Commentary Contact is an intriguing story of the search for extraterrestrial intelligence and eventual contact by an alien civilization. It is based on a novel by Carl Sagan of the same title from 1985, which is one of my favorite books. Although the movie isn't as great as the book, it's still quite excellent in my opinion. Contact makes a good case for the existence of intelligent life forms outside our own solar system as well as the methods which may be used to discover them and how or what they may communicate to us.
Plot Summary The movie concerns Ellie Arroway (Jodie Foster), a young scientist interested in contacting extraterrestrial civilizations. Despite repeated efforts of the director to shut down the project and cancel her research, she eventually discovers an unmistakable signal from an intelligent source from the nearby Vega star system. There turn out to be the following three levels of the message:
The first level contains a list of the prime numbers up to 101. Since no known natural phenomenon can generate prime numbers, this is a good indication that the signal came from an intelligent civilization.
The second level contains a short movie of Hitler's opening ceremony to the 1936 Summer Olympics in Berlin. Although many of the scientists who discover this message interpret it to mean that the aliens are evil, Ellie explains that it was probably the first signal strong enough to be detected by an alien civilization.
The deepest level turns out to be a blueprint of a machine. Its purpose is not completely known but is known to be a transportation device of some sort.
This results in a huge international effort to build the machine. Eventually they succeed and Ellie is invited to take the journey. Along the way she is shown some amazing wonders of the civilization which brought her there. Unfortunately, she returns with no proof of having taken the journey.
Differences Between the Movie and the Novel Like I said, I was much more impressed with the novel, though the stories are similar. The main difference with the novel is that the aliens tell Ellie that they had figured out a way to encode messages in the decimal expansions of certain irrational numbers, including pi. Once Ellie returns, she spends quite some time computing pi to as many places as possible. Finally, the program she's running alerts her of a pattern consisting of a picture of a circle, which the aliens had encoded in order for anyone to be able to decipher by computing pi, thus providing proof of their existence. I was a bit disappointed that this wasn't in the movie. Also, I was somewhat disappointed with the movie's special effects. I think the machine could've been made to appear much more impressive than it was.