By 2020 computers will equal the capacity of the human brain; people will have relationships with virtual personalities. 10 years later machines will have the computing capacity of 1,000 brains; they will learn on their own, create their own literature and claim to be conscious. By the end of the century there will no longer be any clear distinction between humans and computers. Most conscious entities will not have a permanent physical presence and life expectancy will no longer be a viable term in relation to intelligent beings. Ray Kurzweil is a leading technologist and author of the prize-winning The Age of Intelligent Machines. He is also one of the world's leading inventors and entrepreneurs in the field of artificial intelligence.