Why consciousness defies explanation through physics

HostIt's a strange thing to think about, but every morning when we wake up, the lights just kind of turn on. We go from a blank slate to seeing colors, feeling the warmth of a blanket, and hearing the birds. We have all this science to explain how our eyes work and how our hearts beat, but the actual feeling of being alive seems like it's in a different league entirely. How come we can map every cell in the brain and still have no clue why any of it feels like something?

GuestThat's the big wall we keep hitting. If you look at physics, it's mostly about what things do and how they move. You have atoms hitting each other, waves moving through the air, and electricity jumping between points. We can write down the math for all of that. We can see how a light wave hits your eye and turns into a signal that goes to your brain. But there's a huge gap between a signal moving through a wire and the bright, vivid splash of red you see when you look at a rose. Physics tells us how the parts move, but it doesn't say a word about why we actually experience the movement. It's like having the sheet music for a song but never actually hearing the sound.

HostBut isn't that just because we haven't looked close enough yet?

GuestIt's a bit deeper than that. Think of it this way. Imagine there's a woman who lives her whole life in a room where everything is just black and white. She's the smartest scientist in the world, and she learns every single fact there's to know about the color red. She knows the length of the waves, which cells in the eye react to it, and exactly which part of the brain lights up when someone sees a strawberry. She knows the physics inside and out. But then, one day, she walks out of the room and sees a real red rose for the very first time. In that moment, she learns something new, right? She learns what red actually looks like. All the physics in the world couldn't give her that one piece of knowledge, which is the actual feeling of the color.

HostOkay, but the brain is still doing the work.

GuestOh, the brain is definitely doing the work. There's no doubt that when you change the brain, you change what you feel. But the mystery is why there's a feeling at all. Think about a digital camera. It takes in light, turns it into a code, and saves it. The camera is doing something very similar to what your eye and brain do. But we don't think the camera feels anything. It doesn't enjoy the view or feel the heat of the sun. It's just a bunch of switches flipping back and forth. You could build a robot that acts exactly like a human, one that ducks when a ball is thrown at it or says ouch when you tap it. From the outside, it looks fine. But there's nothing going on behind the eyes. No one is home. Physics is great at explaining the robot, but it can't tell us why we're not just robots ourselves.

HostSo what are we missing? Is there some other kind of stuff out there?

GuestWell, some people think we might need a whole new set of rules, like how we needed new rules for gravity or time. Some think that maybe consciousness isn't something the brain makes, but something that's just part of the world, like space or weight. It's a wild idea, but it comes from a place of being stuck. Others say we might just be too limited to get it. It would be like asking a dog to understand how a cell phone works. The dog has a brain, it can see the phone, it can hear the noise, but it just doesn't have the tools to grasp the code and the radio waves. Maybe our brains are great at finding food and staying alive, but when it comes to looking at our own inner light, we just hit a hard limit.

HostIt feels like trying to use a ruler to measure how much a song weighs.

GuestThat's a good way to put it. Physics is the tool we use to measure the outside world, the stuff we can all agree on and point to. But the feeling of being you is the only thing you have that's completely yours. You can tell me you're in pain, and I can see your brain lighting up on a screen, but I can never actually feel your pain. That one-person view is what makes it so tough. Science usually wants things that anyone can test and see for themselves. But you can't step inside someone else's head to see if their blue is the same as your blue.

HostHow do we even start to build a bridge between those two worlds?

GuestWe might have to change what we think of as a fact. Right now, we think facts are only things like how much a rock weighs or how fast a car goes. We might need to start seeing feelings as a basic part of the world, just as real as a rock or a car. It would mean that the world isn't just a bunch of dead matter bumping around in the dark, but something that has a side to it we're only just beginning to name. We're trying to find a way to talk about the light in the room using only the shadows on the wall.

HostThe shadows show us the shapes, but they never quite capture the warmth.

GuestThe biggest question is whether a perfect map of the brain would ever reveal the mapper, or if the person looking at the map is the one thing the map can never show.

HostThe brain can show us the sparks and the wires, but it still leaves us wondering why the lights are on in the first place.