• Septimaeus
    link
    fedilink
    arrow-up
    19
    ·
    4 months ago

    Also it’s interesting that NDT orients his EM spectrum by wavelength rather than frequency, such that “above red” and “below UV” falls outside the visible range. Is ascending wavelength the convention in astrophysics?

    • Little_mouse@lemmy.ca
      link
      fedilink
      arrow-up
      17
      ·
      4 months ago

      I imagine that he is equating the spectrum back to the rainbow, where red is the ‘top’ of the visible arch when a single rainbow is seen from the ground.

      Of course the outer ring from a double rainbow flips the order of the colours, but that’s probably being needlessly pedantic.

      • Septimaeus
        link
        fedilink
        arrow-up
        10
        ·
        4 months ago

        Oh shit, I hadn’t thought of that! That would be more accessible to the uninitiated, which is his thing.

    • cynar@lemmy.world
      link
      fedilink
      English
      arrow-up
      11
      ·
      4 months ago

      Not normally. In physics the general convention is to use photon energy. This puts Radio and IR ‘below’ red, and UV ‘above’.

      • Septimaeus
        link
        fedilink
        arrow-up
        4
        ·
        4 months ago

        That makes sense. Might’ve just been an accidental swap. Tweets aren’t peer reviewed.