.
Models are always simplifications. That is precisely why they are useful. ( A 1:1 scale map is not very useful, especially when we already have one). Models are obtained by ignoring the effect of many known disturbances, but whose effect one deems not to exceed a tolerance bound.
I am thinking more about time, and the ability to sincronise two signals, and say with an analog signal, and a digital time stamps, simply combining the signals 180° out of phase and getting zero verifies the accuracy of both, which is I assume is my crude beginings on modern encryption, and that gives our data the power to resist,entropy.
So can we then reverse entropy by encoding information into
everything?
woooo!
> Blatant Western-centrism within academia (and the strange, almost primitive-hatred for living ancient-cultures) perhaps hasn't led either to the recognition of "ancient" monuments in India or its scientific/astronomical outputs.
Enough with this bullshit please? There are genuine reasons why the knowledge of the calculus of ancient Kerala didn't travel outside India during the late middle ages.
It is a fact that Madhava a mathematician and astronomer from the late middle ages, came up with calculus, and established the Nila School of Mathematics in Kerala. For some reason, the book (Yuktibhasa) that discusses this math is written in the local language Malayalam. Most scholars at the time only understood Sanskrit, including later Western scholars who were unable to find good Malayalam book. Because of this, it was difficult to have the works translated, especially since the works describe formal proofs of concepts like series expansion, which was not even known in the Northern India at the time.
Kerala was also under Portuguese rule at the time and was frequently faced with wars, so the school gradually declined and the math culture sort of died out.
The Mathematics of India by P.P. Divakaran discusses these themes.
P.S: Most of what I've said here is taken from this Numberphile video of another mathematician discussing the life and work of P.P. Divakaran (who recently passed away)
https://www.youtube.com/watch?v=G23Jx0kPCSI
When an aperture is aligned to the winter solstice, it is also aligned to avoid light the rest of the year. An early attempt at air conditioning? Keep the heat out.
The article talks extensively about how these monuments were used for timekeeping. Marking the seasons allowed people to predict animal migrations and plan agricultural activities.
It seems that you are the one who has forgotten the practical uses of these artifacts.
These are all over the place in Norway (as are they everywhere else, presumably!)
When we moved to the island we currently live on, our address was in a road called 'Solsteinen' (The Sun Stone), but I didn't think anything of it until I realized that the roughly hewn stone serving as the property limit marker was juuu-uuust touched by the sun on Winter Solstice. Aha.
A quick call to the local archaeologist confirmed my suspicion - 'Oh, so you're the new resident there, I'd planned on being in touch - that stone monument has been there for more than 2000 years, is A-listed and please, whatever you do, don't do anything with it. Seriously.'
The local archaeologist? Incredible
Oh, he works for the county, but happened to live just up the hill from us.
There's so much old stuff around here that he is basically being called out to perform an assessment every time anyone wishes to build anything.
Where we live now, for instance, there are a handful of burial mounds from God knows when (all plundered long ago), lots of old charcoal pits, a couple of late stone age fish traps in the lake in a corner of our farm.
To exaggerate just a little - where we could build our home was basically dictated by where we could find a spot noone had claimed thousands of years ago...
it seems like you moved to property on "a road called 'Solsteinen' " .. did it occur to anyone that many special local things might be built close to the stable sun stone? I would even guess that no one built a home or horse barn there because they were not allowed to by the community.. this is modern development.. using up the ancient old area for a new sale. That is the appearance from the description above.
As someone from a place that is less than a century old this sounds incredible!
It is until you try to build something!
(Nothing quite like watching an archeologist go 'Oooh, that's interesting!' during a dig to establish whether you can go ahead building on your chosen spot...)
Isn't that solved by rescue archaeology ? Here in the Czech Republic everything has been settled for many thousands of years - so you basically automatically call the archeologists for any construction, they will check the area, record any interesting findings and retrieve artifacts of interest. Then the are is free to be used for the construction project.
Something like that is happening right now here in Brno:
https://www.novinky.cz/clanek/veda-skoly-po-prioru-zbyla-brn...
A massive construction project & equally massive archaeology operation - mapping the remains of old textile factories, an old channel and rail line, fish storage tanks, a mill, a villa and even a cemetery or two.
