> [!tldr] The cylindrical example Here's the sort of "classical" toy example: ![[Projections 2026-08-25 16.28.19.excalidraw.svg]] %%[[Projections 2026-08-25 16.28.19.excalidraw.md|🖋 Edit in Excalidraw]]%% Shining lights on the green object from different perspectives, you see it project onto the two walls either a **circle** or a **square**. So which is it? - It's neither. - Or, rather, it's *both*. It's something from a higher-level dimension that has "squareness" and has "circleness". Among the zillion interesting things there is to say about our eyes - they **do not** perceive 3 dimensions. They perceive 2 dimensions. If you have 2 eyes, they perceive two dimensions then use spatial parallax[^1] to *infer* a 3rd dimension. If you have 1 eye, you just have to use size, focal adjustment tuning, and other clues as a [[Proxy Measures|proxy]] for distance. A [purely black object](https://en.wikipedia.org/wiki/Vantablack) looks completely flat: ![[vanta-gal-5.jpg|vanta-gal-5]] ### Into the 3rd Dimension Here's the thing, though, there are not just 2 [[Dimensions]]. We only every see a projection of any physical object as it exists *right now*. You don't "know" anything, really. You cannot fathom the entirety of *you*. Because *you* are a [[Details are a Fractal|fractal]] of [[Simplicity|Complexity]] that exists at vast scales of time and space. ### And beyond There are not just 3 dimensions, either. I'll leave this tract with this: > [!quote] > _Until the twentieth century, reality was everything humans could touch, smell, see, and hear. Since the initial publication of the chart of electromagnetic spectrum, humans have learned that what they can touch, smell, see, and hear is less than one millionth of reality.​_ **** # More ## Source - self - image source: https://www.sciencealert.com/this-object-has-been-sprayed-with-the-world-s-blackest-pigment-and-it-s-freaking-us-out - quote source: https://genius.com/Incubus-new-skin-lyrics [^1]: I wasn't sure if the term "parallax" can be used this way - turns out it *probably* can, but the term "binocular disparity" is preferred. Thanks Google! I'll keep it as-is.