James, your "only" glosses over a huge amount of engineering. Any machine that can loop through any process to duplicate itself from environmental chemicals will be very complicated.

I don't know what you mean by "holographic methodology" and "instinctive programmability."

Chris

What’s so difficult about self assemblers?, they only need memory, storage, and processing capabilities aligned with a looped program to cause self replication or "mindless" expansion.

Its self replication that would require too much effort if every aspect had to be planned out and verified before continuing on to the next item for assembly, but if a holographic methodology coupled with instinctive programmability was utilized, then the needs for designing self replicators becomes a moot topic.

It not the process that’s so important, it’s the "looping" that counts.

James

Howard sez (Dec. 13): "And that's when those who represent nanotech interests...will finally look beyond their insular world...to see, much to their surprise, that nanotechnology became embedded in popular thought and mythology without any guidance from them."

I think they have already started looking beyond. And they don't like what they see. They see that a huge nanotech meme is gray goo. Gray goo is bad--the stuff of relinquishment and public outcry.

For example, the NY Times Magazine today has a really bad article on gray goo, presenting it as an accidental consequence of general molecular manufacturing. This is the kind of story that damages policy and spreads misinformation. I sent in a letter (we'll see if they print it) and CRN will probably be doing a press release explaining why the story is wrong (also keep reading this posting). http://www.nytimes.com/2003/12/14/magazine/14GRAY.html

Howard continues: "Depending upon the nature of the nano meme, the "official" nanotech community will either launch campaigns against it, or take credit for its existence."

Campaigns against it are also already happening. Notice that the Nano Act was changed at the last minute to remove all mention of molecular manufacturing, and Modzelewski then went out of his way to call Drexler's work "science fiction." Look at Smalley, going to such rhetorical lengths to assert that mechanochemical nanobots are impossible so we should stop scaring "our children."

So the campaigns against it are, unfortunately, targeting all of molecular manufacturing/MNT rather than just the goo idea.

The irony is that the scary, insect-like, goo-like, semiautonomous "assemblers" that started the gray goo meme have not been part of the MNT proposals for over a decade. MNT manufacturing will be done in relatively large factories working from preprocessed specialized feedstock--not at all goo-like.

I agree with Paul Hughes that, with lots of effort, gray goo could be built. But I disagree that it's the biggest danger of MNT. For one thing, it'll take a while after we get MNT before we can build a goo. For another thing, non-goo MNT weapons can be far more destructive (because far more efficient). A likely scenario is an unstable arms race leading to a devastating war. See our Dangers page for more problems.

A third thing, for what it's worth: it turns out that an exponentially replicating population of goo-bots requires only a constant population of hunter-bots to wipe it out. Not to say cleanup would be easy, but it wouldn't require massive emergency crash production of hunter-bots, as many scenarios have assumed.

Chris

Paul: I would take it as a given that someday someone WILL create a gray-goo nanite and unleash it. This is not a reason to scream that the sky is falling, but is a reason to start planning out rational strategies to be prepared for it to shut it down when and where it occurs.

The Luddite's approach of "just stop ALL nanotech development EVERYWHERE!" is simply not in line with reality. It's coming. Start dealing with it. Sticking your fingers in your ears and shouting "LA-LA-LA! I CAN'T HEAR YOU!" is not a viable approach. The real question is "HOW will we deal with this WHEN it gets here?" not "How do we stop all this icky technology stuff from being built by those science-type guys?"

Another problem with the-sky-is-falling crowd is that they just don't take into account environmental and energy factors. Not all environments will be friendly to nanites and they have to get the energy to "eat everything in sight" from SOMEWHERE.

Edited by author 11-10-2003 03:31 PM
I've been a nanotech enthusiast for over 15 years, and although I agree with Merkle that a broadcast approach is far safer than autonomous replicators, there is no reason they still can't be built - and THAT is the danger of nanotechnology, and therefore the 'metaphor of biology' is more than appropriate. Merkle should know better. If a self-replicating toxic virus can exist, then a self-replicating nano-assembler that eats everything (Grey Goo) can also exist.

I can hope that such malicious "apocalyptic" assemblers are never created, but there are over 6 billion people on the planet and growing, and all it takes is one clever human being with a few bits shy of a byte to make it and release it.

Edited by author 10-09-2003 03:23 PM
Public perception is very important in any debate. Unless you can show the average joe on the street how things work (or don't work) he will believe any crank that has an interesting slant on an issue no matter how bizare.

Edited by author 10-01-2003 06:04 PM
How important is public perception (as opposed to reality) in nanotechnology policy debates?