One thing I love about this book is the fact that it exists. It's rare to come across an intelligent author from within the scientific community actually being honest about the many unknowns continue to vex the world's finest minds. The first chapter, about Dark Matter and Dark Energy is really fantastic... but sadly the book peaks round about there and then really starts dragging towards the end. It probably would've been better published as 'Half a dozen things that don't make sense'. Still, for killing hours whilst commuting or sitting by the pool its a great alternative to trashy fiction - and full of random facts for sharing down the pub after one too many.