The archaeology work is wrapping up in a month or two & then the construction crews will take over the site (they already work in the areas that have been fully searched) to finish the construction project (which includes a 13 meter deep water tight "tub" due to a very shallow water table for the basement levels or 200 meter deep geothermal energy piles, etc.).
I suspect most local councils in the UK have an archaeology team and failing that there are a lot of professional consulting archaeologists - a lot (all?) large scale building works often include the need for archaeological surveys and/or remediation.
e.g. Work for what is now the Queensferry Crossing bridge uncovered a 10,000 year old home:
https://www.bbc.co.uk/news/uk-scotland-edinburgh-east-fife-2...
You're that guy who lives on the northeast island of the Chrono Trigger map, aren't you?
We also have these in Germany, in the region where I live it which is North Rhein Westfalis they are quite a common thing actually. Strongly recomment people check it out if they pass by here some time
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> as are they everywhere else, presumably!
They aren't "all over the place" in the US, and I certainly don't have a local archaeologist that I can just call up.
FWIW: The Northeastern US is quite recent with human presence. It wasn't settled until after the last ice age. Pretty much anything old is celebrated because there is so little of anything old.
> They aren't "all over the place" in the US, and I certainly don't have a local archaeologist that I can just call up… The Northeastern US is quite recent with human presence
Fun fact, New England has at least 71 different stonework “prayer sites” that are all astrologically aligned.
Two of the most notable are King Philip’s Cave (Sharon, MA) with a stone aperture through which a "dagger of light" appears specifically during the winter solstice, and Pole Hill (Gloucester, MA) which has fixed boulders that align with the summer solstice sunrise/sunset and the winter solstice sunrise.
Here is a research paper talking about all of them: https://neara.org/pdf/wantofanail.pdf
There are lots of historical preservationists in New England that you can call up. If you want my help finding one let me know where you are located.
When they built the new High School in my old home town in western CT one of the local archaeologists (day job: science teacher) did some exploration on site and discovered all sorts of stuff - no funding for a proper dig so they capped it and put up a plaque about it (ISTR they put the tennis courts on top since that disturbed it least?)
So, yeah, there's lots of archaeology in New England, it's just that a lot of it is literally buried or otherwise not called out. (And "in the US, 100 years is a long time; in the UK, 100 miles is a long distance" is also Just How It Is...)
This is really interesting, thank you.
Norway also wasn't populated until after the last ice age. As an American archaeologist, old stuff is also quite common here. The fun examples I like to use are the structures in Tucson older than Rome.
Your "local archeologist" is one of the staff at the state historic preservation society [0], though you'll likely have more luck contacting a local university archeologist if you find anything.
[0] https://www.ohiohistory.org/preserving-ohio/state-historic-p...
Ohio was populated with numerous earthworks, the Hopewell Earthworks finally being recognized as a UNESCO world heritage spot after being preserved for years by being used as a golf course. Unfortunately many of these have been lost as European settlers destroyed many of them. This continues to this day as Google is building a data center in central Ohio a top of land that was home to numerous native american burial mounds - https://www.datacenterdynamics.com/en/news/google-breaks-gro...
Has no one on Google's datacenter leadership team so much as SEEN a horror movie before?
”You moved the cemetery, but you left the bodies, didn't you? You son of a bitch, you left the bodies and you only moved the headstones! Why? Why?” </Poltergeist>
As the other replies note, there are things. Many were destroyed though and so there is nothing to preserve. However much of North America lacks ready access to building materials that will last and so many of the natives built with organic goods that rotted away in a few decades and so there isn't much to find. You can find many flint arrowheads - but that only tells us when (about) it was made and since there are millions of them there isn't much to learn anymore.
Don't take the above as a sign that the natives were uninteresting or stupid. Just that they didn't leave much for us to learn from, both because they couldn't and because what they did was destroyed.
> It wasn't settled until after the last ice age.
The UK wasn’t permanently settled until the mesolithic either. There are older artifacts like axes, but no monuments.
Probably because the UK didn't exist until 1707.
What I find cute is that every year on the 21st of december a small number of modern day pagans and nature lovers gather at Ales Stenar here in southern Sweden and watch the sun rise over the center stone of the "ship".
