What is the hard problem of consciousness?

The hard problem asks why physical processing comes with experience at all, why seeing deep blue feels like something. David Chalmers set it apart in a 1994 talk in Tucson from the easy problems, where everyone can say what an answer looks like. The problem leans on a list of physical facts compiled from no position, and that list never turns up. Distance counts comparisons between two parties, a rate needs a clock, and every record is held by some observer. OPH starts from observers and builds the physics afterward. What remains is met with an identity. Experience is repair at an observer's boundary, owned by that observer and read from the inside. Chalmers is right that outward function leaves the owned interior out, and Daniel Dennett is right that a hidden viewer in an inner theater would explain nothing. Ownership is the missing variable. The identity is a hypothesis, judged by what it accounts for and by experiment, and it turns consciousness into an engineering problem.