The more fact of communicating, as communication of smallpox, of a secret of power, to intercourse
by words, letters, or messages. In the broadest aspects of communication, much work has recently
been done to clarify theories and make them workable. The era we are entering might well
be characterized as an era of communication. This film will touch in the most elementary
way some aspects of the subject that are of daily concern to all of us. Here is Claude
Shannon's diagram by which almost any communication process can be schematically represented. The
information source selects the desired message out of a set of possible messages. The transmitter
changes the message into the signal, which is sent over the communications channel to
the receiver, where it is decoded back into the message and delivered to the destination.
Every such system contains noise. Noise is a term used in the communications field to designate
any outside force which acts on the transmitted signal to vary it from the original. In this
usage, noise does not necessarily mean sound. Reading is a form of communication where the
word is a signal, a printed page of the transmitter, light the channel, the eye of the receiver.
Here sound can act as noise and interfere with the message, but in some situations like
reading on a train where the sound level is normally high, it is not the sound that interferes
with the communication process as much as the motion and the unpredictable quality of
the light source. Quality of light and motion then becomes noise. In radio, noise could
be static. In television, noise is often the distortion of the picture through transmitting
or receiving. In a typewritten message, the noise source could be in the quality of the
ribbon or the keys, and we are all familiar with the carbon copies that keep getting
progressively worse. If anything acts on the signal so as to vary it in an unpredictable
and undesirable way in the communication system, it is noise.
We can consider telegraphy in terms of this same diagram. We will use a New York Stockbroker's
office as the information source and a Los Angeles Stockbroker's office as the destination.
There may exist at the information source just two possible messages, by or cell. From these
two, the message cell is selected. Then coded the telegraphic transmitter and sent over the
channel in electrical impulse signals decoded by the receiver back into the message cell
and delivered to the destination. Noise, of course, is there, this time acting electrically.
It could distort the signal in such a way as to change cell into self, but as there are
only two possible messages, by and cell, there is sufficient redundancy in the spelling of
the words that even if it did read self, the information would still be clear. Naturally,
this example has nothing to do with the Stockbroker's office of today because of all organized
communication. Market information is perhaps the most efficiently handled. The New York
information enters a signal channel in this form and is automatically decoded in Los Angeles
in this form. But even here, we find redundancy, counteracting noise. The English language
is about one half redundant. This extra framework helps prevent distortion of the message in
the written language or in the spoken language. In speech, the brain is usually the information
source. From it, the message is selected. The message is the thought, not the words.
The vocal mechanism codes the words into vibrations and transmits them as sound across the communications
channel, which is, of course, the air. The sound of the word is a signal. The ear picks
up the signal, and with the associated eighth nerve, decodes the signal and delivers the
message to the destination. This time, noise could originate in the transmitter or in sound
vibrations that disturb the channel. Or it could be a nervous condition on the part of
the receiver, and it could change the message from I love you to I hate you. How do you
combat it? One way is through redundancy. I love you, I love you, I love you, I love
you. Another is increasing the power of the transmitter. This combats noise as does the
careful beaming of the signal or duplicating of the message via other signals.
Now let's consider amount of information communicated. The message cell contained one bit or unit
of information because it was a choice of two possible messages, by or cell. A choice
of two gives one bit of information. This is the amount of information that one on-off
circuit can handle at one time. It can be on or off. Two bits of information is the
amount two circuits can handle. There is a choice of four possible conditions. On-off,
off-on, on-on, or off-off. Three circuits can handle three bits or a choice of eight
possibilities. Four circuits, four bits, or sixteen possibilities. Five bits, thirty-two
possibilities. Six bits, sixty-four. Amount of information increases as the logarithm
of the number of choices. The message I love you to communicate information must also be
a choice of other messages because if the information source were so loaded with feelings
of love as to be incapable of any other thought, then surely by the time the words I love you
were spoken, no information was communicated at all. No information, yet previous experiences
could make those three words convey great meaning. Source, message, transmitter, channel,
message, destination. You could imagine the message being music and the transmitted signal
being tone, or it could be applied equally well to writing or to smoke signals or to
hand signals. But let's take painting as another example of a signal transmitting a
coded message. Information source, mind, and experience of painter. Message, his concept
of a particular painting. Transmitter, his talent and technique. Signal, the painting
itself. Receiver, all the eyes and nervous systems and previous conditionings of those
who see the painting. Destination, their minds, their emotions, their experience. Now in this
case the noise that tends to disrupt the signal can take many forms. It can be the quality
of the light, or the color of the light, or the prejudices of the viewer, or the idiosyncrasies
of the painter. But besides noise, there are other factors which can keep the information
from reaching its destination intact. The background and conditioning of the receiving apparatus
may so differ from that of the transmitter that it may be impossible for the receiver
to pick up the signals without distortion. In any communication system, the receiver
must be able to decode something of what the transmitter coded, or no information gets to
the destination at all. If you speak Chinese to me, I must know Chinese to understand your
words. But even without knowing the Chinese language, I can understand much of your feelings
through other codes we have in common. There are systems of communication where there is
no redundancy, and no duplication of the message. Here knowledge of the code is essential. In
planning one if by land, two if by sea, the fellow on the opposite shore simply had to
know the code. But there are also many examples of times when the message has been conceived
and the signal sent long in advance of understanding or acceptance of the code employed. In the
case of Galileo or Socrates, it did not in time matter that the receivers of their time
were not tuned to receive their signal. The ultimate transmission of such a message represents
communication of a very complex order. Other high-level communication occurs in very different
areas. A wave breaking on a beach brings a world of information about events far out
at sea. It can tell of winds and storms, the distance and the intensity. It can locate reefs
and islands and many things if you know the code.
