Nanotechnology
Toward an Understanding of Nano-Technology
written in E-Prime Text
by Nitupsarus Rex
CONTENTS
1) CONTEXT I- Discussion of spatial scale , pg.4
2) CONTEXT II- Causality, pg.6
3) CONTEXT III- Temporal scale, pg.8
4) Goals of Nano-Technology, pg.10
5) Nano-Tools and Devices
6) Current Advances
7) Warning
INTRODUCTION pg3.
Technology can be defined as the means whereby a society produces
the various 'goods' it uses. Most of us have some familiarity with
micro-technology and its breathtaking changes in our world.
Nano-technology in comparison promises a truly awesome next step for
mankind. This paper attempts to convey some idea of what
this new technology might mean.
Nano-technology proposes an engineering based upon
molecular machinery capable of self-replication and controlled by either
molecular or electronic information
systems. In other words, a technology of minute, invisible
machines programmable by humans and capable of independant
action and reproduction. Eric Drexler calls nano-machines,
"Engines of Creation" in his excellent book by that name.
No one seemed prepared to accept the unbelievable
meteoric storm of the computer-age, but I feel that nano-technology promises
to truly come like "a thief in the night"!
CONTEXT I - Spatial Scale pg.4
For an initial context, consider the principle of scale.
Micro-technology concerns itself with fabrications at the scale
of microns.
A 'micron' represents one millionth of a meter.
A 'nanon' represents one billionth of a meter.
Hence nano-technology goes three orders of magnitude smaller than
micro-technology. Most of us have some familiarity with the now
ubiquitous devices produced by micro-technology, but can we really
visualize the actual size of components at the heart of these devices?
Perhaps a power-of-ten tour of familiar small things will help.
The diameter of a human hair or pollen grain covers about four
thousandths of an inch or 100 microns. An average small cell extends only
about 10 microns. The lowly bacteria breaks in at one micron. Ten bacteria
end-to-end can measure a cell. Ten cells end-to-end can measure a hair.
Three or four hundred bacteria can encircle a hair. Thirty thousand bacteria
can probably sit comfortably around a grain of pollen.
The micro-chip in the computer I used to type this paper has
millions of micro-elements. The limits of micro-technology in its present
form hover at sizes somewhat smaller than one micron. A bacteria could tour
this micro-chip like a bus in a large city and find many objects comparable
in scale to its own. I find that 'bacteria size' makes a convenient reference
point for things on the scale of microns.
Now take a deep breath and imagine a world of still smaller things.
The bacteria above measures in at 1 micron or 1000 nanos. The tiny but
news-worthy virus tops in at about one-tenth of a bacteria or 100 nanos.
Just as the 100 micron hair made a starting point for our initial downward
plunge, let the virus represent the jumping off place into the next smaller
realm. Viruses, by the way, exist at the very limits of what optical
technology can see. A single photon of visible light would probably wash
over a virus like an 'energizing wave at the beach'. We have now entered
the conceptual realm of the invisible. The reader should take the metaphors I
employ as conceptual scaling tools only. I point out, however, that these
quasi-realities have undeniably real effects in our macro-sized world.
To continue, a 100 nano long virus has a 'gut' made of DNA type
material coiled round about like one would expect. A strand of DNA or
other large molecule has a scale of about 10 nanos. Finally, the smaller
constituents of large molecules measure in at 1 nano. Small molecules,
like the ones you learn about in chemistry, compose the stuff of nano
dreams! At last we have reached the nano-level.
Recapping, we have 10 nanos to a DNA rung and 10 DNA rungs to a virus;
10 viruses to a bacteria, 10 bacteria to a cell, and 10 cells to a hair.
At the shop where I work we commonly use the term 'a hair' to represent
the smallest increment one can see with the eye.
"It's a hair off, George", an eye-slave might say.
Little would he know, but that 'that hair' might hide 10 billion nano-ites,
each one vying for its day in the sun.
reference: "From Quark to Quasar- Notes on the scale of the Universe"
by Peter H. Cadogan
Cambridge University Press, 1985
CONTEXT II- Causality pg.6
This section focuses on how events occur on the nano scale.
