George Darwin.
Many attempts have been made to determine the age of the earth and other celestial bodies. Some of these attempts have proven very promising, and some have not. One such not so successful attempt was made by George Darwin, the son of the famous naturalist Charles Darwin. George Darwin was a physicist and an astronomer, and that would explain why he was so interested in ideas such as the formation of the moon and the effects of tidal friction upon the earth and the moon.
For many people, George Darwin may be considered to be the father of modern geophysics, and he contributed much to the study of the origin of the moon. He also made extensive studies on the tides of the earth. He concentrated especially on solid body tides. Solid body tides are the gravitational effects that large bodies have on one another (The Talk.Origins Archive 1999). For example, the moons gravitational field causes the diameter of the earth to be about 4 meters greater at the equator (Odenwald 1995). Darwin proposed that these tidal effects on the spherical shape of the earth have changed as the moon has moved farther away in its orbit.
The truth of the matter is that the moon is receding from the earth. The recession of the moon is caused by the tidal breaking that takes place between the earth and the moon. Tidal breaking causes the moon to accelerate in its orbit and therefore expand the orbit. Based upon measurable data, scientists have calculated that the moon is receding at a rate of 3.8cm/year (Pogge 2005). These measurements are taken by beaming laser rays at reflector arrays that have been positioned on the moon (Pogge 2005). At this rate, some young-earth scientists claim that the moon would have been so close a mere million years ago that the tides would have drowned the creatures on earth. It is said that based upon the rate of the moon's recession that it cannot be older than 10,000 years. Some young earth creationists claim that "The moon is already far too close to the earth. It is now know that, due to tidal friction, it is gradually moving farther away from us. Based on the rate of recession, the moon cannot be very old. If it were even 20,000 to 30,000 years old, it would at some earlier time have been so close-it would have fallen into our planet!" (Pathlights 2005).
It is safe to say that Darwin had good intentions in attempting to date the earth, and for the time period that he lived in, it probably did seem like a reasonable theory. Now, however, we are able to see that no significant age for the earth or the moon could be attained by such a method as observation of tidal friction. It is also interesting to note that the arguments that Darwin proposed for an earth that was at least 60 million years old are now being used by young earth creationists in an attempt to prove that the earth is no more than a few thousand years old.