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Re: Digest Number 157

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  • Christopher J. Phoenix
    There are two different estimates of storage capacity in Nanosystems. For rod-logic registers, Drexler estimates one register (one bit) takes 40 nm^3. For
    Message 1 of 5 , Feb 13, 2000
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      There are two different estimates of storage capacity in Nanosystems. For
      rod-logic registers, Drexler estimates one register (one bit) takes 40 nm^3.
      For partially fluorinated polyethylene tape (1 bit per 2 C atoms), he
      conservatively estimates 5 bits per nm^3, or 200 bits in the space of one
      register. (Register: section 12.4.2 p. 357. Tape: section 12.6.4, p. 366.)

      And let's not forget about the theoretical possibility of storing bits by
      exciting the electron cloud of a single atom--IIRC they said they could
      store 5000 states (>12 bits) per atom, in theory of course!

      Chris

      At 05:16 PM 2/13/00 -0800, Gina Miller wrote:
      >From: "Gina Miller" <nanogirl@...>
      >
      >David,
      >My estimates come from Rob Freitas:
      >
      >http://www.foresight.org/Nanomedicine/NanoMedFAQ.html#FAQ19
      >
      >>Consider that a nanostructured data storage device measuring ~8,000
      >>micron3, a cubic volume about the size of a single human liver cell
      >>and smaller than a typical neuron,
      >>could store an amount of information equivalent to the entire
      >>Library of Congress. If implanted somewhere in the human brain,
      >>together with the appropriate interface
      >>mechanisms, such a device could allow extremely rapid access to this
      >>information.
      >>
      >>A single nanocomputer CPU, also having the volume of just one tiny
      >>human cell, could compute at the rate of 10 teraflops (1013
      >>floating-point operations per second),
      >>approximately equalling (by many estimates) the computational output
      >>of the entire human brain. Such a nanocomputer might produce only
      >>about 0.001 watt of waste heat,
      >>as compared to the ~25 watts of waste heat for the biological brain
      >>in which the nanocomputer might be embedded.
      >
      >>� Copyright 1998, Robert A. Freitas Jr. All rights reserved.
      >
      >
      >Part of the discrepancy is your estimate of the size of a megabrain
      >computer. you state:
      >At 7:10 PM -0500 2/13/00, David Forrest wrote:
      >>Depending on your definition of a desktop, let's say 10^7 brains/m^3.
      >
      >On page 370 of Nanosystems, Drexler talks about a 10^15 MIPS (roughly
      >10^21 operations per second) machine with water cooling as being a
      >cubic cm in volume. Merkle estimates the computational power of the
      >human brain as "It seems reasonable to conclude that the human brain
      >has a raw computational power between
      >10^13 and 10^16 operations per second."
      >(http://www.merkle.com/brainLimits.html)
      >Thus the 1 cubic cm computer is roughly a megabrain computer.
      >Since 1 cubic cm is 10^12 cubic microns, there is one brain per 10^6
      >cubic microns. Using an estimate of 10^4 cubic microns for a larger
      >human cell, that would be one brain per 100 cells. Thus there is a
      >difference of 100 between Drexler and Freitas, probably because
      >Freitas is using less conservative assumptions, or assuming molecular
      >electronics, etc.
      >
      >Anyway, we all agree that an awful lot of computation could be shoved
      >into a nanotechnology-based computer a lot small than the human brain.
      >
      >I'll add IMM when I go in to correct some other errors, (right after this
      >post) such as Robert A. Freitas Jr. and various links. Homestead has no copy
      >and paste, so I had to hand type in the text (as well as the urls)
      >Anyhoo.....
      >Gina "Nanogirl" Miller
      >
      >
      > David Forrest <drf@...> Writes:
      >> Gina,
      >>
      >> I enjoyed reading your interview. One nitpick and one comment.
      >>
      >> One statement you made was:
      >>
      >> "Nano-theorists have estimated that the entire contents of the Library of
      >> Congress could be stored in a
      >> nanocomputer the size of a human cell, and that another nanocomputer the
      >> size of a human cell could have the same raw
      >> computing power as the whole human brain. "
      >>
      >> The Lib. of Congress would fit more like into the volume of 1/4 of a sheet
      >> of office paper, I estimated once based on Drexler's volumetric
      >> calculations. Still small but much more than a human cell.
      >>
      >> Regarding brainpower/cell volume, take Drexler's estimate of a
      >water-cooled
      >> desktop mechanical nanocomputer operating in the megabrain range.
      >> Depending on your definition of a desktop, let's say 10^7 brains/m^3.
      >> That's 10^-11 brains/cubic micron. A single cell (typical cell for a
      >> higher animal) is about 4000+ cubic microns. So that multiplies to 4 x
      >> 10^-8 brains/cell volume. A long way from one brain per cell. Perhaps a
      >> molecular electronic computer will get you three orders of magnitude
      >> closer, but you're still off by 100,000. Your point of course is
      >> nanocomputer brain equivalents could be much much smaller than existing
      >> brains and there is no argument about that from me.
      >>
      >> -------
      >>
      >> Comment: Please don't forget to mention the Institute for Molecular
      >> Manufacturing (http://www.imm.org), too! We're Foresight's much smaller
      >> cousin, but we do critical research that complements Foresight's
      >> educational role.
      >>
      >> Thanks for your continued contributions to the information stream.
      >>
      >> David Forrest
      >> Acting President
      >> Institute for Molecular Manufacturing
      >
      >
      >
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      >
      >
      >
      --
      Chris Phoenix cphoenix@... http://www.best.com/~cphoenix
      Work (Reading Research Council): http://www.dyslexia.com
      Is your paradigm shift automatic or stick?
    • Robert Freitas
      ... Gina, I ve always used 1 Library of Congress (LOC) ~ 40 million volumes x 150,000 words/volume x 6 bytes/word x 8 bits/byte ~ 3 x 10^14 bits. Philip
      Message 2 of 5 , Feb 14, 2000
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        > From: "Gina Miller" <nanogirl@...>
        > David,
        > My estimates come from Rob Freitas:
        > http://www.foresight.org/Nanomedicine/NanoMedFAQ.html#FAQ19
        >Consider that a nanostructured data storage device measuring ~8,000
        >micron3, a cubic volume about the size of a single human liver cell
        >and smaller than a typical neuron,
        >could store an amount of information equivalent to the entire
        >Library of Congress. If implanted somewhere in the human brain,
        >together with the appropriate interface
        >mechanisms, such a device could allow extremely rapid access to this
        >information.


