You can discount the big-brother paranoia and tendentious politics if you want, but James Bamford's review of a new history of the National Security Agency contains some pretty interesting stuff. Here's what caught my eye in the description of NSA's data repository needs:
Just how much information will be stored in these windowless cybertemples? A clue comes from a recent report prepared by the MITRE Corporation, a Pentagon think tank. "As the sensors associated with the various surveillance missions improve," says the report, referring to a variety of technical collection methods, "the data volumes are increasing with a projection that sensor data volume could potentially increase to the level of Yottabytes (1024 Bytes) by 2015."Yottabytes! Yow! (The official name for 1024 is a septillion, a bit of mind-rotting trivia that we'll henceforth ignore.)
To imagine how big 1024 is: think of a gold cube 1 millimeter on a side. (That's pretty small.) It would weigh about 19 milligrams, and at today's prices (say $34/gram), would be worth about 66 cents.
If you (carefully) arranged a million of those tiny cubes into a neat 100x100x100 stack, the result would be a cube 10 centimeters on a side, about 4 inches. In gold, that's a little over 19 kilograms (42 and a half pounds), and worth about $660,000.
You can see where this is going: If you stacked up a billion little cubes (1000x1000x1000), the result would be a cube 1 meter on a side, about 40 inches. It would weigh a smidgen over 21 tons, and it would be worth … of course … $660 million.
But jump to 1024 of the little cubes: they make up a yottacube 100 kilometers (about 62 miles) on a side. And—well it's pointless to imagine that in gold; there just isn't that much gold on earth, nor enough money to buy it.
OK, so we're talking about data, not gold. But even so: you can run down to Best Buy and a one-terabyte (1012) hard drive for somewhere in the ballpark of $100: a huge drive for not that much money.
Storing a Yottabyte would require you to get one trillion of those drives. And you'd be putting $100 trillion on your Mastercard for them.
So apparently NSA has something even cheaper in mind.