Eliezer Yudkowsky has done some great work in the areas of probability theory, decision theory, and artificial intelligence. (Those are important topics for the coming decades as computers become more powerful, so dig in if you’re interested.) I found recently that he has written an especially clever and well-thought-out short story called Three Worlds Collide. This is probably the best portrayal of mankind making first contact with another intelligent race that I’ve ever encountered. He gives it away for free, so check it out!