Jim if he comes back - would be able to explain the different sizes of infinity as Khal;;i pointed out
thre are an infinite number of fractions 1/2. 1/3. 2/3 1/4. 2/4 and so on
and the points between 0 and 1
but they cant be put into a 1:1 corrspondence which means that they are different sizes ....
Cantor was the first to realise this - and the idea forms the basis of his diagonal theorem
https://en.wikipedia.org/wiki/Cantor%27s_diagonal_argument
Marshwarble two sets are clearly both countable tho
\lots of understandable books about Infinity
not quite an infinity of the them -
John D Barrow wrote one ( yeah - " Infinity " )
His real claim to fame is that his predecessor and linear ascendent really did say in 1665, "I shouldnt be Lucasian Prof of math - Mr Newton should !" and that sort of thing doesnt happen very often even when you DO identify someone much brighter than oneself ! !