I'm preparing a demo for my class... I have a light pipe (a clear, solid plastic pipe about a half-inch in diameter). Incoming light is always limited to incident angles less than the critical angle -- so there's total internal reflection (the basis of fiber optics). The pipe is coiled -- like the heating element on top of a stove. If I immerse the light pipe in a mediam with a higher index of refraction than the pipe itself, would the pipe's ability to trap the light be affected?