Radiometric age dating flaws
Such uncertainties are usually glossed over, especially when radioactive dates are communicated to the public and, more importantly, to students.Generally, we are told that scientists have ways to analyze the object they are dating so as to eliminate the uncertainties due to unknown processes that occurred in the past. Hayes has pointed out a problem with isochrons that has, until now, not been considered.One way this is done in many radioactive dating techniques is to use an isochron. To understand the problem, let’s start with an example of how radioactive dating works. Sr-87 is not radioactive, so the change is permanent.The elements rubidium and strontium are found in many rocks. As illustrated above, a neutron in a Rb-87 atom can eject an electron (often called a beta particle), which has a negative charge. We know how long it takes Rb-87 to turn into Sr-87, so in principle, if we analyze the amount of Rb-87 and Sr-87 in a rock, we should be able to tell how long the decay has been occurring.However, it’s important to note that some radioactive dates (like those that come from carbon-14) don’t use the isochron method, so they aren’t affected by this particular flaw.As a young-earth creationist, I look at this issue in a different way.The amount of Sr-87 that was already in the rock when it formed, for example, should be proportional to the amount of Sr-86 that is currently there.
In other words, there is a 95% certainty that the age is somewhere between 4,283 23 million years and 4,283 – 23 million years.As I have stated previously, we just don’t know a lot about radioactive decay.Certainly not enough to justify the incredibly unscientific extrapolation necessary in an old-earth framework.Sr-86 diffuses more quickly than Sr-87, and that has never been taken into account when isochrons are analyzed. Perhaps, but it’s rather tricky, because the rate of diffusion depends on the specific chemical and physical environment of each individual rock.
If the effects of diffusion can be taken into account, it will require an elaborate model that will most certainly require elaborate assumptions. Hayes suggests a couple of other approaches that might work, but its not clear how well. If you believe the earth is very old, then most likely, all of the radioactive dates based on isochrons are probably overestimates. I have no idea, and I don’t think anyone else does, either. Hayes’s model indicates it could add as much as 29 billion years to ages determined with rubidium and strontium, although his model is rather simplistic.
If some process brought Sr-87 into the rock, it probably brought different amounts of the atom into different parts of the rock, so the ratio of Sr-87 to Sr-86 won’t stay consistent from one part of the rock to another. He says that there is one process that has been overlooked in all these isochron analyses: diffusion.