Improperly handled, optimism can be unbearable. One of the (many) problems with Chris Nolan’s Interstellar and Brad Bird’s Tomorrowland, two recent advocates for a return to space-age can-do adventurism in a jaded age, was their wild asymmetry between telling and showing. Both films were too breathlessly busy evangelising about mankind’s untapped potential to actually demonstrate that potential in action: ‘reach for the stars’ bluster can only get you so far. Ridley Scott’s The Martian, a highly polished and entertaining space castaway story based on Andy Weir’s novel, is sort of a fulfillment of these earlier film’s ambitions, selling its golly-gee…