Ef­fect­ive Al­tru­ism Book Review: Rad­ical Abund­ance (Na­n­o­tech­no­logy)

Book Review: Rad­ical Abundance

I. Introduction

As a ma­ter­i­als en­gin­eer­ing ma­jor with, roughly speak­ing, a year of full-time ex­per­i­ence with mo­lecu­lar dy­nam­ics sim­u­la­tions, I have a spe­cial place in my heart for high im­pact ma­ter­i­als both lit­eral and fig­ur­at­ive. As a lurker in ef­fect­ive al­tru­ism, I was de­lighted to see some­thing po­ten­tially rel­ev­ant to my ex­per­i­ence show up. I made a post in the “Na­n­o­tech­nolgy in EA” Face­book group ex­press­ing/​re-it­er­at­ing the fol­low­ing thoughts:

  1. Na­n­o­tech­no­logy will be chaotic and hard-to-pre­dict, re­quir­ing massive ad­vance­ments in com­pu­ta­tion be­fore ef­fect­ive ma­chines can be de­signed.

  2. Our tech­no­logy in terms of ac­tu­ally pro­du­cing APM seems plaus­ible but very un­cer­tain at this point

From my post, I got some in­ter­est­ing com­ments sug­gest­ing an al­tern­at­ive to 1. along with a re­com­mend­a­tion to read K. Eric Drexler’s new book on atom­ic­ally pre­cise man­u­fac­tur­ing (APM), Rad­ical Abund­ance: How a Re­volu­tion in Na­n­o­tech­no­logy Will Change Civil­iz­a­tion. This, in part with some googling, gave me the im­pres­sion that I was also wrong about 2.

The goals of this book re­port from least to most sig­ni­fic­ance are: provid­ing a de­cent sum­mary of Rad­ical Abund­ance, ex­press­ing my own thoughts on what I find to be the most sa­li­ent as­pects of na­n­o­tech­no­logy, and cla­ri­fy­ing pos­sible com­mon mis­con­cep­tions that con­trib­ute to the fre­quent con­fu­sion about na­n­o­tech­no­logy’s place in ef­fect­ive al­tru­ism.

Any­way, Rad­ical Abund­ance lightly dis­cusses three inter-woven con­cepts: how APM would work, how APM could im­pact the world, and how APM can be achieved. Let’s do this.

II. How APM Works

A. Ad­vanced APM in a Nutshell

The de­scrip­tion and un­der­stand­ing of APM can be best char­ac­ter­ized by Drexler’s own words:

APM-based ma­ter­i­als pro­cessing tech­no­logy will em­ploy nano­scale mech­an­ical devices that op­er­ate at high fre­quen­cies and pro­duce pat­terns of atoms...think of an APM sys­tem as a kind of printer that builds ob­jects out of atoms just as a printer builds im­ages out of pat­terns of ink, con­strained by a lim­ited gamut, not of col­ors, but of out­put ma­ter­i­als.

This cla­ri­fies two dis­tinct points that I, as someone work­ing in mo­lecu­lar dy­nam­ics and , would miss. First, des­pite my pri­ors from ex­per­i­ence with soft mat­ter mo­lecu­lar dy­nam­ics, APM sys­tems will be based on mech­an­ic­ally-in­spired ri­gid mech­an­isms rather than bio­lo­gic­ally-in­spired soft mat­ter ma­chines. Se­cond, at its heart, most APM will fo­cus on the fab­ric­a­tion of macro-scale ma­ter­i­als with nano-scale op­tim­iz­a­tion (i.e. really good ma­ter­i­als) rather than nan­oma­chines (i.e. tiny ro­bots), though these will be ne­ces­sary to some ex­tent in cre­at­ing APM in the first place and have massive peri­pheral uses and im­plic­a­tions.

B. Mech­an­ical Devices in Nanotechnology

First, while ex­ist­ing ex­amples of APM (i.e. ri­bosomes) are bio­lo­gical in nature and demon­strate the po­ten­tial for lever­aging nano-scale devices in com­plex ways, Drexler’s APM uses down-scaled mech­an­ical devices like those in mod­ern factor­ies to achieve its ends in­stead of the chaotic com­plex­ity of bio­logy. In or­der to suc­cess­fully im­it­ate the be­ha­vior of mech­an­ical ma­chines, nanomech­an­ical ma­chines will typ­ic­ally be made of “stable co­va­lent struc­tures that con­sist of fused rings; among hy­dro­car­bons, small-scale ex­amples in­clude the adam­antanes and the some­what more flex­ible aro­matic mo­lecules.” Think­ing along these lines sim­ul­tan­eously opens up new pos­sib­il­it­ies and grounds oth­ers. When I think about bio­lo­gical APM, I think of spec­tac­u­larly com­plex inter-plays of atoms and mo­lecules su­perbly op­tim­ized in par­al­lel with their en­vir­on­ments over mil­lions of years to provide the suf­fi­cient but in­cred­ibly im­prob­able con­di­tions for life. When I think about mech­an­ical APM, I think about the Saturn V Rocket.

To il­lus­trate the dif­fer­ence, con­sider the fol­low­ing situ­ation where someone asks me about the fu­ture of lever­aging na­n­o­tech­no­logy to achieve goal a goal in a given en­vir­on­ment:

Me think­ing about bio­lo­gical na­n­o­tech­no­logy: “Of course! We’ll use in­cred­ibly com­plex com­pu­ta­tional tools coupled with auto­mated labor­at­or­ies to build a black-box ma­chine that does the job you need… At least, we will if we ever fig­ure out how to make com­puters and labor­at­or­ies that ef­fect­ive. Once we do though, the sky’s the limit!”

Me think­ing about mech­an­ical na­n­o­tech­no­logy: “Hmm… It looks like achiev­ing your goal also re­quires some flex­ible com­pon­ents or at least a fair num­ber of auto­mated com­pu­ter­ized sys­tems so I’ll need to see if we can get ma­ter­i­als to work well with that at the nano-scale… And your en­vir­on­ment is a bit dif­fer­ent so I might need to se­lect dif­fer­ent mo­lecules to make sure they’re stable and ri­gid un­less you want to in­cor­por­ate homeo­stasis which would add an­other or­der of com­plex­ity… Give me five years, a few mil­lions dol­lars and the atom­ic­ally pre­cise tech I need to build some­thing and I’ll let you know.”