The previous context helped us tune our scaleable conceptuality to the
proper level of spatial dimension. Now we shall consider causality.
In my conversations about nano-technology with people, I have
encountered remarks like "I just dont see how they can squeeze all that
plasic and metal into such a small space". This entirely misses the point.
Man's technology throughout history up to the present has involved
fabrication of devices whose smallest elements involve myriads upon
myriads of molecules. The overall behavior of such devices results from a
statisical averaging of the behavior of these myriads of atoms and molecules.
Even a micron-sized electronic switch might contain a billion atoms.
Nano-technology, in contrast, concerns itself directly with these
building-blocks-of-matter. Nano-technology does not attempt to compress
objects into smaller spaces, nor does it attempt to shave objects and
whittle them down into miniature versions of themselves. Nano-technology
intends to directly manipulate atoms and molecules. Nano-technology, once
in place, composes structures from the bottom up.
I talk here not of extending our current technology into smaller
realms. Nothing less than a totally new paradigm can encompass the scope
of nano-technology. One must first convince oneself that atoms and
molecules have orderly and useful behavior. Knowledge of chemistry
and physics gives overwhelming testimony to this fact. The problem with
current techniques lies in their gross manipulation of behavior. Mix a
zillion molecules of 'A' and a zillion of 'B' and you get 'C'.
Our knowledge, however, tells us that a one-to-one reaction between
individual molecules or atoms forms the basis for this gross-level process.
The chemist merely has to bring the proper elements into close proximity
and a statistical number of reactions or combinations occur.
If one holds an atom of carbon next to a molecule of oxygen,
carbon dioxide results. The elements concerned carry all the information
necessary to carry out a structural commposition. This
structurally-encoded-information determines what will combine with what.
So long as we provide sufficient energy or force and the correct spatial
orientation, a successful synthesis occurs. Of course one must use elements
whose structural-encoding allows them to combine. Present-day chemistry
provides the connection rules. Molecular systems have connection rules
similar to tinker-toys. The process just happens! With appropriately
designed levers and grippers a person could perform the reaction directly
himself. So much for causality!
Nano-technolgy probably will not proceed with hand-held levers.
I offered the remark merely to illustrate the simplicity of causality at
this level. I talk here of the level of molecular points of contact.
Large molecules of course can have increbible complexity of behavior.
pg.7
To recap, this dicussion of causality focused on the points at
which the elements or parts of a nano-device might be structurally attached
or removed. Current efforts to model molecular-dynamics ( see reference 1. )
use very simple assumptions. Most modelers base their descriptions primarily
on newtonian dynamics of charged bodies in electrostatic fields. The
structurally-encoded-combination-rules must be known also. McCammon and
Wolynes have concluded that quantum effects have a minimal impact on
the overall dynamics of such systems.
I believe this means we ultimately can operate at this level of
physical reality in a causally oriented way. Machines and devices can be
constructed molecule by molecule to do mechanical types of things. As the
current level research suggests, no known laws prevent development of
nano-technology.
reference:
1. "Molecular Dynamics and the Modelers' Art"
by Anne Simon Moffat
per. MOSIAC Volume 22 Number 4 Winter 1991
CONTEXT III- Temporal Scale pg.8
Current research on molecular movements ( ref. 1. )
focuses on fleeting motions which may last a pico-second or less over
distances of 1/10 of 1 nano-meter.
1 pico-second = 10 ^ -12 second = one thousandth of one
nano-second
Large molecular systems exhibit behavioral changes which occur in
micro-seconds, and complex biological-scale reactions might last
milli-seconds. (1/1000 sec)
Lets compare these times with those of current micro-processor-
technology. Chips in the computer market today have clock speeds up to
50 megacycles or so. The simplest change or micro-instruction thus takes
about 20 nano-seconds or 20,000 pico-seconds.
If a nano-device has a part capable of moving in 10
pico-seconds, a useable action might occur in say 10 to 100 pico-seconds.
One might thus imagine a nano-device capable of operating 200 to 1000 times
as fast as current micro-processors.
Now prepare yourself for a real surprise. If we assume that we have
created a nano-machine capable of replicating itself, how long will it take
for large scale results to occur? Assume a device the size of a bacteria,
say one cubic micron ( 10^-18 cubic meter in volume ).
