Figure 1-1. Digitizing information: the laser beam in a digital record player reads pits
on the record as zeros, and spaces as ones. These digits are eventually
reconverted into music by the electronic circuitry.
1-3.
NUMBER SYSTEMS
a. Two-Symbol Code. The two-symbol method of encoding information has
been in use for a long time. African bush tribes sent messages using combinations of
low and high pitches, Australian aborigines counted by twos, as did other hunter-
gatherers from New Guinea to South America. More recently, the Morse code used
groups of dots and dashes to represent the letters of the alphabet. In a philosophical
vein, the Chinese viewed the world as a place of dualities: male and female, good and
evil, new and old.
b. Other Codes. There are many other systems besides the decimal and binary
codes. Babylonians used a number system based on 60. English- speaking people
used a 12-based system, whose influence can still be seen in the units of measurement
we use today (the 12 months of the year, the 12 inches in a foot, the two 12-hour
periods in a day). In the West, the decimal system came to predominate, probably
because of the ease of counting by the fingers on a pair of hands.
1-4.
DEVELOPMENT OF THE BINARY CODE
Since the l600s, Western thinkers, logicians, philosophers, mathematicians, and
engineers have studied the two-state simplicity of the binary system with great interest.
a. Gottfrled Wilhelm Lelbnlz (1666). The German mathematical genius,
Leibniz, proposed that rational thinking, with all its ambiguities, could be transposed
from the verbal realm, into precise mathematical terms. He further suggested "a sort of
universal language or script"..(which he never developed). In the next 10 years, he
worked on refining the binary system, spending years transcribing numerals from
decimal to binary. He found validation of his mathematical work in an ancient
MD0058
1-3