I am always confused about the end of the movie Interstellar.
What really happened in that black hole? How could he survive in that black hole and then get out?
The Bulk Beings protected Coop from the effects of the black hole. They manipulated space time to create a tesseract, a fourth dimensional space represented in three dimensions, using their advanced technology and knowledge. They then manipulated gravity to push him in. This allowed Coop to survive the normal results of entering a black hole. Think of it like a train track switch.