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? Featuring interviews with Roger Penrose, Mark Balaguer, Gregory Chaitin, Stephen Wolfram, and Frank Wilczek.

*See also:* Things exist that are unknowable: A tutorial on Chaitin’s number