The Singularity Is Near: When Humans Transcend Biology (40 page)

N
ED:
Okay, I understand that designer baby boomers can’t get away completely from their predesigner genes, but with designer babies they’ll have the genes and the time to express them
.

R
AY:
The “designer baby” revolution is going to be a very slow one; it won’t be a
significant factor in this century. Other revolutions will overtake it. We won’t have the technology for designer babies for another ten to twenty years. To the extent that it is used, it would be adopted gradually, and then it will take those generations another twenty years to reach maturity. By that time, we’re approaching the Singularity, with the real revolution being the predominance of nonbiological intelligence. That will go far beyond the capabilities of any designer genes. The idea of designer babies and baby boomers is just the reprogramming of the information processes in biology. But it’s still biology, with all its profound limitations
.

N
ED:
You’re missing something. Biological is what we are. I think most people would agree that being biological is the quintessential attribute of being human
.

R
AY:
That’s certainly true today
.

N
ED:
And I plan to keep it that way
.

R
AY:
Well, if you’re speaking for yourself, that’s fine with me. But if you stay biological and don’t reprogram your genes, you won’t be around for very long to influence the debate
.

Nanotechnology: The Intersection of Information and the Physical World

The role of the infinitely small is infinitely large.

                   —L
OUIS
P
ASTEUR

But I am not afraid to consider the final question as to whether, ultimately, in the great future, we can arrange the atoms the way we want; the very atoms, all the way down!

                   —R
ICHARD
F
EYNMAN

Nanotechnology has the potential to enhance human performance, to bring sustainable development for materials, water, energy, and food, to protect against unknown bacteria and viruses, and even to diminish the reasons for breaking the peace [by creating universal abundance].

                   —N
ATIONAL
S
CIENCE
F
OUNDATION
N
ANOTECHNOLOGY
R
EPORT

Nanotechnology promises the tools to rebuild the physical world—our bodies and brains included—molecular fragment by molecular fragment, potentially
atom by atom. We are shrinking the key feature size of technology, in accordance with the law of accelerating returns, at the exponential rate of approximately a factor of four per linear dimension per decade.
⁶⁸
At this rate the key feature sizes for most electronic and many mechanical technologies will be in the nanotechnology range—generally considered to be under one hundred nanometers—by the 2020s. (Electronics has already dipped below this threshold, although not yet in three-dimensional structures and not yet self-assembling.) Meanwhile rapid progress has been made, particularly in the last several years, in preparing the conceptual framework and design ideas for the coming age of nanotechnology.

As important as the biotechnology revolution discussed above will be, once its methods are fully mature, limits will be encountered in biology itself. Although biological systems are remarkable in their cleverness, we have also discovered that they are dramatically suboptimal. I’ve mentioned the extremely slow speed of communication in the brain, and as I discuss below (see
p. 253
), robotic replacements for our red blood cells could be thousands of times more efficient than their biological counterparts.
⁶⁹
Biology will never be able to match what we will be capable of engineering once we fully understand biology’s principles of operation.

The revolution in nanotechnology, however, will ultimately enable us to redesign and rebuild, molecule by molecule, our bodies and brains and the world with which we interact.
⁷⁰
These two revolutions are overlapping, but the full realization of nanotechnology lags behind the biotechnology revolution by about one decade.

Most nanotechnology historians date the conceptual birth of nanotechnology to physicist Richard Feynman’s seminal speech in 1959, “There’s Plenty of Room at the Bottom,” in which he described the inevitability and profound implications of engineering machines at the level of atoms:

The principles of physics, as far as I can see, do not speak against the possibility of maneuvering things atom by atom. It would be, in principle, possible . . . for a physicist to synthesize any chemical substance that the chemist writes down. . . . How? Put the atoms down where the chemist says, and so you make the substance. The problems of chemistry and biology can be greatly helped if our ability to see what we are doing, and to do things on an atomic level, is ultimately developed—a development which I think cannot be avoided.
⁷¹

An even earlier conceptual foundation for nanotechnology was formulated by the information theorist John von Neumann in the early 1950s with his
model of a self-replicating system based on a universal constructor, combined with a universal computer.
⁷²
In this proposal the computer runs a program that directs the constructor, which in turn constructs a copy of both the computer (including its self-replication program) and the constructor. At this level of description von Neumann’s proposal is quite abstract—the computer and constructor could be made in a great variety of ways, as well as from diverse materials, and could even be a theoretical mathematical construction. But he took the concept one step further and proposed a “kinematic constructor”: a robot with at least one manipulator (arm) that would build a replica of itself from a “sea of parts” in its midst.
⁷³

It was left to Eric Drexler to found the modern field of nanotechnology, with a draft of his landmark Ph.D. thesis in the mid-1980s, in which he essentially combined these two intriguing suggestions. Drexler described a von Neumann kinematic constructor, which for its sea of parts used atoms and molecular fragments, as suggested in Feynman’s speech. Drexler’s vision cut across many disciplinary boundaries and was so far-reaching that no one was daring enough to be his thesis adviser except for my own mentor, Marvin Minsky. Drexler’s dissertation (which became his book
Engines of Creation
in 1986 and was articulated technically in his 1992 book,
Nanosystems
) laid out the foundation of nanotechnology and provided the road map still being followed today.
⁷⁴

Drexler’s “molecular assembler” will be able to make almost anything in the world. It has been referred to as a “universal assembler,” but Drexler and other nanotechnology theorists do not use the word “universal” because the products of such a system necessarily have to be subject to the laws of physics and chemistry, so only atomically stable structures would be viable. Furthermore, any specific assembler would be restricted to building products from its sea of parts, although the feasibility of using individual atoms has been shown. Nevertheless, such an assembler could make just about any physical device we would want, including highly efficient computers and subsystems for other assemblers.

