Page 35 - Analog Circuit Design Art, Science, and Personalities

It’s an Analog World-Or Is It?

before people. while voltages did (e.g., lightning, which fixed nitrogen, thus fertil-
izing plants without human intervention). Digital as a quantitative idea first occurred
when people learned how to count-using their God-given digits. Digital as a
computational idea is the human-invented number system. Digital is the numbers
marked on an anafog meter. Except for the natural phenomena shaped to embody it,
digital is everything having to do with logic, microprocessors, computers, and so on.
But such natural phenomena, and the quantitative equations governing them, are
analog in nature, because they are analogs for one another.
As a clincher. note that Voyager 11’s information was digitally encoded; but to
find the “digital” signal you had to resort to analog processes, such as amplification,
demodulation. and filtering, to recover some sort of pulses representing the noisy
information before sophisticated digital signal-processing could be employed to
actually pry the information out of the noise. The pulses carrying the digital infor-
mation were analog quantities. The hardware to do all that (the DSP, too) used real-
world analog quantities like voltage and current. The sojhai-e was truly digital.
Have you now been convinced that everything in the world, except for human
creations, is analog? Well, I’m not! Apart from logic and number systems, there’s
another feature of digital that we have to consider: the ability to encode and decode,
to program, to store in memory, and to execute.
That ability existed in nature long before humankind. It exists in the genes of all
living beings, the strings and interconnections of DNA elements A, G, C, and T that
encode, remember, and carry the program for the nature and development of life.
They permit biochemical processes to differentiate between flora and fauna and,
within these, all the many phyla, species, and individuals.
So perhaps. if we are to generalize, we might say that the vibrant world of life is
based on digital phenomena; the physical world is analog and basically noncreative,
except as its random. chaotic, and analog-programmed behaviors act on-and are
acted upon by-living creatures.

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