Doubt: Begins around the time that World War I has ended, when the world of science was exploding in an array of new breakthroughs—one of the greatest coming from a young astronomer named Cecilia Payne. The program follows her exciting quest to find the recipe of the stars utilizing tiny rainbow images to deduce their composition—90% hydrogen. This has been recently thrown into doubt as astronomer Vera Rubin demonstrates. New ways of looking at the heavens have shown that most of the universe is made of something we can’t see . . . something dark, hidden, unknown, perhaps something left over from the beginning of the universe.