The best computer storage devices that exist today are ephemeral compared to primitive technology such as engraved rocks. A stone tablet can last for millennia, but anything we can store files on will very likely be useless in 50 years. However, there are some prospects for seriously long-lived media in the labs.
Researchers at Berkeley Labs and the University of California at Berkeley have developed a method in which a miniscule iron particle can move within a nanotube under the control of an electric current. The state of the particle can be read without moving it. They estimate a billion years before losing data due to particle drift but don’t discuss whether the physical integrity of the tubes will match.
A partnership of Hitachi and Kyoto University says it has a storage medium based on quartz glass which can last for hundreds of millions of years, can be read with an optical microscope, and has a storage density comparable to a CD.
If dinosaurs had that technology and the intelligence to use it, they could have left us messages; but would we have any way of recognizing them? Perhaps it’s better to think in terms comprehensible in human history, like thousands of years. If people in the year 4000 find a nanotube storage device from the 21st century, will they have any idea what it is? The quartz glass device might have a better chance, since it can be read optically, but it’s still just dots that need decoding.
Historians today can recognize symbols carved on a tablet as writing, even if they can’t always tell what they mean. Will historians centuries in the future even recognize the digital records we leave today? If they can’t, what will that do to cultural continuity?