Like the title says: when you see “heat rising” (the wavy/blurry area above a heat source), what are you actually seeing?

Bonus question: How does that cast a shadow? I noticed when I was opening my air fryer, I could see the shadow of the heat rising but, looking at the hot basket itself, couldn’t see it.

  • aubeynarf@lemmynsfw.comEnglish
    63·
    2 months ago

    You are seeing changes in the refractive index of air as a result of heat lowering the density of the air. As air comes in contact with the hot surface, it becomes heated and rises through otherwise cool air - The rising air causes eddies and vortexes that lead to light bending in weird ways as it passes through.

    The shadows are much like the shadows on the bottom of a pool when there are waves on the surface. Incoming wavefront of light are distorted from planar and sent in different directions, some directions get less total light, some get more.

      • pdxfed@lemmy.worldEnglish
        5·
        2 months ago

        “wavefront of light”, “distorted from planar” 🤯

        You took me straight back to a D- in intro to optics and modern physics where my classmates were trying to solve problems based on concepts, where I was trying to solve the problem of not understanding the concepts.