The IDC report that we covered earlier today said that digital content doubles  every 18 months, but there's a problem with this, a big problem.

Picture this, some venomous cross between swine flu and man flu kills 98 percent  of humans in a few years time. The only surviving people live on some islands and  it takes five hundred years for them to build up any kind of civilization again.

They find abandoned cities covered in jungles, big highway, and gradually build up a picture of 21st century culture.

But they don't have any means of reading these shiny disks they find everywhere.  Most of the books have long since crumbled to dust. So much of the civilization's  words, music and pictures are stored digitally that they don't have a clue what  we were interested in.

In fact, such a problem is more real and more pressing for all of us. In my  lifetime I've had 78RPM [not inch, sheesh, sorry]  records, cassette tapes, CDs, DVDs, eight inch floppy  disks, five 1/4 inch floppy disks, 3.5-inch floppy disks and several types of  hard drive. I can't read the 78RPM records, or the eight inch and 3.5-inch  floppy disks.

I've owned computers since 1979. I've stored books and articles on computers  along with photographs and images for all of this time. I've even lost half a  book because a hard drive crashed before I could back it up. Now, all my  photographs are digital and they're also stored on my hard drives.

Magnify this individual picture hundreds of millions of times for other computer  users and then fast forward another 30 years. I'll more or less certainly be dead  but even if I did stagger on into my nineties, I seriously wonder how much of the  content I alone have produced that I'll be able to read, that is if I can still  see, in my dotage.

It is said that the security services have scanned in all their paper records but  quite sensibly haven't shredded them but placed them in mausoleums in case their  digital systems fall over. Let's hope the civilization of 2600 doesn't base its  idea of our culture on those records...

And anyway, perhaps it doesn't matter that much. The Egyptian civilization existed for over 3,000 years and we don't have much of a clue about that apart  from inscriptions and a few fragments of papyrus. The Babylonian civilization consigned their culture to clay tablets and it was only in the late 19th century that archaeologists discovered a trove of tablets that showed their measurement  of the Moon and planets was better than the Victorians could manage.

In 2600, if the locals can find any S-ATA hard drives that are still intact,  they'll have to put together a system to read it. Will they be bothered to re-invent the PC, create expensive fabs to build the chips, and start a company called IBM? I think not. (Picture on front page courtesy of Wikipedia).