The Creation Explanation
|The Age of the Earth|
Time Defined and Measured
The word "time" has several meanings in the English language, depending upon the context in which it is used. But what is the technical definition of the word? Some have said that time cannot be defined. Perhaps, however, time can be defined as the potentiality for a succession of physical events in the real world. The passage of time and the measurement of time involve changes in the world in which physical objects interact and energy is either exchanged between objects or transformed from one form to another, or in which objects emit and absorb radiant energy. In the biblical perspective time had a beginning when God brought into being out of nothing the space-matter-energy universe. Time could not be before that instant, for the passing of time requires the existence of space, matter and energy. Thus we conclude that God created time, in the beginning as recorded in Genesis 1:1. From this it can also be concluded that God exists in eternity, without time. He is the only Eternal One, the only Being for which there is no "before" or "after," the only One who is dependent upon nothing outside of Himself, the One who created all else out of nothing, so that everything outside of Himself is entirely dependent upon Him for its origin and continued existence.
In Chapter-2 it was explained that continual processes of change characterize the entire universe. It was also shown that many kinds of change are cyclical, as in the rotation of the earth on its axis and its revolution around the sun, the swinging of a pendulum, the vibration of a spring, or the oscillation of electricity in a tuned radio circuit. Quite often cyclical changes occur at regular intervals, as the five cases just mentioned illustrate.
A cyclical physical process of change can be used to measure time if each successive cycle takes the same or a previously known length of time. A wristwatch operates on this principle, as does an atomic clock, which depends upon the frequency of light waves emitted by excited atoms. Non-cyclical processes of change may also be used to measure time if the rate of the process is constant, or if it is known how the process varies from a constant rate.
Many different processes of change may be used as clocks to measure time, but for such a clock or timer to be reliable it must meet the following requirements:
Time can be measured for any process for which there is a timer that meets the above essential qualifications. We will mention six general classes of timing or dating methods that have been used to estimate the ages of the universe, the earth and life on the earth.
First, the radiometric methods involve the measurement of the content in rocks, sediments or fossils of such radioactive elements as thorium and several isotopes of uranium which gradually change to several isotopes of lead as they give off radiation over time.
A second class of geological dating methods is based upon more directly observable events and materials, such as the length of time necessary for certain sediments to build up on the earth's crust.
A third class of dating methods depends upon layers deposited by some natural cyclical processes. Annual layers of sediments are laid down under certain conditions in lakes and annual layers of ice are found preserved in the ice packs in Antarctica and Greenland. Dendrochronology estimates time by counting annual growth rings produced by trees.
A fourth kind of dating method makes use of thermoluminescence. This phenomenon depends upon energy from cosmic rays stored in ancient pottery continually bombarded by the radiation during the existence of the pottery. When the pottery is heated, the stored energy appears as luminescence, the strength of which is proportional to the period of time the pottery was bombarded by cosmic rays.
A fifth kind flows from astrophysical theories of star evolution
A sixth class of dating methods depends upon processes of chemical change. One of these which has been used for estimating the age of bones, depends on chemical changes over time.4 Inaugurated several decades ago with considerable fanfare for a few years, it depends on the slow change of the amino acid, L-isoleucine, to its mirror-image D form. This method has not fulfilled the early hopes placed in it by its discoverer.
A seventh class of dating methods depends on various physical processes, such as dissolution of comets, the accumulation of dissolved salts and elements in the oceans, and the production of dust on the surface of the moon.
We will now examine some of the methods by which estimates have been made of the age of the rocks in the earth's crust to see if they meet the requirements of a good timer and also to ascertain the age estimates which they provide. It will become evident that in general the methods of geological and other forms of age estimation do not meet all of the requirements. All of them rest on assumptions which are not necessarily true and which in some instances have been found to be incorrect. Furthermore, all of the radiometric methods have yielded many results which are in disagreement with other methods. In addition, while some of the methods yield very high values--billions of years--for the age of the earth, others yield values measured in thousands of years. Let us call these long-term chronologies and short-term chronologies, respectively. The short-term chronologies do not seem to fit the traditional uniformitarian view of earth history but rather are better in accord with a biblical creation chronology.
4. Bada, Jeffrey L., Earth and Planetary Science Letters, Vol. 15, 1972, pp. 223-231; King, Kenneth, Jr. and Jeffrey L. Bada, Nature, Vol. 281, 13 Sept. 1979, pp. 135-137; Bada, Jeffrey L., I. S. R. InterdisciplinaryScience Reviews, Vol. 7, 1982, No. 1, pp. 30-46.
5. Morris, Henry M. and Gary E. Parker, What Is Creation Science? (Creation-Life Publishers, San Diego, 1982), pp. 249-259.