There is no doubt that the abrupt change in laser light colour once it enters the cola is due to
fluorescence. We hypothesized that the depth dependence of the perceived laser colour inside
the cola could be modelled by the Beer–Lambert law which mainly suppresses short wavelengths,
leaving the laser a bright red the deeper it is immersed. We know that our method for
confirming the hypothesis is suboptimal, because there is a wide range of unknowns about the
internal functioning of the camera that was used to take the pictures. However, with very
limited instrumentation, just using basic principles of light absorption and fluorescence, we
could account for the colour transformation of the immersed laser light at different depths
below the surface of a cola recipient.