Fall of 1973 found me a 16 year old freshman at Guilford College in Greensboro, NC. While I was a science and math geek in high school and I had plans to major in Biology and go to medical school. During orientation, I signed up for classes and got my small stack of computer cards that had my classes listed on them. I thought I had signed up for Introduction to Biology, Freshman English, Being Human in the 20th Century and Calculus. As I looked at the cards, I noticed that instead of Calculus (MATH 101) I had a class called Foundations of Mathematics (MATH 201) and went to the head of the mathematics department to tell him of the error. J.R. Boyd was like no Texan I had ever known. He was short, bald, never wore boots and smoked unfiltered Camel cigarettes all the time. He was also one of the few non-PhDs at Guilford and had arrived in 1962 to impart mathematical knowledge in a way called the “Moore method.” This is a Socratic teaching style made famous in mathematics by R.L. Moore who taught at the University of Texas. Mr. Boyd told me not to worry about the mistake and he thought MATH 201would be a good fit for me. Only later would I find out that it was Mr. Boyd who had identified me as a math major before I even hit the campus and the “mistaken” MATH 201 class was no mistake at all, He wanted me in that class. MATH 201 was one of the pivotal moments in my academic life and my association with JR Boyd continued until his death, 25 years or so after I was graduated. At a later orientation function I met Dr Rex Adelberger who was new to the school and taking over as the head of (well, actually the only person in) the Physics Department. Between Mr. Boyd and Rex, I forgot about the Biology major, cured myself of medical school and became a math and physics major and lifelong geek. I had no idea that the interactions with JR and Rex would have such a profound effect on my life. It changed so many things about how I thought and put me on a completely different path than what I could have ever imagined.
I bet your could sit down and write your own list of people who have had a great impact on you. These interactions were not something you tried to make happen, but happen they did. Humans interact all the time and if you spent a little time thinking about it you’d figure out that interactions are the most important part of your life. I spoke with someone who had the opportunity to go to the Boca Grande, Florida with her family for the week between Christmas and New Years. Boca Grande is a wonderful island in Southwestern Florida with gorgeous winter weather. What did they think about the trip? They weren’t excited because they didn’t want to spend 5 days with their “dysfunctional” family. It wasn’t the location but the people they were going to interact with that made the biggest impression on them. That’s true for pretty much all of us. Interacting with people can change us. That’s the basis for this chapter; looking at how things change. Here is the only law of the universe that you need to know as everything else derives from it:
Universal Rule of Change (U-ROC):
The only way anything changes is through an interaction.
An interaction is the exchange of something between two (or more) objects.
If the universe was made up of only one thing, there would be no interactions, nothing would ever change and there wouldn’t be a universe. If the things that make up the universe did not interact, there would be no universe. In fact, you can describe the universe is an entity whose sole function is to have things interact. It is through interactions that the entire complicated world we live in today came to exist. It might be hard, initially, to believe that the universe, which seems so complicated, can be expressed in this one simple rule.
This idea is not new and has been expressed by other people throughout the years. In 1714, Gottfried Wilhelm von Liebniz, in his Monadology, said that relation gave rise to substance, not, as Newton had it, the other way around. Because we came to the universe after a lot of the hierarchy had been formed, it appeared that the hierarchy gave rise to the interactions. Scientists spent years peeling back the layers of the universe’s hierarchy to understand how things were put together. Not nearly as much effort was put into trying to figure out how the hierarchy was created. The clearest explanation for this imbalance is that reductionism is much simpler to do so scientist went after problems they could solve. Science was able to find a lot of patterns in the hierarchy, enough to allow them to predict things that were previously unpredictable. Eclipses and the path of projectiles were two early applications of science and predicting the future better than someone else grants a competitive advantage to the predictor. Hence science went down the path of reductionism to figure out how things worked to allow more and better predictions.
We’re not saying that all interactions are equal. Interactions differ depending on where you are in the hierarchy of the universe. At the lowest organizational levels of the universe – elementary particles – the interactions consist of the exchange of a single particle. Electrons interact with other electrons by exchanging a photon. This is the simplest type of interaction in the universe. As you move up the hierarchical levels, the interactions become more complex. Living cells interact by exchanging molecules. Organic molecules form the basis of all living things. Compounds like DNA, RNA and ATP form the basis of all cellular interactions. More complex animals, like dogs, can interact through making sounds. Humans, currently at the top of the organizational hierarchy list, have an almost unlimited number of ways to interact. Our senses form a high level means of interacting. What we call hearing is a series of interactions between the air, the bones in our ear and electrical impulses sent to the brain. We’ve developed forms of interaction based on speech so that talking has nuances to it – irony, parody and sarcasms – which makes human speech a complex and powerful interaction. U-ROC applies at all levels, the only thing that changes are the types of interactions.