The dif­fer­ence between these bio­lo­gical and mech­an­ical char­ac­ter­iz­a­tions of na­n­o­tech­no­logy is sim­ul­tan­eously com­plic­ated and subtle. Both seem a long ways off in terms of tech­no­logy but the former de­mands a clear con­cep­tual leap (much bet­ter com­puters) while the lat­ter re­quires an ex­tens­ive but plaus­ible level of tech­no­lo­gical pro­gress (Im­proved know­ledge of chem­istry and ex­ist­ing chem­istry tech­niques). This means that, while the former might never be achieved, the lat­ter will prob­ably be achieved even­tu­ally.

A sim­ilar point can also be made about po­ten­tial im­pact. Bi­olo­gical in­ter­pret­a­tions of na­n­o­tech­no­logy very quickly start hint­ing at massive re­volu­tions in nano-ma­chines that con­stantly re­spond and im­prove all as­pects of hu­man life and en­gin­eer­ing, ag­greg­at­ing to­gether to form macro-level ma­chines of in­cred­ible com­plex­ity and com­pu­ta­tional ca­pa­city. In con­trast, mech­an­ical in­ter­pret­a­tions of na­n­o­tech­no­logy are groun­ded in lim­ited types of ma­ter­i­als in lim­ited en­vir­on­ments with lim­ited cap­ab­il­it­ies.

For the most part, these lim­it­a­tions are the same for both macro-scale mech­an­ical devices and nano-ma­chines since both can be de­scribed in “fa­mil­iar, mech­an­ical terms.” However im­port­ant dif­fer­ences do ex­ist. Drexler notes that “a ma­chine can’t work well if its parts can’t move smoothly and in­ter­ac­tions between atomic-scale bumps on sur­faces might seem to make smooth move­ment im­possible.” This can be re­solved through design­ing bump pat­terns to pro­duce su­per­lubri­city but comes with its own con­straints. Drexler also notes the pres­ence of drag and thermal mo­tion but these forces are not very sig­ni­fic­ant in the con­text of ri­gid mech­an­ical struc­tures. I would also like to add an ad­di­tional con­straint: Be­cause “stretch­ing space and time in equal pro­por­tion scales prop­er­ties like mass, force, and ve­lo­city in ex­actly the right way to make mech­an­ical mo­tion the same,” one quickly real­izes that grav­ity, pro­du­cing an ac­cel­er­a­tion of 9.8 meters/​second down re­gard­less of size, van­ishes in im­port­ance. In this sense, nano-scale factor­ies will not be like the factor­ies seen on Earth but rather more like the ones de­signed in space. Ad­di­tion­ally, they will be driven purely by mo­tors and mech­an­ical devices with no in­cor­por­a­tion of elec­trical wir­ing (clas­sical elec­trical en­gin­eer­ing breaks down at the nano-scale).

Ini­tially, these lim­it­a­tions made me skep­tical about whether APM could feas­ibly cre­ate com­plex de­signer ma­ter­i­als or ex­tend to ad­vanced nano-ma­chines out­side of a man­u­fac­tur­ing con­text. However, this video led me to real­ize that the sort of tar­get ma­ter­i­als to be con­struc­ted could rely on ba­sic pat­terns of pick­ing up and put­ting down dif­fer­ent atoms and mo­lecules. Ad­di­tion­ally, be­cause the nano-scale is so small, re­l­at­ively large nano-ma­chines can still be build at very low size-scales (though this nano-ma­chines are still what I am most skep­tical about).

For the most part though, the out­puts of my bio­lo­gic­ally-in­spired ex­pect­a­tions of na­n­o­tech­no­logy and Drexler’s mech­an­ical vis­ion seem sim­ilar. As Drexler says:

A SCIENTIST WROTE an art­icle about the nan­oma­chines of the gen­eral sot I’ve de­scribed, but he sug­ges­ted that they couldn’t be used in a bio­lo­gical en­vir­on­ment be­cause bio­molecules would gum up gears and other mov­ing parts. The an­swer, of course, is to keep gears in a gear­box, and to place all crit­ical mov­ing parts in­side a sealed shell.

The moral here is that most mech­an­ical nano-ma­chines can be de­signed to avoid many of the prob­lems that they might face re­l­at­ive to their ma­gical bio­lo­gic­ally-in­spired cous­ins. At the same time, this in­dic­ates a more gen­eral prob­lem: to build a func­tional nano-ma­chine, there must be some in­put and some out­put which fa­cil­it­ates ac­tion on the en­vir­on­ment. This means that some of the mech­an­isms in a given nano-ma­chine must be de­signed for the en­vir­on­ment. However, the sever­ity of this lim­it­a­tion also de­pends on the nano-ma­chine’s func­tion­al­ity: For power, mech­an­ical mech­an­isms can be de­signed to min­im­ize com­plex parts ex­ter­ior to a core gear­box. For ex­pelling ob­jects, a nano-ma­chine might in­cor­por­ate a simple air­lock-like design. However, for tak­ing in and pro­cessing new mo­lecules in an un­con­trolled en­vir­on­ment, nano-ma­chines would re­quire both fil­ters and safe-guards to pre­vent clog­ging.

C. APM as Macro-Scale Manufacturing

While these lim­it­a­tions do not pre­clude the ex­ist­ence of nano-ma­chines (and es­pe­cially those that man­u­fac­ture on the fly) in un­con­trolled en­vir­on­ments, they do raise ques­tions. However, this spe­cific tech­no­logy is not the end goal that Drexler fo­cuses on in Rad­ical Abund­ance. Though Drexler does al­lude to “fast, thor­ough data col­lec­tion and the means for rapid de­ploy­ment of nano-scale devices” in the con­text of bio­lo­gical in­ter­ven­tions, the lion-share of spec­u­la­tion about the fu­ture is fo­cused on ma­chines like this one:

Pic­ture your­self stand­ing out­side the fi­nal as­sembly cham­ber of a large-product APM sys­tem and look­ing in through a win­dow to view the ma­chines at work in a space the size of a one-car gar­age....

