Is the Universe All It Seems to Be?

We're not even sure what space is. We talked about it on a podcast episode recently, whether it's possible to even have parts of the universe don't have space in them. You no a universe without space. Is it really three dimensions where all those three dimensions are equivalent, or is it actually two dimensions with one extra tricky dimension that's making us feel like its three dimensions? That's why these are, i think, are deep and important questions.