Science/Engineering
From bikelopedia
Bicycle Science
I really don't know what the current state of bicycle science is. A commonly recommended book is Bicycling Science by David Gordon Wilson and Theodor Schmidt. Obviously a ton of research is going into things like frame shapes and geometries or materials etc...
Bicycle Engineering
Bicycle engineering covers many topics from materials to geometry and shock dynamics. Also the Engineers build and design our helmets. Another word Linkage!!