Lee Smolin, who supported at a time of his life string theory, present alternatives to the theory for the Unification. It discusses the advantages and disadvantage of the main candidates theories and shows us that the climate research in theoretical physics is quite tense: the hegemony of string theory which diverts research funding does not encourage new ideas. The author reveals the often hidden problem to the public and we also explains why theoretical physics is in a bad way for at least four decades. An indispensable book, very interesting and reads easily! What more? :)