Dig in: Turing and the mysterious mathematics of sunflowers

How a citizen science experiment followed the research of the brilliant Nazi codebreaker

Ever heard of an English scientist by the name of Alan Turing? A brilliant mathematician cryptanalyst and the founder of computer science, he was also, as the Oxford Dictionary of Scientific Biography describes him, "the genius loci at Bletchley Park', the British country house where a secret team of codebreakers worked to crack the Nazi codes and ciphers during the second World War.

Man-made riddles aside, Turing was also very interested in how plants produce complex mathematical patterns in their leaves, stems and seed arrangements, a study properly known as “phyllotaxis”. A well-known example is what’s known as “Fibonacci phyllotaxis” in sunflowers, where the flowers’ seeds are arranged in elaborate spirals. Both beautiful and structurally complex, these sequences of clockwise and anti-clockwise spirals demonstrate how mathematical rules can help to shape the natural world, being arranged in ways that seemingly conform to Fibonacci numbers (where each number is the sum of the two before it). Before his death in 1954 (he died of self-inflicted cyanide poisoning), by which time he was working in Manchester University, Turing was one of several scientists attempting to explain how and why this natural phenomenon occurs.

A few years ago, Manchester University decided to follow up on Turing's research as well as to celebrate the centenary of his birth, with an appeal to members of the public to become involved in what it calls a "citizen science experiment". Thousands of members of the public planted sunflowers as part of what was called Turing's Sunflowers Project. Of the resulting sunflowers, a total of 657 were eventually submitted to the study, making it the largest ever of its kind. The results, which were published earlier this year, are exactly the sort of riddle wrapped in a puzzle that would have intrigued Turing. Because although the majority of the sunflowers studied did indeed conform to the principle of Fibonacci phyllotaxis, one in five didn't, with some of them instead exhibiting mathematical patterns that were even more complicated. As Science Magazine put it, "the possibility of capturing sunflower development with math just got more realistic – and more complicated."

Interestingly, Turing's own interest in the complex forms and patterns that can be found in nature dated right back to his childhood, when he was given a copy of a book called Natural Wonders Every Child Should Know, proving that the seeds of scientific curiosity are often sown at a very early age. So if you're one of the many parents helping their children to grow sunflowers this summer, then give yourself a big pat on the back – you could, very possibly, be helping to produce the next generation of brilliant mathematical scientists. (see turingsunflowers.com)