At the final session of the Nuffield workshop, the theoretical physicist Frank Wilczek summarized the conference proceedings, concluding with “A Shopping List of Questions.” Among them was whether omega was equal to 1. “If not,” he said, “we must give up on inflation.” Simple subtraction led you to conclude that for omega to equal 1 while observers were finding evidence that omega equaled 0.2, observers must be missing 0.8, or 80 percent, of the universe.
