Explore raytracing in 2D through this 26-minute lecture from MIT's 18.S191 Fall 2020 course. Dive into light behavior, code implementation, and key concepts like mutable structs, index of refraction, and time-stepping for light ray movement. Learn about mirrors and reflection, including dot product calculations and reflection functions. Delve into refraction, Snell's law, and its vector form solution. Discover total internal reflection and lens applications. Follow along with provided timestamps for easy navigation through topics such as main function creation, refraction equations, and practical implementations in the Julia programming language.