Long-term data storage is never a sure thing–you’d be surprised how quickly many traditional data storage systems degrade. And while consumers are just beginning to experiment with disappearing data (think SnapChat), businesses are looking for ways to make their storage truly archival. Whether it’s NASA being at risk of losing critical moon mission info, or the BBC losing a hundred original Doctor Who episodes, permanent storage is becoming a requisite part of culture. How can we store things that will last for, say, a billion years?
European scientists have published a paper that talks about their success in developing “silicon nitride and tungsten-based systems” for what they call “gigayear storage.” With a high-energy barrier against erasure, this form of storage is so permanent that it would take a very considerable and deliberate effort to delete data so stored.
The trick was in identifying tungsten as the material to encode data to–it has a very high melting temperature, doesn’t expand too much when heated, and has a high activation energy (this is the minimum energy that must be added to cause a chemical reaction, so a high level means it’s harder to “activate” under normal circumstances). Then the team embedded tungsten in silicon nitride–an incredibly strong and inert material that’s used for high-performance engine parts and for medical implants. The silicon material is hugely strong, and thus protects the tungsten–and it’s transparent to light at useful wavelengths, so you can in theory use laser systems to encode and decode data inside it.
The scientists then proved that they could write data to the tungsten, and that it can survive hours of heating at 200 Celsius. Their calculations based on the results suggest that if you went ahead and made some sort of super DVD out of the material it would easily retain data for a million to a billion years at room temperature. That would be useful “if we want to preserve anything about the human race which can outlast the human race itself,” as the paper points out, but it also means that some very important data could be encoded and archived to keep track of our ever-more-digital historical facts.
It sounds extremely promising as a storage system. But the difficulty, of course, is keeping machinery handy that can read the disks decades, centuries, or even millennia after you write them…