I have an interesting demonstration of our inability to fully grasp infinity. Start with the set of all counting numbers, we'll call that A. So set A contains 1,2,3,4,.... Now we are going to make two new sets using A as a start and applying a rule. For the first new set, the rule is to take each element from A and square it; we'll call this set B. So B contains 1^2, 2^2, 3^2, 4^2 --> 1, 4, 9, 16, ... Note well: for every number in A there is a corresponding number in B. For the other new set, we are going to filter elements from A. That is, we won't copy all the elements of A, we'll only copy the perfect squares. So: 1 from A gets copied to C 2 from A does *not* get copied to C 3 from A does *not* get copied to C 4 from A gets copied to C etc So C contains: 1, 4, 9, 16, ... Note well: Not every element in A has a corresponding element in C; we only copied some of them. A quite small fraction, actually, when you consider how perfect squares get more and more spre...
This is a paraphrase of the pasuk in t'hillim 84:7 -- "mei'chayil el chayil" -- which means "from strength to strength". In this case, it is my thoughts and ideas to those who are strong enough to be interested :)