BACKGROUND: Russian astronomer A.L. Tchijevsky published in the twenties of 20th century a study comparing the approximately 11-year cycling of "sunspot activity" and "historical process", analyzed globally since the 5th century B.C. to the 19th century A.D. According to him, phenomena of societal "excitation", as revolutions, occurred synchronously with the solar maxima, and, oppositely, those of peaceful activities of masses, as science and arts, with the solar minima. Recently, Slovak philosopher E. Páles describes periodic fluctuation of historical events in mutually distant geographic areas during more than three millennia. The period lengths, however, are longer, one of the most pronounced being around 500 years. THE QUESTION was therefore posed: does a similar correlation with sunspot activity, as found for 11-year cycles, exist also in the 500-year cycling?
MATERIAL AND METHODS: The historical data consisted of two time series concerning revolutions in Europe and China, and of eight time series from activities in science and arts registered from five geographic areas. For the comparison, parallel time series of sunspot (Wolf) numbers, available since IInd century B.C., were constructed. Using periodic regression function, the times of peaking were estimated for each data set.
RESULTS: In agreement with Tchijevsky's hypothesis, revolutions culminated near to solar maxima while cultural flourishing usually distinctly near to solar minima. This conclusion is based on the level of statistical significance alpha=0.05.
CONCLUSION: Solar impact on geomagnetic field could be one of elucidating mechanisms. Recently, electromagnetic influencing of brain function has been realized artificially.