In the first years of electrical engineering, most future
professionals and academics get immersed in a ludic dialogue with
"(switches and signals)". Around the third year, in several
curricula, they have to take courses on systems control and on
communications. For most of them, the difficulties associated with
these courses is that they require a change on perspective that is
hard to accomplish. I'm not assuming that I'm talking only about the
students. Switches and signals are only part of the "components" used
to deploy systems that accomplish tasks. Many get lost in the
meandrous praxis of their community and end up never reaching other
ones. It is a "Catch-22", a "double-bind" situation. A similar
situation occurs with the study of grammar in relation to discourse,
for example. They may sustain different conceptual schemes, but the
interesting question is how these schemata are historically and
culturally transformed. I know you have this kind of concern, but I
find important to stress it for the others.
In the case of controlling large amounts of energy with small ones, I
would like to add that the energy embedded in the actual material
system has also to be counted. If "technology is society made
durable", as Latour says, there is a price to pay for these
durability. A price that has been paid previously. An energy that will
probably go to the garbage when the systems ends in a junk "yard". The
energy is there, in just not being used now.
> The simplest possible signal is a 'spike', a very short-lived burst of
> energy.
Actually, the spike, for communication engineers, _is_ the most
complex one. It is known as the delta function and it is an
abstraction used to represent an infinite number of tones (or
frequencies). No I'm not going into the details, instead, I will make
use of different metaphors than you did. It may make things easier for
the other members of the list.
When a orthopedist knock a patient's knees to access his, her, or its
reaction, she or he is in part using this property. The reflexive
shivers represent the multiple tones that the procedure has triggered.
It works because the spike is the signal that contains the most
difference of all signals. It never existed, than it exists, then it
does not exist forever. If it exists again, it will be double, and it
will not be as different as a single one. Hearing is being test in
the same way, but with the use of electronic equipment. A short signal
is burst into a patient's ear, and the response is used to access what
the person is able to hear.
> Problem: what is the largest number of switches you can set with
a given signal?
With a single spike, and infinite number, because it has infinite
bandwidth.
It is like to try to climb a post. It is hard to stay on top, and the
thinner the post more difficult the task is. With a couple a narrower
bandwidth is necessary. It you connect an infinite number of posts,
and glue them, you can walk on them, like walking on a fence. Their
difference almost disappear. The difference only occurs when going up
and when going down the fence. If you make a stair, things get easier.
The shape of the fence, what is IN its FORM, the degree in which
it can be compared to the the single post, is related to how much
INFORMATION can walk above the fence, to how fit you are. Electrical
and Electronic Engineers "build electrical" fences that enable signals
to walk around. Walking on a fence that has a strange format is like
playing on a playground in a windy day. That is NOISE. Therefore,
engineers make fences according to the weather. If the wind is two
strong, you make it thicker, or you make a second one, or you carry
two of the same, one foot in each, one in each hand, and you have
REDUNDANCY. If you are carrying lots of stuff, you put them on a bag,
you COMPRESS them.
> None of this depends on which way the individual switches are actually set
> in a particular case. That is, none of it depends on the content or meaning
> of the information, only on "how much" information is needed or used.
I agree that for the mathematical concept it does not make a
difference, but the implications of its use make a lot of difference
in terms of to whom and to what engineers are open. The configuration
of the switches, or the architecture of the systems, is percolated
with the praxis of the involved community. Examples, I can't use
accentuation in portuguese unless I my computer supports it. T write
in Arab, or in Chinese is even more difficult. Where is the key for
???
What that means is that the social practices are enmeshed in the
artifact. Technology scaffold a specific form of meaning and action,
and suppress others, of course. And that is why is so important to
make people aware of the community WITH whom a specific technology
will be developed and maintained. Metaphors that
emphasize their opposition may foster barriers between the
communities.
I have to interrupt now. Another fence is waiting for me, and I still
have to write it. :( ;( :)
luiz