Re: Rational/Irrational Numbers



The mathematical proof which I know goes like this:

(1) Rational numbers are countable: by enumerating all rationals like
this:

1 2 3 4 5 6.......
2 3 4 5 6 7...
3 4 5 6 7 8..
4 5 6 7 8 9...
........................
........................

(2) Then there is proof that real numbers are uncountable by supposing
that a list of real numbers between 0 and 1 (in binary format) exists
and then using Cantor's diagonalization argument to show that it is
impossible.

(3) Construction of real number by Dedekind's cut. From that cut we can
see that
- between two rationals infinite irrational numbers exist. -----(a)
- Between two irrational infinite rational numbers exist. ------(b)

But just by looking at the conclusion (a), and (b) I cannot understand
that there are much more irrational numbers than rational numbers.
Because if I see any two irrational numbers, which may be arbitrarily
close, there are still many(infinite) rational numbers between them.
Then how irrationals are more in number. It looks contradictory to
me...

Thanks for your help...

Alok Bakshi

.



Relevant Pages

  • Re: Fun, weird, sad, cool
    ... >> If, in a mathematical proof, it has been established, for example, that ... > Now you're in rationals unless x, ... > if you're in the ring of integers, then you can't just put up x/2 ... please expand on just that part for now. ...
    (sci.math)
  • Re: Fun, weird, sad, cool
    ... >> If, in a mathematical proof, it has been established, for example, that x, y ... that it's required to -say- that we're now in rationals. ... >if you're in the ring of integers, then you can't just put up x/2 ... please expand on just that part for now. ...
    (sci.math)
  • Re: SF: Generalized SFTs
    ... So it's easy and your request is strange. ... Pick any rationals that fit. ... I'm looking for mathematical proof here. ...
    (sci.crypt)
  • Re: infinitely many nns = infinite nns?
    ... every two irrationals, it would seem that the rationals and the ... Possibly at first glance, but that assumes that the number of rationals between two irrationals is the same as the number of irrationals between two rationals, which is distinctly not the case. ... There are never two or more reals "in a row" without others between them, regardless of their rationality or lack therof. ... Now, if we want to say that we are limited by potential infinity when mentally examining a structure with actually infinitely many elements, I would certainly agree that we cannot mentally examine the elements individually, but in the limit, where actual infinity either CAN be used, or at least predicted, there cannot be a y between ANY two x's. ...
    (sci.logic)
  • Re: Rational/Irrational Numbers
    ... irrationals into the rationals and thus a surjection from the rationals ... for Union Q_h < Q_i.) ... rationals and irrationals are each dense in the reals, ...
    (sci.math)