Suppose you had a very big engineering job to do, and I mean big, like strip-mining the entire surface of the Moon. You could build millions of machines to do it, but that might take centuries, if you were clever enough you'd make just one machine - with the ability to reproduce itself from the raw materials around it. So you'd start a chain reaction, and in a very short time, you'd have...bred enough machines to do the job in decades, instead of millennia. With a sufficiently high rate of reproduction, you could do virtually anything in as short a period of time as you wished.
-Arthur C. Clarke: 2010 Odyssey Two
-Arthur C. Clarke: 2010 Odyssey Two
