Understand how decay and half life work to enable radiometric dating.
Play a game that tests your ability to match the percentage of the dating element that remains to the age of the object. Radiometric Dating and the Geological Time Scale: Circular Reasoning or Reliable Tools? Radioactive dating of rocks and fossils is often misunderstood, even by some scientists. It is not a circular process, and leads to ever-more-reliable data, supported from a number of different avenues. This excerpt offers some insight into the issue, follow the link for the entire article:.
Most commonly, this is characterized by oversimplified statements like: Even some geologists have stated this misconception in slightly different words in seemingly authoritative works e. When a geologist collects a rock sample for radiometric age dating, or collects a fossil, there are independent constraints on the relative and numerical age of the resulting data. Stratigraphic position is an obvious one, but there are many others. The time scale is refined to reflect the relatively few and progressively smaller inconsistencies that are found.
It happens in all sciences. If an inconsistent data point is found, geologists ask the question: However, this statistical likelihood is not assumed, it is testedusually by using other methods e.
If it is a small but significant inconsistency, it could indicate that the geological time scale requires a small revision. The continued revision of the time scale as a result of new data demonstrates that geologists are willing to question it and change it. The geological time scale is far from dogma. Skeptics of conventional geology might think scientists would expect, or at least prefer, every date to be perfectly consistent with the current geological time scale, but realistically, this is not how science works.
The age of a particular sample, and a particular geological time scale, only represents the current understanding, and science is a process of refinement of that understanding. In support of this pattern, there is an unmistakable trend of smaller and smaller revisions of the time scale as the dataset gets larger and more precise Harland et al. If something were seriously wrong with the current geologic time scale, one Radioactive dating enables geologists to determine arterial oxygen expect inconsistencies to grow in number and severity, but they do not.
A Framework for K Science Education: By the end of grade Radioactive decay lifetimes and isotopic content in rocks provide a way of dating rock formations and thereby fixing the scale of geological time.