Refraction and Reflection in a Pool by Matthew Jay Rohr
1st Place - Natural Category
School: Atlee High School
Teacher: Jeremy Watts
This photograph of stairs in a pool, taken from an underwater perspective, demonstrates the critical angle, the angle of incidence that produces a refracted light ray parallel to the boundary between the water and the air. Light rays with angles of incidence that are less than the critical angle are refracted as they cross the boundary between the two media, which is why the handrail appears to be distorted. Alternatively, light rays with angles of incidence greater than the critical angle aren't refracted at all and instead are totally reflected back into the water. In this way, the surface of the water acts as a mirror.