The Singularity Is Near: When Humans Transcend Biology (99 page)

13
. R. Colin Johnson, “IBM Nanotubes May Enable Molecular-Scale Chips,”
EETimes
, April 26, 2001,
http://eetimes.com/article/showArticle.jhtml?articleId=10807704
.

14
. Avi Aviram and Mark A. Ratner, “Molecular Rectifiers,”
Chemical Physics Letters
(November 15, 1974): 277–83, referred to in Charles M. Lieber, “The Incredible Shrinking Circuit,”
Scientific American
(September 2001), at
http://www.sciam.com
and
http://www-mcg.uni-r.de/downloads/lieber.pdf
. The single-molecule rectifier described in Aviram and Ratner could pass current preferentially in either direction.

15
. Will Knight, “Single Atom Memory Device Stores Data,” NewScientist.com, September 10, 2002,
http://www.newscientist.com/news/news.jsp?id=ns99992775
, referring to R. Bennewitz et al., “Atomic Scale Memory at a Silicon Surface,”
Nanotechnology
13 (July 4, 2002): 499–502.

16
. Their transistor is made from indium phosphide and indium gallium arsenide. University of Illinois at Urbana-Champaign news release, “Illinois Researchers Create World’s Fastest Transistor—Again,”
http://www.eurekalert.org/pub_ releases/2003-11/uoia-irc110703.php
.

17
. Michael R. Diehl et al., “Self-Assembled Deterministic Carbon Nanotube Wiring Networks,”
Angewandte Chemie International Edition
41.2 (2002): 353–56; C. P. Collier et al., “Electronically Configurable Molecular-Based Logic Gates,”
Science
285.5426 (July 1999): 391–94. See
http://www.its.caltech.edu/~heathgrp/papers/Paperfiles/2002/
diehlangchemint.pdf
and
http://www.cs.duke.edu/~thl/papers/Heath.Switch.pdf
.

18
. The “rosette nanotubes” designed by the Purdue team contain carbon, nitrogen, hydrogen, and oxygen. The rosettes self-assemble because their interiors are hydrophobic and their exteriors are hydrophilic; therefore, to protect their insides from water, the rosettes stack into nanotubes. “The physical and chemical properties of our rosette nanotubes can now be modified almost at will through a novel dial-in approach,” according to lead researcher Hicham Fenniri. R. Colin Johnson, “Purdue Researchers Build Made-to-Order Nanotubes,”
EETimes
, October 24, 2002,
http://www.eetimes.com/article/showArticle.jhtml?articleId=18307660
; H. Fenniri et al., “Entropically Driven Self-Assembly of Multichannel Rosette Nanotubes,”
Proceedings of the National Academy of Sciences
99, suppl. 2 (April 30, 2002): 6487–92; Purdue news release, “Adaptable Nanotubes Make Way for Custom-Built Structures, Wires,”
http://news.uns.purdue.edu/UNS/html4ever/
020311.Fenniri.scaffold.html
.

Similar work has been done by scientists in the Netherlands: Gaia Vince, “Nano-Transistor Self-Assembles Using Biology,” NewScientist.com, November 20, 2003,
http://www.newscientist.com/news/news.jsp?id=ns99994406
.

19
. Liz Kalaugher, “Lithography Makes a Connection for Nanowire Devices,” June 9, 2004,
http://www.nanotechweb.org/articles/news/3/6/6/1
, referring to Song Jin et
al., “Scalable Interconnection and Integration of Nanowire Devices Without Registration,”
Nano Letters
4.5 (2004): 915–19.

20
. Chao Li et al., “Multilevel Memory Based on Molecular Devices,”
Applied Physics Letters
84.11 (March 15, 2004): 1949–51. Also see
http://www.technologyreview.com/articles/rnb_051304.asp?p=1
. See also
http://nanolab.usc.edu/PDF%5CAPL84-1949.pdf
.

21
. Gary Stix, “Nano Patterning,”
Scientific American
(February 9, 2004),
http://www.sciam.com/print_version.cfm?articleID=000170D6-C99F-101E-861F83414B7F0000
; Michael Kanellos, “IBM Gets Chip Circuits to Draw Themselves,” CNET News.com,
http://zdnet.com.com/2100-1103-5114066.html
. See also
http://www.nanopolis.net/news_ind.php?type_id=3
.

