You are in a room with the Invisible Man. You can’t see him, of course. He is quiet and stealthy and moves around. Your best chance of keeping track of him is a spray bottle of water mixed with food coloring. You guess where the Invisible Man is and spray in that general direction. If you guess right you will catch him on the move: the mist will briefly outline an arm, a head, a distorted torso. That’s not him. That’s the water. He’ll move on and through it, but you’ll have a sense of where he is and what he’s up to. Doing this is second nature.
The thing is: you are invisible too. In fact, everyone is invisible. Everyone carries spray bottles filled with colored water. Back in the olden days people didn’t have spray bottles and so carried around sacks of flour that they would throw into the air to outline their fellow invisibles. For obscure and forgotten reasons, any diffuse material tossed into the air to reveal other people is called “noise”. What today the water misters spray–the same bottle you use to water your plants–that is also called noise.
You have a body. You can’t see it, but you have a sense of its shape, the space it occupies. The vague distorted shapes of the Invisible Man that appear through the noise, they clearly arise from the same sort of thing as you. Almost the same, but not quite. And he is thinking the same about you. What would it be like to see things directly? You can’t even imagine. Throw some noise at it. It will become as clear as it will become.