• mozz@mbin.grits.dev
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    9 months ago

    I have a little reflective disc. I will bet you $100 that a reflection of a sunbeam off of it will be exactly the same size (i.e. the same intensity, since it’s not getting any bigger) several meters away as it is a few inches away.

    • deegeese
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      9 months ago

      Try that in your backyard with a small mirror. You’ll find the sun’s reflection expands by about 1% of the distance.

      • mozz@mbin.grits.dev
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        9 months ago

        Ooooh

        Yes you’re 100% right - it’s not a point-source, so it will expand out slightly. I don’t know the math well enough, but I believe if you if you say you do + it works out to about 1% of distance.