Today, brilliant colours that only appear in UV light, are part of everybody´s everyday experience. Usually photons of higher energy are turned into photons of lower energy. In a fascinating experiment this video shows that this can also work vice versa, and gives a clear and convincing explanation.

Video produced by Beilstein.TV in cooperation with the Wuppertaler Chemiedidaktik. Video licensed under the Creative Commons Licence 4.0 - By, No Derivatives (CC BY-ND 4.0).