Triumph of Reason: Astronomy
by Groff Schroeder
Thanks to public education, the average American
who looks into the night sky knows a great deal about what he or she
is seeing. Many people can easily identify the planet Venus (also
known as the evening or morning star), which appears brightly on the
horizon around sunset and sunrise, sometimes accompanied by the planet
Mercury. Others can identify the red glow of Mars and know when and
where to point their telescopes to observe the ringed planet Saturn.
|
Most of the twinkling white dots in the slowly rotating
background are stars of our Milky Way galaxy. Stars are almost unimaginably
massive spheres of fantastically hot gas, fueled by the fusion of
hydrogen into helium. Other points of light we see as stars in the
night sky are galaxies so far away that it impossible to distinguish
their millions of individual stars from a single point of light. Scientists
can even tell us that the closest star to our sun is about four light
years away and that a light year is the distance light travels at
186,000 miles/second in one year. |
To the earliest humans, the objects in the sky were
unknown, and life on earth might have been a surreal mix of daily
bounty and nightly terror. In the day, the rising sun provided light,
warmth and assurance, peaking at noon at its highest point in the
sky; but as the day wore on, night would approach - dark, cold, and
full of uncertainty and danger. |
It was probably easy for the earliest humans to discern
the phases of the moon. However, at unexpected intervals, the moon
could be full and friendly, then suddenly fade away in minutes as
if being devoured by a giant mouth, slowly disappearing completely
only to reappear a few minutes later. During an eclipse of the sun,
it must have been quite terrifying to live in ignorance about the
solar system. Early humans' actual interpretations of the night sky
are lost to history, but given our current understanding of the universe,
it is clear that at some point people began to study it. |
Studying the moon's waxing into fullness and waning
into darkness is one thing - determining when to migrate is another.
On the survival scale, it probably did not matter if humans understood
eclipses or phases of the moon, but if they failed to recognize seasonal
changes, it could cost the group their lives when winter set in. Once
humans figured out agriculture, it became important to determine when
to plant crops. Since a shadow cast at noon is at its longest on the
winter solstice and shortest on the summer solstice, early human astronomers
may have figured out how to determine the longest and shortest days
of the year quite quickly. |
While early humans' interest in the solstices probably
had eminently practical roots, today many religions celebrate important
holidays in conjunction with the winter solstice, even though a correct
reading of the salient religious texts may suggest that the celebrated
events actually happened at some other time of year. Belief systems
can adjust their customs and even their calendars to meet practical
needs, but astronomy suggests that the movement of the planets and
the stars remains immutable. |
|
|
Send us an Email
Or write to us at:
Freethinkers of Colorado Springs
P.O. Box 62946
Colorado Springs, CO 80962-2946
Phone: 719-594-4506
|