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Many people have written many articles about the NYC subway recently. Because the trains run 24/7, they cannot renovate lines and install advanced train control. Because of the ter…

At the level of arithmetic, there are studies of children performing math in the marketplace, but then being unable to do the same calculation on paper. So translation from notatio…

Spy satellites are regularly tracked by amateur astronomers. There's a bit of a community in finding and sharing their orbital parameters.