Written and compiled by Fred Jaicks
Time has become an exact science on the earth; with the evolution of time zones and the creation of coordinated universal time, anyone can find out the exact time that it is somewhere else in the world. However, many years ago the only way to determine the time of day was by using the sun and its position in the sky. People were dependent on the sun, moon, and stars to perform many calculations, in fact.
Many people identify astrology, or study of horoscopes, with astronomy. However, astronomy is a science that aids in calculations of time, distance, and predictions about the future of the earth and its neighboring planets and galaxies. The first step in knowing how astronomy can be informative and helpful is to learn terms and definitions that are most used in astronomy. By grasping the meaning of terms used by professors of science in astronomy, one will better have the ability to start using astronomy in their everyday lives.
One of the most useful tools in telling time in the ancient world was sun position in the sky and on the horizon. The position of the sun also can also indicate direction, which aids in navigation. The place in the sky can also help people to ascertain the time of year it is. This is done party by estimating the length of the day and how long the sun stays in the sky. Some of the more complex computations one can calculate by the position of the sun include the Julian Day, the hour angle, a time equation, and land and space radiation levels.
The position of the moon in the sky is only one telling factor as to the time, month, and season that it is. The moon evolves through phases throughout the month, and at any given time, a different part of the moon is revealed to those of us on earth. This is caused by the moon’s orbit around the earth as well as the earth’s orbit around the sun. At any time, some, or all, of the moon appears to be missing. This is a shadow, and if you look closely you can, indeed, see the entire moon all the time. When the earth gets in the middle of the path with the sun, we see part of the moon illuminated. As movements take place with the moon, earth, and sun, the moon appears to go through various stages of shadowing. Using this, individuals can glean much information regarding the earth on which they live.
If one would wish to experiment with an experiment, trying to live as they did in the ancient times, creating a sun calendar would one of the most basic. One would need to record the position of the sun in the sky and the time of the sunrise and sunset each day. One must make their observations from the same spot each day, and one should be careful when observing the sun. The brightness can harm unprotected eyes, especially when gazing at it for a long period of time. The longest day of the year is the winter equinox; the shortest is the summer equinox. With either of these reference points, one can note the passing of days and maintain a calendar is the most primitive way.
Following are a list of links that can aid individuals who wish to learn more of astronomy, the sun and moon changes, and other atmospheric phenomena that will give them information about the world in which they live.