From: sinster@cse.ucsc.edu (Darren Senn)
Newsgroups: sci.nanotech
Subject: Re: Snowballing tomk
Date: 21 Aug 92 22:47:09 GMT
Organization: University of California, Santa Cruz (CE/CIS Boards)

In article <Aug.19.20.14.31.1992.28110@planchet.rutgers.edu> portal!cup.portal.com!kr@pyramid.pyramid.com.UUX writes:
>don't you think it would be a worthwile venture to convert todays
>dirty industry into clean molecular manufacturing where the widest range
>of products (from "simple" chemicals to completely assembled devices 
>like aerospace-vehicles and skyscrapers) are being produced with *NO*
>toxic waste byproducts at essentially the cost of the raw materials
>(excluding design costs, though) while using solar energy provided
>by cheap solar cells (instead of burning up petroleum or nuclear stuff) ?

WHOA!  Isn't this a bit far fetched?  Certainly nanotechnology has the
theoretical ability to provide a totally clean method of production,
but that limit won't be reached for the first dozen or so iterations
of the technology.  The first version of the technology that will
appear will be dirty, expensive, slow, and will produce substandard
objects.  Each iteration will improve on that, but it won't be
in our lifetimes that we see mass production of common objects through
atomic or molecular assembly.  We will probably witness the first
iteration.  Maybe a few others.  But certainly not many more.

When speaking about the potential pollution, consider the automobile.
Combustion of gasoline in the right conditions produces water vapor,
carbon dioxide, and heat.  It's not until you try to maintain a
running internal combustion engine at these optimal conditions that
you realize it's just not practical.  So we get fumes pouring out of
our cars dirtying our air.  Great idea, but it doesn't work so well.

You mentioned building a skyscraper.  Let's size that down to
building, say, a two-story townhouse that masses around 10 metric
tons.  I really don't know how accurate that mass estimate is,
but it's not too far off.  Suppose your building blocks mass about
3000 atomic units (that's a pretty sizeable molecule).  So this
house will need ~2x10^36 building blocks.  If you can connect
1 trillion (10^12) building blocks every second, then this
two-story house will need ~6x10^16 years to be built.  In short,
the Earth will be swallowed by the sun long before this house
is built.  So I'd wager that a skyscraper is out of the question. :)

Remember: we're talking about a technology that manipulates some
pretty small particles.  Even if you only consider using large
building-blocks, you'll need an accurate, stable, maintainable,
very high speed manipulator before mass production is even
_considered_.  Then it'll take a good 5-10 years of pulling the
kinks out of that process before mass production is cheap enough
to build, say, an IC.  Then we're talking another 20 years or
so before people start trying to build a toaster.  I suspect
toasters (if the appliance lasts that long :) will be manufactured
from rolled and stamped sheets of metal for a long time to come.

The first few iterations of the technology are going to have
spend a great deal of resources simply maintaining their manipulators.
You don't want to have to throw away and replace a multi-million-dollar
piece of equipment.  So trying to design a molecular manipulator
that can be maintained with macroscopic tools will be a major
hurdle.  Sure, we've got STM's to work with, and they can
be maintained with macroscopic tools, but you can't seriously
consider building a useful product with one...  especially one
that you can make a product off of.

The alchemists of old dreamed of building philosopher's stone --
a object that could turn lead into gold.  Today's high energy
physicists have built one: it's called a linear accelerator, and
can manufacture gold from lead at a cost of a few tens of millions
of dollars per ounce.  We can also manufacture flawless diamonds
at a few orders of magnitude more cost than mining real ones.  All
these technologies are theoretically and intellectually wonderful,
but not too practical.

In general, you can't know a technology's disadvantages until it's
arrived.
-- 
Darren Senn                                            Phone:    (408) 479-1521
sinster@scintilla.capitola.ca.us                       Snail: 1785 Halterman #1
Wasurenaide -- doko e itte mo soko ni anata wa iru yo.     Santa Cruz, Ca 95062
Newsgroups: sci.skeptic