Archival storage poses lots of challenges. We want media that is extremely dense and stable for centuries or more, and, ideally, doesn't consume any energy when not being accessed. Lots of ideas have floated around—even DNA has been considered—but one of the simplest is to etch data into glass. Many forms of glass are very physically and chemically stable, and it's relatively easy to etch things into it.
There's been a lot of preliminary work demonstrating different aspects of a glass-based storage system. But in Wednesday's issue of Nature, Microsoft Research announced Project Silica, a working demonstration of a system that can read and write data into small slabs of glass with a density of over a megabyte per cubic millimeter.
Writing on glass
We tend to think of glass as fragile, prone to shattering, and capable of flowing downward over centuries, although the last claim is a myth. Glass is a category of material, and a variety of chemicals can form glasses. With the right starting chemical, it's possible to make a glass that is, as the researchers put it, "thermally and chemically stable and is resistant to moisture ingress, temperature fluctuations and electromagnetic interference." While it would still need to be handled in a way to minimize damage, glass provides the sort of stability we'd want for long-term storage.
