Question: In the mathematical study of cellular automata, Rule 90 is an elementary cellular automaton based on the exclusive or function, call it "the simplest non-trivial cellular automaton", and it is described extensively in Stephen Wolfram's book, released in what year, "A New Kind of Science", Wolfram, a British-American computer scientist, physicist, and businessman?
Related documents: [0]  [DOC] Stephen Wolfram (born 29 August 1959) is a British-American computer scientist, physicist, and businessman. He is known for his work in computer science, mathematics, and in theoretical physics. He is the author of the book "A New Kind of Science." In 2012 he was named an inaugural fellow of the American Mathematical Society. [END] 
[1]  [DOC] In the mathematical study of cellular automata, Rule 90 is an elementary cellular automaton based on the exclusive or function. It consists of a one-dimensional array of cells, each of which can hold either a 0 or a 1 value. In each time step all values are simultaneously replaced by the exclusive or of their two neighboring values. call it "the simplest non-trivial cellular automaton", and it is described extensively in Stephen Wolfram's 2002 book "A New Kind of Science". [END] 
Answer: 
2002
2002