alt.hn

1/20/2026 at 6:16:09 PM

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

1/20/2026 at 8:06:59 PM

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.

by krisoft

1/20/2026 at 11:47:15 PM

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

by andrejk

1/21/2026 at 12:13:22 AM

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

by waterheater

1/21/2026 at 1:13:17 AM

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

by tyuu

1/21/2026 at 1:52:55 AM

And the best way is...?

by istjohn

1/21/2026 at 4:03:06 AM

Job ads. It's job ads.

by bravoetch

1/21/2026 at 1:15:30 AM

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

by krisoft

1/20/2026 at 8:59:39 PM

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.

by ofalkaed

1/20/2026 at 8:24:49 PM

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

by joezydeco

1/20/2026 at 8:28:30 PM

At a loss for words. :|

by Tylast

1/20/2026 at 9:09:34 PM

[dead]

by wegwerf0815

1/21/2026 at 1:28:58 AM

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

by echelon

1/20/2026 at 8:53:48 PM

That is a crime of humanity. Terrible!

by rburhum

1/21/2026 at 2:49:06 AM

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

by venusenvy47

1/20/2026 at 7:04:18 PM

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 0.1° 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

by throw0101a

1/21/2026 at 12:53:57 AM

"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

by heresie-dabord

1/20/2026 at 8:18:46 PM

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/

by krisoft

1/20/2026 at 9:33:04 PM

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.

by gus_massa

1/20/2026 at 11:00:51 PM

> 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!

by krisoft

1/21/2026 at 2:41:08 AM

> On my instagram the last reel i posted is showing that process, even though with a different design.

Permalink: https://www.instagram.com/cogs_and_curios/reel/DTNtEFPjEGQ/

> And i wanted the inner planets and the Moon so people and future alien minds will recognise it as the solar system.

I think it was successful.

by gus_massa

1/20/2026 at 11:32:07 PM

Out of curiosity were the positions (especially of the Galilean moons) actual simultaneous positions, or positions as seen from Earth, given the ~40 light-minutes distance between the Earth and Jupiter?

by ummonk

1/21/2026 at 1:13:00 AM

Very good question! I believe they are simultaneous positions. Skyfield has facilities to calculate the light propagation adjusted position but i didn’t use them. Would you have? Is one more “correct” or more likely to be anticipated by future sentients? I’m always unsure about ther design details.

Also there is an other skewiness. Because obviously the drawing is not to scale the moon position can be correct from the sun’s coordinate frame or the Earth’s coordinate frame, but not from both. I choose to make the moons “correct” in the sun’s coordinate frame. Meaning that if you were hovering over the ecliptic frame looking down at the Jupiter during the wedding and rotating the pendants so the sun is in the direction the real sun is, then you would see the moons under you in the same arangement as they are on the pendant. But if you would stand on the surface of earth (during the wedding) and look at Jupiter you would see the moons in a different arangements than a tiny human standing on the earth dot looking at the jupiter dot. (And not just because of the time delay difference, but because the coordinate systems are different.)

Which is weird. Because the wedding happened on Earth, not hovering over the plane of the eliptic over Jupiter. So maybe that was a weird choice. (And not even talking about how north-centric it is that i decided to draw the diagram from the “north” looking down at the eliptic, instead of from the “south” side. These are all kinda culturally driven arbitrary choices. Would love to have none of those present but I haven’t found a good and principeled way yet.)

by krisoft

1/21/2026 at 1:54:31 AM

Wow such a great answer, thanks for sharing the thoughts that went into this. It's crazy that there are so many considerations when taking into account the limited speed of light.

by zertrin

1/21/2026 at 2:48:22 AM

The speed of light is most frustrating. I find myself alternately wishing it was infinite or slowed down to 'disc world speeds' depending on which of the two would make my current project easier.

by jacquesm

1/21/2026 at 4:06:35 AM

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/

by hydrox24

1/20/2026 at 9:16:35 PM

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

by BrandonY

1/20/2026 at 11:23:08 PM

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.)

by krisoft

1/20/2026 at 10:14:18 PM

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

by mkesper

1/20/2026 at 8:10:23 PM

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.