We bring thermos bottles, some bring kids, pets, and we just stand there in silence watching the sun.
Afaik it's not coordinated, it's just a bunch of people having the same idea every year.
https://www.bbc.co.uk/news/live/c4g4exnj2p5t?page=2 8,500 turned up at Stonehenge in the UK.
That's.. neat. I guess lots more people show up for summer solstice though? Or are they occupied with the mainstream-pagan Midsummer celebrations then?
This reminded me of The Anasazi Sun Temple that catches the first light of the Summer Solstice in a specific point in the temple. I first discovered this watching Carl Sagan's Cosmos early this year (which I'd highly recommend, BTW)
https://en.wikipedia.org/wiki/Casa_Rinconada
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my modern equivalent(I needed last year for surfing (after i needed to cut a surf trip short as it became night))
https://daylight.franzai.com/
Ha, amazing, I build the same 24 hour clock with night time for daily planning.
You can use an js SVG animation to have it run in real time: https://tomchen.github.io/animated-svg-clock/clock.svg
I have no idea why we stuck with the 12 hour clocks once we stopped using sundials and variable hours: https://en.wikipedia.org/wiki/Unequal_hours
For a modern equivalent, the first thing that came to my mind was Manhattanhenge:
https://en.wikipedia.org/wiki/Manhattanhenge
The street I live on also has a "henge," and it's annoying as all get-out because I have to drive up a big hill with the setting sun in my face to get home.
Love it, bookmarked.
I first saw this idea at https://jmw.name/projects/linear-clock/ and then later I wrote a TUI version for myself
I had tickmarks for stuff (when to go to bed to sleep for 7.5h and wake up near sunrise, things like that). I was working on adding a config file format.
Then I lost the project due to a mishap with a pipx flag... https://github.com/pypa/pipx/issues/1324#issuecomment-211885... ;_; o7
One day maybe I'll come back and do it in Rust.
Doesn't really work on my setup (0). I am curious if it does more than the PhotoPills app, quite a useful thing for city scapes photography.
0. https://drive.google.com/file/d/1FB3Ofl4mUvOO4gGqARro9cO_kjJ...
/edit: Looks like noscript blocks the p5 thing.
With your app, it seems daylight today in Chicago is the same length as yesterday's solstice, although it starts and ends 30 seconds later.
today - 07:18:59 → 16:24:29 = 9:5:30. yesterday - 7:18:23 → 16:23:53 = 9:5:30
Sunrise and sunset aren't in phase (or exactly out of phase). The latest sunrise and the earliest sunset don't happen on the same day and neither happens on the solstice. Not at this northern latitude anyway.
Where I am the sunset is already three minutes later than its earliest time but it will be another two weeks until the sunrises start getting earlier
??? Why?
and yes, the maths fails when you are super super high north or south
You should try to address the latitude issue. (Says the guy who has only to spend a few seconds typing that.)
done
Hey! nice little useful web page. I like the minimalism of it.
Does the math fail because of not considering (i) equation of time and (ii) oblateness of the Earth ?
because mathematically a day can have more than 24h daylight and less than 0
fixed it
Got it. Will happen whenever the latitude is complement of the declination.
Thanks for replying.
There is a temple in India called “Konark Sun Temple”, meant to be worship place of sun god.
It is built east-west to signify sun’s journey. The temple has a wheel sort of structure which kinda acts as sundial with minute level accuracy.
In India, difference in day time between winter and summer solstices is minimal ( 3.5 hours ), I guess it doesn’t signify anything major close to equator.
Depends on where in India you are from. Winter solstice times with chillai kalan [0] which is treated as a headache. Everything basically shuts down in the Western Himalayan regions of India around this time - from Ladakh to Kashmir to Upper Himachal and Uttarakhand [1], though it has gotten much drier/warmer compared to the stories my parents or grandparents told.
[0] - https://www.tribuneindia.com/news/j-k/snow-rain-in-higher-re...
[1] - https://www.tribuneindia.com/news/himachal/snow-likely-on-de...
How did ancient cultures know when the solstice was? If you didn't tell me it was the 21st, I don't know how I'd be able to tell you other than by carefully measuring the sunrise and sunset times
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.
It can be tricky b/c Sun's azimuth at sunrise varies by a hundredth of a degree on days directly before and after the solstice.
