External Links:
Engines Of Creation -
K. Eric Drexler
The
Gray Goo Problem by Robert Freitas, on KurzweilAI.net
Exponential Assembly - Zyvex
Exponential Assembly - An Exponentialist Assessment
(post to sci.nanotech 9th February 2006)
Hi,
Like Drexler, Zyvex are exponents of the exponential nature of manufacturing via
MNT, and have written about exponential assembly:
http://www.zyvex.com/Research
A rough guide to understand what exponential assembly would mean, in terms of
assembler population doubling times, are the two competing memes of the Rule of
70 and the Rule of 72 Basically, divide your growth rate (per fixed time
period) into 70 (or 72) and you get the population "doubling time".
(expressed in multiples of the same fixed time period).
Search Google for these two slightly different versions of these popular rules
of thumb and you get the following:
Rule of 72 - 25,000,000 hits
Rule of 70 - 41,700,000 hits
The former is mainly used in the world of finance, and the latter in population
dynamics, population ecology, demography and so on (and hence exponential
assembly). Essentially, both rules of thumb allow you
to quickly derive a doubling time (for an amount of money, or a population)
I've written an article that compares the Rule of 70 and the Rule of 72:
http://members.optusnet.com.au
I hope you find it useful and interesting. If you did, you might also enjoy the
following:
http://members.optusnet.com.au
"The Scales of 70" extends the Rule of 70/Rule of 72 to positive and
negative rates of variable rate compound interest, and hence is much less naive
than the Rule of 70 / Rule of 72. Essentially, though, it is just a more
flexible rule of thumb.
"The Scales of e" extends the Scales of 70 even further, to a
realistic and accurate model of variable rate compound interest (allowing for
both positive and negative rates of growth):
http://members.optusnet.com.au
I believe that Exponential Assembly, when it arrives, will follow a
"growth" pattern bound by "The Scales of e." Hence, despite
Zyvex's or anyone else's best efforts, assembler population doubling times will
not be fixed or constant.
The Scales of e demonstrates that variable positive rates of compound interest
will result in variable population doubling times. Occasionally, due to lack of
availability of raw materials, growth rates may be temporarily reduced to zero
and the Scales of e will be perfectly balanced between positive and negative
rates of population
growth.
Less rarely, but still possible, might be periods of negative assembler
population growth rates (e.g.. an industrial accident, a "spoiled"
batch, a fire etc). Hence, the Scales of e might will swing the other way, to accommodate
a few "population halvings", before once again swinging
back to irregular population doublings.
Regards,
David
Bibliography
Freitas, Robert, A., Merkle, Ralph, C., Kinematic Self-Replicating Machines. Landes Bioscience. 2004.
pp.138-140.