Although Drexler did not provide a detailed design for an assembler—such a design has still not been fully specified—his thesis did provide extensive feasibility arguments for each of the principal components of a molecular assembler, which include the following subsystems:

• The
  computer:
  to provide the intelligence to control the assembly process. As with all of the device’s subsystems, the computer needs to be small and simple. As I described in
  chapter 3
  , Drexler provides an intriguing conceptual description of a mechanical computer with molecular “locks”
  instead of transistor gates. Each lock would require only sixteen cubic nanometers of space and could switch ten billion times per second. This proposal remains more competitive than any known electronic technology, although electronic computers built from three-dimensional arrays of carbon nanotubes appear to provide even higher densities of computation (that is, calculations per second per gram).
  ⁷⁵
  
• The
  instruction architecture:
  Drexler and his colleague Ralph Merkle have proposed an SIMD (single instruction multiple data) architecture in which a single data store would record the instructions and transmit them to trillions of molecular-sized assemblers (each with its own simple computer) simultaneously. I discussed some of the limitations of the SIMD architecture in
  chapter 3
  , but this design (which is easier to implement than the more flexible multiple-instruction multiple-data approach) is sufficient for the computer in a universal nanotechnology assembler. With this approach each assembler would not have to store the entire program for creating the desired product. A “broadcast” architecture also addresses a key safety concern: the self-replication process could be shut down, if it got out of control, by terminating the centralized source of the replication instructions.
      However, as Drexler points out, a nanoscale assembler does not necessarily have to be self-replicating.
  ⁷⁶
  Given the inherent dangers in self-replication, the ethical standards proposed by the Foresight Institute (a think tank founded by Eric Drexler and Christine Peterson) contain prohibitions against unrestricted self-replication, especially in a natural environment.
      As I will discuss in
  chapter 8
  , this approach should be reasonably effective against inadvertent dangers, although it could be circumvented by a determined and knowledgeable adversary.
  
• Instruction transmission:
  Transmission of the instructions from the centralized data store to each of the many assemblers would be accomplished electronically if the computer is electronic or through mechanical vibrations if Drexler’s concept of a mechanical computer were used.
  
• The
  construction robot:
  The constructor would be a simple molecular robot with a single arm, similar to von Neumann’s kinematic constructor but on a tiny scale. There are already examples of experimental molecular-scale systems that can act as motors and robot legs, as I discuss below.
  
• The
  robot arm tip:
  Drexler’s
  Nanosystems
  provided a number of feasible chemistries for the tip of the robot arm to make it capable of grasping (using appropriate atomic-force fields) a molecular fragment, or even a single atom, and then depositing it in a desired location. In the chemical-vapor deposition process used to construct artificial diamonds, individual
  carbon atoms, as well as molecular fragments, are moved to other locations through chemical reactions at the tip. Building artificial diamonds is a chaotic process involving trillions of atoms, but conceptual proposals by Robert Freitas and Ralph Merkle contemplate robot arm tips that can remove hydrogen atoms from a source material and deposit them at desired locations in the construction of a molecular machine. In this proposal, the tiny machines are built out of a diamondoid material. In addition to having great strength, the material can be doped with impurities in a precise fashion to create electronic components such as transistors. Simulations have shown that such molecular-scale gears, levers, motors, and other mechanical systems would operate properly as intended.
  ⁷⁷
  More recently attention has been focused on carbon nanotubes, comprising hexagonal arrays of carbon atoms assembled in three dimensions, which are also capable of providing both mechanical and electronic functions at the molecular level. I provide examples below of molecular-scale machines that have already been built.
  
• The assembler’s
  internal environment
  needs to prevent environmental impurities from interfering with the delicate assembly process. Drexler’s proposal is to maintain a near vacuum and build the assembler walls out of the same diamondoid material that the assembler itself is capable of making.
  
• The
  energy
  required for the assembly process can be provided either through electricity or through chemical energy. Drexler proposed a chemical process with the fuel interlaced with the raw building material. More recent proposals use nanoengineered fuel cells incorporating hydrogen and oxygen or glucose and oxygen, or acoustic power at ultrasonic frequencies.
  ⁷⁸
  

Although many configurations have been proposed, the typical assembler has been described as a tabletop unit that can manufacture almost any physically possible product for which we have a software description, ranging from computers, clothes, and works of art to cooked meals.
⁷⁹
Larger products, such as furniture, cars, or even houses, can be built in a modular fashion or using larger assemblers. Of particular importance is the fact that an assembler can create copies of itself, unless its design specifically prohibits this (to avoid potentially dangerous self-replication). The incremental cost of creating any physical product, including the assemblers themselves, would be pennies per pound—basically the cost of the raw materials. Drexler estimates total manufacturing cost for a molecular-manufacturing process in the range of ten cents
to fifty cents per kilogram, regardless of whether the manufactured product were clothing, massively parallel supercomputers, or additional manufacturing systems.
⁸⁰