[HN Gopher] A 26,000-year astronomical monument hidden in plain ...
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       A 26,000-year astronomical monument hidden in plain sight (2019)
        
       Author : mkmk
       Score  : 272 points
       Date   : 2026-01-20 18:16 UTC (4 hours ago)
        
 (HTM) web link (longnow.org)
 (TXT) w3m dump (longnow.org)
        
       | ifh-hn wrote:
       | I first heard about this in a Graham Hancock book. Found it a
       | fascinating example of an attempt to encode a date that far
       | distant future generations might understand (provided it
       | survives).
        
       | DougN7 wrote:
       | That was an excellent rabbit hole to go down while eating lunch
       | :)
        
       | aebtebeten wrote:
       | For a hypothesis concerning the precession of the equinoxes and
       | religious pantheons, see
       | https://news.ycombinator.com/item?id=38761574
        
         | GrowingSideways wrote:
         | The concept of "religion" didn't exist until the 17th century
         | or so. Let's not use it here.
        
           | MarcelOlsz wrote:
           | What?
        
             | tzs wrote:
             | Wikipedia says similar [1]:
             | 
             | > The concept of "religion" was formed in the 16th and 17th
             | centuries. Sacred texts like the Bible, the Quran, and
             | others did not have a word or even a concept of religion in
             | the original languages and neither did the people or the
             | cultures in which these sacred texts were written
             | 
             | That said, GrowingSideways is mistaken. He is confusing the
             | thing with the category of the thing.
             | 
             | [1] https://en.wikipedia.org/wiki/History_of_religion
        
               | toasterlovin wrote:
               | > or even a concept of religion in the original languages
               | 
               | IMO this and the sources it cites are wrong. A huge chunk
               | of the Old Testament is about how God had to keep sending
               | prophets to tell the Israelites to stop worshipping other
               | deities. So while they may not have had a single word
               | that was equivalent to 'religion,' they clearly possessed
               | the same concept. They would just use the phrase
               | "worshipping other gods."
        
           | tzs wrote:
           | You are confusing the thing with the category of the thing.
           | 
           | Religion the category is only a few hundred years old. The
           | things that fall under that category go back at least as far
           | as Neanderthal times.
        
             | maebert wrote:
             | cf. "The Map is not the Territory"
        
             | testaccount28 wrote:
             | it's an interesting point, and i don't think it can be
             | resolved quite so neatly. to the people building such
             | monuments, or writing such texts, the activity may have
             | been closer to what we now refer to as "history" or
             | "natural philosophy" (or even "civic infrastructure").
             | 
             | the fact that _now_, we have independent traditions
             | referred to by those terms, and so categorize the ancient
             | practices under "religion" is quite confusing, and it may
             | be productive to make the distinction clear.
             | 
             | for a modern example, suppose we build a skyscraper in such
             | a way that it lines up with, or reflects the setting sun on
             | the solstice. we would regard this as "architecture", not
             | "religion". i would be quite offended if, some thousand
             | years from now, the aesthetic decision is dismissed as
             | primitive superstition.
        
               | Aloisius wrote:
               | _> i would be quite offended if, some thousand years from
               | now, the aesthetic decision is dismissed as primitive
               | superstition._
               | 
               | Why? I can't imagine being offended if people _today_ ,
               | ignorant of the true motivations, dismissed it as
               | primitive superstition, let alone a thousand years from
               | now when I'm long dead.
        
             | Aloisius wrote:
             | The conceptualization of religion as a category, is
             | actually quite a bit older. The idea that it was created
             | recently was, well, created recently.[1]
             | 
             | Casadio details it going back thousands of years across
             | cultures.[2]
             | 
             | [1] https://plato.stanford.edu/entries/concept-
             | religion/index.ht...
             | 
             | [2] https://api.pageplace.de/preview/DT0400.9780191045882_A
             | 29773...
        
       | akshay326 wrote:
       | > There is an angle for doubt, for sorrow, for hate, for joy, for
       | contemplation, and for devotion.
       | 
       | I'm so intrigued - what was going on inside Hansen's brain?
        
         | Liquix wrote:
         | Makes sense when talking about human postures and emotions.
         | 
         | Victory/elation/worship corresponds to extending the arms above
         | the head or in a "V" shape, sorrow/grief corresponds to
         | dropping to the knees and holding the head in the hands, etc.
         | These associations seem to persist despite language barriers
         | and great spans of time.
        
           | myrdynEmbrys wrote:
           | You solved the riddle good sir!
           | 
           | Walking along the millennia, viewing the night's glorious
           | celestial panorama, the registrations on the floor, you'll
           | have successfully circumnavigated the Long Now.
        