Also fun fact: date of latest sunrise is slightly out of phase with seasons https://xkcd.com/2792/
I have read that the auspicious date of December 25th may have been intended to be the Solstice but that the degree of error for "making a note on a fence" is why we have the 25th.
Merry Sun-Fence Day everyone. ;-)
IIRC The 25th was the solstice on the Julian calendar, but when you switch it to Gregorian the solstice moves to the 21st.
no - it is currently three nights after the longest night. The three refers to a similar three days at Easter time.
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.
Also because today we have accurate clocks and most of us don't depend on seasons for anything. Farmers care about when to plant, and a few gardeners pay attention, but for most of us nothing changes in life. (I'm carefully not counting the traditional vacations that most of us have around this time - though that is important to us and historically related, we could move the date and it wouldn't affect anything else).
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.
If you can I strongly suggest going to a Bortle 1 site and staying there for a month, preferably in winter.
The sheer amount of _stuff_ in the sky is mind boggling, the silence is deafening.
That we spend all of human existence until little over a century ago living like that is something I have a hard time wrapping my head around.
https://share.google/v6DtkBoWsfDWakBwO
That's amazing. Thank you.
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!
Just need to be lucky one year.
> 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.
Wikipedia says it's indeed not a trivial thing
https://en.wikipedia.org/wiki/Solstice#Solstice_determinatio...
They didn't.
They didn't like go out on Dec 21st, and look where the sun was and mark it. They didn't even have calendars like that. They watched the sun every day, and waited until it stopped being lower in the sky at it's highest point in the day (or whatever other sign of the solstice they wanted to use), and marked that angle and built whatever viewport they wanted (a door, tunnel, etc).
Then they could just go wherever they built the thing that pointed at that point in the sky, and go, oh, okay, the solstice is soon, or just happened, or whatever and plan accordingly.
It actually wasn't really accurate to the day, anyway. There are a few days on either side of the solstice where the effect is basically the same for the viewer.
Something to keep in mind is that this isn't only useful for determining the exact date of the winter solstice, which they may not have even cared that much about. You can see roughly where you are in the year on either side of the solstice by looking at how far out of alignment the sun is on a given day. So it could be useful throughout the fall and even well into the winter for gauging the passing of time. People didn't need to plan day by day or even week by week, but they did need to do things in roughly the right part of the year.
People act like this is some unexplainable advanced technology, and anybody can just do this with a stick and some rocks.
Pre technology, the sky was very central to life. Sunlight, rain and snow dictated much of your life (and death), and you probably considered the sun, moon and five planets as gods.
You and I personally may not have kept track, but our local religious leader did, and maybe the even staged a ceremony at the winter solstice to ask the sun to make the days longer.
>and you probably considered the sun, moon and five planets as gods.
I find it strange that today knowing much more about sun and moon we don't consider them as gods. Today we know for sure they are the origin of all life on this planet and yet many cultures decided to go for an abstract intangeable entities instead of what is directly in front of us and can't be debated.
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.
For very ancient people, it's the longest/shortest day.
After you notice that, if you want more precision, it's the day the Sun rises and sets most on the North/South. It's also the day things cast the largest shadow at noon. You will need some special device to get very precise on the sun raising position (like a pair of stones or something with a hole), and you won't be able to get precision on the shadow thing.
For more modern people, starting about only half a dozen millennia ago, it's the hour the Sun stops moving North/South within the stars and starts moving the other way around. You will need to look at it and take notes many times, and average things out to get any precision. Even more because you can't see the Sun and the stars at the same time, so you have to model them.
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.
Try making it through a few northern European winters as a pre-modern farmer. I'm sure you will develop a keener interest in measuring these things.
It’s probably not a coincidence that these monuments that seem to serve as calendars happened to spring up just as farming was becoming widespread .
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.
Cultures? You do not even need to be mammal to notice that. Try next years - stop scrolling and notice if you can spot it.
Where I live, I find it wild that there is a 5.75-hour difference between the summer and winter solstices, nearly a quarter of a whole day.
For Orkney the difference in day length between winter and summer solstices is about 12 hours?
December: https://www.timeanddate.com/sun/uk/kirkwall?month=12&year=20...
