Is Stephen Hawking an atheist?

Stephen Hawking is an outspoken atheist. He's famously quoted as stating that he believes there is no afterlife, and the human brain "shuts off" like a computer after a person dies.

Stephen Hawking credits the creation of the universe not to a higher being but to nature itself. In his book "The Grand Design," Hawking suggests the law of gravity proves the universe created itself from nothingness through an act of spontaneous creation. The lacking reference to God in this book is a noticeable change from his 1988 bestseller, "A Brief History of Time," where Hawking stated that discovering the source of creation would be understanding the mind of God.