I know that N is countable and has cardinality ℵ0, and that R has cardinality 2ℵ0=C and is uncountable.
Are sets with cardinalities greater than C (like 2R, for instance) "more uncountable" in some sense than the reals are?
Edit: I am familiar with the proof of the fact that there is no bijection from a set to its powerset. What I'm looking for is this: do we lose some more properties when we go from R to 2R, like we lose countability when we go from N to R? Are there any notions of "higher countability", or some sort of analog of countability, that R has, but which we miss when we consider the powerset of the reals?
Answer
You use the phrase "cardinalities greater than C," so I assume you know that Cantor's diagonal argument shows that for any set X, P(X) is strictly larger than X (in that X injects into P(X) but does not surject onto P(X)).
Based on this, I think the real question is: what do you mean by "more uncountable"?
One possible answer is the following: there may be sets with combinatorial properties which are characteristic of extremely large objects, which "reasonable" infinite sets like the naturals and the reals cannot have. For example, measurability: a cardinal κ is measurable iff there is a countably complete ultrafilter on κ which is not principal. By combining "countably complete" with "nonprincipal," this is clearly an "uncountability property" if anything is!
I would guess that you would find large cardinals very interesting; and, I suspect that in general large cardinal properties provide positive answers to your question.
For a related question - given a set X with cardinality in between ω and C, is X "closer" to ω or C? - you should check out cardinal characteristics of the continuum.
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