Aeronautics and cognition, neuropsychology.
My grandfather's father:
The importance of fluid resistance (aerodynamic drag) for aircraft.
My grandfather's godfather:
Quanta, Fluid Dynamics, and Wave Theory.
My grandfather's godfather's grandfather:
y'know... that logic dude...
My youngest brother:
Want's to fly planes.
Cognition and machine-human interaction (??)
And fun times were had by all.