Re:How can some infinities be bigger than others?
by tsimionescu on Wednesday April 19, 2023 @09:19PM
(#35635256)
> Irrationals are uncountable, but there are fewer of them between 0 and 1 than reals between 0 and 1, by virtue of the fact that all irrationals are reals but not all reals are irrationals.
This is the important point where you are wrong. For a simpler to explain example : the naturals are a subset of the integers, and yet the set of all integers is exactly as big as the set of all naturals. We say this because we can actually find a natural number that corresponds to every integer number: 0:0, 1:+1, 2:-1, 3:+2, 4:-2,... A slightly more complicated construction exists for the naturals compared to the rationals: they are also the same size.
However, it can be shown that the same can't be done between the naturals and the reals, or even any real interval. So, by this definition, there are more real numbers between 0 and 1 than there are in the entire set of natural numbers.
This is the important point where you are wrong. For a simpler to explain example : the naturals are a subset of the integers, and yet the set of all integers is exactly as big as the set of all naturals. We say this because we can actually find a natural number that corresponds to every integer number: 0:0, 1:+1, 2:-1, 3:+2, 4:-2,... A slightly more complicated construction exists for the naturals compared to the rationals: they are also the same size.
However, it can be shown that the same can't be done between the naturals and the reals, or even any real interval. So, by this definition, there are more real numbers between 0 and 1 than there are in the entire set of natural numbers.