In the years following the original publication of my essays on molecular nanotechnology, certain criticisms of the theories supporting this hypothetical technology have forced me to re-evaluate my position regarding MNT’s feasibility. This addendum to the ‘Snowcrashing’ essays was originally part of an opinion piece I wrote for the Kurzweilai forums called ‘James G76’s Miracle Machine’…
MYSTERIES, PROBLEMS, SOLUTIONS.
When thinking about an invention, it is helpful to consider three stages of knowledge: Mystery, Problem, and Solution. According to Steven Pinker, while at the mystery stage of knowledge “we can only stare in wonder and bewilderment, not knowing what an explanation would even look like”. On the other hand, (again, quoting Pinker) “when we face a problem, we may not know its solution, but we have insight, increasing knowledge, and an inkling of what it is we are looking for”. So, basically, the difference between ‘mystery’ and ‘problem’ is all to do with being able to ask useful questions, such that even mistakes and wrong answers help you make progress more than they keep you totally blind as to the correct route toward the solution.
Molecular nanotechnology, surely, is at the ‘problem’ stage? After all, didn’t Eric Drexler design blueprints for all the components, subsystems and systems of nanobots in his book ‘Nanosystems’? Yeah, kind of, but before we get too excited, Drexler has some sobering words for us:
“The work outlined here could rapidly absorb researcher-centuries of effort. Many of the steps described here will, if attempted, spawn a host of sub problems, each demanding long, hard, and creative work… Developments that will one day make molecular manufacturing fast and easy will result from efforts that are slow and difficult”.
BURSTING THE NANOTECH HYPE BUBBLE
Still, despite this cautionary remark, Drexler had confidence in the swift realization of molecular nanotechnology. “Image interpretation software able to determine the types, positions, and orientations of specific sets of reagent binding molecules; control software to automate reagent positioning and sensing, thereby automating the execution of long sequences of reactions” would be feasible, Drexler reckoned, “in a fraction of a decade”.
However, he said that in 1992 and it is safe to say that, here in 2011, nanotechnologists are nowhere close to this level of capability. But, when it comes to Drexler’s prediction that attempts to build his nanotechnology would “spawn a host of sub problems” it seems he was right on the money.
Richard Jones, professor of Physics at the University of Sheffield and senior advisor for the UK Government’s Physical Sciences and Engineering Funding Agency surveyed the progress being made in nanotech for IEEE Spectrum. “In 15 years of intense nanotech research, we have not even come close to experiencing the exponentially accelerating technological progress toward the goals set by singularitarians… the Drexlerian vision… seems to be accumulating obstacles faster than it can overcome them”.
Jones does admit that “impressive advances are emerging from the laboratories of real-world nanotechnologies”, but this kind of nanotech has little to do with the stuff Drexler sketched out in ‘Nanosystems’ and ‘Engines Of Creation’. The same thing could be said for life itself, which is often held up as proof that molecular nanotechnology is achievable. Proponents of nanobots are fond of reminding us of biology’s numerous natural nanoassemblers, molecular motors, software-controlled manufacturing, and more besides. But, they fail to take into consideration the fact that this is a ’nanotech’ of a radically different nature to what people like Ray Kurzweil talk about. That nanotech is basically robotic factories like the kind that automate car manufacturing shrunk down to sub microscopic sizes. But life’s nanotech is nothing like that. According to Professor Jones, life’s nanotech “operates on principles that are fundamentally different to the mechanical principles that macro scale engineering works with”.
In some ways, the argument ‘life provides proof-of-principle of molecular machinery’ is like saying ‘the brain creates an intelligent mind and it is a kind of computer, so we have a proof-of-principle that artificial general intelligence is possible’. The flaw in this argument is that the brain is nothing like any computer you are familiar with, so no matter how more sufficient current computing technology becomes, humanlike intelligence may never arise. Nothing less than a complete paradigm shift to a new kind of computer (one more ‘brainlike’) might be required before we have genuine AGI. Similarly, nature’s nanotechnology (often referred to as ‘wet’ nano) is a totally different design philosophy to the diamandoid-based machines outlined by Drexler (‘dry’ nano.) Again, this means all that progress in ‘wet’ nano does not necessarily lead inevitably to the kind of nanotech outlined in ‘Nanosystems’. We require a paradigm leap to an entirely new kind of nanotechnology for which nature has no precedent.
Frankly, the people who claim ’nanorobots that can build anything physically possible out of atoms or molecules they got from disassembling garbage are but decades away’ have no clue regarding the tower of near-intractable problems Drexlerian nanotechnology has stacked up. These include problems to do with the stability of ’machine parts’ (ie, the cogs and gears of nanosystems), problems caused by thermal noise and Brownian motion, problems to do with friction and energy dissipation, and, perhaps most concerning of all for those who hold out hopes of owning a desktop nanofactory by 2020,30, 40, there are the problems caused when trying to make the transition between two completely incompatible environments and two completely incompatible design philosophies (ie, bio nanotechnology like DNA origami, and manufactured proteins on the one hand and diamondoid gears, motors, actuators on the other). And, let’s be clear that we are not talking about insignificant little problems here. These are show-stopping problems that seriously challenge the very feasibility of nanobots. This is not to say that zero progress toward Drexlerian nanotechnology has been made. Through heroic efforts, folks like Rob Frietas and Ralph Merkle are inching toward theoretical solutions to some of these problems. But still, the fact remains that the gap between what has been accomplished and what needs to be accomplished before we can even begin to design nanorobotics like transhumanists talk about is A) immense and B) (if Jone’s survey is correct) growing wider instead of shrinking.
The nanotech situation is an important lesson regarding whether or not the ‘problem’ stage is close to transitioning into the ‘solution’ stage. If subproblems are accumulating faster than partial solutions, you can safely assume there is no chance of the final goal being in sight.
For more information on the difficulties facing MNT, google ‘Richard Jones Soft Machines’