       | vedmakk wrote:
       | This is the kind of stuff I love about ancient architecture. It
       | seems they were full of such clever things (or maybe only the few
       | constructions which survived until today).
       | 
       | Its nice to see that some people still care about creating such
       | thoughtful art for modern constructions. It seems that most
       | building of our time are just optimized for fast and efficient
       | construction.
       | 
       | I hope there are many more out there, so that Earth's Graham
       | Hancock of the year 16000 has something to explore on his/her
       | ayahuasca trip.
        
         | dylan604 wrote:
         | When you had no electricity to produce light pollution, when
         | you have no TV, printing press, or any other thing to distract
         | your attention, you had plenty of time to look at the night
         | sky. When that also means you didn't have a way to have a
         | shared calendar, you paid more attention to the sky to know
         | when the seasons were changing. When the changing of seasons
         | were key into surviving, you gave it a lot of importance. It's
         | hard to put that into perspective when we can just look at an
         | app to see the specific time/date of astronomical events well
         | into the future.
        
           | praveen9920 wrote:
           | Having something built IRL would at least inspire a few to
           | actually be interested in astronomy or star gazing.
        
         | sneak wrote:
         | The buildings then were also optimized for fast and efficient
         | construction.
         | 
         | Those buildings are, of course, gone now.
        
       | calibas wrote:
       | Sounds like it's about the precession of the equinoxes and the
       | new "Age of Aquarius".
        
       | throw0101a wrote:
       | More:
       | 
       | > _Due to the precession of the equinoxes (as well as the stars '
       | proper motions), the role of North Star has passed from one star
       | to another in the remote past, and will pass in the remote
       | future. In 3000 BC, the faint star Thuban in the constellation
       | Draco was the North Star, aligning within 0.1deg distance from
       | the celestial pole, the closest of any of the visible pole
       | stars.[8][9] However, at magnitude 3.67 (fourth magnitude) it is
       | only one-fifth as bright as Polaris, and today it is invisible in
       | light-polluted urban skies._
       | 
       | > _During the 1st millennium BC, Beta Ursae Minoris (Kochab) was
       | the bright star closest to the celestial pole, but it was never
       | close enough to be taken as marking the pole, and the Greek
       | navigator Pytheas in ca. 320 BC described the celestial pole as
       | devoid of stars.[6][10] In the Roman era, the celestial pole was
       | about equally distant between Polaris and Kochab._
       | 
       | * https://en.wikipedia.org/wiki/Pole_star
       | 
       | * https://en.wikipedia.org/wiki/Celestial_pole
        
       | kraig911 wrote:
       | I loved this. I wish I had the ability to do the same innocuous
       | deep dive into a easter egg in code - but I fear it would never
       | be discovered at this rate of which AI is generating similar
       | stuff. But much like this article maybe there's a time and place.
        
       | lalos wrote:
       | > Having this one fixed point in the sky is the foundation of all
       | celestial navigation.
       | 
       | Only in the northern hemisphere.
        
       | ProllyInfamous wrote:
       | During DEF CON XX, I got bored/overwhelmed (it was not my first
       | year attending) -- so I decided to rent a car and visit Hoover
       | Dam (this was before the bypass bridge was completed). I drove
       | through the desert 100mph+, in my own little HST jaunt, searching
       | for nothing but concrete's _high water mark_.
       | 
       | The statues in OP's article are absolutely beautiful examples of
       | Art Deco / 1930s Americana (my local post office was built then,
       | too, and has eaglettes of similar [but smaller] design). I had no
       | idea they were out there until stumbling upon them, and they
       | definitely leave a lasting impression of our forefather's
       | imposing _presence_. America, _fuck yeah_!
       | 
       | Wish I had then-known about this "clock," which is definitely
       | _hidden in plain sight_. Wish we had similarly-lavish federal
       | budgets, today. But worth visiting, both article, statues  & dam.
        
       | giraffe_lady wrote:
       | In the extremely interesting book about water, cadillac desert,
       | there is a great discussion with a scholar of some kind, I think
       | an archeologist, about the large western US dams and the future.
       | The gist is that the reservoirs will eventually silt up and
       | disappear, but the dams will remain for thousands of years. The
       | silted lakes will preserve clear evidence of their construction
       | in the geologic record of these regions.
       | 
       | We will quite plausibly be known as the dam builder civilization,
       | as these artifacts could very easily outlast the memory of what
       | we call ourselves. It is fitting to embellish them in this way.
        
       | avhception wrote:
       | Haha, I clicked without reading the URL. Then I read the "01931"
       | in the text, immediately looked at the URL and of course it was
       | longnow.org. Brought a smile to my face.
        
