Line graphs and radiometric dating benefits of dating me
The figures shown in that article are based on radiometric dating.
Radiometric dating is rooted in the rates of radioactive decay of various isotopes, which rates have been measured carefully in numerous laboratories beginning in the early 20th century.
Radioactive decay is in turn a very basic physical phenomenon, well understood as a consequence of quantum mechanics.
Quantum mechanics is one of two cornerstones of modern physics (the other is general relativity), and has been precisely confirmed in thousands of very exacting experiments.
Also, such a calculation does not provide us with any statistical error margin to double-check the result.
By some simple algebraic manipulation of the basic radioactivity formula above, one can show that the following formula must hold at any time t: (Sr87/Sr86) is the ratio of these two isotopes at time t.
The problems below walk you through the steps for reading points from a line.
You can click on any of the graphs to open a bigger version or you can click the link under the graph to download a pdf of the graph for printing!
But if we have multiple data points -- multiple measurements of different samples say within a single igneous rock, then these should all lie on a straight line, whose slope m is simply related to the age of the specimen by the formula m = e; instead, this original ratio actually comes out as a result of the calculation!
As mentioned above, the isochron dating method boils down to plotting multiple data points, after some calculation, on a graph, which, if the measurements and calculations are done properly, should lie on a straight line, or very nearly on a straight line.