To the right, you see an exit door for products ready for de­liv­ery. To the left, you see what look like wall-to-wall, floor-to-ceil­ing shelves, with each shelf par­ti­tioned to make a row of box-shaped cham­bers. In the middle of the gar­age-sized cham­ber in front of you is a mov­able lift sur­roun­ded by a set of ma­chines.

The ma­chines look un­com­monly sleek, yet very fa­mil­iar. They re­semble ma­chines in an auto­mated fact­ory, with ro­botic arms pro­grammed to swing around, pick up com­pon­ents, and swing back to snap the com­pon­ents to­gether. The ma­chines look like this be­cause they are, in fact, ma­chines in an auto­mated fact­ory and be­cause ma­chines that per­form sim­ilar mo­tions of­ten have sim­ilar shapes and sim­ilar mov­ing parts. Be­cause they are made of ma­ter­i­als bet­ter than steel, how­ever, they can be faster, lighter, and more ef­fi­cient.

Look­ing back at the wall on the left, you can get a clear view into sev­eral cham­bers that hap­pen to be at eye level and near the win­dow. Each smal­ler cham­ber con­tains ma­chines with swinging arms, and the over­all setup in­side looks like a scale model of the lar­ger cham­ber, com­plete with a rear wall with wall-to-wall, top-to-bot­tom rows of yet smal­ler cham­bers. It’s hard to see in de­tail what these small cham­bers-within-cham­bers con­tain, but they seem to hold a tiny yet fa­mil­iar set of ma­chines moun­ted in front of a rear wall with rows of yet smal­ler cham­bers.

With the press of a but­ton, the ma­chinery kicks into gear. At first noth­ing seems to hap­pen, but in less than a minute the large ma­chines in front of you start to pick up parts as they pop out of the cham­bers in the wall at the left, mov­ing these parts to the plat­form in the cen­ter where the first parts are clamped, and the rest snap to­gether. As the ma­chines put the parts to­gether, a fa­mil­iar product takes shape, an auto­mobile, dif­fer­ent in al­most every de­tail from those built today, yet hav­ing a form that re­veals the same func­tion. cham­bers.

With the press of a but­ton, the ma­chinery kicks into gear.

At first noth­ing seems to hap­pen, but in less than a minute the large ma­chines in front of you start to pick up parts as they pop out of the cham­bers in the wall at the left, mov­ing these parts to the plat­form in the cen­ter where the first parts are clamped, and the rest snap to­gether. As the ma­chines put the parts to­gether, a fa­mil­iar product takes shape, an auto­mobile, dif­fer­ent in al­most every de­tail from those built today, yet hav­ing a form that re­veals the same func­tion.

Each part takes sev­eral seconds to put into place and new parts slide out of the cham­bers at a cor­res­pond­ing rate, each cham­ber de­liv­er­ing a com­pon­ent every few seconds. To the left, in­side the closest cham­ber, you can see the ma­chines work­ing in­side. These mini­ature ma­chines seem to be per­form­ing sim­ilar tasks, but at a rate of sev­eral cycles per second, their mo­tions are al­most too quick to fol­low. It’s easy to guess what’s hap­pen­ing in the yet-smal­ler cham­bers farther back, yet the mo­tions there are no more than a blur.

In the main cham­ber the work is com­plete in less than a minute. The door to the right then un­seals and opens, and a car moves out into a re­ceiv­ing area, sealed in what looks like a plastic sleeve. A mo­ment after the door re­seals, the sleeve is pulled back for re­cyc­ling and the pro­cess is done. (This exit man­euver is part of a cycle that pre­vents con­tam­in­ants from en­ter­ing when the product exits.

This de­scrip­tion is in line with the video linked earlier and leads me to in­fer that, though many other uses also ex­ist for na­n­o­tech­no­logy, the main use-case em­phas­ized in Rad­ical Abund­ance is ex­tremely ef­fi­cient factor­ies that build ex­tremely high qual­ity ma­ter­i­als by ex­ploit­ing “light­weight, car­bon-based ma­ter­i­als” and in­ter­est­ing already-dis­covered pat­terns that may pro­duce exotic elec­tronic prop­er­ties on the macro-scale. I men­tion this be­cause APM as ad­vanced man­u­fac­tur­ing and APM nano-ma­chine tech­no­logy it­self re­flect dif­fer­ent risk pro­files that ought to be dis­cussed in the im­pact sec­tion. As Drexler says, “where the phys­ical nature of APM tech­no­lo­gies is con­cerned, the rel­ev­ant ques­tions per­tain to the phys­ics and en­gin­eer­ing of com­pact, highly cap­able factor­ies—not vague dreams, exotic products or nan­obugs.”

III. APM Will Change Everything

A. Drexler’s Par­tial Notes on APM Benefits

Be­cause APM will use cheap, read­ily avail­able ma­ter­i­als like car­bon to pro­duce high qual­ity ma­ter­i­als in minutes from a com­pact ma­chine, it has the in­gredi­ents to re­vo­lu­tion­ize the ex­ist­ing means of pro­duc­tion:

“Nano­scale size en­ables ex­treme pro­ductiv­ity as a con­sequence of mech­an­ical scal­ing laws. In ad­di­tion, small-scale, ver­sat­ile, highly pro­duct­ive ma­chinery can col­lapse globe-span­ning in­dus­trial sup­ply chains to just a few links.”

This massive sim­pli­fic­a­tion of sup­ply chains coupled with APM’s use of abund­ant mo­lecules im­plies a massive eco­nomic shift. Loca­tions im­pov­er­ished by lack of cap­ital, busi­ness con­nec­tions and re­sources could, in prin­ciple, use na­n­o­tech­no­logy to sus­tain­ably and loc­ally pro­duce high qual­ity in­fra­struc­ture and re­li­able food sources.

