Joseph Lorenzo Hall, PhD on Nostr: Three arrows (3↑↑↑3) means a stack of tiny superscripts 7.6 trillion levels ...

Three arrows (3↑↑↑3) means a stack of tiny superscripts 7.6 trillion levels tall, physically stretching past the Sun. At four arrows, that solar-system-spanning stack is merely the starting equation to set up the next step. https://en.wikipedia.org/wiki/Knuth's_up-arrow_notation