<<But really, what is
the square root of negative one?
ERiC
>>
I highly recommend Tobias Dantzig's _Number: The Language of Science_. It's readable and intelligent. (It's also recommended by some guy named Einstein)
http://www.amazon.com/exec/obidos/ASIN/0029069904/qid=918448922/sr=1-1/0 02-6921658-0405408
Cheers,
Deron