Theory 29/Event chronology/Radioisotope chronometry
Resolution Is a Measurement Ratio
The claim
The resolvable time between two events is set by the ratio of analytical precision to decay constant, so a long-lived isotope can date old rocks precisely and recent ones not at all.
01Mechanism
Age uncertainty scales inversely with decay constant and with the number of atoms counted; the ratio sets the resolution.
02Prediction
Resolution should improve with shorter half-life at the cost of range.
03Refutation
Resolution independent of decay constant would remove the trade-off.
04What makes it checkable
Modern mass spectrometry counts enough atoms that the limit is now the decay constant itself rather than the instrument.
05Why it was not testable before
Precision was the binding limit until multi-collector instruments removed it.