We’ve never seen anything 2 dimensional. Everything we can see has some form of all 3 dimensions in it. Even shadows are 3 dimensional. We conceptualize them as 2 dimensional on a wall, but they have depth. (Think of how when you see a line it’s actually 2 dimensional due to the width of the line, then apply that concept to depth as well)
A shadow is not the same as a line drawn by a pencil. And a 2d line can be for example the contrast of two colours, the “line” that delimits an object from your perspective - these are no drawn lines with any width, they are not there as full 3d objects. I would think a shadow is a similar case, just as a film projection. It has no thickness.
Well shadows are the absence of light, so defining them is a little weird, but they exist the entire distance from where the light source is interrupted to where they are projected on, same with projections, it’s not just what’s on the screen, but the light the whole way to the screen.
Even ignoring that, the surface that a projection lands on has texture and depth.
Well, you can definitely ignore that and just take thw projection and view it as something 2d. The fact that the surface is structured doesn’t mean the projection is not 2d - it is 2d curved in the 3d dimension, just like a 1d line can be curved without gaining any thickness. Just like our 3d space is curved.
We’ve never seen anything 2 dimensional. Everything we can see has some form of all 3 dimensions in it. Even shadows are 3 dimensional. We conceptualize them as 2 dimensional on a wall, but they have depth. (Think of how when you see a line it’s actually 2 dimensional due to the width of the line, then apply that concept to depth as well)
A shadow is not the same as a line drawn by a pencil. And a 2d line can be for example the contrast of two colours, the “line” that delimits an object from your perspective - these are no drawn lines with any width, they are not there as full 3d objects. I would think a shadow is a similar case, just as a film projection. It has no thickness.
Well shadows are the absence of light, so defining them is a little weird, but they exist the entire distance from where the light source is interrupted to where they are projected on, same with projections, it’s not just what’s on the screen, but the light the whole way to the screen.
Even ignoring that, the surface that a projection lands on has texture and depth.
Well, you can definitely ignore that and just take thw projection and view it as something 2d. The fact that the surface is structured doesn’t mean the projection is not 2d - it is 2d curved in the 3d dimension, just like a 1d line can be curved without gaining any thickness. Just like our 3d space is curved.
A shadow is a 2d projection of a 3d object projected back onto 3d space.