Saturday 23 February 2002

Pic of the day: Like the interesting parts of a Mandelbrot fractal, life itself is a borderline phenomenon, changing remarkably depending on what level of detail you look at it.

Schroedinger's god

I find it slightly ironic that Erwin Schroedinger (or Schrodinger, in German it is spelled Schrödinger) is best known for the cat. Schroedinger's cat is a thought experiment in which a microscopic quantum event is used to determinate a course of action in the macro world where we live. In the original thought experiment, a cat is enclosed in a box (basically any place where it cannot be observed and cannot escape) and a canister of poison is coupled to a detector trained on one particular atom. If a certain quantum event occurs, such as the radioactive decay of an atom, the detector will react and release the poison which will kill the cat. Now a fundamental part of quantum lore is that quantum events are not binary on/off things. They are probabilities. An atom exists in a state of decay and non-decay for a while, and the two states are superimposed on the same atom. (And so on for other quantum events.) Logically then, the cat should be both dead and alive, superimposed on the same cat. This makes no sense. We do not have the power to observe whether the cat is alive or dead; but ignorance is not the same as the cat actually being in two different conditions.

Modern textbooks explains that the detector actually resolves the quantum event. A human observer is not necessary. Even the cat would not be necessary, though it would certainly observe the poisoning too. However, until measured, the quantum objects are indeed "smeared out" over a probability area. This has been tested in practice. Sometimes an electron will jump through an insulator, because there is a small probability that it is on the other side. A ball will not tunnel through a wall however, because the probability of all the atoms being on the other side of the wall is so exceedingly low. It is not because the observer does not believe that it is possible; it is pure math.

So there is our first lesson: Contrary to wild-eyed New Age permutations of quantum physics, we do not create the world by observing it. If a tree falls in the forest and there is no one to hear, it still makes a sound. Consequently, neither can we change the world by willing it, by closing our eyes to reality and hoping that it will go away.

***

Schroedinger did not just dabble in quantum physics. (He did dabble so well in it that his equation became essential to the later understanding of this field.) He also was a philosopher, as you may guess from him doing thought experiments on cats. He wrote a small book called "What is life?", a very condensed version of which is available on the Net. I have not read the original, but I was taken aback by the conclusion in the condensed version. I myself have written about the strangeness that it is to be human: The atoms in our body follow the normal laws of physics. There are no special laws known for atoms in living matter: They are just like any other atoms. In fact, a large number of them enter or leave the system known as "body" every day. Before the body came into being, they were all elsewhere; afterwards, they dissipate. Just normal atoms. Yet I am in control of this enormously complex systems of billions and billions of atoms. When I want to raise my hand, I do so, even though the atoms just obey their normal laws of physics. Schroedinger seems to conclude that I am the person who controls the behavior of atoms, therefore, I am God.

Well, I certainly am not. For one thing, I don't always control my body. Sometimes I get a running nose, or running guts, or constipation, or cold sores. And willing them away is not all that efficient. (Though it may help slightly with the constipation.) Clearly then my control over the world is not godlike, even for the tiny fleck of matter that is assigned to me.

I also notice that the range of things I can do with the body seems somewhat pre-defined. I can run, but I cannot fly. Yes, I know this has been taken care of with balloons, airplanes, rockets etc. But these are things we make and use through our bodies. We cannot just decide for the car to turn right, and the wheels will start turning on their own. We do this with the body, though. In fact, without a lengthy education you won't know what muscles are involved in what actions. You just will it to happen, and it does. Within pre-defined bounds.

My proposition is that, metaphysically speaking, you are not (and have not) a god, but a spirit. A lesser being but of the same substance, except spirit is not a substance. But this is metaphysics ... it comes after physics and is different from it. Where is the connection? Somewhere in our brain is a link between the visible and invisible world, between hardware and software. We know how to selectively disable one of them, but we don't know they work in the first place. It works, but it defies logic. Just like Schroedinger's cat. Just like quantum physics.

***

There are billions of cells in the brain, though some seem to have rather specialized functions. There are cells in the back of the head that only recognize certain patterns in what we see. Even if you are born blind, those cells will never do anything else and more useful for you. That's all they are there for. But some seem to be more directly involved in consciousness and decision-making.

Each cell is typically touching 1000-10000 other cells, thanks to a vaguely tree-like set of nerve fibers, dendrites, and single long fibers, axons. The points where they meet are called a synapse. Along the fiber, a signal travels electrochemically, as a wandering difference in electric potential. At the synapse, curiously, it changes nature completely for a moment, and becomes purely chemical. An amount of neurotransmitter is released into the very small fluid-filled gap that separates and at the same time joins the two cells. Depending on the amount of neurotransmitters, and the sensibility of the receiving end, a signal may or may not cross over in its original strength.

Lots of people have independently of one another imagined that this brief transition to a more chaotic state is the place where the quantum world meets the classical world. That for a brief moment, the signal travels through a quantum state ... where it both is and is not, until resolved by an invisible observer.

While I am one of those who have independently thought of this idea, I am still not convinced that it is correct. The more notorious New Age thinkers I see implying the same, the more skeptical I become.

I suspect that even though we seem to experience a spiritual reality as well as the physical, we will not know for sure until we open the box. Until we wake up one day and find out that we are dead, as they say. Or, in the case that we discover anything at all, it would be that we are not just alive, but out of the box. I'm not in a hurry to check it out, though. I kind of like it in here.