What is the interval from C to G, assuming that C is the bottom pitch?

A diminished interval  has one less semitone than a perfect interval. Since C to G is a perfect fifth (7 half steps), C to Gb would be a diminished fifth (6 half steps). Since C to G is a perfect fifth (7 semitones), C to Gb would be a diminished fifth (6 semitones).

modernism is a 20th century movement

based on the images pictured above, the major difference between the two cathedrals: the cathedral of notre dame and the amiens cathedral, is that the cathedral of notre dame emphasizes the horizontal lines while the amiens cathedral emphasizes the vertical lines.