22
. IBM is working on chips that automatically reconfigure as needed, such as by adding memory or accelerators. “In the future, the chip you have may not be the chip you bought,” said Bernard Meyerson, chief technologist, IBM Systems and Technology Group. IBM press release, “IBM Plans Industry’s First Openly Customizable Microprocessor,”
http://www.ibm.com/investor/press/mar-2004/31-03-04-1.phtml
.

23
. BBC News, “ ‘Nanowire’ Breakthrough Hailed,” April 1, 2003,
http://news.bbc.co.uk/1/hi/sci/tech/2906621.stm
. Published article is Thomas Scheibel et al., “Conducting Nanowires Built by Controlled Self-Assembly of Amyloid Fibers and Selective Metal Deposition,”
Proceedings of the National Academy of Sciences
100.8 (April 15, 2003): 4527–32, published online April 2, 2003,
http://www.pnas.org/cgi/content/full/100/8/4527
.

24
. Duke University press release, “Duke Scientists ‘Program’ DNA Molecules to Self Assemble into Patterned Nanostructures,”
http://www.eurekalert.org/pub_releases/2003-09/du-ds092403.php
, referring to Hao Yan et al., “DNA-Templated Self-Assembly of Protein Arrays and Highly Conductive Nanowires,”
Science
301.5641 (September 26, 2003): 1882–84. See also
http://www.phy.duke.edu/~gleb/Pdf_FILES/DNA_science.pdf
.

25
. Ibid.

26
. Here is an example of the procedure to solve what’s called the traveling-salesperson problem. We try to find an optimal route for a hypothetical traveler among multiple cities without having to visit a city more than once. Only certain city pairs are connected by routes, so finding the right path is not straightforward.
     To solve the traveling-salesperson problem, mathematician Leonard Adleman of the University of Southern California performed the following steps:

        1.    Generate a small strand of DNA with a unique code for each city.

        2.    Replicate each such strand (one for each city) trillions of times using PCR.

        3.    Next, put the pools of DNA (one for each city) together in a test tube. This step uses DNA’s affinity to link strands together. Longer strands will form automatically. Each such strand represents a possible route of multiple cities. The small strands representing each city link up with each other in a random fashion, so
there is no mathematical certainty that a linked strand representing the correct answer (sequence of cities) will be formed. However, the number of strands is so vast that it is virtually certain that at least one strand—and probably millions—will be formed that represents the correct answer.
    The next steps use specially designed enzymes to eliminate the trillions of strands that represent wrong answers, leaving only the strands representing the correct answer:

        4.    Use molecules called “primers” to destroy those DNA strands that do not start with the start city, as well as those that do not end with the end city; then replicate the surviving strands, using PCR.

        5.    Use an enzyme reaction to eliminate those DNA strands that represent a travel path greater than the total number of cities.

        6.    Use an enzyme reaction to destroy those strands that do not include city 1. Repeat for each of the cities.

        7.    Now, each of the surviving strands represents the correct answer. Replicate these surviving strands (using PCR) until there are billions of such strands.

        8.    Using a technique called electrophoresis, read out the DNA sequence of these correct strands (as a group). The readout looks like a set of distinct lines, which specifies the correct sequence of cities.

See L. M. Adleman, “Molecular Computation of Solutions to Combinatorial Problems,”
Science
266 (1994): 1021–24.

27
. Charles Choi, “DNA Computer Sets Guinness Record,”
http://www.upi.com/view.cfm?StoryID=20030224-045551-7398r
. See also Y. Benenson et al., “DNA Molecule Provides a Computing Machine with Both Data and Fuel,”
Proceedings of the National Academy of Sciences
100.5 (March 4, 2003): 2191–96, available at
http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=12601148
; Y. Benenson et al., “An Autonomous Molecular Computer for Logical Control of Gene Expression,”
Nature
429.6990 (May 27, 2004): 423–29 (published online, April 28, 2004), available at
http://www.wisdom.weizmann.ac.il/~udi/ShapiroNature2004.pdf
.

