A 26,000-year astronomical monument hidden in plain sight (2019)

https://longnow.org/ideas/the-26000-year-astronomical-monument-hidden-in-plain-sight/

by mkmk • 6 months ago

565 86 6 months ago

ifh-hn2• 6 months ago

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).

spartanatreyu• 6 months ago

Graham Hancock the fraud?

ifh-hn2• 6 months ago

I think author and journalist is how he presents himself. Or pseudo-scientist according to Wikipedia. But yes Graham Hancock.

DougN7• 6 months ago

That was an excellent rabbit hole to go down while eating lunch :)

aebtebeten• 6 months ago

For a hypothesis concerning the precession of the equinoxes and religious pantheons, see https://news.ycombinator.com/item?id=38761574

akshay326• 6 months ago

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• 6 months ago

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• 6 months ago

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, as well the total integral of your own life.

vedmakk• 6 months ago

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• 6 months ago

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• 6 months ago

Having something built IRL would at least inspire a few to actually be interested in astronomy or star gazing.

sneak• 6 months ago

The buildings then were also optimized for fast and efficient construction.

Those buildings are, of course, gone now.

creshal• 6 months ago

A few pharaos remain only known for being so poor architects that their hastily built temples needed renovations after only 2-3 generations.

calibas• 6 months ago

Sounds like it's about the precession of the equinoxes and the new "Age of Aquarius".

throw0101a• 6 months ago

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 0.1° 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

heresie-dabord• 6 months ago

"Milankovitch cycles describe the collective effects of changes in the Earth's movements on its climate over thousands of years. The phenomenon is named after the Serbian geophysicist and astronomer Milutin Milanković. [...] variations in eccentricity, axial tilt, and precession combined to result in cyclical variations in the intra-annual and latitudinal distribution of solar radiation at the Earth's surface, and that this orbital forcing strongly influenced the Earth's climatic patterns.

The Earth's rotation around its axis, and revolution around the Sun, evolve over time due to gravitational interactions with other bodies in the Solar System. The variations are complex, but a few cycles are dominant."

https://en.wikipedia.org/wiki/Milankovitch_cycles

kraig911• 6 months ago

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• 6 months ago

Having this one fixed point in the sky is the foundation of all celestial navigation.

Only in the northern hemisphere.

kevinpet• 6 months ago

Not even in the northern hemisphere. Celestial navigation is about shooting altitudes for known bright stars. At least three ideally five. This could include Polaris, but it doesn't need to. Source: watched some old training videos about celestial navigation after reading Fate is the Hunter a while back.

ProllyInfamous2• 6 months ago

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.

hakkoru• 6 months ago

Heh, a group of friends and I also visited the Hoover Dam while we were in Vegas for DEF CON one year. Was a really cool experience for sure.

ProllyInfamous2• 6 months ago

I actually went to get away from some friends, whom were presenting that year (they needed prep time — and I needed escape). Top 10 memories made by myself out at Hoover Dam, watching as the bypass got completed (that is another incredible feat of engineering).

Definitely a cool experience, and I'm glad I did. My last year attending DEF CON me and a Hadoop buddy (nobodies) just walked up onto a stage [during a terrible presentation] and started drinking whiskey with the ESL speaker (again: nobodies) — predicting we'd get banned from attending (but didn't — nobody cared... audience appreciated the break from hard-to-understandings).

giraffe_lady• 6 months ago

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.

avhception2• 6 months ago

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.

antonvs3• 6 months ago

I find it a bit silly. When we refer to 70 CE or 500 CE we don’t add zeros in front.

sponnath• 6 months ago

It's not silly when you consider what longnow stands for. They look at "now" on a 20,000 year scale so the extra zero is just emphasizing that 01931 is still the "long now".

timc3• 6 months ago

As a European it took me a few seconds to parse.

Nonsense formatting.

krisoft6• 6 months ago

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• 6 months ago

It's in pieces, evidenced here: https://www.oskarjwhansen.org/news/save-the-star-map-decembe...

