An article by Martin Hilbert and Priscila Lopez in the April 1 issue of Science attempts to estimate "The World's Technological Capacity to Store, Communicate, and Compute Information," from 1986 to 2007. For the moment, let's consider only the capacity to store information.
My own house might be a good representation of 1986. It was chuck full of stored info, almost all in analog form: books, magazines, vinyl LPs, 8-mm film, photographic slides, photo negatives and prints, audio cassettes, VHS cassettes. Digital storage? My Macintosh 512K and a few floppy disks.
Hilbert and Lopez estimate that about 1 percent of the world's stored information in 1986 was digital, which sounds about right for my house. No, I suppose 1 percent is too generous. My Mac and floppies contained less info than one volume of our Encyclopedia Britannica.
In 2007, according to Hilbert and Lopez, only about 4 percent of the world's stored information was analog, and that included all libraries.
In 1986, the amount of digitally stored information was less than one CD-ROM per person. In 2007, each of us could claim over 60 CD-ROMs. Piling up all of the 404 billion CD-ROMS from 2007 would create a stack that would reach from Earth to the Moon and then a quarter of that distance beyond!
That sounds like a humungous amount of digitally stored info, but consider this: It is still somewhat less than the roughly 10 (23) bits stored in the total DNA of a human adult. And the 6.4x10(18) instructions per second that humankind could carry out on all of its general-purpose computers in 2007 is in the same ballpark as the maximum number of nerve impulses executed by one human brain per second. Which is an illuminating way of thinking about just what a wondrous thing is a human being.
Anyway, back to my house. Which is an ever-growing monument to analog. Books are jammed into every available cranny. Once the kids moved out, their bedrooms became dumps for books and paper. File cabinets bulge at the seams. A glance around the house would suggest that the analysis of Hilbert and Lopez doesn't apply.
But there are more photos stored on my MacBook than in all of our albums. A single flash drive -- the size of a stick of gum -- could store the equivalent of every book in the house, with room left over for the file cabinets and piles of paper. Yes, all of this colossal analog mess could slip into my pocket. But, ah, would those invisible bits have the same power to evoke memories of a lifetime of reading and writing and being part of a wonderful family? I think not. I'll take my avalanche of analog -- visual, tactile evidence of the way that I went.