When you’re watching a film it’s just a flat picture that has 2 dimensions, length and width.

The real world is very different because it has a 3rd dimension which is depth.

We can see in 3d because we have two eyes that triangulate what we see and so can tell how far away something is.

You can test this yourself by closing one eye and trying to pick things up, you should notice that it’s harder to tell how far away the things are because your eyes are not working together to triangulate what you see.

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