June: https://www.timeanddate.com/sun/uk/kirkwall?month=6&year=202...
Where I live, the difference is almost six months!
Compiler-brain.
So roughly your latitude is 40 degrees ?
Now if you disclose your local time offset from GMT, say, Palantir can send a drone carrying roses.
Of course this is meant as a joke, but wanted to emphasize how easy it is for location information to leak. And if one really doesn't care about collateral deaths how easy it is to exploit location data.
We’re I live it is a little bit more than 21 hours. Quite noticeable.
I lived briefly where the sun doesn't really shift that much in the sky. I didn't think about it at the time, but that constant noon day sun really messed with my sense of time passing. Weird.
Vert interesting ! One of the cited monuments is 30 min by bike from my home, incredible !
How to say I love Math and Astronomy without saying …
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That's regrettable yes, as any centrism. But people interested in epistemology certainly are aware of major contributions to sciences by Indian thinkers.
Biased coverage is unfortunately rather widespread in more general media. And rise of nationalisms don't help in the matter. Which is true for western and eastern countries by the way.
Regarding a case of several millennia of prior art, there is Pāṇini, who employed metalanguage long before the idea become of interest in western side.
https://en.wikipedia.org/wiki/P%C4%81%E1%B9%87ini
Although western centrism is definitely a thing, the link you provided states that temple, for example, was started in the 16th century. The article link is about something from 2800BC
The article is about more than just that one monument and has a few contemporary examples as well.
I don’t know if it’s related to Western-centrism or not, but I recall thinking it was weird that my English-speaking colleagues do not know the formula to solve second-degree polynomials as the “Bhaskara formula”, as we call it in Brazil.
By the way, Wolfram’s website has an interesting summary of the history of this formula.[0]
[0]: https://mathworld.wolfram.com/QuadraticEquation.html
Interesting that it is called Bhaskara formula.
In India and also in general it's called Sridharacharya formula or method. It's named after the Indian algebraist Sridhar
https://en.wikipedia.org/wiki/Sridhara
whom Bhaskara quotes extensively.
Depends on the details of how you define calculus. Archimedes was doing integration, Descartes was evaluating slopes and tangents of algebraic curves. Isaac Barrow had a good grasp of fundamental theorem of calculus -- that differentiation and integration are inverse operations. Brook Taylor did Taylor series before Newton.
Newton and Leibnitz get credit because they placed calculus as a general technique that is immensely broadly applicable not just for extrapolating the tangent function or the sin function as a series, but to any function that's smooth in some sense.
They worked out the details that do not depend on the specifics of the function and called them out as rules/results of broad applicability. Especially how to push the differential and integral operations through +,-,×,÷ and function composition sign. It did not matter what the function was as long as it was built up from those operations.
I am familiar with the work of Kerala school and also of Aryabhatta's work on using differential coefficients to extrapolate the sin function (this being much before Kerala school), his work on difference equations.
Rather than getting caught up with us versus them narratives , spend some time learning about the beauty of math and how different cultures have thought about them in such creative ways. Otherwise you risk sounding ignorant and rageful conspiracy monger.
The inaccuracies in the Hindu calendar is and was a lot more than the Julian calendar. The Julian calendar assumed that a year was 365 1/4 the day. This is slightly inaccurate and therefore there was a need to correct for the leap day that's added every 4 years by skipping it every 100 years, adding it back every 400 years. At time of Gregorian correction it was off by 10~11 days because of an error of 10 minutes in their estimate of the length of an year.
Hindu civilization's estimate of the length of an year, although remarkably accurate for its time, was less accurate than the estimate of 365 1/4th. Usually the length of an year has been overestimated, making the Hindu calendar lose accuracy quicker. These errors were order of a day per year versus off by about 10 minutes like the Julian calendar.
This was less of a problem historically because Ujjain observatory would correct the calendar time time using accurate observation of the Equinox. Since the fall of Ujjain observatory the Hindu calendar has been accumulating drift error for centuries.
