  Mehra and Rechenberg (2000, 482) note in this context:  “Actually, we have mentioned in previous volumes Weyl’s early  reactions to both matrix mechanics (in 1925) and wave mechanics (in  early 1926), and they were very enthusiastic. Therefore, we have to  assume quite firmly that it was only his deep involvement with the  last stages of his work on the theory of semisimple continuous groups that prevented Weyl ‘to get in the act’  immediately.” 