Near the end of the book, Contact, by Carl Sagan, the main character is told there are messages hidden deep in the base-11 digits of π.
From the Wikipedia article:
Acting on the suggestion of "Ted", Ellie works on a program to compute the digits of π to heretofore-unprecedented lengths. When Ellie looks at what the computer has found, she sees a circle rasterized from 0's and 1's that appear after 10^20 places in the base 11 representation of π. This not only provides evidence of her journey, but suggests that intelligence is behind the universe itself.
Somebody as smart as Carl Sagan should know that the creator(s) of the universe can no more change the value of π than they can change any other fact. Math itself must precede both the universe and anything or anyone that created it.
I could better believe a deity chose to hide a message inside the Fine-Structure Constant than in π.
Did Carl Sagan ever provide an explanation for how a deity would embed hidden messages deep inside the value of π?
I am looking for answers from the novel or from Carl Sagan's writings or interviews. I don't want answers from the movie, Contact, since that does not mention any messages hidden in the value of π.