To explain this concept, David Chalmers, a philosopher at the University of California Santa Cruz, first describes the so-called easy problems of consciousness, the sorts of questions being tackled in neuroscience laboratories around the world: How does sensory information get integrated in the brain? How do we see and reach out for an object? How are we able to verbalize our internal states and report what we are doing or feeling?
Chalmers does not contend that these problems are trivial. He claims that they may take 100 years to solve, but that progress is being made.
He phrases the hard problem as this: What is the nature of subjective experience? Why do we have vividly felt experiences of the world?
Thus far, nothing in physics or chemistry or biology can explain these subjective feelings, Chalmers says. "What really happens when you see the deep red of a sunset or hear the haunting sound of a distant oboe, feel the agony of intense pain, the sparkle of happiness or meditative quality of a moment lost in thought?" he asks. "It is these phenomena, often called qualia, that pose the deep mystery of consciousness."
According to Chalmers, scientists need to come up with new fundamental laws of nature. Physicists postulate that certain properties--gravity, space-time, electromagnetism- are basic to any understanding of the universe, he said. His approach is to think of conscious experience itself as a fundamental property of the universe. Thus the world has two kinds of information, one physical, one experiential. The challenge is to make theoretical connections between physical processes and conscious experience.