Beginning with his own near death experience, Koch write anout consciousness. Christof Koch is a neuroscientist at the Allen Institute for Brain Science, and a former professor at the California Institute of Technology. He lives on San Juan Island.  He writes about what science has learned about the brain basis of consciousness in the past several decades; the difficulties of materialism/physicalism in dealing with both the fundamental nature of reality at the quantum level and with consciousness; psychedelics; near death experiences; and the future of advanced brain-machine interfaces.