Contact and the Implementation of the Twin Paradox
Are we alone in the universe? That is one of humanities biggest questions. In the movie, the writers tackle this topic in a fictional sense but try their best to keep it as realistic as possible. Such as the backfire from the religious community such a discovery might have and the physics that would go along with intergalactic travel (somewhat).
During the course of the movie, and humanity discovers that they had been sent blueprints for a device that will send one human out into space to make contact with the aliens, the characters in the movie discuss what we call the "Twin Paradox". The paradox is described like this:
Two twins exists. One goes on an interstellar/intergalactic trip at or close to the speed of light, while the other stays on Earth. Hypothetically, when each twin decides to observe the other, they will notice that the other has experienced time dilation (time moves slower at higher speeds) and that their twin has aged to be older then them. However, this is impossible and that is where the "paradox" comes in, but there is an answer. Time dilation can only be properly observed from an inertial reference frame (a reference frame that is not moving or accelerating) therefore the twin that is accelerating off into space is not a valid reference point and that the twin on Earth is actually aging while the twin that is traveling is staying younger.
Going forward, the problem in the movie is that they got this idea reversed. When the main character traveled through the wormhole which propelled her faster than the speed light, she experienced approximately 18 hours of space travel while on the Earth is happened so quick that no camera caught it causing people to believe she didn't travel at all. The main character should have experienced her trip on a shorter time interval than the time interval that occurred on Earth which is exactly what they discussed back towards the middle of the movie. The movie even contradicted itself! The movie should have had her return to an Earth where everyone was older or even dead. Just some kind of evidence that Earth experienced more time than she had.
Overall, the plot of this movie was good and while the ending left the audience somewhat unsatisfied I still believe it was a very enjoyable watch! But since the movie contradicted the Twin Paradox, an idea that they had explained in the movie itself, I am going to have the rate this movie a PGP-13.