Tylast• 6 months ago

At a loss for words. :|

rburhum• 6 months ago

That is a crime of humanity. Terrible!

echelon• 6 months ago

This is horrible! I always wanted to visit this. :(

ofalkaed• 6 months ago

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• 6 months ago

The same website says that as of 2024, it is slowly being reconstructed: https://www.oskarjwhansen.org/news/2024-hoover-dam-star-map-...

andrejk• 6 months ago

I'd have to look at what it looked like before, but when I visited there earlier this month, I didn't see any restoration in progress and the star map was open. I didn't take a ton of photos in that area, and here are the only two of the monument I grabbed:

https://photos.app.goo.gl/qgJ3x5za82EiFz5P7

waterheater• 6 months ago

From my cursory web searches, your photos may be the first online evidence that the restoration project was indeed completed.

tyuu• 6 months ago

This is the second-best way to doxx HN users I've ever seen.

krisoft6• 6 months ago

Thank you for the confirmation! This is so good to hear.

venusenvy47• 6 months ago

On Google maps, someone posted a photo from 9 months ago, explaining the restoration.

breckinloggins• 6 months ago

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.

krisoft6• 6 months ago

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• 6 months ago

That's so cool! Is there a calculator somewhere that can convert to/from dates and solar system position charts?

mkesper• 6 months ago

Positions at a given time could be simulated in e.g. Celestia (and then projected). The other direction, I don't know.

krisoft6• 6 months ago

To calculate the orbital positions i used the skyfield python library. https://rhodesmill.org/skyfield/

They have a very handy example right on the landing page how one can calculate the positions and angles of a planet from a date.

The inverse was a bit trickier. But I also implemented a script which could “solve” a given picture backwards and give us a date. I believe i used binary search to narrow the date down first for the planet with the slowest period, and then refined the date around that timestamp using the position of the planet one faster. That way the estimate got more and more accurate and i didn’t need to brute force search a large time interval. (I applied the assumption that the date to be found is within half a saturn year from our current date, but if that assumption were incorrect it would have resulted in a solver failure during the refinement and thus detected.)

gus_massa2• 6 months ago

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.

krisoft6• 6 months ago

If you have a blog post with a few more technical details, it may be a nice submission for HN.

Oh. That is very kind of you. I do have many more pictures and details. I will try to collect them together, and will publish it once it is done. But can’t promise that it will happen soon. So i will answer your questions here in the meantime.

How is it painted?

The shapes are recessed and the recesses are filled with black nail polish. The excess nail polish was then scraped off from the flat upper surfaces leaving it only in the recesses.

It was very fiddly, and i don’t necessarily recommend this method for anyone. I have since learned how to enamel by melting glass powders onto the metal surface which is both easier and gives a better result. That is how i would do it today. (On my instagram the last reel i posted is showing that process, even though with a different design.)

Is it laser cut or by hand?

A third and a fourth option. The planet side is machined on a cnc. First I etched the orbits with a v-bit, then cut the planets with a 0.8mm flat endmill, then cut the hole, and finally cut the outline. After that i etched the initials side chemically. As a resist i used self-adhesive vinyl which i cut with a plotter.

To be honest. I wouldn’t recommend this process either. It was super finicky, slow, and error prone. Today i would just etch and cut the metal with a fiber laser. In fact i bought a fiber laser because i got sick of the chemical etching and mechanical machining during this project. :)

Did you designed it? How did you do the calculations?

I did design it! I’m very proud of it. The initials side was designed in inkscape while the planet side was generated with a python script. The script used the super handy skyfield python library for the calculations. (Which in turn uses the planetary ephemeris files published by the Jet Propulsion Laboratory.)

Does Saturn have rings?

No ring of Saturn unfortunately. But it would be a cool idea!

Where is the cutoff? (No Neptune/Uranus/Fobos/Deimos/...)

Unfortunately I don’t have a real good principled answer to this. Because of the machining I had a hard limit on the smallest details I could put on the metal. I did know that i wanted to put the Gallilean moons on there because their short periods meant that they provide good basis for the minutes and hours part of the date. I did know that i also wanted one of the gas giants to provide a “slow hand” to the clock to show the years, and to hopefully stretch out the period before the next time the solar system is in a similar position to very far into the future. And i wanted the inner planets and the Moon so people and future alien minds will recognise it as the solar system. Everything else was just futzing around with the script and finding a good compromise between not making it too large to wear and not making it too crowded either.

