Can a drop of water cause sunburn or fire?
To the gardening world it may have always been considered a fact, but science has never proved the widely held belief that watering your garden in the midday sun can lead to burnt plants. Now a study into sunlit water droplets, published in New Phytologist, provides an answer that not only reverberates across gardens and allotments, but may have implications for forest fires and human sunburn. “The problem of light focusing by water droplets adhered to plants has never been thoroughly investigated, neither theoretically, nor experimentally”, said lead researcher Dr Gabor Horvath, from Hungary’s Eotvos University. “However, this is far from a trivial question. The prevailing opinion is that forest fires can be sparked by intense sunlight focused by water drops on dried-out vegetation.” The team conducted both computational and experimental studies to determine how the contact angle between the water droplet and a leaf affects the light environment on a leaf blade. The aim was to clarify