Gavin writes:

> Duane writes:
>  > It was a trinary logic computer. It had 3
>  > states: off, on, maybe off/on.
>
>  Trinary.  Ho hum.  What about fractional bases, or better yet *negative*
>  bases!  This quote from a post to the Python developer's list from a
>  couple years ago gives a nice quick introduction:
>
>  > Negative bases allow the unique representation of both positive
>  > and negative integers without use of a sign. For example, "-3" in
>  > decimal equals, in base -2, "1101" (-3 = 1*(-2)^3 + 1*(-2)^2 +
>  > 0*(-2)^1 + 1*(-2)^0). It has been suggested that this property
>  > makes negative bases a more natural representation for integers
>  > than positive bases. There is more detailed information on the
>  > subject in [Knuth's] The Art of Computer Programming, Vol. 2.

Real systems are never likely to be esoteric. Life, the universe and
everything real tends to aim for the prosaic, boring, reliable solution.
However, that doesn't mean that it has to work at its most canonical form.
Every bit of life that we know of it -- and so far we know of only one form
of it -- sits a couple of notches up from the binary encoding structure we
chose for computers. Rather, it uses a quaternary code, {0, 1, 2, 3},
although it's usually written as {A, T, G, C}. This quaternary code is common
to all life on this planet (with a few exceptions as to which four base
nucleotides constitute the base pairs), from bacteria to bats to bald-headed
men.

The amount of information that's required to encode any single individual
human being is only 1GB (4 billion base pairs * 2 bits (4 choices) / 8
bits/byte). Twenty, thirty or forty years ago, when computers were still
young, that number would have seemed quite large, but now it seems
surprisingly small. You can now fit all of you that you were at birth on a CD.

Nevertheless, in fit of very fine engineering, your code (and that of your
rose bushes in front of your house) is stored in a few dozen strings of
molecules totalling only about 100 billion atoms. If you were to take all of
your DNA and lay it out end-to-end, in a single strand, it adds up to about 6
feet, but even at that it's small enough so that every cell in your body
(other than your mature sex cells) have two copies of your complete genome
(the CD) in every cell of your body, with room left over for an auxiliary
mitochodrial genome that has been inherited only mother-to-daughter since
prior to the evolutionary invention of sex.

And you are composed of approx. 13 x 10^12 cells, not so much as an
individual as you like to think, but rather more as a colony of several
trillion cellular automata. All of this suggests that perhaps the
breakthrough we're waiting for before we can build intelligent machinery is
not some profound bit of philosophy but rather merely much better
miniaturization.

Wirt Atmar

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