The K M Links Game - June 2024 Week 1
Quizzes & Puzzles1 min ago
No best answer has yet been selected by jamesy boy. Once a best answer has been selected, it will be shown here.
For more on marking an answer as the "Best Answer", please visit our FAQ.As kempie says, the angle of incidence can only be in the range 0 - 90�.
However, as an example, in my aquarium the sand/gravel substrate is 'illuminated' from the top surface down to about �" / 1.5cm-ish depth. This is irrespective of the total depth of the gravel, as the 'illumination' follows the contours.
This is due to internal reflection within the glass.