They shaped the two most fundamental concepts of the universe INFORMATION & COMPUTATION. Claude Shannon and Alan Turing not only changed the way we live, but also the way we think. From your iPad to the center of our Galaxy everything boils down to these two concepts. Read Turing’s Vision: The Birth of Computer Science (The MIT Press) And his PhD dissertation: Alan Turing’s Systems of Logic: The Princeton Thesis.  Just arrived today a great book about Shannon: A Mind at Play: How Claude Shannon Invented the Information Age.  And if you have time his famous paper: The Mathematical Theory of Communication