The Dynamics of Scientific Knowledge - Mapping Scientific Frontiers: The Quest for Knowledge Visualization - page 28

This plate was attached to the antenna support struts of the spacecraft in a position
where it would be shielded from erosion by interstellar dust. The bracketing bars on
the far right are the representation of the number 8 in binary form (1,000), where
one is indicated above by the spin-flip radiation transition of a hydrogen atom from
electron state spin up to state spin down that gives a characteristic radio wave length
of 21 cm (8.3 in.). Therefore, the woman is 8 21 cm D 168 cm, or about 5 0 6 00 tall.
The bottom of the plaque shows schematically the path that Pioneers 10 and 11 took
to escape the solar system - starting at the third planet from the Sun accelerating
with a gravity assist from Jupiter out of the solar system. Also shown to help identify
the origin of the spacecraft is a radial pattern etched on the plaque that represents
the position of our Sun relative to 14 nearby pulsars (i.e., spinning neutron stars)
and a line directed to the center of our Galaxy. The plaque may be considered as
the cosmic equivalent to a message in a bottle cast into the sea. Sometime in the
far distant future, perhaps billions of years from now, Pioneer may pass through
a planetary system of a remote stellar neighbor, one of whose planets may have
evolved intelligent life. If that life possesses the technical ability and curiosity,
it may detect and pick up the spacecraft and inspect it. Then the plaque with its
message from Earth may be found and deciphered.
Pioneer 10 will be out there in interstellar space for billions of years. One day it
may pass through the planetary system of a remote stellar neighbor, one of whose
planets may have evolved intelligent life. If that life possesses sufficient capability to
detect the Pioneer spacecraft - needing a higher technology than mankind possesses
today - it may also have the curiosity and the technical ability to pick up the
spacecraft and take it into a laboratory to inspect it. Then the plaque with its
message from Earth should be found and possibly deciphered. Due to the loss of
communication, we may never hear from it again unless one day it could be picked
up by intelligent aliens in the deep space.
Voyager 1 and 2 were launched in the summer of 1977. They have become the
third and fourth human built artifacts to escape our solar system. The two spacecraft
will not make a close approach to another planetary system for at least 40,000 years.
The Voyager carried sounds and images to portray the diversity of life and culture
on Earth. These materials are recorded on a 12-in. gold-plated copper disk. Carl
Sagan was responsible for selecting the contents of the record for NASA (See
Fig. 1.13 ). They assembled 115 images and a variety of natural sounds, such as
those made by surf, wind and thunder, birds, whales, and other animals. They also
included musical selections from different cultures and eras, and spoken greetings
from Earth-people in fifty-five languages, and printed messages from President
Carter of the United States of America and United Nation's Secretary General
Waldheim. Each record is encased in a protective aluminum jacket, together with a
cartridge and a needle. Instructions, in symbolic language, explain the origin of the
spacecraft and indicate how the record is to be played. The 115 images are encoded
in analog form. The remainder of the record is in audio, designed to be played at
16-2/3 rev/s. It contains the spoken greetings, beginning with Akkadian, which was