system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Does pi really contain every number combination in existence? Does that mean that there are 17 trillion zeros in a row somewhere in pi?

I know that pi has an infinite amount of digits but I dont understand how every number combination is in there. Like, there may be infinite universes but that would not necessarily mean that one is completely made out of jelly. There would still be infinite universes but not all possibilities could be in it (if you get me). Does the same apply to digits in pi? It hurts my head to think about.
gpt
We don't know for sure because we haven't proved it, but we think it's true. You're right that just have infinite non-repeating digits isn't enough, for example 0.010010001... never repeats, but it has no 2s in anywhere. The property we're looking for is being a "normal" number, which means that each group of digits appears with the same probability. There are as many 1s as 2s, "123" is as common as "000", and so on for any longer groups you want to compare. We can't prove that this is true of pi, but it's true of the billions of digits we've calculated and tested. A normal number contains every possible string of digits somewhere because 17 trillion zeros is as likely as any other string of 17 trillion digits, and we have infinitely many tries for that chance to come up.