Thursday, May 22, 2003

The Oldest Computer

Okay, a couple of weeks ago we talked about what the fastest computer in the world is. Now, what's the oldest? As Neil Gaiman might say, no, older than that? Older than that?

A good candidate is the Antikythera Mechanism, a first-century B.C. Greek device for calculating the positions of the planets. (Also see simulations of it working and another description.)

But no, even older. A lot older.

The ciliate protozoans of genus Oxytricha and Stylonychia do a peculiar thing: they rewrite their DNA, editing and rearranging it in the process. The end result is a clean, junk-free DNA sequence that correctly codes all the various proteins that these little guys need. But what's bizarre and fascinating about it is that this rearranging process is provably equivalent to the Turing Machine. It's a universal computer, and it's millions of years old.