Is There a Fifth Dimension?
Imagine a world where you can only move forwards and backwards along a line. You’d see nothing but single points in front of you, and nothing but single points behind you—a one-dimensional world. Now expand this to a second dimension—you can move forwards and backwards, and also left and right, experiencing the world as flat lines moving around one another. But you couldn’t drill a hole into something in this universe—you’d split it in half. Add a third dimension, and you’ve got depth—things take on visible forms and can move around one another, becoming the rich world we live in today. The...