       | kazinator wrote:
       | > _construction of the dam began in 01931_
       | 
       | Person in far future:
       | 
       | Was that in _the_ original 01931 as in 1931? Or is that the usual
       | truncation of 101931, since most relevant dates are in this
       | decamillennium?
       | 
       | Leading zeros don't do what you think they do; you need look no
       | further than how people say 03 when they mean 2003. A leading
       | zero does not unambiguously say "there are no implied nonzero
       | digits to the left of this zero".
       | 
       | Just, stop.
       | 
       | Or find some other convention, like, say, =1931. The = means,
       | this is an exact value and not some value truncated modulo a
       | power of ten.
        
         | ofalkaed wrote:
         | It is a convention of The Long Now Foundation to get people to
         | think of time in terms of 10k years instead of a lifetime at
         | best. It goes hand in hand with their 10k year clock.
         | 
         | https://en.wikipedia.org/wiki/Clock_of_the_Long_Now
        
           | kazinator wrote:
           | > 10k year clock
           | 
           | a.k.a. cuckoo clock
        
           | zamadatix wrote:
           | I think they are speaking to, not ignorant of, this.
        
         | bregma wrote:
         | I just look at it and think someone can't even count to 010 in
         | octal.
        
         | GavinMcG wrote:
         | Why do you imagine that =1931 wouldn't be equally confusing in
         | some future decamillenium? Arabic numerals have only been
         | around for (charitably) 0.12 decamillenia. Sorry, =.12
         | decamillenia.
        
         | eddieh wrote:
         | error: invalid digit '9' in octal constant
        
       | krisoft wrote:
       | But is the star map there? This article seems to imply that it
       | got demolished in 2022: https://www.oskarjwhansen.org/news/save-
       | the-star-map
       | 
       | If so that is somewhat ironic. A message intended to communicate
       | a date to thousands of years into the future got demolished a
       | mere 86 years after its creation due to a drainage issue and a
       | contract dispute.
        
         | joezydeco wrote:
         | It's in pieces, evidenced here:
         | https://www.oskarjwhansen.org/news/save-the-star-map-decembe...
        
           | Tylast wrote:
           | At a loss for words. :|
        
           | rburhum wrote:
           | That is a crime of humanity. Terrible!
        
         | ofalkaed wrote:
         | It is currently under reconstruction, it sounds like much of it
         | was beyond salvage and has to be remade but it is difficult to
         | find much info on this, bits and pieces strewn about the web.
         | The project was resumed in 2023 and the BOR stated they were
         | still committed to reconstructing the star map. In 2024 they
         | completed the new underlayment and I have yet to find anything
         | from 2025 other than that Monument plaza is still closed to the
         | public.
        
         | tempaccsoz5 wrote:
         | The same website says that as of 2024, it is slowly being
         | reconstructed: https://www.oskarjwhansen.org/news/2024-hoover-
         | dam-star-map-...
        
       | breckinloggins wrote:
       | I somehow doubt there is any future version of me that regrets
       | joining The Long Now Foundation, and work like this is the main
       | reason why.
       | 
       | If you're in SF you should pay them a visit and buy a coffee at
       | The Interval; I think you'll find it worth the trip.
        
       | krisoft wrote:
       | I have once created a pendant to my friends' wedding following a
       | similar idea. A silver disk engraved one one side with the
       | position of the planets and major moons at the moment of the
       | ceremony. Fun thing is that the Galilean moons orbit fast enough
       | that you can even read the intended minute.
       | https://www.instagram.com/reel/DIpFTPOIP60/
        
         | BrandonY wrote:
         | That's so cool! Is there a calculator somewhere that can
         | convert to/from dates and solar system position charts?
        
           | mkesper wrote:
           | Positions at a given time could be simulated in e.g. Celestia
           | (and then projected). The other direction, I don't know.
        
         | gus_massa wrote:
         | If you have a blog post with a few more technical details, it
         | may be a nice submission for HN. (Do you have a few photos of
         | the intermediate steps to share?)
         | 
         | Some ideas/questions: How is it painted? Is it laser cut or by
         | hand? Did you designed it? How did you do the calculations?
         | Does Saturn have rings? Where is the cutoff? (No
         | Neptune/Uranus/Fobos/Deimos/...) Have you tried to give a
         | different size to each planet?
         | 
         | PS: I showed the video to my older daughter that is interested
         | in astronomy and she likes it.
        
       | flomo wrote:
       | Thanks for this, at one point I tried to google this monument and
       | didn't find much.
        
       | peter303 wrote:
       | The precession circle is 144 arc degrees sin 23.5. In an 80 year
       | lifespan precession would move the rotation pole about .44 arc
       | degrees or the diameter of the full moon. Any long lived
       | astronomical observatory in ancient times would have noticed
       | this.
        
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       (page generated 2026-01-20 23:00 UTC)