中根元圭『律原発揮』の音律論 (数学史の研究)

Abstract

Nakane Genkei presented a way to arrive at an 12 equal temperament by opening one octave into the 12th root in his Ritsugen-hakki [律原発揮]. His achievement was that his calculation-methods were groundbreaking at the world history level. It can be explained because he had clearly more advanced computational power than other music researchers in his era and had the ability to handle higher-order and exponential calculations freely. In this paper, I consider based on the comparison of Nakane Genkei 's Ritsugen-hakki and Cai Yuan-ding's Lülüxinshu [律呂新書]. And, I clarify the following four points by investigating historical documents. i)Why did Genkei, a famous mathematician , participate in the study of system of tuning? And what was his purpose? ii)What was the underlying mathematical thought of his pursuit? iii)What are the characteristics of the mathematics used in his pursuit? iv)What was his influence on academic research in Japan?