The infinite monkey theory states that a monkey (or a group of monkeys, is the way I heard it) typing on a typewriter for an infinite amount of time will type out any specific piece of literature at some time. Some people have used this as a metaphor of evolution but I want to say that it is not even close to evolution. A monkey or a computer generating random letters (which is equivalent and not so hard on the monkey) is generating independent events, by the very definition of random. However, you’ll have a hard time (it may be impossible) finding a sequence of events in the universe that are independent. Some things are more independent than others; but every interaction changes the things that interact so the next interaction depends on the previous one. We tend to ignore the dependency if it is small but this is a convenience of science or mathematics to make the computations easier. I submit that random change by itself would be a pretty uninteresting thing and it isn’t obvious that random change would be much more interesting than no change at all.
As another example, consider the random walk. It is described as a drunken person who needs to hold on to lamp post to steady him self. (It’s always a guy, never a drunk co-ed from some party school. Oh, the indignity of it all!) He wants to go home but is too incapacitated to see where he’s going so he takes his steps at random. This turns into a stagger where the steps go away from and back towards lamppost but over time he moves away from the post but probably never gets home without some help.. We can accomplish the same thing (and eliminate the inherent political incorrectness) by replacing the drunk with a sober person (or even a robot) who decides which direction to move by tossing a dice. This notion of random, independent events leads to a universe where random things happen. Clearly that is not the universe we live in. There appears to be something “driving” the universe towards some place or something. It clearly is not random! So what is going on here?
As we discussed before, the way things change is through interactions and these interactions constitute a force. In the elementary particle world, these forces wither attract or repel the other particle. Nothing more and nothing less is going on here. What a simple way to put a universe together. But how on earth could such a simple set of rules create the complicated universe we see around us? Let’s see if we can look into this a little more. First off, let’s note that no one will ever be sure how it came to be that the universe was created. Volumes upon volumes of writing and speeches have been made trying to decide what I believe is a truly un-decidable issue. (It’s one of the differences between science and religion that I’ll discuss in a later post.) I have come up with four things that exist in the universe that have lead to it evolve from its initial state to the current state we’re in:
1. The universe is made up of individual objects. It is not an amorphous blob of protoplasm. These individual objects range from sub-atomic particles, atoms, molecules, rocks, elements, gases, viruses, bacterium, plants and animals - all the way through humans. This is not to imply that humans are the reason the universe was created but we are one of the most complex objects the universe has created to date. We’re all inter-related and inter-connected and dependent on other objects for existence. You’ll also notice a hierarchy within objects – we have sub-atomic particles that make up atoms which make up molecules, etc. One of the most fascinating things about this hierarchy is how the individual-ness of objects get hidden as they come together to make a more complex object. For example, when you are looking at a piece of gold, you do not need to know how the individual gold atoms join into a crystal structure to make a piece of gold large enough for you to see. You need not consider that the gold atoms are made up of neutrons, protons and electrons. We even see this sort of behavior when people get together ad act as a group. I believe this phenomenon is related the item 3, below, and I’ll deal with this phenomenon in a later post.
2. Objects change thorough an interaction and these interactions are the embodiment of forces. In the case of physics, there are four basic forces that make up all forces known to us – weak nuclear force, strong nuclear force, electro-magnetic force and gravity. When an electron and proton (which are opposite charges) exchange a proton, they are attracted to each other. That attraction is the electro-magnetic force.
3. Forces lead to attraction or repulsion and define the notion of entropy. Hence interactions are not just random events, but the forces of nature (and their corresponding biological and cultural forces) in some sense guide the direction of interactions. It is this sense of guiding that we’ll spend some time discussing. I find it fascinating that there are four basic forces of nature and three of them are attractive and only one of them is repulsive. (Actually, only part of one of the four is repulsive – the like charges repel portion of the electro-magnetic force,) Having more attraction than repulsion makes it seem more likely that things arrange themselves into groups of objects. The forces of nature are also hierarchical in their range. Gravity seems to apply no matter how far apart two objects are as does the electro-magnetic force. However, the strong nuclear force operates in the range of nano-meters and the weak-nuclear force on the order of 1/100 of a nano- meter. It follows that there should be a hierarchy in the way objects gather together and the whole is more than the sum of the parts. (More on this in a later post.) Forces and interactions also give us the ability to define "progress", which we’ll also discuss more later on.