Other be­ne­fits of APM in­clude trans­form­ing in­form­a­tion tech­no­lo­gies through more ad­vanced ma­ter­i­als, im­prov­ing in­fra­struc­ture through bet­ter con­struc­tion and trans­port­a­tion tech­no­logy, im­prov­ing ag­ri­cul­ture through ef­fi­cient re­cyc­ling and wa­ter-pro­cessing/​de­sal­in­a­tion, and resolv­ing global warm­ing car­bon di­ox­ide cap­ture. The run­ning theme themes in each of these solu­tions are APM’s blend of ef­fi­ciency and abil­ity to cheaply con­struct many of the ad­vanced nan­o­ma­ter­ial solu­tions which cur­rently ex­ist but are too costly to im­ple­ment in­dus­tri­ally.

The be­ne­fits of APM in im­prov­ing ag­ri­cul­ture also struck me as par­tic­u­larly sig­ni­fic­ant. In par­tic­u­lar, Drexler notes that en­closed ag­ri­cul­ture (i.e. large-scale green­houses) of­fers “higher yield per hec­tare, bet­ter food qual­ity, free­dom from pesti­cides, ex­ten­ded grow­ing sea­sons, free­dom from con­straints of soil qual­ity and avail­able wa­ter, and pro­tec­tion from drought” while also re­du­cing “wa­ter de­mand and con­tam­in­a­tion.” These lat­ter be­ne­fits—free­dom from soil, wa­ter and weather con­straints—are already achieved achieved in mod­ern gree­houses and act as the corner stone for al­le­vi­at­ing star­va­tion in im­pov­er­ished re­gions. Never­the­less, the mod­ern world, let alone im­pov­er­ished re­gions, can­not meet the ef­fi­ciency and in­fra­struc­tural re­quire­ments that would make im­ple­ment­ing green­houses eco­nom­ical. APM’s ca­pa­city for rapid and cheap in­fra­struc­ture along with highly ef­fi­cient en­ergy sys­tems (i.e. solar power) will change that.

Over­all, I see only two reas­ons to doubt these be­ne­fits. The first reason is eco­nomic. His­tor­ic­ally, in­ter­na­tional trade has been a ne­ces­sity for tech­no­lo­gic­ally ad­vanced coun­tries which has al­lowed the flow of money to less de­veloped coun­tries. However, APM will fi­nally al­low tech­no­lo­gic­ally ad­vanced coun­tries to be­come self-suf­fi­cient to the ex­tent that they do not need to im­port goods from less ad­vanced coun­tries. If these coun­tries can­not amass the wealth to gain na­n­o­tech­no­logy, the ab­sence of eco­nomic ties with tech­no­lo­gic­ally ad­vanced aut­ark­ies may lock them into poverty. However, the pres­ence of these self-suf­fi­cient coun­tries also makes this situ­ation un­likely. Be­cause APM-driven coun­tries will be so wealthy and likely re­tain some al­tru­istic lean­ing, the only reason for them not to provide APM to less ad­vanced coun­tries would be some sort of non-eco­nomic cost or risk—that is, a mil­it­ary risk. For­tunately, be­cause APM factor­ies will likely be both tech­no­lo­gic­ally com­plex and op­tim­ized for use in fab­ric­at­ing spe­cific ma­ter­i­als rather than every ma­ter­ial, the mil­it­ary risk of provid­ing factor­ies de­signed with food and in­fra­struc­ture in mind is re­l­at­ively low. This is es­pe­cially true when not­ing how mil­it­ary APM will em­power the most ad­vanced coun­tries re­l­at­ive to oth­ers. To be fair though—in the era of semi-costly/​only par­tially ef­fect­ive na­n­o­tech­no­logy—eco­nomic con­cerns could be very ser­i­ous even if they are only short-term con­sid­er­a­tions.

The second reason for doubt is more sig­ni­fic­ant and relates to an im­port­ant cri­ti­cism of Rad­ical Abund­ance: Drexler ef­fect­ively dis­cusses the cap­ab­il­it­ies of na­n­o­tech­no­logy but does not ser­i­ously dis­cuss the de­tails of the prob­lems he claims that it will solve. In prac­tical terms, the most im­port­ant al­tru­istic con­tri­bu­tion of na­n­o­tech­no­logy would be poverty re­duc­tion. Ex­pli­citly, na­n­o­tech­no­logy should provide sus­tain­able food sources in places where food can­not cur­rently grow, wa­ter in places where wa­ter is cur­rently in­ac­cess­ible, in­fra­struc­ture in places where in­fra­struc­ture can­not cur­rently be es­tab­lished, and en­ergy in places with lim­ited en­ergy re­sources. These prob­lems are al­most all geo­graph­ical con­straints and, while Drexler claims that “the most use­ful ele­ments—in­clud­ing car­bon ni­tro­gen, oxy­gen, and sil­icon—are not all that scarce,” ni­tro­gen de­fi­ciency is one of the reas­ons for ag­ri­cul­tural dif­fi­culties in Africa. Moreover, many im­pov­er­ished coun­tries suf­fer from lack of wa­ter/​re­li­ance on con­tam­in­ated ground wa­ter and, while na­n­o­tech­no­logy may provide cheap puri­fic­a­tion meth­ods, I am not con­vinced that it will either of­fer puri­fic­a­tion meth­ods or wa­ter trans­port­a­tion meth­ods bet­ter than the on­go­ing sci­ence in those fields. Fin­ally, many im­pov­er­ished coun­tries suf­fer from rocky, moun­tain­ous and swampy ter­rain which in­hib­its move­ment and the feas­ib­il­ity of tak­ing ad­vant­age of large-scale in­fra­struc­ture. En­closed ag­ri­cul­ture on forty-five de­gree rocky in­clines does not seem very prom­ising, es­pe­cially when com­pared to just us­ing longer sup­ply chains which APM would hope­fully avoid. In short, while na­n­o­tech­no­logy might al­low the col­lapsing of globe-span­ning sup­ply chains to a few ef­fi­cient links, Drexler does not dis­cuss how the loc­a­tions that are most harmed by the need for these sup­ply struc­tures would sur­mount their ex­ist­ing geo­graph­ical con­straints us­ing na­n­o­tech­no­logy. If this is not ad­dressed, it cre­ates a massive prob­lem for APM. After all, if geo­graph­ical is­sues limit the ef­fic­acy of al­tru­ism through na­n­o­tech­no­logy, then—for im­pov­er­ished coun­tries—ac­cess to na­n­o­tech­no­logy may not out­weigh the eco­nomic loss of be­ing un­able to trade with wealthy coun­tries.

