Looking for more? Next week I will cover "Top 5 Geant4 Physics Lists You Should Never Use."
You aren't supposed to "run" the manual like a script. You are supposed to inherit from classes ( G4VUserDetectorConstruction , G4VUserPhysicsList ). The manual is telling you which virtual functions to override. geant4 manual
It is over 1,000 pages of dense, technical, physics-heavy documentation. Newcomers often open it, search for "Hello World," find nothing, and close the tab in despair. Looking for more
And when you finally get that G4Trajectory to draw a beautiful line through your detector, you will thank the manual—even if you just used it to find that one parameter name you forgot. 000 pages of dense