Paul Davies is a theoretical physicist, cosmologist and astrobiologist, who won The Templeton Prize in 1995. Here he reflects on the centenary of quantum mechanics, the future of quantum physics, the progress of AI, the potential for colonising Mars, the compatibility of God and quantum mechanics, theories of the Universe, the meaning of life, the history of scientific discovery, and coming up against intellectual brick walls. Paul's latest book, Quantum 2.0, is available to pre-order.