Visually, Calculus was based on a real scientist, the Swiss inventor Auguste Piccard, who had been the first man to explore the stratosphere in a hot air balloon in 1931. Hergé had observed Piccard walking about Brussels on a number of occasions, however the character of Calculus would be notably much shorter than Piccard. Hergé named this character Tryphon Tournesol; while the surname meant "sunflower",...