To be precise in 1903 they predicted it will take one million years in the best possible case (sarcasm i guess) for humans to build useful heavier-than-air craft. Well it took 70 days. The very same year the Wright brothers arrived or rather "left"...upwards with their airplane:
https://en.wikipedia.org/wiki/Wright_Flyer
https://www.reddit.com/r/AskHistorians/comments/1ocua1b/in_1903_the_nyt_published_an_editorial_declaring/
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