Assume replication occurs every 5 minutes. In 5 minutes, we may achieve
over 10 billion actions at the rate of 100 pico-seconds each. This roughly
corresponds to a computer program giga-bytes long. Sounds plausible to me,
even if a little shaky in logic. Anyway, assume the device manages to clone
itself in 5 minutes. After 60 replicative doublings, we
have 2^60 devices or approximately 10^18 units. Now 10^18
units at 10^-18 cubic meters each, yields 1 solid cubic meter of nano-stuff.
This all takes place in only 5X60 = 300 minutes or 5 hours. The next few
hours give enough time to cover the surface of the planet.
The reader may of course have objections, but exponential doubling
means extraordinary growth rates no matter how you slice it. One may add to
this picture by realizing that these units must have encoded-instruction-
processors, so one might have in effect a barrel-full of nano-processors
all churning away in parallel with each one doing its specialty on cue at
any particular point in the replication chain.
If feeling a little threatened now, turn to the
WARNING at the end of this paper.
Goals of Nano-Technology pg.9
As stated previously, nano-technology aims to create
molecular-based devices capable of self-replication and
programmability. One can imagine artificial-intelligence capability also.
If the devices remain in our control, we can no doubt expect marvels in
the bio-medical industry. A plethora of possibilities exist for the
imagination.
I point out that, in a sense, nano-machines flourish
everywhere life does. The 'chemistry' of life presents
no inherent problems to nano-devices. Nano-machines exhibit
one major difference from living creatures, however. Life
evolved, while nano-ites arise, if at all, from intelligent
human design and craft. We as humans must decide what goals
to strive for. Nano-technology provides the leverage to move
worlds.
Projections:
Global information storage and retrieval
Super-intelligent global mind machine
Totally automated food & resource industries
Deformable voice-activated convience objects
Cures for all ills of the body
Relative immortality
Transmigration of Mind
Travel to the stars
Nested Virtual reality
An anwser to the question "Why ask why?"
Tools and Devices pg.10
Man fashions material objects in three basic ways:
by machining, deformation, and fabrication. He uses his mind, hands, and
senses as primary or first-order tools. With this basic assembledge, he
creates second-order tools.These second-order tools consist of grippers,
cutting-wedges, impact-hammers, belts, gears, pulleys, platforms etc.
Second-order tools primarily originate from machined or shaved objects
although deformation provides more capable versions. Third-order devices
make their appearance as fabrications of second-order parts into machines
with multi-functionality. Fourth-order devices come into service as engines
or motors which continue in motion as long as resources are available.
Fifth-order devices (computers) encode information and control other devices.
Sixth-order devices (robots or assemblers or knowbots) have
self-programmability.
Seventh-order devices replicate.
Replicators make use of all lower-order devices.
Replicators evolve.
Nano-technology potentially may make use of all lower-order
tools to arrive at self-replicating assemblers. A first
generation replicator might consist of these parts:
information tape and store
tape decoder or reader
central processor or control unit
motive engine
drive linkages
conveyor system
assembler unit
parts and tools rack
raw materials bins
input and output ports
manipulators
and sensors
Fashioning all of the above parts requires much ingenuity, but please
recall that a group of students once made a working computer from
tinker-toys. Information plus material equals creativity.
Imagine a nano-machine as large as a bacteria again.
We might expect it to have about 10^12 or 1000 billion atoms.
If individual working elements consist of about 100 atoms, we count about
10 billion functioning parts. This allows approximately 1,000,000 parts
per functional-system division of a replicator as listed above. I think
the Space Shuttle sounds rather simple in comparison. If the reader thinks
100 atoms is too few to make something out of, read the next section on
current advances.
reference: "Engines of Creation" by Eric Drexler, 1987?
WARNING
Physical reality, as we know it now, has little meaning
once nano-machines take over. Objects in space-time can have
no essential nature if composed of multi-programmable-replicating-
universal-information-bearing-Turing-machines! Reality will probably
collapse like a 'house of cards' with lot of nightmares on the way down.
The funny thing IS, though, I think IT'S always BEEN that way.
Vino and Veritas
