The idea of building things from the atoms-up, rather than by crudely machining substances down as we've done since the dawn of tools, holds fascinating potentials. As scientists are learning to move individual atoms around "just so," and are even learning ways to cause the atoms to automatically form up in explicit formations that would make any drill instructor proud, we're poised on the edge of a revolution that, if it matures in ways that many believe, holds the potential for dramatic change in almost every field!
The Seemingly Probable Future.
Consider cloth that repels water, regulates temperature, changes its appearance to blend in with its surroundings, stiffens-up into a cast over an area that has been damaged, or even stiffens-up on command to harden the edge of a palm about to deliver a Karate chop.
Or how about machines far smaller than blood cells that will patrol our bodies on seek-and-destroy missions, targeting cancerous or other unfriendly cells.
Or wires just 20 billionths of a meter in diameter that instead of simply transporting electrons from one circuit to the next, actually ARE the circuits.
Or, how about a "Quantum Confined Atom" (QCA), which is an atom trapped within a "nanocrystal cage" (a tiny cage made from the atoms of a semiconductor) where the semiconductor atoms of the cage alter the properties of the trapped atom. (That is the opposite of today's semiconductors, where the trapped atom alters the properties of its semiconductor host). These developments could lead to ultra-dense quantum dot storage far beyond anything we use today. (http://www.wired.com/news/print/0,1294,54093,00.html) In fact, quantum devices may not be as far away as many expect, considering that University of Wisconsin researchers believe that they can create quantum structures using existing semiconductor fabrication technology by building on-chip vertical structures to contain the quantum dots (http://www.eet.com/at/news/OEG20020806S0030 - with thanks to reader Raoul Teeuwen.)
On another front, one DARPA team believes that their molecular self-assembly process will enable them to demonstrate a 12.5 gigabyte, one centimeter-square storage device -- in 2004! (http://www.upi.com/view.cfm?StoryID=20020804-124925-6113r - with thanks to reader Dana Hoggatt).
These are just a few of the growing number of stepping stones that we're creating on the road towards the tiny and we should consider them well, because the premier laboratories around the world that are working on these things, such as at MIT, have a track record of changing lots of rules.
The Ultimate Tool?
Perhaps the most speculated-about, and the most important "enablers" of a world of nanotechnology manufacturing, is the "nano-assembler" -- a tiny nanobot whose purpose is to use the atomic detritus around it to build the actual nano-machines that will eventually do our bidding. Some envision a nano-project as beginning with a single nano-assembler that is "programmed" with what it's supposed to build. It sizes up the problem and scavenges atomic raw material in its vicinity to build another nano-assembler. The second nano-assembler joins in this task, as does every subsequently-built nano-assembler, dramatically increasing the pace until an optimally-sized fleet of nano-assemblers is ready. At that time they quit replicating themselves and begin the actual construction project.
This idea of, nano-assemblers, may seem like good science fiction. But reader Kenneth LaCross brings our attention to an interesting timeline in a July 15 "Nanotechnology Now" article titled "Ten-Year Assembler Timeline and Weather Forecast" (http://nanotech-now.com/chris-phoenix-assembler-article-071502.htm). Chris Phoenix makes the case that nano-assemblers (or as he calls them, an "industrial revolution in a box") aren't an "if" question, but only a "when" question determined by research dollars and (hence) by political will, which might well come to fruition in ten to fifteen years!
The problem, though, is what if a nano-assembler's programming went awry! Instead of building what we wanted it to build and then shutting down or going into maintenance mode, suppose that it and its progeny continued savaging the atomic material around them to build an unchecked swarm of nano-assemblers, which in turn build more nano-assemblers, ad nauseam. Consider that if these nano-assemblers have the ability to build nano-things, then they must necessarily also have the ability to UN-build the things around them as they mine atomic resources to feed their now out-of-control project!
