Scientific Essay from the year 2021 in the subject Physics - Applied physics, grade: A, The Technical University of Kenya, language: English, abstract: After learning the refractive index concept in class, the author started wondering what will be the effect of changing temperature on the refractive index. Being a fan of swimming, concepts of apparent and real depth have always been fascinating to me. In this paper, he wanted to explore how the apparent and real depth of a liquid would change with an increase in temperature at different times of the day. The speed of light keeps changing as light moves from one medium to another of different optical densities. For instance, the speed of a ray of light moving from a denser medium to a rarer medium will decrease. If the ray reverse in the same direction, this time moving from a rarer medium to a denser medium, its speed will increase. Ideally, when the ray moves from a denser medium to a rarer medium, its particles collect together, hence reducing speed. On the other hand, when the ray is moving from the rarer medium to a denser medium, its particles spread out, and speed increases.