FILE PHOTO: British astrophysicist Professor Stephen Hawking and his wife Elaine (R) visit the stand of German bookseller Rowohlt at the Frankfurt book fair

FILE PHOTO: British astrophysicist Professor Stephen Hawking and his wife Elaine (R) visit the stand of German bookseller Rowohlt at the Frankfurt book fair, October 19, 2005. REUTERS/Alex Grimm/File Photo