Is Mathematics Invented or Discovered?

Mathematics describes the real world of atoms and acorns, stars and stairs, with remarkable precision. So is mathematics invented by humans—like chisels and hammers and pieces of music? Or is mathematics discovered—always out there, somewhere, like mysterious islands waiting to be found? Whenever mathematics is will help define reality itself.   Featuring interviews with Roger Penrose, Stephen Wolfram, Max Tegmark, David Gross, and George Lakoff.