Konstantin Tsiolkovsky in Russia, Hermann Olberth in Germany, and Robert Goddard in the United States all came up with an eerily similar concept for using liquid fuel to power rockets for human spaceflight. I've seen this pointed out as an odd coincidence, one of those moments when an idea inexplicably emerges in multiple places at once. But when I read through each of these three men's biographies I discovered why they all had the same idea: all three of them were obsessed with Jules Verne's 1865 novel "De la terre a la lune (From the Earth to the Moon)." The novel details the strange adventures of three space explorers who travel to the moon together. What sets Verne's book apart from the other speculative fiction of the time was his careful attention to the physics involved in space travel -- his characters take pains to explain to each other exactly how and why each concept would work. All three real-life scientists -- the Russian, the German, and the American -- were following what they had learned from a French science fiction writer.