Active spectroscopy: detecting what the eye cannot see When does the difference between what something looks like and what it is really like matter? Take an example from agriculture: traditionally a farmer has relied on the sense of sight, alongside touch and taste, to estimate the ripeness of fruit in the orchard, but the results are often hit-and-miss. The science of spectroscopy replaces guesswork with measurement: spectral techniques allow the grower, and in fact the whole supply chain for fresh produce, to look beneath the skin of the fruit to analyze the crucial parameters of moi…