A few years ago, the price of hard-disk drives started to drop, while their capacities jumped exponentially. That's why I've got three little beasts like this sitting behind my iMac, for random backups (alongside my Time Machine backup, which runs permanently):
Like most computer users, I simply greeted this hardware affair with pleasure, without ever bothering to think about the reasons for the hugely positive evolution of the economics of hard-disk backups. I imagined naively that manufacturers had simply improved their production methods in such a way that prices could be slashed while the drives themselves could have increased storage capacity. In fact, the explanations are considerably more complicated than that. These days, customers have indeed been reaping vast benefits from the development and commercial availability of entirely new storage technologies... and things are still getting better all the time.
In a recent issue of Scientific American (the only paper publication to which I subscribe), there's a splendid article on this subject written by an English physicist named Stuart Parkin, who has been working in California on the invention of astounding new storage technologies. [Click the photo to access the Wikipedia article on this man.] In the context of my blog, I cannot of course attempt to explain the nature of the complex technologies at the origin of our low-cost high-capacity hard-disk drives. But I can't resist the temptation of quoting an amazing item of information provided by Parkin in his Scientific American article:
Today the collective storage capacity of all hard-disk drives manufactured in one month exceeds 200 exabytes, or 2 x 10-to-the-power-20 bytes [I don't know how to display an exponent in Blogger]—enough to store all the extant analog data in the world, that is, all the data on paper, film and videotape.
You might ask: Who is actually purchasing this astronomical quantity of storage potential? And what are all these storage devices being used for? Those are good questions, which I'm incapable of answering. It can't all be Google...