The 2D reality encountering a 3D reality is often used for higher-dimensional analogies, but it doesn't have much physical meaning. However, it is true that if we could figure out how to access other dimensions, we'd be able to move through the universe like never before. Almost every single attempt at a grand unifying theory of physics invokes higher dimensions, and I think it's likely that they exist, but our simulation rules (or whatever) don't let us access them without a technology that may or may not even be possible. We won't know in our lifetimes :(. I'm agnostic on whether I think this is all a simulation or not. I'm also just agnostic, because it's kinda the same question. Thanks for the questions, everyone! I didn't have time to read Fox News today :).