BrainOnLost posted a topic in Other SciencesHello there, I found when light ray pass a transparent material on wet and dry surface, there is some phenomenon happened. This is what seem on a dry surface. https://i.imgur.com/ouPkmpP.png The observation could seem the light was spread evenly on the surface. This is what seem on a wet surface. https://i.imgur.com/1Y95wAm.png Something weird happened, the light was spread like a ring with a hollow on the center. I guess this phenomenon was related to Frustrated Total Internal Reflection, but could somebody can explain briefly on this?