ABSTRACT
It has been estimated that the age of the earth is 4.6 m 109 years, corresponding to the number of orbits about the sun. Due to the inclination of earth's axis of rotation relative to its plane of revolution, seasonal changes occur periodically, resulting in differences in light: dark ratios within each day. In northern California, for example, there are 5 more hours of light on June 21 (the summer solstice) than on December 21 (the winter solstice).
