No to the nanoPosted by goatchurch at 5:00 PM
"Nano-technologies" from the cutting edge of physics remain surprisingly mundane, limited to a few interesting crystals and one or two bent molecular wires. Yet SF people continually get excited, and dare I say "distracted", by it.
It's not a failure of imagination, so much as a problem of over-imagination. You can read about a hat that can talk in a book, and you can easily imagine it can happen. The image might be so compelling that you can write stories about it, although there might be more important things to think about.
The idea that there are going to be invisibly small self-propelled little machines swimming and running around the environment, rearranging matter in cool ways, curing cancer, and allowing us to live longer, is nothing more than wish fullfillment. However, it ought to be dismissed immediately after a moment's thought. We cannot even build a self-propelled machine that could get to the end of the garden and back, unless it was a tank that didn't care what it drove over. If you want to see the state of the art in terms of this technology, recall the Mars Exploration Rover with an average speed of 1mm/second over hard packed ground, while having to stop every half minute. Admittedly it did a lot more than just drive around, but it's embarrassing. It's worse than a tortoise.
As to relative sizes, the critique is obvious. In 12th century England they couldn't build reliable mechanical clocks. Therefore it's safe to assume they also couldn't build miniature wrist-watches.
This common-law rule should apply when you are imagining stuff that's like nano-technology. I call it the Law of Techno-precedence:
If the ability to build mechanism X implies that you can build mechanism A, then a world which contains X without A must be sufficiently explained. There may be no explanation that is sufficient.A trivial example: a metal worker who can build scissors, but can't make a knife. An important example: a world where there is atomic power but there has never been an atomic bomb.
The nano-bot example: a scientist makes self-propelled miniature machines, but we still don't have a robot that can vacuum the living room.
I wrote a story about the invention of a robot that could travel as much as one kilometre at the speed of a gecko, and assassinate anyone who could be identified by their odour. It could be built with off-the-shelf parts, and the only technical difficulty was getting the software. Within a few months we could eliminate every world leader, policeman, irritating boss, Bill Gates; anyone who is well-known and has annoyed anyone -- that's about 0.0001% of the population; most of us are pretty well anonymous. The world would be changed beyond all recognition.
I'd argue that a scenario like that was considerably more likely than the building of robots the size of a pinpoint that could chew a hole in some rich white guy's lung cancer. But which one always fills the pages of NewScientist? Why? Whatever happened the techno-precedence?
The point is to get something that connects with reality through more than the usual points of contact. Nano-technology may or may not be possible. Eventually. But as a theme for today, it's entirely misused. Before technology X, there will exist technologies A, B, C, D, E, and G, as well as human extinction threats P, Q, and S. There will be cameras on fleas, an honest man in the White House, and clones without heads, carpets made of worms; before there is ever a self-replicating nano-bot in a petri-dish.
Banning nano-bots from mundane-SF is called playing it safe. It's like stopping you drinking whiskey while you are writing. It's not that you can't handle it, or that it doesn't make you feel great. But we want some different results, apart from the usual ramblings. Maybe after you have deliberately exercised your mind without, it'll be safe to use this substance in small doses. But for this exercise I don't want to see the usual drunkenness on the job.