Bey­ond the po­ten­tial for provid­ing the ba­sic staples of hu­man life, an ad­ja­cent sig­ni­fic­ant con­tri­bu­tion that highly ad­vanced na­n­o­tech­no­logy brings is con­trol of the eco­sys­tems that make these staples. As someone con­cerned about wild an­imal suf­fer­ing, this de­vel­op­ment could massively re­duce hu­man harm to in­sects and po­ten­tially of­fer strategies for sys­temic wild­life in­ter­ven­tions. While re­straint and hes­it­a­tion should gen­er­ally be ap­plied to ac­tions like this as they cur­rently have dra­matic and un­pre­dict­able im­pacts on wild eco­sys­tems, the ex­tens­ive sur­veil­lance tech­no­lo­gies provided by APM (dis­cussed later as a draw­back) along with ad­van­cing sci­ence may provide the ex­act kind of eco­lo­gical know­ledge needed to make these ad­just­ments wisely.

While I have pre­vi­ously sus­pec­ted that lim­it­a­tions on chem­ic­als and man­u­fac­tur­ing meth­ods may render APM less use­ful than it seems, I think that these views fail to ap­pre­ci­ate simply how much can be ac­com­plished through the cheap pro­duc­tion of high qual­ity in­fra­struc­ture and elec­tron­ics alone. With this in mind, I think that the only scen­arios where APM is less-than-re­volu­tion­ary are scen­arios where some other easier-to-de­velop tech­no­logy fo­cused on par­tic­u­larly im­port­ant use-cases suc­ceeds faster by vir­tue of a more dir­ect path to im­ple­ment­a­tion. Off the top of my head, these might look like some of the fol­low­ing:

  • Plant growth in bar­ren en­vir­on­ments through ge­netic en­gin­eer­ing couples with mass auto­ma­tion of farm­ing to pro­duce cheap, abund­ant food that is not lim­ited by dis­tri­bu­tion costs.

  • Some large-scale tech­nique for pro­cessing abund­ant ele­ments ef­fi­ciently into use­ful ma­ter­i­als is es­tab­lished (though I am not aware of meth­ods for this out­side of na­n­o­tech­no­logy)

  • Mass trial and er­ror fa­cil­it­ated by mi­cro­fluidics en­ables suf­fi­ciently fast and per­son­al­ized med­ical treat­ment that APM may only be able to en­hance rather than revolutionize

  • The gradual arc of sci­ence im­prov­ing ef­fi­ciency across the board in trans­port lo­gist­ics coupled with ex­ist­ing in­form­a­tion tech­no­logy drive a shift to a di­gital, de-loc­al­ized eco­nomy be­fore APM makes uni­ver­sal wealth feas­ible.

This is my greatest and most ex­pli­cit un­cer­tainty with re­spect to APM’s be­ne­fits. I agree that APM would provide these be­ne­fits but I am not sure whether APM will be the first to provide them. Heur­ist­ic­ally, I usu­ally ex­pect that tech­no­logy spe­cific­ally de­signed to ad­dress a spe­cific is­sue will ad­vance much faster than a more gen­eric ab­stract ap­proach. This leads me to doubt the com­par­at­ive be­ne­fits of pur­su­ing APM as op­posed to other more ex­pli­citly ori­ented re­search en­deavors. On the other hand, APM is a re­l­at­ively con­crete idea and, even if it is likely more dif­fi­cult to pur­sue than a more fo­cused tech­no­logy, may be worth it due to its large po­ten­tial range of im­pact.

B. Drexler’s Notes On How APM May Go Wrong

One of the dan­ger­ous as­pects of APM that Drexler notes is sur­veil­lance.

Small-scale com­pon­ents and sys­tems open new pos­sib­il­it­ies. For per­spect­ive, con­sider that a one-gram plat­form built with ad­vanced tech­no­lo­gies could pro­duce ter­a­flops of com­pu­ta­tional power (and much more, in bursts), to­gether with a mil­lion-tera­byte data stor­age ca­pa­city and bet­ter-than-hu­man sensors, all with a power de­mand com­par­able to that of a cell phone on standby. Now con­sider what could be done if devices of this class cost about $1.00 per kilo­gram and could be de­livered by small drone air­craft. $100 bil­lion would buy roughly one device of this sort per square meter of land area, world­wide.

Be­cause most of this tech­no­logy will not need ter­aFLOPs of com­put­ing power, this raises the pos­sib­il­ity of glob­ally abund­ant third-party sur­veil­lance as easy to bring to work as it is to track dirt into a house. Coupled with the abil­ity to re­lay in­form­a­tion, these sens­ing devices would be able to trivi­ally trans­port massive amounts of data to a cent­ral­ized sys­tem for fast (>petaFLOP) pro­cessing. This could quickly lead to a race-to-the-bot­tom fa­vor­ing those who are will­ing to care less. Com­bin­ing these same devices with chem­ical pay­loads may also en­able groups to en­gage in the soft psy­cho­lo­gical ma­nip­u­la­tion or un­detect­able as­sas­sin­a­tion of their en­emies. Com­bin­ing these “se­cret­ive sur­veil­lance re­gimes” with a world that re­places wealth with in­di­vidual vir­tue as a status sym­bol in ab­sence of poverty may also lead to the mi­cro-reg­u­la­tion of hu­man be­ha­vior. Ad­di­tion­ally, be­cause sur­veil­lance does con­fer ad­vant­ages onto the groups that use it and many coun­tries vary sig­ni­fic­antly in their at­ti­tudes to­ward in­di­vidual pri­vacy, es­tab­lish­ing a com­mon pro-pri­vacy agree­ment to avoid a race-to-the-bot­tom will be un­likely.

