In the 1960s, fears of overpopulation sparked campaigns for population control. But whatever became of the population bomb?CreditCredit...Rajanish Kakade/Associated Press The second half of the 1960s was a boom time for nightmarish visions of what lay ahead for humankind. In 1966, for example, a writer named Harry Harrison came out with a science fiction novel titled “Make Room! Make Room!” Sketch