Print and Run!
The wide use of radiocarbon dates in determining the approximate age of specimens is evidence of the acceptance that scientists and archeologists have of both the laboratory process as well as the assumptions needed in producing the numbers generated. The reason why Radiocarbon dates are viewed so positively is that the answers seem to be consistent with what is expected to occur by those who think in terms of time as being longer than what the Bible presents as the history of our world.
Archeologists and scientists are dependent on the use of dating methods to ascertain the approximate age of an artifact or ruin he or she finds. The archeologist or scientist assumes that the date they receive is generally correct. However, dating mechanisms have their own set of assumptions that need to be realized.
Is the prevalent view held by the majority of scientists the only plausible way of approaching the problems of time? If the Creation/Flood scenario as indicated by the Bible is correct, then any age significantly over 6000 years would have to be incorrect. Yet Carbon dates, for example, can theoretically go back to possibly 50,000 - 70,000 years or more using the development of accelerator mass spectrometry. That is an order of magnitude of difference! How can these dates be made to agree with each other?
This page is dedicated to looking at the assumptions that are made in radiocarbon age determinations. A distinctly Creation/Flood perspective will be taken and the assumptions needed for what ever position taken will be discussed; However, the alternative assumptions held by long age scientists will also be included.
But first, I will discuss the basics of Carbon 14 dating.
Carbon 14 is an isotope of Carbon. Simply put, we could substitute the word isotope with variety. It would mean the same thing; Carbon 14 is a variety of Carbon. So, Carbon 14 must be a specific variety of Carbon that has specific characteristics.
What is Carbon? Carbon is an atom having 6 protons and 6 electrons, however different isotopes of carbon have different numbers of neutrons. Notice in the first diagram below that eight different isotopes of Carbon is illustrated. Three of the Carbon isotopes (C12, C13, and C14) are found in nature. The rest of the Carbon isotopes (C9, C10, C11, C15, and C16) are only produced in the laboratory.
To the left side of each C (C is the symbol for Carbon) are two numbers, the bottom number indicates the Atomic Number or the number of protons in the nucleus. Since all the atoms are Carbon, they should all have an Atomic Number of 6. The top number is the Mass Number for each Isotope. The Mass Number for any Isotope is the addition of all the protons and neutrons in the nucleus. Looking at the first isotope in the chart, Carbon 9 has 9 (protons + neutrons). Remember that the Atomic Number (the bottom number) indicates the number of protons. So simple arithmetic should tell us the number of neutrons. Carbon 9 has 3 neutrons. Carbon 10 would have 4 neutrons and Carbon 11 would have 5 neutrons, and so on.
What should catch your attention is the nature of the various Carbon Isotopes. Only two of the Carbon Isotopes are stable (C12 and C13). They constitute essentially 100% of the Carbon in our world, although C12 is obviously much more common (99%). All the other Carbon Isotopes are unstable and they degrade into something else. Notice that the farther away the Mass Number gets from 12-13, the faster they break down (The blue numbers indicate half-lives, the time it takes for one half of the atoms in a sample to break down.). So the farther the Carbon is from the norm, the more unstable it is.
C9, C10, and C11 have too few neutrons so when they breakdown, they release a positron which effectively turns a proton into a neutron. The opposite occurs with C14, C15, and C16. They have too many neutrons so they breakdown, releasing a beta particle which effectively converts a neutron into a proton. Thus the breakdown of radioactive atoms is a self-corrective process; those Isotopes which have too many neutrons loose a neutron in the beta decay, and those Isotopes which have too few neutrons gain a neutron in the positron decay.
Looking specifically at Carbon 14, (The reaction box to the right) we see that it is a Beta emitter with a half life of 5730 years. When Carbon 14 emits a beta particle, the Carbon 14 atom becomes a Nitrogen 14 Atom. Looking at the Mass Number and Atomic Number of the atoms we see that the atom has lost a neutron and gained a proton. Also you will see that the Mass and Atomic Numbers in the equation are equal on both sides of the equation.
Since half-life has been introduced, lets explore it a little.
Radioactive atoms are unstable so they decay into a something else. The rate that atoms decay or break down is not constant. The rate changes and it is dependent on how many radioactive atoms are in a sample.
If all radioactive atoms have the same chance of breaking down we might expect that the more atoms present, the more atoms would be breaking down at any one time. This is exactly what happens.
However something interesting happens. It doesn't matter how much radioactive material we start with, if we stick with the same radioisotope, such as Carbon 14, it will always take the same amount of time for one half of the radioactive material to turn into something else. It's a first ordered reaction which means that it doesn't matter how much material we start with, we always will have the same half-live. So we will have half of what we started with when that half-life is reached.
The Half-life is defined as the amount of time required for one-half of a sample to decay to a new substance. For Carbon 14 it is always 5730 years. For Carbon 15 it is always 2.25 seconds. For Uranium 238 it is always 4,500,000,000 years. Each different isotope has a different half-life but the half-life of each specific isotope stays constant and as far as we can tell, it never changes.
The Chart (left or above) shows what happens to one gram of Carbon over a greater amount of time than just one half-life. The effect is compounded. After one half-life there is 1/2 present, but after two half-lives 1/2 of 1/2 (or 1/4) is present, and after three half-lives 1/2 of 1/2 of 1/2 (or 1/8) is present, and so on. So as we count the half-lives in time we see the amount C14 decline from the original gram of material to 1/2 gram, to 1/4 gram, to 1/8 gram, to 1/16 gram, etc. The loss of C14 is high initially but than slows down thus allowing the half-life rule to work throughout the whole time period. Every 5730 years, half of the C14 is lost.
For your information, some Carbon 14 labs will now endeavor to date things as far back as far as 75,000 years ago. Of course an extra fee is required to try to measure such small levels of Carbon 14 radiation.
Copyright © 1998 - 2014 by Michael Brown all rights reserved
Officially posted September 25, 1998
last revised January 1, 2014