I did not intend to dive into the questions of emergence and intelligence so early in this blog, but the content of my last post made this the natural step forward in the conversation.
This will be a brief introduction. On the one hand, the topic of emergence fills library shelves full of books; on the other, the sciences seem to ignore the topic of emergence all together. This is odd because if you look at the natural world around you, almost everything you see is an example of an emergent phenomenon.
Sometimes, the hardest things to see are those that are right in front us. The phenomenon of emergence is so ubiquitous in the natural world, it’s almost like the water a fish swims in; we so take it for granted, we cease to notice it. Emergence is not so much a new subject to learn; rather it’s a new way of looking at the world.
Emergence is what happens when many simple things come together to form a collection, that then takes on properties, or behaves in ways, that none of its simpler constituent elements ever possessed or displayed.
One good indicator that you are dealing with an emergent system is that you find yourself remarking that the whole is greater than the sum of the parts. If you’re dealing with systems that can heal themselves; there’s a good chance you’re looking at emergence. Another indication is if, in describing a system’s operation, you find that you’re unable to localize it. For example, the fact that the question, “where is the Internet?” has no simple answer establishes the Internet as an emergent phenomenon.
Here is the Wikipedia entry for Emergence; it is as good a short introduction to the topic as I think you can find.
An alternate to reading something as technical as a Wikipedia page is this short YouTube video, which does a reasonable job of explaining emergence, "Emergence – How Stupid Things Become Smart Together".
To quote from the Wikipedia page: “The ability to reduce everything to simple fundamental laws does not imply the ability to start from those laws and reconstruct the universe. The constructionist hypothesis breaks down when confronted with the twin difficulties of scale and complexity. At each level of complexity entirely new properties appear. Psychology is not applied biology, nor is biology applied chemistry. We can now see that the whole becomes not merely more, but very different from the sum of its parts (Anderson 1972).”
The most important distinction, when it comes to emergent phenomena, is the distinction between weak and strong behaviors. Weak behaviors are those that can be predicted a priori starting with the knowledge of how the individual elements of an emergent system interact with each other. Strong behaviors are those which cannot be predicted starting from first principles alone. Note that the underlined sentence in the above quote is a specific reference to strong emergent behavior.
And in regards to physics, it should be noted that the laws of thermodynamics apply not to the behaviors of individual particles, but to the resultant emergent group behavior of systems. This is why the laws of thermodynamics apply in both the classical and quantum worlds; since these laws are not about how the individual particles in a system behave, but rather how they interact as a whole.
In a past post, I suggested the concept of choice should be added as a new law of thermodynamics to the existing four laws. In this case, choice joins the ranks as an emergent property; one independent of the underlying physics of the individual elements comprising a system. That is, the phenomenon of choice, like other thermodynamic properties, should show up as a property in both classical and quantum mechanical systems.
Returning to the classifications of weak and strong emergence…
A classic example of weak emergent behavior is classical thermodynamics. Quantities such as entropy, temperature, pressure, and etc., are not properties of the individual particles making up a thermodynamic system; rather, they are properties of the system as a whole. But in the case of classical thermodynamics, these properties are predictable starting from the basic laws of physics that govern the individual particles making up the complete thermodynamic system.
But going forward , what will be most important for this blog, is what is referred to as strong emergent behavior; that is, the observation that there are things in nature that are consistent with, but not predictable from, the basic laws of physics. In other words, it is possible for a physical system to display behaviors that are not a priori predictable from first principles.
A good example of a strong emergent system would be Conway’s "Game of Life".
In between these two extremes, there are countless examples of emergent systems in our day-to-day lives; for example, the ant colony. Whether an ant colony falls into the strictly weak or strong categories is something that still gets debated. But there is no doubt that the colony behaves in ways that no individual ant ever could. Also note that the colony’s function does not depend on the life of a single ant. As long as the queen can produce new workers, drones and soldiers, that colony can survive for decades.
But the appearance of strong emergent behavior has, like the Anthropic Principle and the Problem of Fine Tuning, become yet another elephant in the room, one that everyone knows is there, but no one knows what to do with. So the various scientific disciplines generally just walk quietly around it.
At least one prominent physicist/mathematician, Stefan Wolfram, wrote a book a while back, “A New Kind of Science”, in which he argues for the recognition of strong emergent behavior as a legitimate field of inquiry. Accepting this thesis would represent a rather radical shift in how science is conceived; it’s what Thomas Kuhn would consider a paradigm shift.
In closing, reductionism, materialism, and constructability are concepts which occur in concert with emergence. Diving deeper into emergence by contrasting these concepts will be a topic for a future post.
No comments:
Post a Comment