A few minutes into this clip, 5.15c climber Jakob Schubert says he is not sure a more substantial challenge than ‘Project Big’ exists. Schubert and Adam Ondra’s objective: the conclusory open project in the Flatanger Cave in Norway. I don’t mean “Project Big” is the last line there that anyone can climb. I mean that one of the only people trying it, who happens to be among the two or three best climbers in the world, isn’t convinced anything harder exists anywhere. Watch the two rock jocks try to slay a dragon in this one. Learn the difficulties the best…