The evolution of views on the possibility of external influence on the process of radioactive decay is briefly presented. Such an effect can lead to the appearance of periods in the time series of the radioactive decay rate fluctuations, which have been the subject of intensive study in the last decade. Two mechanisms for identifying periods are considered: the study of deviations from the theoretical curve of the radioactive decay law and the study of the properties of fluctuations. It is shown that the latter method leads to a universal spectrum of periods observed not only in the time series of the radioactive decay rate fluctuations, but also in the time series of fluctuations of processes of various nature. The main object of our study are periods in the radioactive decay rate fluctuations. The presence of such periods suggests the possibility of external influence on the process of radioactive decay. Therefore, we briefly consider the evolution of views on the possibility of such an effect. To do this, we distinguish several stages. The division into stages is only partially historical, but, mainly, each stage characterizes a certain ideas that is implemented in it.
On external influences on the radioactive decay rate fluctuations