A short flash of ultraviolet radiation causes each frog to be in two different states at the same time: the base state (bottom image) and the excited state (top image). A strong laser field rips an electron from each of the states and leads back to the original state (red arrows). When the electrons collide with the particles they emit a very short burst of X-rays (purple arrows). The light emitted from the two separates is merged together for a highly sensitive measurement of the broken bond. Photo: University of Ottawa