Stephen Hawking's final work, which tackles issues from the existence of God to the potential for time travel, was launched yesterday by his children, who helped complete the book after the British astrophysics giant's death.
Hawking was forever being asked the same things and started work on "Brief Answers to the Big Questions" last year but did not finish it before he died in March, aged 76.
It has been completed by the theoretical physicist's family and academic colleagues, with material drawn from his vast personal archive.
"He was regularly asked a set of questions," his daughter Lucy Hawking said at the Science Museum in London.
The book was an attempt to "bring together the most definitive, clearest, most authentic answers that he gave. "We all just wish he has here to see it."
Hawking, who was wheelchair bound due to motor neurone disease, dedicated his life's work to unravelling the mysteries of the universe.
The cosmologist was propelled to stardom by his 1988 book "A Brief History of Time", an unlikely worldwide bestseller. It won over fans from far beyond the rarefied world of astrophysics and prompted people into asking the mastermind his thoughts on broader topics, answered in his final work.