(This blog entry is the longest of all that I made so far, but it's about something very important to me, so I need to be thorough with it.)

That's a hard question. Actually I think it's the hardest question of all. We don't have a mathematical or physical equation to describe consciousness. So, let's try to use a very powerful tool, that is able to explain almost everything in our universe. It's called reductionism.

What is reductionism? It's a process that is used very often in science. It means explaining the functions of a whole by the functions of its parts, including their interactions with each other and the outside world. It can be used repeatedly to reach the most basic known elements of the universe. Let's consider a tree for example. To figure out how it works, we can use our biological knowledge to define the functions of its cells, and explain how they interact and make up the whole thing. Then we can explain cells by the chemical reactions of molecules within them. Then we explain molecules using atoms, atoms using protons, neutrons and electrons, and protons and neutrons using quarks. That's the most basic level of our current physical knowledge, maybe there is something even more basic behind it, but we don't know yet. (Note that reductionism is good at explaining things, but usually not at exact predictions or simulations of their behavior, because often the complexity of the system is too big to make such simulations feasible. So most mathematical models that are actually used for such purposes, for example weather predictions, are a simplified version of the system, rather than an exact representation of its parts.)

So now that we know how reductionism works, let's try to use this procedure on consciousness. Can we reduce it into something more basic? In fact we can. It's called "qualia", the single "feelings" that make up our whole conscious experience. But that's it, we can't get any further. We know that qualia have something to do with the activity of neurons in the brain, but we have no idea how to make this connection. I think it's the biggest problem in all science, and my answer to it is that there must be some currently unknown physical process involved here.

But maybe, as some authors suggest, consciousness is an emergent phenomenon? Well, let's say it's emergent so we don't have to explain it. Problem solved... or not. First we need to know what an emergent phenomenon is. For example, let's consider the movement of air molecules. Depending on conditions, it can be just random, or all of them can be moving roughly in the same direction (in this case we call it "wind"). But sometimes we can see interesting patterns in it, for example with some kinds of rapid circular motion we call it a hurricane. It's a typical emergent phenomenon, because a single air molecule can't make a hurricane, we need a very large amount of them to create it. And it has some specific properties that we can study, so we consider it a thing on its own. But on the basic level it's still movement of air molecules, so "hurricane" is just our interpretation of a large scale pattern in this movement. That's how I understand emergence - it's our interpretation of some patterns in behavior of some more basic elements.

So, let's assume there is nothing mysterious in the workings of a single neuron, and consciousness is an emergent phenomenon that appears when a large number of them are working together. For some people it's a very good explanation, but I can see a problem with it. It's kind of hard to explain, but I feel that consciousness just exists, regardless of our interpretation. So it can't be composed from some basic things that have nothing to do with it. But maybe it doesn't need neurons specifically, but it's just associated with complex information processing in general? Well, "information processing" is something similar to an "emergent phenomenon", it's just our interpretation, while actually some basic physical processes are happening, for example when we use a computer, we see it as information processing, but actually it's just movement of electrons in semiconductor materials. I just can't see the connection between these kinds of processes and consciousness, or how it could "arise" from them, so I'm sure there must be some "new physics" involved. Of course you can disagree with me, but that's how I feel about it. Also I feel that I explained it badly, but I have no idea how to do it better.