Isochron methods avoid the problems which can potentially result from both of the above assumptions.
Isochron dating requires a fourth measurement to be taken, which is the amount of a different isotope of the same element as the daughter product of radioactive decay.
The calendar years are the number of years before 1950. The 2SD (1404 – 1438) range of dates for the Voynich Manuscript (VM) lies on the double peak D of the distribution graph C close to an ambiguous region of the curve.
The error in the precision of the calendar date is determined by the reciprocal of the slope of the curve.
Consequently, the trend in Mauna Loa CO2 (1.64 ppm per year) is statistically indistinguishable from the trend in global CO2 levels (1.66 ppm per year).
If global CO2 was used in Figure 1 above, the result "hockey stick" shape would be identical.
Dedicated at the University of Chicago on October 10, 2016.
In 1946, Willard Libby proposed an innovative method for dating organic materials by measuring their content of carbon-14, a newly discovered radioactive isotope of carbon.