>>11291481>Why can't we present the 4th dimension using 3D planes, like we can present 3D using 2D planes (like screens)?By 3D plane I assume you mean a 3D volume, and we can't represent 3D objects in a 2D sheet, we can only represent their 2D projection. A drawing doesn't have depth. You cant hide something behind the drawing of a coffee mug in a painting. Since we only have 2D vision, we can only see in two dimensions, but our FOV, background/foreground organization, interpretation of shadows and lighting and the parallax created by having 2 moving eyeballs allows our brain to project a sense of depth.
>What would need to change in human anatomy/perception to become able to see in 4 dimensions?First, the entirety of the brain since it is wired for perception of a 3D environment, as well as your eyes and ears. Second, you'd actually need to have access to a place with 4 spatial dimensions in order for one of your heavily modified "humans" to look around. It's likely your modded humans would need to see in 3D with several layers of focus in order to perceive 4D environments.
>>11291682>missing the pointOP is talking exclusively about orthogonal and normalized spatial dimensions. Time is not normal to space and spin/polarity/parity symmetry isn't orthogonal.
