The pyramids are almost 4,600 years old and will last at least as long again. The Long Now Foundation has famously built a clock designed to last 10,000 Years. In the last hundred years or so have we started to create artifacts that are likely to survive for most of the remaining lifetime of Earth: Vast areas covered in concrete that will show up in future geological strata, say, or spheres of almost indestructible tungsten carbide in ballpoint pens. The messages the Voyager and Pioneer probes carry may last billions of years.
In other words, if humanity disappeared today, its artefacts would still bear testament to its existence for a long time. It’s unlikely anyone would ever find them: The clocks, and the concrete, and whatever is left of the pyramids will be covered by rubble, trees, and oceans. Our surviving space probes will be somewhere in interstellar space, close to impossible to find.
Could we build a monument to ourselves that’s easy to find, easy to identify as artificial, and that will last at least a billion years? Something that says, we have been here, and we were capable of building this. Just like you, we were a civilization of curiosity. It’d be a monument to humanity. Not to any particular idea, or person, or time, but to all of us, our past, and our aspirations.
Any radio beacon that sends messages into the void would not last for a billion years. Anything we build on Earth would be subject to its elements and erode away. Should we build our monument in space then? A large, space-based monument, maybe on the moon or maybe at a stable Lagrange point, seems appealing. It’d be something we can look up to and visit ourselves. However, any space-based monument that’s big enough to be easily noticed and without an expiration date is likely beyond us for the foreseeable future.
A swarm of messages engraved in a durable metal, sent to different corners of the universe, may have the best chance to eventually be found and to survive. There’s safety in numbers.
