The Invisible Fishing Line · AI Generator #GEN-7D85D46D
Physics · optics
Problem
A fishing enthusiast notices that their transparent monofilament fishing line becomes nearly invisible when submerged in water, making it difficult to see where the line enters the water surface. The fishing line is made of nylon with a refractive index of nline=1.50. Water has a refractive index of nwater=1.33.
When light travels from the nylon fishing line into the surrounding water, at what angle of incidence θi (measured from the normal to the line's surface) will the light be refracted at exactly 90° to the normal? This angle represents the critical angle beyond which total internal reflection occurs, making the line appear invisible from that direction.