Given the task definition and input, reply with output. Given scene/plot descriptions from movies or TV shows, and given a specific question about the scene, summarize the question into a title

In the movie Interstellar it's shown that after Cooper fell into the Black Hole, he communicates with his daughter Murph through some codes as Ghost. My doubt is how can he communicate to his daughter before he goes into space? I didn't get the logic of that part. Can anyone please make it clear?
How can Cooper communicate with his daughter before the time he went to space?