The current state is such that we can, with great authority, give an exact measure of each "years" length, with every one bieng unique. You touch on but dont quite state that math is a usefull game, but miss that reality does not use math consistantly, and we force arbitrary units and measures onto what we are trying to understand, but are still clueless as to what the nature of reality is, and how it works. Testable theorys are thin on the ground now,Newton and his peers, past,present,here, and there, would be and are, unsatisfied with the meager conclusions we have, sure we can sincronise, and our tools and toys are wonderfull, but the universe remains,theoretical.
unless you bump your toe on part of it.
It's the other way around.
It takes my breath away how consistent the mean length of a day is and how accurately we can measure it. So accurately that if it deviates by mere tens of milliseconds, and it does, we can notice it.
It boggles my mind that a hunk of rock made up of differing densities, with so much of salty water sloshing around, Moon exerting her brakes, bombardments by extraterrestrial matter, Earth still remains so consistent. Of course, this is not surprising if one does the math.
Yes math and physics are different. It's the the fact that math can model the physics so accurately at all that it's breathtaking.
ha ha ha!, we state the same thing, I think, maybe, but it's the "10's of milliseconds" of inconsistancy that I am refering to, we can measure things in as you well state, a "breathtaking" way, but are then reduced to bieng reality's mad, overworkered, note keepers, and ALL of the clocks are still ALWAYS wrong, with the very definition of time becoming something that we must descibe as "realitys ongoing mistake, that we must correct for". I will indulge myself and go a bit farther into woooooo, teritory, in that this new ability to keep time so accuratly is something that resists entropy by creating order, where there is none.
Frankly there is nothing woo about it.
Even without venturing into the realms of Quantam Mechanics or Chaotic Dynamics, all measurements are, by physical definition, upto the resolution of the measuring instrument. So it always come with inherent +/- error bars. Sometimes these error bars are made explicit, at other times they are elided, often with the assumption that it's obvious.
Models are always simplifications. That is precisely why they are useful. ( A 1:1 scale map is not very useful, especially when we already have one). Models are obtained by ignoring the effect of many known disturbances, but whose effect one deems not to exceed a tolerance bound.
I am thinking more about time, and the ability to sincronise two signals, and say with an analog signal, and a digital time stamps, simply combining the signals 180° out of phase and getting zero verifies the accuracy of both, which is I assume is my crude beginings on modern encryption, and that gives our data the power to resist,entropy. So can we then reverse entropy by encoding information into everything? woooo!
That would be Asimov's last question
> Blatant Western-centrism within academia (and the strange, almost primitive-hatred for living ancient-cultures) perhaps hasn't led either to the recognition of "ancient" monuments in India or its scientific/astronomical outputs.
Enough with this bullshit please? There are genuine reasons why the knowledge of the calculus of ancient Kerala didn't travel outside India during the late middle ages.
It is a fact that Madhava a mathematician and astronomer from the late middle ages, came up with calculus, and established the Nila School of Mathematics in Kerala. For some reason, the book (Yuktibhasa) that discusses this math is written in the local language Malayalam. Most scholars at the time only understood Sanskrit, including later Western scholars who were unable to find good Malayalam book. Because of this, it was difficult to have the works translated, especially since the works describe formal proofs of concepts like series expansion, which was not even known in the Northern India at the time.
Kerala was also under Portuguese rule at the time and was frequently faced with wars, so the school gradually declined and the math culture sort of died out.
The Mathematics of India by P.P. Divakaran discusses these themes.
P.S: Most of what I've said here is taken from this Numberphile video of another mathematician discussing the life and work of P.P. Divakaran (who recently passed away) https://www.youtube.com/watch?v=G23Jx0kPCSI
We probably move in similar circles because not everyone will be familiar with Prof Divakaran's passing.
When an aperture is aligned to the winter solstice, it is also aligned to avoid light the rest of the year. An early attempt at air conditioning? Keep the heat out.
We jump so quickly to religious significance.
Why not just point the door to the north if the goal was to keep the sun out?
In Scandinavia we have no heat to anor condition out.
> When an aperture is aligned to the winter solstice, it is also aligned to avoid light the rest of the year. An early attempt at air conditioning?
In the northern latitudes, doubtful. It would be cool enough year round.
> We jump so quickly to religious significance.
The article talks extensively about how these monuments were used for timekeeping. Marking the seasons allowed people to predict animal migrations and plan agricultural activities.
It seems that you are the one who has forgotten the practical uses of these artifacts.