ELI5: Explain Like I'm 5

Borel's paradox

Hey kiddo! Have you ever heard of Borel's Paradox? It's a puzzle that mathematicians and scientists have been trying to figure out for a long time. Let me try to explain it to you like you're five years old.

Okay, so imagine you have an infinite number of monkeys randomly hitting keys on a typewriter. There's a chance that eventually, they'll type out a complete play of William Shakespeare. It might take a really long time, but it's technically possible, right?

Now, let's say you have an infinite number of monkeys and an infinite number of typewriters. There's a much better chance that at least one of those monkeys will eventually type out Shakespeare's complete play, don't you think?

But wait, it gets a little tricky here. What if we try to predict the probability of a monkey typing out the word "banana" on any given typewriter? At first, it might seem like the probability is tiny, since there are so many possible combinations of keys. But if you take into account that there are an infinite number of monkeys and an infinite number of typewriters, it becomes infinitely more likely that at least one monkey will type out the word "banana" at some point.

So, the paradox is this: how can the probability of one specific event (like a monkey typing "banana") be both infinitesimally small and infinitely likely at the same time?

It's a tricky problem, and mathematicians are still trying to figure out the best way to explain it. But hopefully, that gives you an idea of what Borel's Paradox is all about.
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