by breckinloggins

1/20/2026 at 6:59:34 PM

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.

by vedmakk

1/20/2026 at 7:05:05 PM

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.

by dylan604

1/20/2026 at 8:49:09 PM

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

by praveen9920

1/20/2026 at 9:07:00 PM

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

Those buildings are, of course, gone now.

by sneak

1/21/2026 at 4:53:34 PM

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

by creshal

1/20/2026 at 7:43:51 PM

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.

by giraffe_lady

1/21/2026 at 11:38:43 AM

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_

by laszlojamf

1/21/2026 at 11:39:32 AM

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.

by interleave

1/21/2026 at 2:15:20 PM

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.

by aaronstreet

1/21/2026 at 2:16:34 PM

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

by aaronstreet

1/21/2026 at 2:26:27 PM

“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”?

by bergerjac

1/21/2026 at 8:23:09 PM

That quote actually comes from Zander Rose’s Long Now Foundation article, not from me or Oskar Hansen.

by aaronstreet

1/20/2026 at 11:13:37 PM

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.

by ummonk

1/22/2026 at 9:36:23 PM

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

by rosefutures

1/31/2026 at 2:13:19 AM

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.

by MomsAVoxell

1/20/2026 at 6:47:06 PM

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

by aebtebeten

1/20/2026 at 7:00:21 PM

[flagged]

by GrowingSideways

1/20/2026 at 7:22:08 PM

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.

by tzs

1/20/2026 at 8:02:40 PM

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.

by testaccount28

1/20/2026 at 9:04:53 PM

> 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.

by Aloisius

1/21/2026 at 4:12:35 AM

look on my works, ye mighty, and dismiss them as mere superstition.

did the use of the word "offended" trigger this comment? fine, then i would not take offense. my point is this:

i prefer to be remembered by a future that feels it can learn something from the past. it would be sad to me to find out that the people of tomorrow do not regard my contributions.

by testaccount28

1/20/2026 at 7:41:14 PM

cf. "The Map is not the Territory"

by maebert

1/22/2026 at 4:16:08 PM

[dead]

by GrowingSideways

1/20/2026 at 7:01:57 PM

What?

by MarcelOlsz

1/20/2026 at 7:17:22 PM

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

by tzs

1/20/2026 at 9:08:56 PM

> 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."

by toasterlovin

1/20/2026 at 11:23:50 PM

Indeed.

There are many texts written in the Greek or Roman antiquity that compare the religions of various nations known to them, i.e. which compare their beliefs about their "gods" and their methods for worshiping or for praying.

There are entire books written about such subjects, e.g. "De natura deorum" ("The nature of gods") by Cicero.

The ancient people usually did not have a precise word with the definite meaning that "religion" has today, mainly because religious practices were intermingled with most of their daily activities, so there was not a very clear separation between religion and other things.

For example, a treatise on agriculture, besides explaining how to prepare the soil and how to select the seeds for sowing, would also give the text of a prayer that should address a certain god before or after the sowing, so that it will be successful. Similarly for any other activities where divine help was believed to be necessary.

Nevertheless, they had the concept of religion and they were able to distinguish things that were related to gods from unrelated things.

by adrian_b

1/20/2026 at 7:04:23 PM

[dead]

by GrowingSideways

1/20/2026 at 6:58:50 PM

> 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?

by akshay326

1/20/2026 at 7:07:28 PM

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.

by Liquix

1/20/2026 at 10:36:41 PM

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.

by myrdynEmbrys

1/20/2026 at 10:39:13 PM

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.

by peter303

1/20/2026 at 6:46:54 PM

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

by DougN7

1/21/2026 at 6:54:05 PM

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.

by staplung

1/20/2026 at 6:45:01 PM

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).

by ifh-hn

1/21/2026 at 1:50:47 AM

Graham Hancock the fraud?

by spartanatreyu

1/21/2026 at 6:26:09 AM

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

by ifh-hn

1/20/2026 at 11:41:12 PM

And to think we're all here building b2b SaaS

by carlcortright

1/21/2026 at 5:06:30 AM

Those ad impressions won't optimize themselves!

by fc417fc802

1/21/2026 at 6:15:06 PM

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.

