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The natural numbers are analogous to an infinite line with a beginning and no end. We can continue that line into the integers and it becomes infinite in two directions. A line is defined by two points, we'll denote those two points as a set {x,y}. For the natural numbers x is 1 and y is infinitely large. For the integers x is infinitely small and y is infinitely large. As such I'll denote the naturals as {1,y} and the integers as {x,y}. When we expand into the rational numbers we are doubling this set in the sense that each rational number can be represented using one of infinitely many pairs of natural numbers. Thus I'll denote the rational numbers as {{1,y},{1,y}}. This new set expands in a new direction analogously connecting two infinite lines instead of two points, resulting in an infinite plane. However as the notation suggests, this plane is not infinite in all available directions. Instead it is only infinite in one direction and thus has the same cardinality as the natural numbers. When expanding this notion to the reals we find similarly that each real number can be represented as a pair of integers and natural numbers. Through replacement of like terms this means that the reals are of the form {{x,y},{1,y}} where {x,y} is the whole number component and {1,y} is the fractional component. This plane grows infinitely in three directions so it has a higher cardinality than the rationals. However, if we consider only the fractional component then we see it identical in distribution to the natural numbers. This relationship can be seen in my bijection between the reals between 0 and 1 and the natural numbers here: https://www.math-forums.com/threads/a-very-simple-bijection-between-reals-and-naturals.443469/
Thinking about the reals this way also shows that a bijection between the real numbers and the natural numbers should be possible utilizing a chain of reversable pairing functions such as the the Rosenbloom-Tsfasman function. Furthermore the only uncountable infinities should be those that utilize an infinite number of directions.
Thinking about the reals this way also shows that a bijection between the real numbers and the natural numbers should be possible utilizing a chain of reversable pairing functions such as the the Rosenbloom-Tsfasman function. Furthermore the only uncountable infinities should be those that utilize an infinite number of directions.