If you don’t know what Fibonacci day is then go now and have a look at the calendar, write today’s date in the Month/Day format (11/23), … ...

Celebrate the simple mathematical sequence that is hidden in everything from sunflower spirals to Da Vinci's paintings ...

I wasn't attracted to Dan Brown's 2003 bestseller The Da Vinci Code, but I gather that to decode "the code" you need a passing knowledge of the golden ratio and its mathematical mate the Fibonacci ...