"""

by staplung

1/20/2026 at 7:52:00 PM

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.

by avhception

1/21/2026 at 12:38:24 AM

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

by antonvs

1/21/2026 at 1:09:22 AM

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".

by sponnath

1/21/2026 at 8:54:36 AM

It’s so arbitrary. We have at least a few hundred million years before Earth is entirely uninhabitable. Why not use 000001931, then? Not ambitious enough, I guess.

Our written history already goes back over 6,000 years. We can actually understand what people back then wrote. We don’t need unbroken year numbering, or leading zeros, to understand that. The calendar has been reset and changed multiple times. It seems like a mis-focus on something that doesn’t really matter.

by antonvs

1/22/2026 at 12:03:18 AM

I don't see it as a serious attempt to create a better way to write down the year. To me, it's a whimsical attempt to give the reader a little pause to think about long time periods, which is what this project is all about. That makes me smile and remember that I'm just a small spec of dust, not to be taken too seriously in the grand scheme of things. I like it.

by avhception

1/21/2026 at 11:16:36 AM

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

Nonsense formatting.

by timc3

1/20/2026 at 11:54:59 PM

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

https://thestarposter.com/

by NetMageSCW

1/20/2026 at 11:08:26 PM

> 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...

by accrual

1/21/2026 at 12:36:05 AM

> transport to Earth

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

by antonvs

1/20/2026 at 7:32:20 PM

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

Only in the northern hemisphere.

by lalos

1/21/2026 at 12:13:44 AM

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.

by kevinpet

1/20/2026 at 7:07:11 PM

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.

by kraig911

1/21/2026 at 12:52:00 PM

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.

by tim333

1/20/2026 at 7:43:07 PM

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.

by ProllyInfamous

1/21/2026 at 12:22:32 AM

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.

by hakkoru

1/21/2026 at 12:49:31 AM

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).

by ProllyInfamous

1/20/2026 at 11:36:38 PM

>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.

by ljsprague

1/21/2026 at 8:54:28 AM

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.

by u1hcw9nx

1/21/2026 at 11:26:17 AM

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

by anentropic

1/21/2026 at 6:35:30 PM

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.

by staplung

1/20/2026 at 9:42:39 PM

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

by flomo

1/21/2026 at 12:50:51 PM

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.

by hopelite

1/21/2026 at 3:56:43 PM

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

by gku

1/21/2026 at 4:00:47 PM

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 ?

by IG_Semmelweiss

1/21/2026 at 5:14:01 AM

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

by zehagray

1/21/2026 at 12:02:22 AM

3.82

plein d’impressement: a series of cordialities

by mockbuild

1/20/2026 at 9:47:10 PM

[dead]

by maximgeorge

1/21/2026 at 2:26:07 PM

[dead]

by BLACKCRAB

1/20/2026 at 7:58:22 PM

[flagged]

by kazinator

1/20/2026 at 8:17:34 PM

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

by ofalkaed

1/20/2026 at 9:26:39 PM

I think they are speaking to, not ignorant of, this.

by zamadatix

1/21/2026 at 12:46:18 AM

Yes. It’s an artistic choice, about as meaningful as the Hoover artist’s claim that, “There is an angle for doubt, for sorrow, for hate, for joy, for contemplation, and for devotion.” Both have a meaningful denotation in the mind of the creator, but don’t necessarily resonate with others.

by antonvs

1/20/2026 at 8:21:18 PM

> 10k year clock

a.k.a. cuckoo clock

by kazinator

1/21/2026 at 12:01:06 AM

> Just, stop.

Why do you mind what others do?

> A leading zero does not unambiguously say "there are no implied nonzero digits to the left of this zero".

Nor does it anywhere say that it means that or that it should mean that. To me the the leading zero in front of 1931 means “Do you think a thousand year is long? Think on a longer scale.” It is a vibe.

> Or is that the usual truncation of 101931, since most relevant dates are in this decamillennium?

