After a long day of rehearsing for her upcoming world tour, Katy Perry decided to peruse a few books to help her unwind ...

“I was listening to ‘Cosmos’ by Carl Sagan and reading a book on string theory,” she recalled. “I’ve always been interested in astrophysics and interested in astronomy and astrology ...

“I was listening to ‘Cosmos’ by Carl Sagan and reading a book on string theory,” she recalled. “I’ve always been interested in astrophysics and interested in astronomy and astrology ...

“I was listening to ‘Cosmos’ by Carl Sagan and reading a book on string theory,” she recalled. “I’ve always been interested in astrophysics and interested in astronomy and astrology ...