Re:It doesn't take half a brain to see this. (Score 0, Troll)

Nanotech doesn't play by the same rules as currently extant terrestrial biology.

We can't 'eat' air and dirt and use it (and it alone) to grow and reproduce. Nanites could, in theory, do just that, by using raw materials in the air and the earth to reproduce. It all depends on (A) how they are programmed, (B) how they mutate, and (C) how lucky (or unlucky) we are.- Well, as the other reply below so eloquently put it, humans are imperfect. To create a grey-goo doomsday nanodevice would require perfect engineering, ensuring the device withstands all climates, can consume any material, and can avoid all attempts by people to stop it from growing. While I agree we need to be cautious, raising this cautiousness to absurd heights is just as dangerous as being completely carefree.