how often have we wondered what holds such birds together in their flight? Communication
is that which links any organism together. It is communication that keeps a society together.
And though these people seem unaware of each other's existence, neither looking nor speaking,
one group meets and filters through the other with hardly two individuals coming in contact.
So constant is the flow of information and so complex the web of communication that keeps
them apart and holds them together. The symbol, the abstracting of an idea, communication
at once anonymous and personal. Personal because of the countless individuals that created
its form. Each one who in his turn added something good or who took something bad away. Anonymous
because of the numbers of individuals involved and because of their consistent attitude.
These are examples of communication of an idea through symbols. But there can also be
communication through symbols to an idea, as in the burnt offering or in the flame of
the candle. The use of flame as a transmitter in the communications channel is probably
as old as man's first fire. It stands for all the wonder and mystery of forces beyond
man's knowledge. The storm warning flags are part of a long evolutionary tradition
of signals. But their beginnings were probably in basic reactions to color and form. Basic
enough to make their communications carry beyond the barriers of language and custom.
But symbols also change and evolve. Some methods of transmitting messages rapidly become symbols,
then pass into obscurity to become readable only to the anthropologist, while other symbols
of communication remain. The myth being transmitted here may be unlimited at the range and the
subtlety of its ideas. Yet the method and the signal are such that they must be fed to
the transmitter in a series of positive decisions. The system calls for the key to be either
up or down. The code calls for a dot or a dash. The current flows, it ceases to flow,
it flows, it is black or white, it is stop or go, on or off, one or none, go or no go,
are black or white, as in this small area from a half-tone reproduction in a magazine.
The press that printed it is capable of printing but one color of ink at a time, in this case
black ink on white paper. In order to transmit the image, it had to be broken down to many
points of decision, black or white. We know that such a limitation is not at all restricting
if enough decisions are made. In this case, half a million decided points give fair rendition.
A million would be better. Conventional printing of color is no different except that with
the added factor of color, four times the number of decisions had to be made, one set
in yellow, one in red, in blue and in black. Whenever added factors in a problem are recognized,
the number of decisions necessary for the solution grows by large leaps. As theories
and equipment and men develop, it becomes apparent that one sure way of handling multiple
factors is to build a system that can handle each decision in its time. Men have long known
the theory on which complex problems of many factors can be solved, but the number of decisions,
the calculations necessary were prodigious. And not until the recent development of the
electronic calculator could these areas be touched. The problem became one of communication
between man and machine, between machine and machine, between machine and man. The cards
are punched or not punched. Light passes or stops. And by this binary system, information
is fed to machine. In a moment, we will hear sounds which are an actual product of a huge
calculator. The frequencies are made audible to check its functioning and in a way feel
its pulse. Here it is.
The ability of these machines to store information, manipulate, sort and deliver it is fantastic.
And with their complex feedback systems, their memories, their almost human reactions to
situations, it is understandable that they are popularly referred to as brains. The greatest
fallacy in the comparison is one of degree. The decisions made by the machines are comparable
in number to half million in this half tone. But far greater is the number of stops and
goes performed by the human nervous system in order to complete the simplest act. So great
that each decision were represented by a small half tone dot. The total area of dots would
cover several earths, such as the magnitude we reach when a number like a half million
is raised to the fourth power. As flowing as the human movements may seem, they are actually
the product of these countless yes-no decisions communicated with great speed to and from
all parts of the body. The channel is the nervous system. Each nerve is made up of hundreds
of fibers. The decision is the impulse of a single nerve fiber. An all out event, a trigger
process which is set off like an explosion when a stimulus exceeds the ignition point.
The dot and the half tone, the hole in the tape, each is a separate fire no fire signal.
But together they add up to a smooth, sometimes incredibly complex action that often seems
more vague than decisive. Yet many things which we accept as undecided vagaries would
be, if we could bring our focus in sharp, decisive individual units. It is the responsibility
of selecting and relating parts that makes possible a whole which itself has unity. The
line on which each color breaks, and the point at which each dot that makes up this painting
is placed, affects the whole canvas. The communication of the total message contains
the responsibility of innumerable decisions made again and again, always checking with
the total concept through a constant feedback system. These elements of a communication
system act together as one great tool. And though the tool may be a complex task, it
never relieved the man of his responsibility. No matter where it occurs, no matter what
the technique, communication means the responsibility of decision all the way down the line.
