Unit 8, Physical Optics
Light can be modeled in several ways, including as a ray, a particle, or a wave. Is it "really" one, two, all three, or none of these things? I'm pretty sure I can't answer that question to everyone's satisfaction, so let's just focus on the different models and see what they teach us. The model we explore in this unit is the wave model. The diagram above is by Thomas Young (who had a truly amazing career), and he formulated it about 1800 to explain some truly fascinating characteristics of light.