It sounds a bit ridiculous at first. Dozens of gigabytes of data can now be encoded on a virtually indestructible glass hard drive that’s the size and shape of a drink coaster. Microsoft just revealed a proof of concept. It’s a thin square of glass that’s been laser-etched with microscopic geometric shapes called “voxels” that contain a combined 75.6 gigabytes of data, which contains the 1978 film Superman in its entirety.