BUTTERCUPS SOAK UP SUNSHINE Friday in Topsham. Holding a buttercup flower under the chin on a sunny day produces a yellow glow on the underside of the chin. Folklore holds that the yellow glow under a person’s chin indicates a love of butter. Now, by examining the petals of one species of buttercup, Ranunculus repens, scientists have figured out how the flower manipulates light to make this trick possible. For an explanation, visit www.livescience.com/17460-buttercup yellow-chin-optics.