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  • Re: [rainbow] what's beyond the edges?

    From Michael Uplawski@21:1/5 to Michael Uplawski on Sat Jun 28 09:03:53 2025
    Just an addition for clarity.

    Michael Uplawski wrote in sci.optics:

    Can there be a simple explanation for the difference in size of the
    “unused space” above and below a rainbow?

    You do not need to explain the origin of the rainbow to me. It is
    just not the subject of my post. I have read « Descartes » and know
    about the retina.

    Just the difference in size of those areas.

    TIA and sorry for making you doubt.
    --
    Eating and drinking is no walk in the park.
    (Ruby-Gem „Sprichwoerter” - German version)

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  • From Michael Uplawski@21:1/5 to All on Sat Jun 28 08:53:55 2025
    Good morning.

    This is not about apples, although I mention “The Spectrum”. Again.

    Can there be a simple explanation for the difference in size of the
    “unused space” above and below a rainbow?

    I venture that the “lower” edge is the violet and the upper edge the
    red line. If I remember rain and rainbows correctly (it has been a
    while), there is much less space after violet but much more before
    red.

    Or maybe I am just nuts.
    --
    Work knows no virtue.
    (Ruby-Gem „Sprichwoerter“ - German version)

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  • From Phil Hobbs@21:1/5 to Michael Uplawski on Mon Jun 30 00:52:50 2025
    Michael Uplawski <[email protected]> wrote:
    Good morning.

    This is not about apples, although I mention “The Spectrum”. Again.

    Can there be a simple explanation for the difference in size of the
    “unused space” above and below a rainbow?

    I venture that the “lower” edge is the violet and the upper edge the
    red line. If I remember rain and rainbows correctly (it has been a
    while), there is much less space after violet but much more before
    red.

    Or maybe I am just nuts.

    More context needed. The rainbow is generally circular, with an angular diameter of 84 degrees.

    That’s a solid angle of

    2pi*(1-cos(42 deg)) =1.614 steradians,

    which is big, but still less than 13% of the sphere, so the inside is
    smaller than the outside.

    Or do you have something else in mind?

    Cheers

    Phil Hobbs



    --
    Dr Philip C D Hobbs Principal Consultant
    ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics,
    Electro-optics, Photonics, Analog Electronics

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  • From Michael Uplawski@21:1/5 to Phil Hobbs on Mon Jun 30 07:29:26 2025
    Phil Hobbs wrote in sci.optics:
    Or maybe I am just nuts.

    That’s a solid angle of

    2pi*(1-cos(42 deg)) =1.614 steradians,

    which is big, but still less than 13% of the sphere, so the inside is
    smaller than the outside.

    Perfect. Geometry was none of the solutions that I could think of.

    Or do you have something else in mind?

    Probably not. TY.
    I will find a way to express the facts with frugal (rural) words.

    Have a nice week, all.

    Michael
    --
    “Museums are nothing but a pack of lies
    and the people who make a business out of art
    are mostly swindlers.”
    (Pablo Picasso)

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