Hacker News new | ask | show | jobs
by NotAtWork 4299 days ago
Disclaimer: my views on this are still being formed, and I don't necessarily have good, concise explanations for some of the ideas the way I'd want.

> I think that the fact that there are uncountable sets which means there is not a way to map the natural numbers in any "relation" to that set seems like it undermines the Aristotelian idea of linking mathematical objects with physical things.

I try to think of infinite things as extending finite mathematics by replacing a simple set with an equivalence class of pairs of (set, make_more_elms), where set is a set and make_more_elms is a constructor to make set in to a set with more of the "whole" set in it.

Then we can view acting on infinite sets (as long as we generate finite results, which we by default always will) as interacting with these tuples using finite math.

The fact that the naturals have a different cardinality than the reals can be expressed by ({}, build_naturals) and ({}, build_reals) being in different equivalence classes.

At no point do we have to deal with anything actually infinite to come to these conclusions, we're just looking at objects that are both finite with a pretend "infinity" constructed out of them.