## Specola Guestbook: October 11, 1909 – Eduard Study

Since its founding in 1891, many people have passed through the doors of the Vatican Observatory. A quick perusal of our guestbook reveals several Names, including Popes, nobel laureates, astronauts, actors, and saints. Today’s guestbook entry is from October 11, 1909, when Eduard Study made a visit. Next to his name, Christian Hugo Eduard Study (1862-1930) wrote “Bonn a. Rh. Argelanderstr. 126” (Bonn am Rhein, Argelanderstraße 126). He signed the guestbook again on April 10 of the following year. Eduard Study was a mathematician who made significant contributions in the field. At the time of his visit, he was a professor of mathematics at the University of Bonn. His contributions include the associative algebra of dual quaternions, kinematics, hypercomplex numbers, and, pertaining to quantum chemistry, a theory governing the coupling of angular momenta (that also applied to electron spin couplings). At least two mathematical concepts bear his name: Study quaternions (aka semiquaternions) and the Fubini-Study metric. … Continue reading →