Have you tried to give a different size to each planet?

I did, but it looked uneven and too haphazard to my eyes. Not saying it is impossible to make it neat with different planet sizes but I liked the diagram simplicity of keeping all the planets one size and the moons an other smaller size.

I showed the video to my older daughter that is interested in astronomy and she likes it.

Oh thank you! That is lovely!

hydrox24• 6 months ago

If others are interested in getting something like this — there's an Australian firm already doing a good job at scale (but slightly different to parent).

https://www.thenightsky.com/

flomo• 6 months ago

Thanks for this, at one point I tried to google this monument and didn't find much.

peter303• 6 months ago

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.

accrual• 6 months ago

Marking in the terrazzo floor of Monument Plaza showing the location of Vega, which will be our North Star in roughly 12,000 years. (Photo by Alexander Rose)

I wonder if some content creator 12K years from now will transport to Earth and stream the North Star from this position for likes/views. If that's even a thing then...

antonvs3• 6 months ago

transport to Earth

They’ll almost certainly still be on Earth. Fundamental physics is unlikely to change in the next 12,000 years.

ummonk2• 6 months ago

Many Hindus celebrated Malay Sankranti a week ago. It was originally meant to coincide with winter solstice but because the Hindu dates are based on the position of the Sun against the background stars (as viewed from the Earth), precession over the last ~1700 years has driven it out of sync with the tropical calendar.

ljsprague• 6 months ago

It is likely that at least major portions of the Hoover Dam will still be in place hundreds of thousands of years from now.

Kinda sus of this.

u1hcw9nx• 6 months ago

It can be hard to recognize the heaps of dirt on the riverbanks. The internet claims the Hoover Dam could last 10,000 years, but I don't believe that for a second.

Dams are not permanent structures without maintenance. If they are holding back water or if water is flowing through them, they will eventually erode and their foundations will collapse.

Because the main structure lacks rebar , it will last longer than most modern structures, but it won't last nearly as long as 2,000-year-old Roman structures made with volcanic ash and lime because it uses Portland cement.

There is bigger and more immediate problem. Hoover Dam ends with siltation long before concrete erodes. The Colorado River carries massive amounts of sediment. Eventually, the lake behind the dam will fill with mud, turning the dam into a giant waterfall. Once water starts flowing over the top of a arch-gravity dam rather than through controlled pipes, scouring at the base will undermine the foundation.

carlcortright• 6 months ago

And to think we're all here building b2b SaaS

fc417fc802• 6 months ago

Those ad impressions won't optimize themselves!

NetMageSCW• 6 months ago

My wife has bought a few of these for significant dates as gifts:

https://thestarposter.com/

mockbuild• 6 months ago

3.82

plein d’impressement: a series of cordialities

lisp2240• 6 months ago

Destruction of art is the only crime I think should receive the death penalty. You’re making the world darker for everyone.

dang• 6 months ago

Discussed at the time (of the article):

A 26,000-Year Astronomical Monument Hidden in Plain Sight - https://news.ycombinator.com/item?id=19124698 - Feb 2019 (57 comments)

zehagray• 6 months ago

The fact is; this kind of knowledge are mostly pursued by people called "lunatics" and this is taking science held back in fringe cases. But sometimes lunatics are right too

anentropic• 6 months ago

Could plate tectonics conceivably throw off the alignment of this monument within the ~10ky timescales involved?

staplung3• 6 months ago

Not really. The axis of the earth's rotation is not affected by plate tectonics and the star map is recording where the earth's northern axis is pointing as precession slowly moves it around a circle. The star map could certainly move around or get broken up by plate tectonics over that timescale but it's not really aligned with anything in a meaningful way so that doesn't matter.

The stars themselves will move - relative to us - and eventually some of them will disappear but nothing much is expected on that front for much longer than 10ky timeframes.

laszlojamf• 6 months ago

Slightly off topic, but it's interesting to see the same phrase "the long now" pop up in different contexts independently and mean very different things:

https://www.epsilontheory.com/the-long-now/

Both are pretty obscure references for now, but I can easily imagine a world where they both become widely known in separate groups. Like the word "legacy" has hilariously different connotations for software engineers as compared to _everyone else_

interleave• 6 months ago

Related: Huge fan of Long Now here.

