A few scientists have lately asked a curious question: If extraterrestrial intelligence is abundant, why have we not already seen its manifestations?
A few scientists have lately asked a curious question: If extraterrestrial intelligence is abundant, why have we not already seen its manifestations?
很少的科学家事后已经问了一系列的问题：地球外的智慧生命是不是大量的，为什么我们迄今还没有看到他们存在的迹象？