Is Radioactive Decay Really Exponential?

TL;DR

This paper questions the assumption that radioactive decay is strictly exponential, providing theoretical and experimental arguments that suggest non-exponential decay for slowly decaying isotopes like 14C, which could impact dating methods.

Contribution

It introduces a mathematical and experimental framework to test non-exponential decay in 14C, challenging a fundamental assumption in radiometric dating.

Findings

Mathematical arguments indicate non-exponential decay for slow isotopes.

Proposes an experimental test to verify non-exponential decay in 14C.

Potential implications for the accuracy of radiocarbon dating methods.

Abstract

Radioactive decay of an unstable isotope is widely believed to be exponential. This view is supported by experiments on rapidly decaying isotopes but is more difficult to verify for slowly decaying isotopes. The decay of 14C can be calibrated over a period of 12,550 years by comparing radiocarbon dates with dates obtained from dendrochronology. It is well known that this approach shows that radiocarbon dates of over 3,000 years are in error, which is generally attributed to past variation in atmospheric levels of 14C. We note that predicted atmospheric variation (assuming exponential decay) does not agree with results from modelling, and that theoretical quantum mechanics does not predict exact exponential decay. We give mathematical arguments that non-exponential decay should be expected for slowly decaying isotopes and explore the consequences of non-exponential decay. We propose an experimental test of this prediction of non-exponential decay for 14C. If confirmed, a foundation stone of current dating methods will have been removed, requiring a radical reappraisal both of radioisotope dating methods and of currently predicted dates obtained using these methods.