You sit down in a restaurant to buy a meal. A young person steps up, smiles, and hands you a menu of delicious-sounding choices. You ponder your options, then pass your order to the waiter, who, after a while, returns with your food. Your significant other looks at your bowl of gumbo and, with a shake of the head, wonders about this person with whom they share a life.
In computer-speak, what you see when you go to the toy store’s … er … the telescope shop’s webpage is a user interface, or UI. It might seem a bit impersonal to also call the waiter who served your meal a user interface, but the shoe fits.
User interfaces are the outward-facing parts of what the geek set call application programming interfaces, or APIs. An API sits between you and a service provider, carrying things back and forth, allowing both of you to get what you need without either of you having to know very much about the other. Back to the restaurant: The waiter/API takes your order and passes it on in terms the chef will understand. The chef does whatever it is that chefs do, and the waiter reappears with the goods to appease your hunger. You don’t need to know anything about what is happening in the kitchen to order and enjoy your food. Mercifully, good UIs and APIs hide how the sausage gets made.
UIs and APIs simplify the world and isolate us from complex realities. That’s their job; it’s how they make it possible for us to accomplish what we set out to do.
That’s all fine for websites and fancy dinners, but what about our direct experiences of the world? Surely those offer us the real scoop about what is out there, don’t they? Philosophers call the idea that our senses give us reliable information about the world naïve realism. Naïve might seem pejorative, but it just means something that is taken for granted by someone who doesn’t know any better.
Surely there is no experience of the world more direct, immediate, and reliable than sight. Seeing is believing, right? Yet the interfaces between the world and our perceptions are legion. An optical interface converts information about the direction in which electromagnetic radiation is traveling into locations on the retina. (Of course, the properties of that radiation are only indirectly related to the properties of the objects from which it is emitted and off of which it reflects.) Next, an electro-optical interface turns information about the intensity and spectrum of light into electrochemical impulses. Those are further processed in the retina before being sent down the optic nerve. Deep in the brain, those signals reach structures that are really more chefs than waiters.
You call it seafood gumbo, but look at the recipe and you might discover that not much of what is in the bowl ever lived in the ocean. Likewise, deep in our brains, signals from the optic nerve are combined with signals coming from many other sources. Only about 5 percent of the signals that affect what we see comes from the eyes. Most of that information comes from the visual cortex itself; what you see depends far more on your own expectations and prior experiences than it does on anything coming from your eyes.
Once that witch’s brew has been stirred, the chef hands it off to another API, which carries it to the visual cortex, where the real processing begins. How many waiters and chefs are involved in finally conveying something to us?
Face it. The notion that vision provides us with direct, true information about the world is about as naïve as it gets. Going further, just talking about “us” and the world is naïve. An inescapable but radically counterintuitive conclusion of recent neuroscience is that our very perception of a unified self is an illusion. It is a useful product of layers upon layers of interfaces, no more direct a window on our own fundamental nature than are our visual perceptions a direct experience of the world.
Descartes famously said, “I think, therefore I am.” But, having realized that my sense of self emerges from a tangle of chefs and waiters cooking up and carrying information around in my brain, I’m not sure what Descartes’ truism even means.