• tonylowe@lemmy.sdf.org
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    5 months ago

    There’s only a couple theories as to why we perceive the moon’s size differently and the best one is context/contrast with the moon’s surroundings in our visual field. Pretty sure there’s a wiki article about it. Not settled science yet either. Remember going down a rabbit hole about that a couple years ago. Neat stuff.

    • ch00f@lemmy.world
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      5 months ago

      Best explanation I’ve seen is that humans judge distance and size assuming a relatively flat surface (a dozen miles or so in any direction is fairly flat even though the Earth is round).

      Things far along the horizon tend to be small because they’re far away. This isn’t the case for the Moon. So our brains assume it’s far away, but it’s the same apparent size, ergo, it must be massive.

      Like we know Mt Rainier is massive and far away, so given this photo, we might assume the moon is massive.

      Higher in the sky, there’s no real point of reference. Also, you might visually process the sky as a flat layer above the ground, so the same parallax trick applies. I.e. the sky above you is closer than the sky/ground at the horizon. Therefore Moon is “closer” and appears smaller.

    • PunnyName@lemmy.world
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      5 months ago

      It’s an illusion. Extend your arm to its full length, and stick out your thumb. Compare the size when the full moon is near the horizon, vs when it’s closer to zenith near midnight. It’ll be the same relative size.