4. The outcome of an interaction is a change in the state of an object which directly relates to the next interaction. This is the notion of feedback. A lot of work has been done for interactions that are independent. For example, when you are trying to calculate probabilities of heads coming up when you flip a coin, one of the assumptions you make is that the result from one coin flip does not affect the next coin flip. A sI mentioned above, there is no such thing as complete independence, one coin flip changes the coin and hence the next flip is different from the next. However, the change is very small and seems like it could be ignored for most of these calculations. Therefore, independence is merely one side of the feedback continuum. On one end is complete independence and on the other is complete dependency. Nothing is ever one of these extremes, but everything is somewhere in between.
Independent ------------------------------------------àDependent
A system set up with these four characteristics evolves. Evolution has gotten a bad rap in religious fields so I want to take a few moments to address evolution. In the current press, evolution is identified with biological evolution and, specifically, that evolution is the process invoked that allowed apes to evolve into humans. First off, I want to keep in the mode of Dennett and make sure that every time we refer to the process of evolution we remind ourselves that it is a forward-looking process and it has no pre-ordained destination. When you say humans descended from apes it leads one to the conclusion that there was a pathway the apes followed in becoming human. That is not at all what we mean by evolution! Apes evolved and humans are one of the things along the path. More than likely, there were other paths (dead ends) that apes took during their evolutionary journey. As Dennett points out, evolution does not know where it is going. The evolution we describe above is just a process and can be applied to many different systems. In this way of thinking, evolution is a Theory along the lines of the Theory of Gravity and the Theory of Quantum Mechanics. It is not just an idea with no facts to support it. It is supported by an incredible body of evidence. (See the April 2007 National Geographic for a detailed report on the evidence supporting biological evolution.) Evolution is also supported in non-biological studies – physical and cultural. In short, to deny evolution is to participate in what I call willful ignorance. [Ignorance is a part of life. There are many more things we don’t know than we know. However, to purposefully ignore factual evidence is something that should be outlawed. It leads to a number of corollaries but the biggest problem I have with willful ignorance is that if you can ignore some facts because they do not fit with what you want the world to be, then you can be lead to ignore other facts. In short, you can more easily taken advantage of by those who can use your willful ignorance against you. I hope to get back to willful ignorance at a later date.]
I want to concentrate on the idea that evolution is not just a biological or social idea, but the very fabric of the universe. Biological evolution is a special case. Now, as we’ll discuss later on, science cannot explain how evolution lead to life on the earth. That doesn’t mean evolution is not a valid theory, it just means there is a lot to discover about the evolutionary process. Science has not fully explained how human life evolved from lower primates. That does not mean evolution is “wrong,” but it certainly indicates a lot more work is necessary in biological evolution. A better question to ask the scientists, “How did life come to be?” As hard as it might be to explain how primates evolved into humans, we are much further away from a reasonable explanation of how life came into existence. There have been some early experiments where a primordial broth was put into a flask and electrical sparks shot into it. These experiments showed that some complex molecules could be created from simpler compounds but we’re nowhere close to figuring out the chain of events that lead to the creation of RNA/DNA and the associated life that came into being.
Is it true that simple rules can lead to complex behavior? The simple answer is yes. There has been increased interest in the study of complexity in recent years but I believe the first hint of simple rules leading to a complex system was done by the German mathematician Georg Cantor in late 1800s. He came up with a set of simple rules as follows:
1. Start with an inch long line segment.
a. 0 .-------------------------------------.1
2. Remove all the points between 1/3 and 2/3.
a. 0.--------.1/3 2/3.-----------.1
b. Now we have two intervals, each 1/3 of an inch long so the total length of the intervals (when you add the segment lengths together) is 2/3rd.
3. Next remove two line segments, between 1/9th and 2/9th and 7/9th and 8/9th.
a. 0.--.1/9 2/9.---.1/3 2/3.---.7/9 8/9.---.1
b. Now we have four segments, each 1/9th of an inch long so the total length of intervals is 4/9th.
