On earth clay tablets have done a great job : we have tablets 6000 years old, so we know that works. That’s 60% of 10k already. Titanium seems expensive and might be melted down in time of need, like bronze has been often in the past. Clay tablets survived partly because it’s a ‘worthless’ material.

Imagine if you were an alien species who somehow comes across this capsule hundreds of millions or billions of years from now. It's proof of sentient life elsewhere! But then you date the U-238 and realize that they're probably all dead...

But, they've left all of their civilization, culture, heritage, and knowledge behind. And you get to experience that, even recreate a tiny simulacrum of their world. And it gives you something, it's a tangible form of communication and cooperation across aeons.

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In the short term, the backup is probably useful to have. Imagine if a collection is lost to fire or some other catastrophe, and one of the closer ones could be used to bring it back. Case in point, the fire at Notre-Dame. In 2015, Dr. Andrew Tallon, an art historian, painstakingly scanned all of Notre Dame, https://www.forbes.com/sites/trevornace/2019/04/16/we-have-b...

I think it's important to be honest. Would you have flagged his work as pointless in 2015? After all, the Cathedral has stood for centuries, been photographed so many times, what's the point of a 3D scan?

After 2019's fire, those scans became important (unsure to what degree) to the restoration effort. At some level, by capturing and preserving history, Andrew Tallon helped save history. And now it becomes a part of the story.

That's the goal. To engage in an act of optimism for the betterment of us and all of humanity.

At that point someone can just put it on a thumb drive and take it with.

It's not beyond the realm of possibility that people ultimately inhabit a spaceship that wanders the universe looking for a new home.

But of course you need some marker then on the ground so people know where to look for it later if they want to read the data. Maybe some artwork? A giant monolith perhaps?

> The hardest part might be putting it all together in a way that can be trivially decoded by human descendants, even if they don't speak our language or share our subspecies.

Though other crystals should be highly stable. Quartz seems geologically and chemically stable, plain old glass ain't bad. Something reasonably cheap is probably preferable, both from the cost basis (an expensive-to-create archive is a challenge) and the repurposing challenge (a diamond-etched bibliographic archive might have other appeals to those who chance across it).

Even parchment proved sufficiently valuable that works were often repurposed (and lost) through palimpsests.

isn't the same idea viable if applied to silicon crystals (which we already grow lots of)?

The Long Now Foundation has extensively studied the language loss problem and arrived at a fairly elegant set of solutions.

https://longnow.org/ideas/02022/01/20/linguistic-data-in-the...