Friends,
On Mon, 20 Mar 2000 17:27:04 -0800
hal@finney.org responded to Eliezer as follows:
Eliezer:
>> There's no way - that I know of, anyway, correct me if I'm wrong - to
>> read out the atomic positions inside a complex molecular structure. <snip>
Hal:
>At the time of assembly it is much easier to check for errors.
>Repeated insertion and verification steps can reduce the error to a
>very low level. It is true that after assembly is complete, internal
>spontaneous or radiation generated errors may be difficult to detect.
>Nevertheless functional tests of the entire unit can be used to
>characterize and detect many failure modes.
Um, er, well, that is, I think there is a way "to read out the atomic
positions inside a complex molecular structure." In fact, a multitude of
ways.
I would like to suggest that the above quotes seem to reflect a somewhat
impoverished view of the likely characteristics of the operational regimen
of a mature nanotechnology. Inspection will, more logically, be entirely
routine, and VERY easy. Inspection and testing is at the heart of any
technology. Quality control is fundamental, and an essential part of
establishing reliable functionality. Technology without measurement and
inspection and testing, is a contradiction in terms. It is blind and
ignorant. It lacks the INFORMATION about the state of the system that is
inferred by the very term "design".
There will be a whole array of methods to test for damaged nanocomponents,
and to obtain PERFECTLY precise information about the structural details in
question. For instance, from what I know of chemical analysis, various
spectroscopic techniques currently in use involve EM irradiation of a
specimen, and the determination of the structure of the various molecules
by comparison with known spectral characteristics. There's absorbtion,
emission, and NMR spectroscopy to name a few. (In contrast to the testing
of a solitary nanobot, these spectral analyses are conducted on mixtures of
vast billions upon billions of molecules, which even at the highest purity
still have substantial levels of impurities. Thus, though the analytical
techniques give perfectly usable informational results, the spectra
reflect, in their fuzziness, the bulk nature of the samples being
analyzed.) Why should these standard techniques not apply to inspecting
nanobots? In fact, why should they not work even more definitively and
precisely, being applied as they inevitably would be, to a single isolated
bot unit?
A perfect nanobot has every atom in its proper place. Such a bot will
absorb EM energy, and vibrate in a very precise manner. It should have
spectral characteristics that PRECISELY reflect its structural
particulars. If even one atom is out of place, it will vibrate
differently, absorb differently, emit differently, across an entire
spectrum. Thus an inspection procedure carried out by an inspection bot
should be able to tell you if it's subject bot is perfect or not, and if
not, precisely what the variance from perfection is, referencing a
compendium of collected spectra of previously analysed defective bots.
Simple acoustic spectroscopy might do the trick. Grab the bot. Give it a
whack. Listen to the returning hum/vibration. Move on to the next bot.
If you catch a bot between cycles, you don't even have any down time.
I don't know, maybe I'm completely out of my depth here. But it really
seems like you're imagining that it will be "hard" because, well,
...because no one knows how to do it yet. Comes back to what my boy Ray says.
Best, Jeff Davis
"Everything's hard till you know how to do it."
Ray Charles
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