Thursday, May 25, 2006

No to the nano

Posted by goatchurch at 5:00 PM
Unexplaned fascination with nano-technology refuses to get out of the way.

"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.


Anonymous Anonymous said...

Just an observation:

We can build robots that do amazing things. In a sense, the computer in which I'm typing this message is a robot capable of performing calculations that I can barely imagine.

You center your argument about the fact that we can't build robots autonomous enough to move around, wich might be more or less true. However, if we manage to somehow construct a nanobot, locomotion is not an issue. Nanobots should be able to float around and perform things 'on site', as opposed to going somewhere and doing something.


5/26/2006 05:52:00 AM  
Blogger epkat said...

The failure of modern robotics is a software problem. But whether or not that is solvable is not relevant to nanotechnology, which rarely considers molecular robots. There is vast potential in nanotech products and materials that are not only dumb, but downright inert and permanently motionless. The potential of nanosystems which, while not motionless, are nevertheless dumb and sessile, is even more vast.

Look at This computer animation concept. Note that nothing in the assembly line depicted here involves individual nanorobots with independent self-propulsion, self-guidance or decision-making. Independence and intelligence are not required of molecular machinery. Don't confuse the "Universal Assembler/Disassembler" myth with the nanosystems that are actually being proposed.

One reason these systems will work so much better than existing technology is the simplicity of an atom in a vaccuum chamber in its interaction as a component. (One of the challenges of building nanosystems and nanofactories will be establishing a molecular vaccuum chamber to prevent interference from the churning of liquid and gaseous collisions.) If we have small enough fingers (which have only recently been developed) atoms act like snapping together Lego bricks, and are very reliable when placed with precision. The large-scale robots you refer to are made of unruly mountains of atoms, shaped with backhoes which, from the molecular level, are the size of skyscrapers.

A cloud of dumb molecular machines that would eradicate a tumor is likely to resemble an advanced form of drug to those who don't know what it is. It would likely be controlled and powered from outside the body with ultrasound or another directionally-focused emitter.

6/01/2006 07:35:00 AM  
Anonymous Damien said...

A nanobot in a bloodstream would have to float or swim around, guided by "smell" or by making random contact with cells until it found its target. This seems rather easier than not only identifying an assassination target by smell but also having the vision to wander around the world safely.

I am not sure the Mars Rover is a good example of the state of the art. It was limited by power supplies and lack of repair ability; caution was much more important than speed. Contrast it with a Roomba (which vacuums the liviing room, with some help). And again, vision is a hard problem, which nanobots wouldn't have.

What does "an honest man in the White House" have to do with self-replicating robots? This seems to be empty rhetoric, not a scientific argument, mundane or otherwise.

Little self-replicating machines swimming around curing cancer and allowing us to live longer might be more easily done with bionano, custom bacteria or prokaryotes. Of course they'd have to dodge the immune system, unless one's own white blood cells were modified for the task.

And the assassin bot seems to have problems of its own: where would it get the smell? How easy would it be to detect and guard against?

6/03/2006 11:49:00 PM  
Anonymous Lucy Kemnitzer said...

The problem with this argument is that it is contrary to the facts. Nano simple machines are already manufactured. They aren't sophisticated enough for medical tasks, but they're being used as lab equipment, as tools, not just as subjects of experiments. Increasingly sophisticated small robots are being used in all fields.

I think some people have a problem with this because they think of a robot as having to be an anthropomorphic, or at least a theriomorphic thing. (is that a legal word? I took the therium part of megatherium to mean "animal") In reality, the really cutting-edge robots don't look like anything but what they are, which is self-guiding tools.

6/14/2006 12:04:00 PM  
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