I will discuss the central role of Physics in Robert Millikan's innovative ideas about research and education when Caltech started in the 1920's ; how these ideas shaped the early research program at Caltech ; how they are reflected even today in the Core Curriculum taken by all students ; other special aspects of Caltech such as the Honor Code and the SURF program for undergraduate research ; post-Millikan revisions of the Physics Core Curriculum by Richard Feynman (Feynman Lectures) and later by David Goodstein (The Mechanical Universe, 26 hours of video on Freshman Physics) ; what Physics majors study at Caltech today.