[HN Gopher] The ancient monuments saluting the winter solstice
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The ancient monuments saluting the winter solstice
Author : 1659447091
Score : 161 points
Date : 2025-12-22 09:30 UTC (13 hours ago)
(HTM) web link (www.bbc.com)
(TXT) w3m dump (www.bbc.com)
| voidUpdate wrote:
| 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
| srean wrote:
| 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.
| arethuza wrote:
| 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!
| JKCalhoun wrote:
| Just need to be lucky one year.
| clickety_clack wrote:
| 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.
| exitb wrote:
| 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.
| bluGill wrote:
| 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).
| jcims wrote:
| 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.
| noosphr wrote:
| 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.
| srean wrote:
| https://share.google/v6DtkBoWsfDWakBwO
| mmooss wrote:
| That's amazing. Thank you.
| mapcars wrote:
| > 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.
| empiko wrote:
| 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.
| JKCalhoun wrote:
| 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. ;-)
| stryan wrote:
| IIRC The 25th was the solstice on the Julian calendar, but
| when you switch it to Gregorian the solstice moves to the
| 21st.
| mistrial9 wrote:
| no - it is currently three nights after the longest night.
| The three refers to a similar three days at Easter time.
| eitau_1 wrote:
| 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/
| beejiu wrote:
| 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.
| eitau_1 wrote:
| Wikipedia says it's indeed not a trivial thing
|
| https://en.wikipedia.org/wiki/Solstice#Solstice_determinatio...
| BurningFrog wrote:
| 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.
| mapcars wrote:
| >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.
| marcosdumay wrote:
| 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.
| empath75 wrote:
| 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.
| rags2riches wrote:
| 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.
| franze wrote:
| 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/
| franze wrote:
| and yes, the maths fails when you are super super high north or
| south
| srean wrote:
| 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 ?
| franze wrote:
| because mathematically a day can have more than 24h
| daylight and less than 0
|
| fixed it
| srean wrote:
| Got it. Will happen whenever the latitude is complement
| of the declination.
|
| Thanks for replying.
| JKCalhoun wrote:
| You should try to address the latitude issue. (Says the guy
| who has only to spend a few seconds typing that.)
| franze wrote:
| done
| noosphr wrote:
| 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
| pbalau wrote:
| 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.
| busfahrer wrote:
| For a modern equivalent, the first thing that came to my mind
| was Manhattanhenge:
|
| https://en.wikipedia.org/wiki/Manhattanhenge
| psunavy03 wrote:
| 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.
| aworks wrote:
| 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
| masfuerte wrote:
| 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.
| KineticLensman wrote:
| 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
| mos_basik wrote:
| 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.
| arionmiles wrote:
| 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
| andrewinardeer wrote:
| 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.
| jstanley wrote:
| Where I live, the difference is almost six months!
| JKCalhoun wrote:
| Compiler-brain.
| arethuza wrote:
| 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...
| srean wrote:
| 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.
| designerarvid wrote:
| We're I live it is a little bit more than 21 hours. Quite
| noticeable.
| Loughla wrote:
| 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.
| lb1lf wrote:
| 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.'
| YJfcboaDaJRDw wrote:
| 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
| phinnaeus wrote:
| The local archaeologist? Incredible
| lb1lf wrote:
| 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...
| systemtest wrote:
| As someone from a place that is less than a century old
| this sounds incredible!
| arethuza wrote:
| 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...
| gwbas1c wrote:
| > 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.
| robotbikes wrote:
| 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...
| psunavy03 wrote:
| Has no one on Google's datacenter leadership team so much
| as SEEN a horror movie before?
| mixmastamyk wrote:
| _"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>
| bluGill wrote:
| 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.
| AlotOfReading wrote:
| 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...
| hammock wrote:
| _> 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.
| lemonberry wrote:
| This is really interesting, thank you.
| eichin wrote:
| 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...)
| debo_ wrote:
| You're that guy who lives on the northeast island of the Chrono
| Trigger map, aren't you?
| JoeAltmaier wrote:
| 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.
| theoreticalmal wrote:
| Why not just point the door to the north if the goal was to
| keep the sun out?
| inejge wrote:
| > 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.
| designerarvid wrote:
| In Scandinavia we have no heat to anor condition out.
| INTPenis wrote:
| 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.
| onion2k wrote:
| https://www.bbc.co.uk/news/live/c4g4exnj2p5t?page=2 8,500
| turned up at Stonehenge in the UK.
| kzrdude wrote:
| 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?
| maelito wrote:
| Vert interesting ! One of the cited monuments is 30 min by bike
| from my home, incredible !
| praveen9920 wrote:
| 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.
| alephnerd wrote:
| 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...
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(page generated 2025-12-22 23:00 UTC)