Over­all, I am not con­cerned about this risk mainly be­cause this sur­veil­lance tech­no­logy is ori­ented around act­ive nano-ma­chines in com­plex and un­pre­dict­able en­vir­on­mental situ­ations. Un­like the be­ne­fits of na­n­o­tech­no­logy which are pro­duced in con­trolled man­u­fac­tur­ing con­texts, this tech­no­logy must func­tion in a less man­age­able space and I ex­pect phys­ical and design lim­it­a­tions to ser­i­ously come into play here. Undoubtedly, na­n­o­tech­no­logy will cheapen sur­veil­lance but I doubt that it will be suf­fi­ciently cheap to sub­vert per­sonal pri­vacy more than it would be any­way. Fur­ther­more, while a race-to-the-bot­tom may hap­pen, it may be par­tially mit­ig­ated by the rad­ic­ally dif­fer­ent eco­nomic cir­cum­stances which more simple na­n­o­tech­no­logy will have already provided the world, mak­ing it “hard to find an ex­ternal re­source that would con­tinue to be a vi­tal na­tional in­terest.”

These are also the same reas­ons that I am not ser­i­ously con­cerned with na­n­o­tech­no­logy caus­ing massive en­vir­on­mental dam­age through self-rep­lic­at­ing ro­bots: the prob­lem is uniquely chal­len­ging and strong in­cent­ives for do­ing so ap­pear to be ab­sent. In fact, Drexler notes that na­tions have “strong, shared in­terests in con­strain­ing non-state act­ors” from the use of un­res­trained APM. A weaker vari­ant of this is­sue is the po­ten­tial for na­n­o­tech­no­logy to cre­ate nan­o­particle pol­lut­ants on a massive scale, lead­ing to massive eco­sys­temic dam­age. However, coun­tries cap­able of pro­du­cing na­n­o­tech­no­logy at this level will also likely have tech­no­logy cap­able of rap­idly identi­fy­ing (via sur­veil­lance) and ad­dress­ing pol­lut­ants any­where on the globe. This means that mass pol­lu­tion is only a risk if done by a coun­try that would not fear re­tali­ation. Be­cause this type of coun­try can already threaten the world in many more ways than just pol­lu­tion, I con­sider this to be a minor con­cern.

The second main risk that Drexler dis­cusses is a two-pronged change in mil­it­ary strategy. First, be­cause APM will be used to design se­quen­tial gen­er­a­tions of APM, “it is there­fore easy to en­vi­sion scen­arios in which a mod­est de­gree of asyn­chrony, meas­ured in months or less, could swiftly lead to rad­ical mil­it­ary asym­met­ries even with re­l­at­ively shal­low ex­ploit­a­tion of the over­all po­ten­tial of APM-level tech­no­lo­gies.” Se­cond, APM would provide “abund­ant, af­ford­able, non-lethal, re­motely op­er­ated weapons” that re­duce risk of harm and en­cour­age more war-like policies. While these shifts may en­cour­age tech­no­lo­gic­ally ad­vanced coun­tries to pur­sue ag­gress­ive ex­pan­sion­ist policies, ex­pan­sion­ist ac­tions will of­fer little in terms of re­source gain and cost a level of so­ci­etal sta­bil­ity due to cul­tural con­flicts. In fact, be­cause of the ab­sence of re­source gain, ex­pan­sion­ism will primar­ily be driven by a de­sire to es­tab­lish dif­fer­ent so­ci­etal val­ues—a goal that gov­ern­ments will more likely pur­sue through subtler meth­ods than out­right con­flict.

Lastly, Drexler also notes that one of the com­monly dis­cussed risks—the idea that self-re­pro­du­cing nano-ma­chines will con­sume vast swathes of the world—is un­likely given a man­u­fac­tur­ing model of na­n­o­tech­no­logy in­stead of a bio­lo­gical model. I agree that this is un­likely for the same reason that I saw sur­veil­lance as un­likely but mul­ti­plied sev­eral-fold. Build­ing en­vir­on­ment­ally ro­bust re­pro­du­cing nano-ma­chines us­ing abund­ant nat­ural sup­plies and es­tab­lish­ing enough stable com­plex­ity for those nano-ma­chines to re­con­struct them­selves both re­quire an enorm­ous amount of ef­fort far bey­ond the scope of the primary be­ne­fits of na­n­o­tech­no­logy which Drexler dis­cusses.

One danger that I be­lieve mer­its con­cern but goes un­men­tioned by Drexler per­tains to ad­vanced gen­eral in­tel­li­gence. If Drexler is cor­rect in his claim that na­n­o­tech­no­logy will of­fer ter­aFLOP/​gram com­puters, then an av­er­age laptop com­puter weigh­ing five pounds would have about a petaFLOP of com­pu­ta­tional power and a thou­sand of such com­puters would start push­ing on the cap­ab­il­it­ies of a hu­man brain (ac­cord­ing to Kurz­weil) without any ad­di­tional de­lib­er­ate op­tim­iz­a­tion bey­ond emu­lat­ing nature. This is more than suf­fi­cient to pro­duce in­tel­li­gence far more com­pet­ent than any hu­man and in­ter­twines na­n­o­tech­no­logy deeply with its re­la­tion­ship to ar­ti­fi­cial in­tel­li­gence. If hu­man­ity is not con­fid­ent in its abil­ity to align the goals of ad­vanced gen­eral in­tel­li­gence (which it is not), then na­n­o­tech­no­logy in this re­gard ought only be pur­sued if does not in­crease the risk of mis­aligned ad­vanced gen­eral in­tel­li­gence. This will be the case if either ad­vanced gen­eral in­tel­li­gence is ex­pec­ted to emerge prior to ad­vanced na­n­o­tech­no­logy (in which case AI Safety re­search is a much more press­ing con­cern than na­n­o­tech­no­logy) or Drexler is in­cor­rect about ter­aFLOP/​gram com­puters.

