ELI5: Explain Like I'm 5

Physical optics

Physical optics is like playing with light. Remember when you used to catch a ray of light with a magnifying glass and make it bigger? That's physical optics! Physical optics is all about understanding how light behaves when it hits different objects.

So, when light travels from one place to another, it can be bent, reflected or even absorbed by different objects. For example, when light hits a mirror, it reflects and changes direction. This is why we see ourselves in a mirror! When light hits a red shirt, it absorbs all the colors except for red, which is why the shirt looks red.

Physical optics is also about understanding how light travels through different materials, such as glass or water. When light travels through a material like glass, it can slow down and change direction. This is why objects can look bigger or smaller when we look through a magnifying glass.

Scientists and engineers use physical optics to understand and design things like lenses, cameras, telescopes, and even lasers! Physical optics helps us understand how light behaves and how we can use it in everyday life.