A couple centuries ago, the brightest minds thought that humans flying in the air would take a million years. Two centuries ago humans actually flew. A centur

A couple centuries ago, the brightest minds thought that humans flying in the air would take a million years. Two centuries ago humans actually flew. A century ago, almost everyone thought that stepping on a divine body like the moon Nobody seriously thought the moon was a 'divine body' a century ago. The rocket equation was known and understood to form a possible theoretical basis for interplanetary travel technology. A century ago, everyone thought it was impossible to fling a tiny device to blow up an entire city. HG Wells thought it was possible as did many others. https://www.bbc.com/news/magazine-33365776 https://www.bbc.com/news/magazine-33365776 "Churchill grasped the danger of technology running ahead of human maturity, penning a 1924 article in the Pall Mall Gazette called "Shall we all commit suicide?". In the article, Churchill wrote: "Might a bomb no bigger than an orange be found to possess a secret power to destroy a whole block of buildings - nay to concentrate the force of a thousand tons of cordite and blast a township at a stroke?"" Now, we think that it would be impossible to travel very long distances in space. Well, this challenge seems a piece of cake compared to flying in the air, walking on the moon, or generating unimaginable energy from atoms. We think it's very difficult compared to the challenge of flying through the air or walking on the moon or generating energy from atoms in part because we understand those past challenges and can reasonably compare it to something like interstellar travel. It is decidedly nontrivial.