At the recent International Symposium on Optical Memory in Tokyo, Hitachi, working with Kyoto University, presented their new type of digital storage. It works on a principle similar to CDs but with a few added benefits like withstanding over 1000℃ temperatures.
First, so everyone’s up to speed, CDs, DVDs, etc. all work by etching or marking tiny dots along an expanding spiral on the face of a disc. Each dot corresponds to 1bit of data which the laser reads, computer interprets and you enjoy.
The improved storage of Blu-ray and such simply use more efficient lasers and dots. Hitachi’s new technology also improves on this formula but instead of the plastic used by other discs it has quartz glass.
The dots are imprinted inside the quartz glass by a femtosecond laser pulse (which you don’t really need to know but is cool to say) on four separate layers 100 at a time. Each layer’s dots also have different refractive indices which makes light bend in different angles.
This means that the layers don’t interfere with each other at all. The layer that you are focused on appears clearly but the other layers become a cloudy unreadable blur. This method creates a 40MB per square inch storage compared to a CD’s 35MB per square inch.
You might be scratching your head thinking, “that’s not much.” And in an era where Micro SD cards hold GBs of data, you’d be right on. The data capacity is nothing to brag about but that’s not the aim of this project.
People say that data has never been more valuable than it is now, but is that really true? Imagine how much history we’ve lost because carvings, parchments, books, even films simply eroded away over time.
Burning a traditional CD will probably last you a decade or two. You might get more lifespan out of flash memory, but they can be unpredictable and no one is sure how long they’ll really last.
This new storage technology underwent an accelerated degradation test submitting it to two hours under 1000℃. Afterwards the data embedded in quartz glass was retrievable with no corruption. Translating these results under real world conditions we can expect this medium to survive into hundreds of millions of years. Conceivably, culture could never be lost again.
If this was around in biblical times we could have had 100% intact records with some pristine digital photos of Jesus and his wife that we’re just getting around to hearing about now.