Audio problem: In several scenes, Sandra Bullock used radio equipment in efforts to call for assistance. There is a sound made by vintage, mechanically tuned radios called "heterodyning" that results in a squealing, variable frequency sound in the speaker. While heterodyning added a degree of drama to the scenes in "Gravity", contemporary radios operate on a different, highly stable technique for tuning, and do not produce heterodyne sounds. (00:13:15 - 00:41:00)
Audio problem: Ryan is on the International Space Station and looking through the window in an attempt to communicate with Matt. During this transmission, Ryan says "Please talk to me. Please." When she says "Please" the second time, her lips move before the word can be heard. Her lips are very visible through the reflection of the window. (00:42:15)
Answer: If they had been tightly tethered to the space station, he would have bounced back toward her. But her foot was only tangled in parachute cords, so that when the tether snapped taught all it did was begin to pull her away from the station as the parachute cords gave more and more slack, slipping more and more loose as they drifted further away.
Phixius ★