Is it “fair” that the universality of U-ROC depends on changing the definition of interaction, based the level of the hierarchy? To some, it seems that there should be one definition of an interaction. In that view, the interactions of the electrons are so different from human interaction that they should be considered entirely different things. Fair enough but consider that it is the universe itself that builds up the hierarchy, which introduces new interactions. With an interaction defined as simply an exchange of something we take advantage of the hierarchy to define what that something actually is. The development of new interactions is at the heart of the universe’s hierarchy and is why the first chapter started with hierarchy. Hierarchy hides the lower levels of interaction which I believes give us free reign to consider the new “higher level” interactions as equivalent to the lower level interactions. It is simply amazing that the universe would take so simple a concept to build up the universe so it makes sense to ask if it can be done this way. We have a ways to go before we can make that claim but first let’s look at how the U-ROC maps onto one of the basic laws of physics.
Since we were mentioning Newton a little while ago, let’s look at Sir Isaac Newton’s laws of motion and how they fit with the universal rule of change:
1. An object at rest remains at rest unless acted upon by a force.
2. An object experiencing a force experiences acceleration.
3. For every action there is an equal and opposite reaction.
Let’s see how this maps into the U-ROC. In physics the terms force and interaction are different words for the same idea.
1. The first law says if an object does not interact, nothing changes – the object remains at rest.
2. The second law says that an interaction between a moving object and something else leads to an acceleration (speeding up, slowing down or changing direction are the three ways a moving body can accelerate) which is a change.
3. The third law says that when two things interact, they are both affected by the interaction, a byproduct of the exchange of something.
Newton’s three laws are just a special case of the U-ROC for objects that move. When it comes to moving objects, the only way an object changes speed or direction is if it interacts and that interaction affects the objects that interact.
In the previous chapter, I discussed how things are organized hierarchically and the fact that moving through different levels of the hierarchy introduces additional ways to interact. Let’s spend a little time discussing the relationship between hierarchy and interactions; starting at the lowest levels – elementary particles.
Electrons are very simple. They have only five things you can say about them:
1. Charge (negative 1)
2. Spin (1/2 - don’t ask one half of what - spin is a scientific term associated with angular momentum which, to us humans feels like spinning)
3. Mass (similar to weight for us humans)
4. Location (where is it)
5. Velocity (where it is going)
The limited organization leads to only one way for elementary particles to interact. Not only do they have no feelings but they don’t have a structure like a rock or even liquid or gaseous water. Lack of structure limits them to interactions that consist of the exchange of a single particle. Electrons (and other particles that have a charge) interact by exchanging photons. In fact, at this quantum level, there are only three ways for elementary particles to interact. These are so fundamental they are described as the three fundamental forces. (Remember that force is the physics term for exchanging particles which is the same as interacting.)
1. Electromagnetic – All charged particles interact through the exchange of photons.
2. Weak Nuclear Force – The exchange of W and Z particles account for the weak nuclear force. There are two types of W particles so a total of three particles are responsible for this force. This force is responsible for the nuclear decay which is, in turn, responsible for nuclear reactions.
3. Strong Nuclear Force – Neutrons and protons exchange gluons (8 different ones) for the strong nuclear force. This is the force that keeps the atomic nucleus together. Since all protons in the nucleus are positively charged and repel each, you can imagine that this is a very strong force (hence the name). It takes a lot of force to keep them in the nucleus.
Why is gravity not on this list? We’ll postpone that discussion but suffice it to say that while gravity is well understood at some levels, trying to unify our knowledge of gravity with our knowledge of how elementary particles interact has been a source of frustration. For now, I believe (as do some others) that the force of gravity does not derive from the interactions of particles (some scientists believe gravitons exist, but no one has ever provided experimental evidence of their existence). Gravity is an essential part of the story but we’ll not deal with it just yet.
We are ready to approach the question of how the U-ROC – things change through interaction – lead to the complex universe we see around us. The short answer is – we don’t know exactly how, but there are some ideas how this could happen and we’ll look into those now. First off, is there any reason to think that a simple set of rules for interaction between something like elementary particles could lead to anything approaching complexity? Yes. Stephen Wolfram’s “New Kind of Science” is an unwieldy, over 1,200 pages, tome that shows how simple rules of interaction can do just that. He starts with a type of program called cellular automata. The great thing about cell automata programs is that their results can be expressed visually so you can see what he’s talking about. In his initial work, a cell is a square that can be either black or white. He starts with a line of white squares with a single black square in the middle. He then studies how many sets of interactions (he calls them rules but the tell us how adjacent squares interact) can there be in this simple systems – black and white squares – and found there were exactly 256 sets of rules. Being a computer literate individual, Wolfram wrote a program to start with the initial configuration (one black and the rest white squares) and apply a specific set of rules. Since I can only interact with my immediate neighbors, each of his rules consists of 8 outcomes. As an example, rule 254 is as follows:
If you are a black square
If your two neighbors are black, remain black.