Asking "How would you build a 10k year clock?" is one of my favorite ways to get to know people, say, at parties.

With a few seconds to mull it over, so far EVERYONE has had at least one strong, novel and leftfield idea that I had not heard or thought of before.

My favorites included: A mirror on the moon, bio-engineered crops and the Pyramids of Gizeh.

hopelite• 6 months ago

The civilization that created that must have been a wonderful place and probably was taught how to create such things by aliens.

Is sarcasm, but it may as well not be since that America is long dead and gone and has been replaced by an America that really needs to be renamed at this point.

tim333• 6 months ago

I wonder if you can pin down other cycles in the sky to pinpoint how many years after the big bang? I guess the appearance of galaxies must change.

aaronstreet3• 6 months ago

I’m the author of the original posts on https://oskarjwhansen.org and can confirm that the Star Map restoration project finished near the end of 2025. I’d been planning to get an announcement post up this week but saw the HN attention and wanted to put fears to rest.

aaronstreet3• 6 months ago

Also, since y’all seem interested, feel free to AMA.

bergerjac• 6 months ago

“It is likely that at least major portions of the Hoover Dam will still be in place hundreds of thousands of years from now.”

From the article itself, the Pyramids are only 12,000 years old. Every other Ancient Wonder has been destroyed.

Essentially there’s a Major Cataclysm about every 10,000 years, and a ‘Minor’ one about every 5000 years (Burkle Crater impact being the most recent).

How do you assume any parts of the Hoover Dam would be intact or even visible “hundreds of thousands of years from now”?

gku• 6 months ago

The 26,000-year cycle is also known as the Platonic Year.

IG_Semmelweiss• 6 months ago

is that the time it would require to complete 1 revolution, shown specifically in figure 1 of the article ?

Also - wouldn't the north star(s) (polaris, deneb etc) also move, even if slightly, in that period of time as well ?

staplung3• 6 months ago

The star map comes up at the end of Joan Didion's essay "At the Dam":

""" I walked across the marble star map that traces a sidereal revolution of the equinox and fixes forever, the Reclamation man had told me, for all time and for all people who can read the stars, the date the dam was dedicated. The star map was, he had said, for when we were all gone and the dam was left. I had not though much of it when he said it, but I thought of it then, with the wind whining and the sun dropping behind a mesa with the finality of a sunset in space. Of course that was the image I had seen always, seen it without quite realizing what I saw, a dynamo finally free of man, splendid at last in its absolute isolation, transmitting power and releasing water to a world where no one is.

"""

staplung3• 6 months ago

I think the most likely end fate of the Hoover dam is that humans dismantle it. Eventually, Lake Mead will silt up enough to make the hydro plant useless (it will take centuries to silt up completely but silt will choke the plant long before that). De-silting the reservoir is not a realistic option.

Hopefully, we'll have alternate means of power generation that nullify the dam's economic viability long before then but water supply and flood mitigation are other functions that need consideration. Silt will eventually destroy those functions as well however.

rosefutures• 6 months ago

Thanks for your interest in this piece, I am happy to hear that the restoration of this work has been completed! aaronstreet over at https://www.oskarjwhansen.org has been doing great work in documenting Hansen's work and Im sure will have an update on that soon.

I am happy to answer any questions about this and if you want to see any of my other writing please take a look at: https://medium.com/@zander_longnow and https://www.rosefutures.com

MomsAVoxell• 6 months ago

I visited it the first time as a teenager in 1986 part-way through a driving tour from LA to Mexicali and Vegas and Tahoe and so on.

I had a Sony Walkman and one of the 'trip tapes' I'd had packed for my family driving-tour vacation, was Eddy Jobson, Theme of Secrets. So his visceral strings and landscape arrangements were my personal soundtrack all the way to those crazy angel sculptures and beyond, to Death Valley and Vegas and all that jazz, until we got back to San Francisco, where I'd got his tape.

The eternal nature of that spot really seemed feasible to me. Even if the water dried up completely, it'd still be somewhere, some time in the future, some people would meet .. and perhaps wonder just what it was all about, some tens of thousands of years ago.

A 26,000-year astronomical monument hidden in plain sight (2019)

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