|Action & Reaction - April 1997|
|by Do-While Jones|
We ran the cartoon above in the November 14, 1996, Swap Sheet. Someone said the ad was misleading. He agreed that the generally accepted age of the Earth has changed from 2 billion years to 4.6 billion years in the time frame implied by the cartoon, but he said the ad leads people to believe that scientists change their view of the age of the Earth every 20 years. He is correct that the age of the Earth doesn't change every 20 years, and we did not mean to imply that. Carbon 14 has a half-life of 5730 years. When one says that half of the carbon decays every 5730 years, it doesn't mean that half of the carbon decays instantaneously every 5730 years. It merely means that the decay follows an exponential curve that decreases by 50 percent every 5730 years. When we said that the age of the Earth has doubled every 20 years, we meant that the trend of accepted ages has approximately followed an exponential curve that doubles every 20 years.
We are grateful for this opportunity to set the record straight. Well-known geologist, Dr. S. Warren Carey has published a book1 containing a chapter devoted to The Age of the Earth . It describes how, in the years from 1862 through 1868, Lord Kelvin calculated the age of the Earth using three different methods. In the late 19th century, Kelvin was one of the hottest scientists around. He was so hot, they named a temperature scale after him. It is not surprising that with his interest in thermodynamics, two of his methods involved heat. The first had to do with the heat generated by the sun. It was his conclusion that the Sun must be less than 100 million years old, so therefore the Earth must be less than 100 million years old. His second method was based on how fast the core of the Earth is losing heat. His maximum and minimum assumptions led him to conclude that the Earth must be at least 20 million years old, but no more than 400 million years old. His third method, based on the slowing of the Earth's rotation due to tidal friction, led Kelvin to conclude that the Earth must be less than 100 million years old. During this same time, Van Helmholz came up with an age of 22 million years (based on gravitational condensation of the Sun), and Buffon concluded that the Earth was 75 thousand years old (based on the rate of cooling of the Earth). So, there was a wide spread of ages, from 75,000 years to 400 million years, with various levels of acceptance in the 1860's. Most of them, however, were less than 100 million years, and I would say that 62.5 million years is in the ball park.
In 1913, Arthur Holms (professor of geology at Durham) published a booklet entitled, "The Age of the Earth", in which he proposed an age of 500 million years.
I went to high school and college in the 1960's, and like the old professor in the cartoon, I was taught that the world was 2 billion years old.
The conventional wisdom (for about the past 10 years) has been that the Earth is 4.6 billion years old. If you compare these "known" ages with the equation AGE = 62.5x106 e(YEAR - 1860)/(28,8539 YEARS) , whose values at 20 year intervals are shown in the table, you can see that the "known" age of the Earth has generally followed that exponentially increasing age curve.
Near the middle of his chapter on the age of the Earth, at the bottom of page 72, Dr. Carey makes this significant observation: "It is an amusing fact that when a scientist knows the answer believed to be correct, that is the result that comes out of the data." This seems to imply that he believes there might be some connection between the age of the Earth required by the theory of evolution and the results of the scientific studies to determine the Earth's actual age.
|Quick links to|
|Science Against Evolution
|Back issues of
of the Month
Carey, Theories of the Earth and Universe (A History of Dogma
in the Earth Sciences) 1989, Stanford University Press.