Negative Universe: Old World

Why have humans searched for extraterrestrial civilizations for decades but found nothing? This problem has troubled Yunqianjin for twenty years. He made calculations, conjectures and experiments over and over again, but made no progress. During a space expedition held by the Academy of Sciences, he saw something that shocked him for the rest of his life. The mystery that had not been solved for twenty years slowly unfolded in front of Yun Qianjin and his colleagues...