Over­all, my opin­ion is that Drexler’s be­ne­fits of na­n­o­tech­no­logy out­weigh Drexler’s risks but, when I con­sider na­n­o­tech­no­logy’s re­la­tion­ship with ar­ti­fi­cial in­tel­li­gence, I be­gin to sus­pect that it is far more dan­ger­ous than it ini­tially ap­pears. That be­ing said, this only ap­plies dir­ectly to the de­vel­op­ment of na­n­o­tech­no­logy it­self. Devel­op­ment of na­n­o­tech­no­logy policy on the other hand may have sig­ni­fic­ant value in the case where hu­man­ity weath­ers ad­vanced gen­eral in­tel­li­gence. However, the be­ne­fits of this work may be lim­ited by the like­li­hood that ad­vanced gen­eral in­tel­li­gence will trans­form the polit­ical land­scape to such an ex­tent that any cur­rent policy design would be in­ap­plic­able.

IV. Path­ways to Nanotechnology

When won­der­ing about the like­li­hood of achiev­ing some­thing like APM, a use­ful ques­tion is “Why has this not been achieved already?” This is an es­pe­cially sa­li­ent ques­tion for APM both be­cause of the ex­tens­ive fund­ing provid­ing in the field of na­n­o­tech­no­logy and the re­l­at­ive age of the idea it­self. Drexler an­swers this ques­tion with two main ex­plan­a­tions. The first is that ex­tens­ive fund­ing may have been fo­cused on “na­n­o­tech­no­logy” but min­imal fund­ing has been fo­cused on APM.

“The great prom­ise of na­n­o­tech­no­logy is atom­ic­ally pre­cise man­u­fac­tur­ing, and the US Con­gress es­tab­lished a pro­gram dir­ec­ted to­ward this ob­ject­ive, but the pro­gram in­stead did some­thing en­tirely dif­fer­ent. The pro­gram’s lead­ers re­defined “na­n­o­tech­no­logy and sup­por­ted only nano­scale ma­ter­i­als and devices, tech­no­lo­gies as dif­fer­ent from APM as cloth, ce­ment, and wires are from a pro­gram­me­able di­gital com­puter. Most re­search ad­vert­ised as “na­n­o­tech­no­logy” has there­fore been ir­rel­ev­ant to what had been widely ex­pec­ted, and while atom­ic­ally pre­cise fab­ric­a­tion has flour­ished in the mo­lecu­lar sci­ences, people look­ing for pro­gress to­ward APM-level tech­no­lo­gies have been led to look in the wrong dir­ec­tion.”

The second is a rather philo­soph­ical dis­cus­sion about how the ba­sic sci­ence that mostly com­prises na­n­o­tech­no­logy re­search is in­ef­fect­ive at pro­du­cing the sys­tem-en­gin­eer­ing co­ordin­a­tion re­quired to make an ac­tual tech­no­logy. As Drexler says, “no mat­ter how re­search-in­tens­ive a pro­ject may be, work co­ordin­ated around con­crete en­gin­eer­ing ob­ject­ives will even­tu­ally be re­quired to pro­duce con­crete en­gin­eer­ing res­ults.” So far, work at this level of co­ordin­a­tion has not been pur­sued.

Both of these ex­plan­a­tions demon­strate that the ex­ist­ing lim­ited state of APM is due to polit­ical and or­gan­iz­a­tional con­straints that do not re­flect neg­at­ively on the feas­ib­il­ity of APM it­self. As for that feas­ib­il­ity, Drexler notes that design­ing the mech­an­isms of APM devices is already re­l­at­ively feas­ible: “Machine com­pon­ents based on ri­gid co­va­lent struc­tures can­not yet be im­ple­men­ted, yet are already easy to design and model us­ing stand­ard com­pu­ta­tional chem­istry soft­ware.” Indeed, I sus­pect that one way to mo­tiv­ate APM-dir­ec­ted re­search would be to use the tools we have to pree­mpt­ively design an ad­vanced APM ma­chine and then to use that device as a mo­tiv­ator for na­tions to fun­nel re­search into its ul­ti­mate con­struc­tion.

The main cur­rent method for de­vel­op­ing APM will in­volve ad­van­cing ste­reotactic chem­ical re­ac­tions. While “con­ven­tional, solu­tion-phase chem­ical re­ac­tions are en­abled by local struc­tural fea­tures of mo­lecules,” more com­plex syn­thetic tar­gets with many more struc­tural fea­tures would be “dif­fi­cult or im­possible to dir­ect re­ac­tions with suf­fi­cient spe­cificity.” Ste­reotactic chem­ical re­ac­tions ad­dress this is­sue by hav­ing “link­ing struc­tures dir­ect re­ac­tions by con­strain­ing en­coun­ters among po­ten­tially re­act­ive groups, sep­ar­at­ing some pairs while in­creas­ing en­counter rates between oth­ers.” By defin­i­tion, ste­reotactic chem­ical re­ac­tions re­flect the atom­ic­ally pre­cise man­u­fac­tur­ing of com­plex struc­tures through se­quen­tially bond­ing mo­lecules to­gether. This de­scrip­tion ap­plies to bio­lo­gical pro­teins as well but un­like pro­teins, APM will de­velop ste­reotactic re­ac­tions through mech­an­ical designs rather than thermally driven ones.

