Sky1981
Fending off the urge
did you actually watch the film? Caine finished his equation years ago, the equation proved that his theory wasn't possible. Hence why Option A was never a feasible one and he 'tricked' them.
Murph is the one who then managed to finish it correctly using the information Coop gave her from inside the black hole.
It's like Caine successfully built a cart, while what they need is a car.
Murp finally found how to built a car, because he got advance knowledge from Coop
Probably the gravity stuffs creates atmosphere, probably it can float platform so they don't need a very advance planet, who knows. Let's just take it as it is, coop help humanity to survive