Then imagine where the 4th dimension is.
Our brains simply aren’t capable of conceiving that.
I mean, we can make a 4 dimensional math problem and do all the calculations correctly. We can treat time like a “4th dimension” and plot our trajectory through that space. Still, we can never conceive of where “the past” might go off to once we aren’t in it anymore.
In the simplest terms a “dimension” is just a direction that we have freedom of movement in that is perpendicular to all the other directions we have freedom of movement in. We can only move in 3 directions that meet that definition, and we can only perceive the world around us as a space that is bounded by those 3 dimensions defined by those directions. However we can conceive of certain effects a 4th dimension might have on our the 3 dimensions we perceive, and one of those is this “triangle problem”, which is something we can actually make measurements of and evaluate.
re: “Then imagine where the 4th dimension is.”
Was he thinking the Fifth Dimension maybe? Its where the sun shines it -
The 5th Dimension = AQUARIUS = Let The Sunshine In
https://www.youtube.com/watch?v=ILSr9BbhoJQ&feature=youtu.be