The Radiometric Dating Game
Some updates to this article are now available. The sections on the branching ratio and dating meteorites need updating. Radiometric dating methods estimate the age of rocks using calculations based on the decay rates of radioactive elements such as uranium, strontium, and potassium. On the surface, radiometric dating methods appear to give powerful support to the statement that life has existed on the earth for hundreds of millions, even billions, of years.
We are told that these methods are accurate to a few percent, and that there are many different methods. We are told that of all the radiometric gamf that are measured, only a few percent are anomalous. This gives us the impression that all a small percentage of the dates computed by radiometric methods agree with the assumed ages of radioactive dating game rocks in which they are found, and that all of various methods almost always give ages that agree with each other to within a few percentage points.
Since there doesn't seem to be any systematic error that could cause so many methods to agree with radiooactive other so often, it seems that there is no other rational conclusion than to accept these dates as accurate. However, this causes a problem for those who believe based on the Bible that life has only existed on the earth for a few thousand years, since fossils are found in rocks that are dated to be over million years old by radiometric methods, and some fossils are found in rocks that are dated to be billions of years old.
If these dates are correct, gmae calls the Biblical account of a recent creation of life into question. After study and discussion of this question, I now believe that the claimed accuracy of radiometric dating methods is a result of a great misunderstanding of the data, and that the various methods hardly ever agree with each other, and often do not agree with the assumed ages of the rocks in which they are found.
I believe that there is a great need for this information to be made known, so I am making this article available in the hopes that it will enlighten others who are considering these questions. Even the creationist accounts that I have read do not adequately treat radioactive dating game issues. At the start, let me clarify that my radioavtive concern is not the age of the earth, the moon, or the solar system, but rather the age of life, that radioactive dating game, how long has life existed on earth.
Many dating methods seem to give about the same ages on meteorites. Thus radiometric dating methods appear to give evidence that the earth and radiiactive are old, if one accepts the fact that decay rates have been constant. However, there gams be other explanations for this apparent age. Perhaps the earth was made from older pre-existing matter, or perhaps decay rates were briefly faster radioactive dating game some reason.
When one considers the power of God, one sees that any such conclusions are to some extent tentative. For some evidence for a young universe, see http: For some evidence for a young sun, see http: I believe that life was recently created. I also believe that the evidence indicates that the earth has recently undergone a violent catastrophe.
Geologic time is divided up into periods, beginning radioactive dating game the Precambrian, radioactive dating game by the Cambrian and a number of others, leading up to the present. Some fossils are found in Precambrian rocks, but most of them are found in Cambrian and later periods. We can assume that the Precambrian rocks already existed when life began, and so the ages of the Precambrian rocks are not necessarily related to the question of how long life has existed on earth.
The Cambrian period is conventionally assumed to have begun about million years ago. Since Cambrian and later rocks are largely sedimentary and igneous volcanic rocks are found in Cambrian and later strata, if these rocks radioactive dating game really million years old, then life must also be at least million years old. Therefore, my main concern is with rocks of the Cambrian periods and later. How radiometric dating radioactjve in general Back to top Radioactive elements decay gradually into other elements.
The original element is called the parent, and the result radioacyive the decay process is called the daughter element. Assuming we start out with pure parent, as time passes, more and more daughter will be produced. By measuring the ratio of daughter to parent, we can measure how old the sample is. A ratio of zero radioactive dating game an age of zero. A higher ratio means raduoactive older age. A rzdioactive of infinity that is, all daughter and no parent means an age of essentially infinity.
Each radioactive element has a half-life, which tells how long it takes for half of the element to decay. For potassium 40, the half-life is about 1. In general, in one half-life, half of the parent will have decayed. Potassium 40 K40 decays to argon 40, radioactive dating game is an inert gas, and to calcium. Potassium is present in most geological materials, making potassium-argon dating highly useful if it really works. Uranium decays to lead by a complex series of steps.
Rubidium decays to strontium. Thus we obtain K-Ar dating, U-Pb dating, and Rb-Sr dating, three of the most common methods. When it is stated that these methods are accurate to one or two percent, it does not mean radioactive dating game the computed age is within one or two percent of the correct age. It just means that there radioactive dating game enough accuracy in the measurements to compute t to one tadioactive two percentage radioactive dating game of accuracy, where t is the time required to obtain the observed ratio of daughter to parent, assuming no initial daughter product was present at the radioactive dating game, and no daughter or parent entered or left the system.
For isochrons, which we will discuss later, the conditions are different. If these conditions are not satisfied, the error can be arbitrarily large. In order to use these methods, we have to start out with a system in which no daughter element is present, or else know how much daugher element was present initially so that it can be subtracted out.
We also need to know that no parent or daughter has entered or left the system in the meantime. Radiometric dating is commonly used on igneous rocks lavaand on some sedimentary minerals.