If your left neighbor is black and your right neighbor is white, remain black.
If your left neighbor is white and your right neighbor is black, remain black.
If your left neighbor is white and your right neighbor is white, remain black.
If you are a white square
If your two neighbors are black, turn black.
If your left neighbor is black and your right neighbor is white, turn black.
If your left neighbor is white and your right neighbor is black, turn black.
If your left neighbor is white and your right neighbor is white, remain white.
I have included the pictures of the rule and the results of 10 sets of interactions below.
I don’t want to underestimate the power of Wolfram’s work. Using a system that has only one descriptive element (black and white) and a simple set of interactions he generated highly complex systems. We previously discussed how simple elementary particles are - photons only have velocity and spin and electrons and protons add mass and charge but are still pretty simple. So we can imagine that elementary particles interacting in simple ways could lead to a complex set of outcomes. Now the number of particles in the universe is almost impossible to imagine. So if only a few black and white squares can lead to complex behavior, the insanely large number of particles interacting should have no problem generating even more complex behavior.
Can anything in the real world support the idea that a simple set of interactions can lead to a complex result? The clearest example comes from embryology. In humans, a single egg and sperm cell merge to form a single cell that then begins to divide. (This division makes up the interaction.) From a single cell, an entire human being is created in just 9 months. There is no over arching blueprint that governs the emergence of a human from a single egg. At every point, the local cell division determines what happens next. Now, as the cells divide and start to specialize, the interactions get more and more complex. But that is the nature of complex systems, as they grow and organize, they build up more levels of hierarchy that contain different interaction methods, which leads to more hierarchy and more interactions. All of this comes from a single cell with no “grand plan.”
I want to spend a little time discussing what it means for elementary particles to interact and look at one of the corollaries of that behavior. In reality, we really don’t understand elementary particle behavior because they are so different from things in our world. Trying to put elementary particle behavior into what is a called our classical world always fails, or leads to paradoxes. However, experimental data indicates that when two particles interact, the exchange another (different) particle. The elementary particle world is neatly divided into particles that “carry” the force (we called them out above when we talked about the three basic forces) and particles that interact using the force particles (electrons, protons, neutrinos, etc.) When two electrons interact via the electro-magnetic force, one electron emits a photon which is absorbed by the second electron and then the second photon emits a photon. As far as we know, there is no way to tell different photons apart so it makes no sense to ask if it is the same photon that is absorbed and emitted. When the second electron absorbs the photon, it adds energy and so is changed. When it emits the photon, it changes energy levels again and may change position in response to the emission. Since there’s not in the description of an electron, there’s not much change going on here. However, as we move up the level of hierarchy interactions will become much more complex and can lead to massive change. A tornado interacting with a house leads to a lot of change in short amount of time but a tornado is a long ways away (hierarchically speaking) from an electron.
Remember how most interactions lead to patterns and only a few lead to complex, random behavior. If you look around, you’ll see that reflected in the world around you. We have a lot of patterns in the universe and some complex behavior. The universe could have started differently, but you’d find that you need that stability in order to consolidate the change that comes from the random behavior. If everything was random, you could never get anything to “stand still” long enough to be anything other than chaos. If everything was a pattern, nothing new would come into being – things like living beings. The universe is built with just the right balance between chaos and patterns to allow the changes to solidify and then build new changes upon them. Daniel Dennett, in his book, Darwin’s Dangerous Idea, calls this “The Principle of Accumulated Design.” I prefer to describe it as you can always make something better. (It is interesting that you things can only get so bad. We’ll discuss this after we’ve had some time to explore entropy.) As the changes in the universe build up a new level of hierarchy, a stable pattern on interactions forms. From that stable level, new levels of hierarchy can develop, and so one and so on.
East coast white water enthusiasts have a term for this phenomenon, drop and pool. As you go down almost any white water river on the east coast, there are periods where the river runs fast and hard (drop) and periods where the waters deepens and slows (pool). The action is during the drop and the pool (the old saying, still waters run deep comes from this pooling) portion allows you to rest and sort things out for the next drop. While I don’t believe there is any direct connection between the process the river uses to form these drop and pool sections, I am amazed at how much the drop and pool has permeated the universe.
Let’s explore in more detail how this combination of complex interactions and patterns interactions are manifested in the real world.
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