In the third episode of this series, Dr Helen Czerski looks at the colours beyond the rainbow and the invisible world of infra-red and ultra-violet. While these wave froms of light are invisble to us, many animals in the animal kingdom can tap into them giving them a massive evolutionary advantage over the competition. This episode also looks at how different wave lengths of light are being used in modern science through x-rays and new experimental techniques, in order gain unpresented access into the body.