The sentients of 101931 won’t be confused because they will know that 01931 refers to our time. Simply from all the context clues acrued. Such as the fact that the document was written in HTML (an archaic markup format rarely used past 8470 as any historicaly inclined sentient of that age would know) and found saved on an SD—card in the backpack of an astronaut who crash landed on the far side of the moon in 2457. Same as you don’t get confused about which milenia a roman public inscription unearthed in Pompei refers to.

by krisoft

1/21/2026 at 12:06:47 AM

> The sentients of 101931 won’t be confused because they will know that 01931 refers to our time.

They may well be confused, because by then this silly "long now" stuff will be long since forgotten.

by AnimalMuppet

1/21/2026 at 5:34:05 AM

Consider that every culture's predominant method of writing has undergone significant changes over a given millennia long period. I'm not about to confuse the date on a photograph of a wax tablet for a modern one.

by fc417fc802

1/21/2026 at 2:06:44 PM

Right. But the long now format is a rarity, and doesn't look like it's ever going to become the norm. If someone from the far future stumbles upon it, they may well not know what millennium it comes from. It's just some date in an unknown format.

by AnimalMuppet

1/21/2026 at 2:40:09 PM

That's like supposing that I (in the modern day) would stumble upon an ancient sumerian date formatted in a slightly unusual manner (for the time), lack the context to identify the approximate era, but somehow if it had been written without the extra character (or whatever) I would have been able to figure things out.

Either a future archeologist has sufficient context to localize the writing to within plus or minus 5k years or the situation was hopeless to begin with. In all likelihood the latin script itself will be sufficient. In the unlikely event that latin numerals remain in near continuous use for another 100k years the writing system alone would then prove insufficient but hopefully you see my point.

That said, it seems the latin alphabet has been in use for 2700 years and is used by approximately 70% of the global population at this point so I guess if any alphabet is going to survive that far into the future it's one of the top contenders. But even then the scripts and usage conventions have changed drastically since its advent. Do we really expect anyone to be employing anything that even vaguely resembles a present day font face that far into the future?

by fc417fc802

1/21/2026 at 4:08:10 AM

Their stated aim is to encourage long term thinking. It appears they scored a bullseye with your response.

by bravoetch

1/20/2026 at 9:35:20 PM

error: invalid digit '9' in octal constant

by eddieh

1/20/2026 at 8:52:30 PM

I just look at it and think someone can't even count to 010 in octal.

by bregma

1/20/2026 at 9:24:28 PM

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.

by GavinMcG

1/21/2026 at 12:01:27 AM

> Leading zeros don't do what you think they do

It's has been pretty normal for clocks with digital displays to include leading zeros for seconds, minutes, hours and/or days for about a century. Doing the same for years, while unusual, doesn't seem particularly confusing. And of course, there is precedent with things like ISO86011 - where 0400 is the year 400 CE.

I'm not sure why one would assume it was a truncation of 101931. That doesn't really make much sense. The first decamillennium digit started at 0, just like the first millennium digit started at 0. 101931 would be 99,905 years in the future.

> how people say 03 when they mean 2003

Making people think beyond that form of casual shorthand (even omitting the apostrophe which would indicate the omission!) is sort of the point? Never mind that 03 doesn't necessarily mean 2003.

by Aloisius

1/21/2026 at 11:30:12 PM

If it is not reasonable that someone would assume 01931 is a truncation of some figure where some nonzero digits are implied, why is it reasonable that someone would assume that about 1931? (And that adding a 0 fixes it?)

How about this: 1931 is a complete decimal integer requiring no further adornment.

by kazinator

1/21/2026 at 5:38:04 AM

> I'm not sure why one would assume it was a truncation of 101931.

For the same reason one assumes that 03 refers to 2003 rather than 1903 (or 1803, or ...).

Of course, it's the surrounding historical context that resolves such confusion.

by fc417fc802

1/21/2026 at 2:53:15 AM

IS086011 or 15O86O11 to be less precise.

by robocat

1/20/2026 at 7:00:08 PM

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

by calibas

1/21/2026 at 12:56:35 AM

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

by lisp2240