In the 1860s, toward the end of his life, “father of computing” Charles Babbage “never abstained from the publication of his sentiments when he thought that his silence might imply his approbation,” wrote his friend Harry Buxton, “nor did he ever take refuge in silence when he believed it might be interpreted as cowardice.”

In the Arabian Nights, Shahrazad tells of a merman who guides a fisherman around the ocean floor, where underwater societies shun clothing, commerce, and religious restrictions. “I have seen enough,” the fisherman says after eighty days, “for I am getting tired of eating fish.”

Students at the Federal Polytechnic Institute in Zurich wrote to Carl Jung in 1949 to ask what effect he thought technology had on the human psyche. “The danger lies not in technology,” Jung responded, “but in the possibilities awaiting discovery.” The question regarding new discoveries was “whether man is sufficiently equipped with reason to be able to resist the temptation to use them for destructive purposes.” This, Jung concluded, “experience alone can answer.”

Hero of Alexandria invented the aeolipile, a primitive steam engine, in the first century. A hollow sphere with elbow-shaped tubes mounted on an axle and suspended over a cauldron of boiling water, the engine likely could not have powered anything. “It should probably be remembered,” wrote historian William Rosen, “as the first in a line of engineering dead ends.”