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?
When cooper got pulled in Gargantua and ejected before spacecraft got destroyed, he got stuck in some extra dimension where time is non-linear. It's like a space where he can communicate with her daughter on earth through gravity. That's why Murph thought it was a ghost. So he can communicate with past time Murph because of the non-linear time structure of that extra dimension.
This extra dimension space can be treated as parallel plane which can assess multiple time frames of earth.