11-13] which reported characteristic histograms for the decay of Pu-239 which were periodic over a 24 h interval (the solar day, thus the spin of the Earth), a ~28 day interval (the lunar month, thus the period of the Moon), and the sidereal year, and also reported characteristic histograms of radioactive decay rate associated with a New Moon and a total solar eclipse.
This interruption of neutrinos, due to the nucleons of Jupiter scattering and inelastically capturing some small, but non-trivial, proportion of particles and/or radiation causes a decrease in radioactive decay rate because of the consequent decrease in the particle flux transferring momentum to the nuclei of Po-210.
On 4 Dec 2002, a total solar eclipse occurred, during which the radioactive decay rate of Co-60 was measured at Pittsburg State University in southeastern Kansas , and the radioactive decay rate of Po-210  was measured in the Boston area, both at/near the time of totality in southern Australia.
A major multi-year study by Purdue University researchers at Brookhaven National Laboratory clearly show that the radioactive decay rates of many isotopes correlate very well with the distance of the source isotope from the Sun, as well as changes in radioactive decay rate correlated with major solar flares .
Using tree-ring time data, sediment core analyses from bodies of water, and ice layer dating from Greenland, he suggested that "comparisons of [these] ice core dates, radiocarbon dates, and uranium-thorium dates indicate that there were several periods in the late Pleistocene and early Holocenc when abnormally large ratios of [carbon-14] effectively counterbalanced the radioactive decay rate
, such that radiocarbon ages appear to remain constant over centuries .