Why, in reality, Achilles always reach the tortoise? It's considered to be one of the earliest idea leading to the concept of quantum.
Perhaps, but there isn't really any evidence that Zeno thought so. He actually thought that motion was an illusion. It did supposedly inspire Archimedes to come up with the idea of infinitesimals as a method of summing geometric series, though. It's not that far of a step from there to calculus, but I guess the Greeks never took it far enough in that direction. Interestingly, this was the topic of this week's existential comics.
With Von Neumann probes it should be way faster.
But what if an even older, more powerful, more spiteful civilization created evil Von Neumann probes that hunt down any Von Neumann probes built by other civilizations, and even try to destroy any sufficiently advanced interstellar civilizations that they encounter? Not that I'm rooting for that possibility, but it's yet another odd possibility to consider.