There are three standard creationist responses: First, creationists assert that current rates (Y) are different than past rates.
It is possible that these rates changed — but under uniformitarianism, which is necessary for science to function, we must assume that rates did not change unless there is evidence for this change.
The slope of the line determines the date, and the closeness of fit is a measure of the statistical reliability of the resulting date.
Technical details on how these dates are calculated are given in Radiometric dating. As with any experimental procedure in any field of science, these measurements are subject to certain "glitches" and "anomalies," as noted in the literature.
Dating schemes based on rates of radioactivity have been refined and scrutinized for several decades.
Here is one example of an isochron, based on measurements of basaltic meteorites (in this case the resulting date is 4.4 billion years) [Basaltic1981, pg. Skeptics of old-earth geology make great hay of these examples.
For example, creationist writer Henry Morris [Morris2000, pg.
The evidence against a recent creation is overwhelming.
There is perhaps no greater attack on science than Young Earth creationism (YEC).