Will glass be the long-term storage medium of the future? This is believed by Microsoft research teams who are developing their Project Silica.
Taking the appearance of a glass plate (quartz glass, in fact), this advanced technology uses femtosecond lasers for writing and microscopes for reading. Clearly: this is currently a research project. But it is advanced enough that the Warner Bros movie studio decides to start experimenting with it for a few films like Superman from 1978. A film that was chosen for a reason of communication: one of the oldest audio recordings of the Warner from the 40’s is a radio fiction starring the superhero. The loop seems buckled.
Project Silica wants to meet two needs: to save space and ensure long-term preservation. Two issues at the heart of film preservation by film studios like Warner.
In addition to digital copies, saving movies (yes, even digital) requires separating the three component colors that will be archived each on black and white films. Coils that must be further stored in an ultra-controlled environment in terms of temperature and humidity so as not to degrade the chemical compounds.
As you can see in the photos, preserving a movie in a physical way is very cumbersome, but necessary since the lifetime of hard disk digital backups is so limited that Warner migrates all of its digital data every three to five years. Here again, the task is cumbersome, costly and provides only short-term preservation.
Project Silica: Store for a thousand years … at a lower cost
This is where Project Silica comes in: Microsoft’s project allows you to record a film on a glass plate 75 mm wide and two millimeters thick, all for a thousand years! Quartz glass is indeed a stable and very solid compound. Microsoft researchers tortured recorded plates (boiling, demagnetization, microwaves, abrasion with iron straw, etc.) a thousand times and were able to retrieve the data each time.
Insensitive to anything that would destroy any spool or hard drive, Microsoft’s quartz glass plate could, if industrialization proves possible, become the reference cold storage system. Archiving “cold” because Silica is cut for read-only use and not a permanent read / rewrite such as hard disk drives or flash memory. The limit of Project Silica is for the moment its experimental character, all happening in the laboratory with expensive equipment and scientists “turntables”.
In theory, this type of storage should cost much less than any other medium. Indeed, the word “Silica” of the project was not chosen at random: the quartz that serves as a support is a crystalline form of silica, silicon dioxide (SiO2), which constitutes nothing less than 60% of Earth’s crust. If obtaining a quartz glass is a fairly complex process, silica remains common compared to metal compounds (not to mention rare earths!).
Femtosecond laser and polarized light microscope
The video presentation of the project is undoubtedly the best way to understand how the process works. The support is a “simple” quartz glass plate, without organic substrate – the purest form of glass. This plate is placed under a variable intensity femtosecond laser equipped with a polarization mechanism that will engrave three-dimensional points called voxels. The laser, very fast (100 femto seconds corresponds to 1 / 10,000,000,000,000th of a second!), Will burn voxels of different size (intensity) and orientation (polarization) to code the data, and this, on several layers. varying the focus area.
Thus, a Project Silica plate can receive complex coded data over several dozen layers (last year, the prototype had up to 75!).
Reading is also very complex at the moment because it is necessary to place the glass plate under a computer-controlled microscope. A polarized light source will allow a camera placed below to read the different layers of the plate. The three-dimensional information will then be combined and milled by algorithms derived from machine learning, to be finally converted into binary code to be exploited by computer programs.