Tuesday, June 10, 2014

Earth Motion Myths

A recent motor trip to the east coast afforded the opportunity to contemplate the simple motions of planet Earth—rotation and revolution. While traveling east by automobile, clock times advance one hour each 800 miles at our latitude of 40 degrees. For a trip of that length we need to advance our clocks one hour. If we travel east by air we must advance our clocks six or seven hours on a 10-hour flight. Traveling west we must set our clocks back. Our clock adjustments do not signal any actual change in the speed at which time passes. Rather, the clock adjustments help humans reckon clock time on a spherical planet. Mid-day lunch should occur around noon by our clocks no matter where we live. Regular events such as work time, meal time, or sleep time traditionally occur as a consequence of living on a spherical planetary globe. We set our clocks to correspond to these events. 

God’s creative plan for the formation of a habitable spherical planet as man’s abode included the motions of rotation and revolution. A central star is the body around which planets revolve. Presently we have discovered about 2000 rotating planets revolving around stars in our region of the Milky Way Galaxy. In our galaxy alone, scientists believe there are tens of billions of planets. More planets are discovered each year. The possibility that any one of these planets has characteristics necessary to support earth life is incomprehensibly remote. Earth is a unique planet with hundreds of life-supporting requirements, all of which must be present. The presence of liquid water is merely the opening page of a catalog of “musts.” Scientists identify more life-enabling characteristics necessary for earth life each passing year. The belief of secular scientists that inevitably we will discover a life-supporting planet which actually possesses life becomes less likely even as discovery of more extrasolar planets multiplies.

The myth of a flat earth has been spread by some secularist attempts to denigrate religious believers. In reality, very few people historically believed in a flat earth. Exceptions were believers in mythology. Surprisingly, most early thinkers correctly identified the shape of the earth as spherical. A few believed in the reality of earth rotation. Others proposed incorrect explanations of sky motion. The geo-centrists, proponents of the Ptolemaic system, thought the stationary, non-rotating earth was at the center of the cosmic system and that heavenly bodies such as the moon and sun revolved around us. These conclusions were based on visual observation that bodies seem to circle around us. This view generally prevailed until Copernicus (1473-1543) introduced the heliocentric system.

One early Indian thinker, Aryabhata (456-550 AD), envisioned earth’s rotation and attributed star motion to our own real rotational motion. His vision of the sun traveling around earth, however was errant. Aristarchus (310-230 BC) was an early believer in heliocentrism—the sun is located at the center of the universe with the earth revolving around it. His ideas were revived by Copernicus in the early Modern Age. Traditional beliefs were not easy to discard. Some early church leaders saw the new cosmology as a threat to their interpretation of what the Bible taught. In the years following Copernicus, Johannes Kepler, Galileo Galilei, and Isaac Newton made refinements to Copernicus’s cosmology.

Knowledge of why we must turn our clocks forward or backward when we travel long distances east or west on our planet is an extra challenge for the student. Observations of day lengthening and night shortening as the beginning of summer approaches, or day shortening and night lengthening as winter approaches adds extra interest. Likewise we attempt to explain seasonal changes, why the moon changes its shape, how eclipses occur, or why each star appears to revolve around Polaris once each day. We may ask why the moon’s elevation above the horizon is lower in summer and higher in the winter, or why the sun sets in the southwest in winter, but in the northwest in summer.

Teachers and parents may inspire curiosity about how myths have been dispelled and our accurate knowledge of astronomy has been achieved. We must teach our students to be good observers of the wonders surrounding us. God is the author of the wonders of the cosmos. As we learn more about our natural world we learn more about the Creator.