Transcript

Right now, you are looking at this screen. You are certain of what you see-the colors, the shapes, the brightness. It all feels immediate, direct, real. But here's the problem: none of it is. 

What you are experiencing right now is not the world. It is your brain's best guess about the world, and the gap between those two things is larger, stranger, and more unsettling than almost anyone is prepared to admit. Let's start with light. Your eyes detect electromagnetic radiation in a narrow band of frequencies, roughly 400 to 700 nanometers.