This is the "gray goo" scenario previously popularized by Bill Joy (http://www.wired.com/wired/archive/8.04/joy_pr.html) and by several science fiction writers, and which is being explored in some new detail by Sean Howard in the August "Acronym Institute" article "Nanotechnology and Mass Destruction: The Need for an Inner Space Treaty" (http://www.acronym.org.uk/dd/dd65/65op1.htm). He sums up the issue, while pointing out that nano-accidents aren't the only consideration:
"Processes of [nano] self-replication, self-repair and self-assembly are an important goal of mainstream nanotechnological research. [But] either accidentally or by design, precisely such processes could act to rapidly and drastically alter environments, structures and living beings from within. In extremis, such alteration could develop into a 'doomsday scenario', the nanotechnological equivalent of a nuclear chain-reaction - an uncontrollable, exponential, self-replicating proliferation of 'nanodevices' chewing up the atmosphere, poisoning the oceans, etc.
While accidental mass-destruction, even global destruction, is generally regarded as unlikely - equivalent to fears that a nuclear explosion could ignite the atmosphere, a prospect seriously investigated during the Manhattan Project - a deliberately malicious programming of nanosystems, with devastating results, seems hard to rule out. As Ray Kurzweil points out, if the potential for atomic self-replication is a pipedream, so is nanotechnology, but if the potential is real, so is the risk:
'Without self-replication, nanotechnology is neither practical nor economically feasible. And therein lies the rub. What happens if a little software problem (inadvertent or otherwise) fails to halt the self-replication? We may have more nanobots than we want. They could eat up everything in sight. ... I believe that it will be possible to engineer self-replicating nanobots in such a way that an inadvertent, undesired population explosion would be unlikely. ... But the bigger danger is the intentional hostile use of nanotechnology. Once the basic technology is available, it would not be difficult to adapt it into an instrument of war or terrorism. ... Nuclear weapons, for all their destructive potential, are at least relatively local in their effects. The self-replicating nature of nanotechnology makes it a far greater danger.'"
(Personally, I'm rather glad that the Manhattan Project did consider the potential of igniting the atmosphere; it would have been SO embarrassing if that had turned out to be a real possibility...)
Don't get me wrong -- I believe that the potential benefits of nanotechnology are immense, and that nanotechnology will eventually (positively) transform both us and our world. But as we are now just beginning this journey, THIS is the time to be thinking about not only its benefits, but also about the dangers of this radical shrinking of our "Tinker Toys." THIS is the time to build-in protections to keep the grey goo at bay. (Of course, if you believe that software errors in nano-assemblers' code could never happen, then this isn't worth worrying about...)
WMD vs. KMD.
There's one other aspect of this move towards nanotechnology that we should be considering. Today, many nations are having to deal with the threats of Weapons of Mass Destruction (WMD), but historically it's taken the resources of nation-states to develop WMDs such as atomic bombs and biological weapons and their traditional delivery systems. Unfortunately, it was demonstrated about a year ago that technology had advanced to the extent that "off the shelf" devices could all too easily be subverted to a WMD role.
Now, as we're on the cusp of NBIC convergence (Nanotechnology, Biology, Information sciences, and Cognitive sciences), Moore's Law and its fallout could conceivably enable the "desktop creation" of nano-devices, and even totally new strings of DNA (such as the Polio virus which was recently created from scratch - http://news.bbc.co.uk/2/low/science/nature/2124354.stm - this short article is WELL worth reading).
As we can appreciate, this demonstrated ability to create deadly viruses from recipes downloaded from the Internet, and by using only components ordered by mail, could be used for both good and for ill. Bill Joy coined the term "Knowledge-enabled Mass Destruction" (KMDs) to describe this offshoot of the Knowledge Age, and it warrants considerable attention. Terrorism aside, imagine what little Suzy might unintentionally do with a "Home Life Creation Kit." (Remember your "mixing and matching" with your first chemistry sets?)
Sean Howard also explores several related ideas in his thought-provoking and interesting article (http://www.acronym.org.uk/dd/dd65/65op1.htm), which I believe is worthwhile reading. Not because KMDs are an issue today, but because, due to the exponential growth of the related NBIC technologies, and because by definition, exponential results sneak up on us before we're ready, we really don't want to be surprised by the potential of "Knowledge-enabled Mass Destruction". Howard concludes, as do I:
"The danger of new means of mass destruction emerging from the development of nanotechnology is, by definition, as yet neither present nor clear. By the time it is, [though,] it may be too late to either eliminate or control.
While there is no realistic possibility of early arms control negotiations to tackle the threat, the international community should at least take cognizance of the issue - in all its aspects, to use the appropriate diplomatic term for far-reaching, open-ended and open-minded deliberation."
DO -- please -- blink!