Continue this process forever, [Cantor did a lot of work defining what is meant by infinity which, while fascinating to mathematicians, is a little impenetrable. David Foster Wallace has written a magnificent little book on infinity, called “Everything and More,” which goes into enough detail to help you understand how truly amazing and difficult it is to get your arms around infinity. ] When you are done you have what is now known as the Cantor Set. We had a very simple rule above,” remove the middle third from the line segment.” What’s left has some remarkable properties:
· The “total” length of the line segment is zero.
a. We started with a line of length one inch. At the first step we removed a segment of length 1/3, at the second step we removed a segment of length 1/9, etc. If you add up the length of the removed segments, it adds up to 1 inch. So what’s left has length zero. However, there are still an infinite number of points (all of the end points of the intervals we removed) like 0, 1/9, 2/9, 1/3. etc.
· Between any two points in this set there are an infinite number of points but there is also a non-zero “gap” between any two points. The mathematical term is that the Cantor set is totally disconnected. No point is “close” to any other point.
Wolfram in his book, "A New Kind of Science," has an enormous number of examples of simple rules leading to complex behavior.
Not much work was done in trying to understand complex behavior in this way (simple rules leading to complex behavior) until the 20th century. Some of early understanding was done by Edward Lorenz, who was trying to understand why his weather model behaved so strangely when he changed some of the inputs. This lead to a whole new branch of mathematics now referred to as chaos theory. Benoit Mandlebrot did a lot of the work in chaos theory, applying chaos theory to a number of problems, most recently Economics in his book - The (Mis)Behavior of Markets: A Fractal View of Risk, Ruin, and Reward . Stephen Wolfram has opened up a new way of analysis in his book, “A New Kind of Science.” He explores (in over a thousand pages) in great detail how simple rules for interaction can lead to complex behavior. We’re now seeing this work spreading to other areas of study. A recent National Geographic article on swarming talks about ants and ant colonies. “Ants aren’t smart. Ant colonies are” says Deborah M. Gordon in this article. The intelligence of the colony comes from “the collective abilities of such animals – none of which grasps the bug picture.” When handling the problem of job allocation, “Ants communicate by touch and smell. When one ant bumps into another, it sniffs with its antennae to find out if the other belongs to the same nest and where it has been working.” Communication is just another way of interaction so by “dumb” individuals interacting with each other, the entire colony can become intelligent. This also looks like a good model to describe humans. We’re made up of cells, none of which are smart. Even the brain cells are not smart as individuals. It is ONLY when they interact and communicate that intelligence comes into existence. So not only can simple rules for interactions and communications lead to complex behavior, they also lead to intelligence.
The power of these evolutionary systems is what Dennett calls “The Principle of Accumulated Design.” I prefer to talk about the idea that things can only get so bad but there is no limit to how good things can get. A few examples are in order:
Example 1: Microprocessors
You might not believe it (depending on your age) but there was a time when appliances and phone did not have microprocessors. In fact, microprocessors didn’t exist at all! The first microprocessors were slow as molasses compared to today’s computers but, amazingly, the technology behind microprocessors has remained steady over the past 50 years. What engineers have been able to do is continually improve the process by which the chips are made. In the 1960s, Gordon Moore (co-founder of Intel) made the observation that microprocessor speeds doubled about every 2 years. Considering how poor most predictions go, this one has been quite accurate. The reason it is amazing that the doubling has remained at 2 years is that to double the speed of a processor takes on the order of 4 times as much work. This is a great example of how engineers can take advances two years ago and use them to advance the technology at a an ever increasing pace.
Example 2: Frontal Lobe
I just finished a book, “Stumbling upon Happiness” by Daniel Gilbert. It has a lot of things in common with the Physics of Hope, from a psychological point of view. Some psychological experiments show that the frontal lobe of the brain is involved in thinking about the future. People who have had their frontal lobes damaged cannot think about the future. Gilbert goes into some detail on the ability to think about the future and how it developed. I’ll let you read his book for the details but one of the things I took umbrage to in his writing was that it made it appear as if evolution “caused” the frontal lobe to develop. As mentioned above, evolution is not forward thinking and does not cause anything to happen. Things happen and interact and they lead to new things that are useful and increase survivability.
I’ll take some time in the next post to go after the notion of progress, since it seems to flow from evolution. However, progress will mean different things at different levels of the evolutionary chain. What is progress for the atomic world is definitely not what applies to the biological or cultural world. Just be clear, while there appears to be a direction to evolution, it is an illusion, just like time is an illusion. There are forces directing the evolutionary process, but while the forces shape the outcome, the outcome is not pre-ordained at all – remember the non-computability of a feedback system.
No comments:
Post a Comment