Posted by mkmk 1/20/2026
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.
> 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.
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."
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.
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!
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.
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.)
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.)
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.
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.
Those buildings are, of course, gone now.
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.
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_
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.
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”?