28
. Stanford University news release, “ ‘Spintronics’ Could Enable a New Generation of Electronic Devices, Physicists Say,”
http://www.eurekalert.org/pub_releases/2003-08/su-ce080803.php
, referring to Shuichi Murakami, Naoto Nagaosa, and Shou-Cheng Zhang, “Dissipationless Quantum Spin Current at Room Temperature,”
Science
301.5638 (September 5, 2003): 1348–51.

29
. Celeste Biever, “Silicon-Based Magnets Boost Spintronics,” NewScientist.com, March 22, 2004,
http://www.newscientist.com/news/news.jsp?id=ns99994801
, referring to Steve Pearton,“Silicon-Based Spintronics,”
Nature Materials
3.4 (April 2004): 203–4.

30
. Will Knight, “Digital Image Stored in Single Molecule,” NewScientist.com, December 1, 2002,
http://www.newscientist.com/news/news.jsp?id=ns99993129
,
referring to Anatoly K. Khitrin, Vladimir L. Ermakov, and B. M. Fung, “Nuclear Magnetic Resonance Molecular Photography,”
Journal of Chemical Physics
117.15 (October 15, 2002): 6903–6.

31
. Reuters, “Processing at the Speed of Light,”
Wired News
,
http://www.wired.com/news/technology/0,1282,61009,00.html
.

32
. To date, the largest number to be factored is one of 512 bits, according to RSA Security.

33
. Stephan Gulde et al., “Implementation of the Deutsch-Jozsa Algorithm on an Ion-Trap Quantum Computer,”
Nature
421 (January 2, 2003): 48–50. See
http://heart-c704.uibk.ac.at/Papers/Nature03–Gulde.pdf
.

34
. Since we are currently doubling the price-performance of computation each year, a factor of a thousand requires ten doublings, or ten years. But we are also (slowly) decreasing the doubling time itself, so the actual figure is eight years.

35
. Each subsequent thousandfold increase is itself occurring at a slightly faster rate. See the previous note.

36
. Hans Moravec, “Rise of the Robots,”
Scientific American
(December 1999): 124–35,
http://www.sciam.com
and
http://www.frc.ri.cmu.edu/~hpm/project
. archive/robot.papers/1999/SciAm.scan.html. Moravec is a professor at the Robotics Institute at Carnegie Mellon University. His Mobile Robot Laboratory explores how to use cameras, sonars, and other sensors to give robots 3-D spatial awareness. In the 1990s, he described a succession of robot generations that would “essentially [be] our off-spring, by unconventional means. Ultimately, I think they’re on their own and they’ll do things that we can’t imagine or understand — you know, just the way children do” (Nova Online interview with Hans Moravec, October 1997,
http://www.pbs.org/wgbh/nova/robots/moravec.html
). His books
Mind Children: The Future of Robot and Human Intelligence
and
Robot: Mere Machine to Transcendent Mind
explore the capabilities of the current and future robot generations.

Disclosure: The author is an investor in and on the board of directors of Moravec’s robotics company, Seegrid.

37
. Although instructions per second as used by Moravec and calculations per second are slightly different concepts, these are close enough for the purposes of these order-of-magnitude estimates. Moravec developed the mathematical techniques for his robot vision independent of biological models, but similarities (between Moravec’s algorithms and those performed biologically) were noted after the fact. Functionally, Moravec’s computations re-create what is accomplished in these neural regions, so computational estimates based on Moravec’s algorithms are appropriate in determining what is required to achieve functionally equivalent transformations.

38
. Lloyd Watts, “Event-Driven Simulation of Networks of Spiking Neurons,” seventh Neural Information Processing Systems Foundation Conference, 1993; Lloyd Watts, “The Mode-Coupling Liouville-Green Approximation for a Two-Dimensional Cochlear Model,”
Journal of the Acoustical Society of America
108.5 (November
2000): 2266–71. Watts is the founder of Audience, Inc., which is devoted to applying functional simulation of regions of the human auditory system to applications in sound processing, including creating a way of preprocessing sound for automated speech-recognition systems. For more information, see
http://www.lloydwatts.com/neuroscience.shtml
.