Intelligent life in the universe

From the Preface: "As the reader might expect for a book written by two authors, one in the Soviet Union and one in the United States, there are occasional ideological differences....When Shklovskii expresses his belief that lasting world peace is impossible while capitalism survives, or implies that lasers are being actively developed in the United States for their possible military applications alone, I have let the content of these statements stand, despite their political intent. I have occasionally interjected some remarks on related subjects, with which, perhaps, Shklovskii would disagree. I do not think the reader will be distressed by the occasional appearance of a dialogue...."