        Gina, I've always used 1 Library of Congress (LOC) ~ 40 million volumes x 150,000 words/volume x 6 bytes/word x 8 bits/byte ~ 3 x 10^14 bits. Philip Morrison [SciAm(July98):115] claims the 1998 LOC has only 20 million volumes but that there are also ~2 x 10^15 bits of sound recordings -- assume 10:1 data compression of the sound for nano-storage, and our total LOC figures agree. Or make your own estimate. Below, I'll use mine.

        Assuming fluorocarbon tape information density of ~26 bits/nm^3 [NMI:178], 1 LOC can be stored in ~12,000 micron^3 (~one large-ish human liver cell volume). Using Drexler's slightly more conservative ~5 bits/nm^3 for tape storage [NS:366], 1 LOC can be stored in 60,000 micron^3 (~one very fat macrophage cell volume).

        Assuming rod logic register storage with information storage density of ~0.025 bits/nm^3 [NS:357], 1 LOC requires a storage volume of 0.012 mm^3, a cube ~230 microns on an edge.





        >>A single nanocomputer CPU, also having the volume of just one tiny
        >>human cell, could compute at the rate of 10 teraflops (1013
        >>floating-point operations per second),
        >>approximately equalling (by many estimates) the computational output
        >>of the entire human brain.

        > On page 370 of Nanosystems, Drexler talks about a 10^15 MIPS (roughly
        > 10^21 operations per second) machine with water cooling as being a
        > cubic cm in volume. Merkle estimates the computational power of the
        > human brain as "It seems reasonable to conclude that the human brain
        > has a raw computational power between 10^13 and 10^16 operations per second."
        > (http://www.merkle.com/brainLimits.html)
        > Thus the 1 cubic cm computer is roughly a megabrain computer.
        > Since 1 cubic cm is 10^12 cubic microns, there is one brain per 10^6
        > cubic microns. Using an estimate of 10^4 cubic microns for a larger
        > human cell, that would be one brain per 100 cells. Thus there is a
        > difference of 100 between Drexler and Freitas, probably because
        > Freitas is using less conservative assumptions, or assuming molecular
        > electronics, etc.


        Drexler's 10^15 MIPS/cm^3 figure [NS:370] equals 10 teraflops per 10,000-micron^3 (mammalian cell size) volume. Ten teraflops is simply Merkle's lower 10^13 ops/sec brain-capacity figure. If instead you use Merkle's upper 10^16 ops/sec brain-capacity figure, then you need 1000 tissue-cell volumes, a cube ~200 microns on an edge, roughly the size of a human ovum (also a mammalian single cell). Take your pick. AFAIK, there is no "difference of 100" involved; our assumptions are identical.


        Robert A. Freitas Jr.
      • Eugene Leitl
        ... Gina: raw computing power is a meaningless metric in that context. You re guaranteed to be misunderstood here, which is probably not what you want. Apart
        Message 3 of 5 , Feb 14, 2000
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          David Forrest writes:

          > "Nano-theorists have estimated that the entire contents of the Library of
          > Congress could be stored in a
          > nanocomputer the size of a human cell, and that another nanocomputer the
          > size of a human cell could have the same raw
          > computing power as the whole human brain. "


          Gina: "raw computing power" is a meaningless metric in that
          context. You're guaranteed to be misunderstood here, which is probably
          not what you want. Apart from that, estimates on how many OPS the
          brain actually does are 1) notoriously unreliable ad hoc numbers 2) in
          my estimates several orders of magnitude too low
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