Planetstory

In the Tesseract, Cooper learns how to communicate with Murph in the past and the present by using gravitational forces to affect both the books on her shelf and the watch hands on the watch he gave her which is on the shelf. Using this newly discovered process of communication, he manages to relay the data from the black hole that Murph needs back on earth, to solve the equation and get humanity into outer space and off the dying planet.