Home Feedback Links Books. 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, this calls the Biblical account What does radiometric dating look at 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 these issues. At the start, let me clarify that my main concern is not the age of the earth, the moon, or the solar system, but rather the age of life, that is, 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 meteorites are old, if one accepts the fact that decay rates have been constant. However, there may be other explanations for this apparent age.
Perhaps the earth was made from older pre-existing matter, or perhaps decay rates were briefly faster for 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 with the Precambrian, followed by the Cambrian and a number of others, leading up to What does radiometric dating look at present. Some fossils are found in Precambrian rocks, but most of them are found in Cambrian and later What does radiometric dating look at. 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 are 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. The original element is called the parent, and the result of 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 means an age of zero. A higher ratio means an older age. A ratio of infinity that is, all daughter and no parent means an What does radiometric dating look at 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, which 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. When it is stated that these methods are accurate to one or two percent, it does not mean that the computed age is within one or two percent of the correct age. It just means that there is enough accuracy in the measurements to compute t to one or two percentage points 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 beginning, 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 What does radiometric dating look at has entered or left the system in the meantime. Radiometric dating is commonly used on igneous rocks lavaand on some sedimentary minerals. But fossils can generally not be dated directly. When lava is hot, argon escapes, so it is generally assumed that no argon is present when lava What does radiometric dating look at. Thus we can date lava by K-Ar dating to determine its age.
As for the other methods, some minerals when they form exclude daughter products.