[quote=@whizzball1]
<Snipped quote by Etcetera>

According to my maths book, most of what comes after calculus is all about creativity, and not rigorous standards. It says that the greatest proofs were most creative, and many maths concepts came from people bucking the predefined trend and making stuff up. Then again, the person who made up the irrational (notice, they're called irrational) numbers was killed by the Pythagoreans for figuring it out, and the imaginary numbers were, well, called imaginary even after they were accepted.

*high five*
[/quote]

To your second example, it's because said numbers don't exist.