Drexler notes that ste­reotactic re­ac­tions in ad­vanced APM must sat­isfy a num­ber of con­straints: struc­tures must be stable and ri­gid; struc­ture mo­tion must be well con­trolled; re­ac­tions must hap­pen re­li­ably; re­ac­tions must be ir­re­vers­ible; and re­ac­tions must yield only a single product. Many of these re­quire­ments (mo­tion con­trol, re­li­able pro­cesses, ir­re­vers­ib­il­ity, single product) are con­sist­ent with most fab­ric­a­tion pro­ced­ures. However, ri­gid­ity holds spe­cial im­port­ance for APM be­cause it al­lows fab­ric­ated ma­ter­i­als to oc­cupy meta-stable states. This means that, while flex­ible bio­lo­gical ma­ter­i­als can quickly re­struc­ture them­selves into lower en­ergy/​higher en­tropy states by just mov­ing, APM ma­ter­i­als move in a slow man­ner due to ri­gid­ity that pre­vents them from find­ing those states as quickly. This en­sures that while APM ma­ter­i­als, like dia­mond, main­tain their prop­er­ties for a long time even though they might not be nat­ur­ally stable.

Cur­rent tech­no­logy can­not meet all these re­quire­ments how­ever the as­sembly of “poly­meric build­ing blocks, cross-linked via con­ven­tional re­ac­tions, with all ste­reotactic op­er­a­tions per­formed in aqueous en­vir­on­ments” may read­ily be achieved through ex­ist­ing meth­ods like DNA ori­gami. This of­fers a bot­tom-up APM start­ing point wherein “large self-align­ing build­ing blocks, loose po­s­i­tional tol­er­ance mar­gins, low stiff­ness ma­ter­i­als, simple ma­chines, and simple mo­tion con­straints” are it­er­ated upon to pro­duce the more com­plex, more pre­cise, and higher qual­ity nano-devices needed to reach ad­vanced APM. In other words, simply it­er­at­ing on ex­ist­ing na­n­o­tech­no­logy re­lated to ste­reotactic con­trol will fa­cil­it­ate the im­prove­ment of ste­reotactic con­trol.

Drexler also ad­dresses an­other as­pect of na­n­o­tech­no­logy that had pre­vi­ously led me to be more sus­pi­cious about its suc­cess: On the macro-scale level, a fact­ory may rely on ma­chines pro­duced by other factor­ies but those factor­ies them­selves are as­sembled by hu­mans (though of­ten hu­mans pi­lot­ing ma­chines them­selves). On the nano-scale though, hu­man as­sembly is im­possible so factor­ies would need to pro­duce factor­ies—which seems hard. In ac­tu­al­ity, the solu­tion is simple and prac­tical: Ste­reotactic con­trol will lead to “im­prove­ments that fa­cil­it­ate the design and fab­ric­a­tion of com­ple­ment­ary sur­faces… Ste­reotactic syn­thesis can en­able ad­vances in com­pon­ent level self-as­sembly.” Once hu­man­ity can pro­duce nano-ma­chines, hu­man­ity will be able to pro­duce nano-ma­chines at­tached to sur­faces with bind­ing af­fin­it­ies for com­ple­ment­ary sur­faces. At this point, near cur­rent-day tech­no­logy would be able to pro­duce large-scale com­ple­ment­ary sur­face pat­terned sheets that bind only the right nano-ma­chines in only the right places. In other words, suc­cess will not ini­tially be achieved through a closed sys­tem of nano-factor­ies mak­ing nano-factor­ies but rather through a blend of man­u­fac­tur­ing nano-ma­chines to more eas­ily in­ter­act with higher level self-as­sembly meth­ods.

V. Conclusion

Throughout Rad­ical Abund­ance, Drexler em­phas­izes two com­mon mis­rep­res­ent­a­tions of na­n­o­tech­no­logy: the pop­u­lar rep­res­ent­a­tion of na­n­o­tech­no­logy as al­most ma­gical nano­bot swarms and the aca­demic rep­res­ent­a­tion of na­n­o­tech­no­logy as per­tain­ing to sci­ence at a given size-scale rather than tech­no­logy at a given size-scale. As someone both aware of pop­u­lar cul­ture and closely in­volved with con­ven­tional aca­demic re­search in na­n­o­tech­no­logy (i.e. self-as­sem­bling nano-particles), I blen­ded these ideas to­gether into an im­prob­ably in­flu­en­tial tech­no­logy me­di­ated by an im­prob­ably hard-to-con­trol sci­ence. In real­ity, APM is a com­pre­hens­ibly im­pact­ful tech­no­logy me­di­ated by un­der-re­searched but high-po­ten­tial it­er­at­ive design. Fin­ish­ing the book, I feel reas­on­ably con­vinced that APM is achiev­able based on ex­ist­ing tech­no­lo­gical pro­gress, par­tially con­vinced that APM will have the be­ne­fits that Drexler claims it has, and un­con­vinced that the be­ne­fits out­weigh the risks if we limit them to those that Drexler has de­scribed.

Never­the­less, while un­der­stand­able in the con­text of na­n­o­tech­no­logy’s pre­vi­ous over-hyped his­tory in pop-cul­ture, I think Rad­ical Abund­ance’s dis­cus­sion of risks is too con­ser­vat­ive in es­tim­at­ing their mag­nitude. This is be­cause, in a sig­ni­fic­ant num­ber of cir­cum­stances where hu­man-de­veloped na­n­o­tech­no­logy be­comes im­port­ant, I en­vi­sion scen­arios that ac­cel­er­ate the emer­gence of a mis­aligned gen­eral ar­ti­fi­cial in­tel­li­gence. These scen­arios may be ab­so­lutely low prob­ab­il­ity but should be ac­coun­ted for in na­n­o­tech­no­logy policy given the ex­ist­en­tial nature of the threat. Bey­ond this, I think that Drexler’s goal of ad­dress­ing mis­con­cep­tions about out-of-con­trol nano-ma­chines may also fail to re­cog­nize risks from out-of-con­trol nano-ma­chines which are out­side the pur­view of com­par­at­ively lim­ited APM. I have no reas­on­ing for this bey­ond the sense that any the­or­et­ic­ally pos­sible ex­ist­en­tial risk ought to merit closer con­sid­er­a­tion and that many people have given closer con­sid­er­a­tion to it.

So in sum­mary, APM is a lot more likely than I ini­tially ex­pec­ted and I also sus­pect it could be a lot more dan­ger­ous as well. Let me know your thoughts!