Funny you should mention this. I'm fairly certain your definition is incorrect for the physical sciences:
Maybe so, but my definition fits well into the computer sciences.
I will respond to the thread you started about emergence, later tonight, after I study the issue a bit more.
As far as programming is concerned, it is really mathematics. In mathematics, everything is reductive, so there is no emergence.
I think the behavior is reducible to the original programming.
Well, yes, strictly speaking, emergent behavior can be traced back to what is going on in the programming.
My usage of the term "Emergent Behavior" is admittedly subjective, referring to the programmer's judgment of what he or she was expecting or not.
However, it is clear that "complex behavior", no doubt, can be the result of simple coding. A programmer working on a simplified natural selection simulator may not have programmed anything specifically for introducing parasite-like behavior into it. But, if something that appears to be parasite-like behavior emerges in some of the virtual entities, anyway, that would be emergent behavior. And could be very complex at that.
In a similar way, the rules for natural selection, in the real world, are very simple:
1. Reproduce. Reproduction is not always perfect. Sometimes mutations occur, for whatever various reasons.
2. Some of the entities from that reproduction die off for whatever various reasons.
3. Those entities that happen to survive, can obviously pass their traits to the next generation, if they were to reproduce as well.
4. Repeat.
And yet, from such a simple algorithm, complex structures and behavior can emerge: For example: structures that only appear to be irreducibly complex, if their cumulative adaptations are not yet worked out. Another example: parasite-like behavior.
But, guess what:
What makes something seem "irreducibly complex" or "parasite-like" is equally subjective as my definition of "emergent behavior". It all depends on the judgment of someone examining the environment.
Given the wide variety of materials and forces, etc. we have on the planet, it seems ever more likely the above algorithm could have developed without a programmer.
Some of you may want to read Dawkins'
The Selfish Gene for more information on this.
With regard to the computer simulation, we have evidence, apart from the computer simulation itself, of the existence of the programmer. If this is as analogous as the OP suggests, then if there is a real-world designer there should be independent evidence, aside from the running of the real world, of this designer's existence.
So the analogy shows this lack of designer, no?
Yes, this is also a valid point. If we are the product of an intelligent designer, then where is the evidence of this designer?
When we study ancient tools, carved from rock, we often have other evidence of the entities that carved the rocks.: Bones, left-over evidence of habitat, etc.
We do not have any such evidence for the designer of our lives. Therefore, given that evolution is an adequate algorithm for explaining all of life, it seems scientifically more reasonable not to rely on their being an intelligent designer: Such a concept will not be helpful in discovering anything about the world.
Complex behavior comes from complex coding. In the case of evolution, coding so complex, that, I guess Tai Chi is closer to being right than I thought.
Whoa, not necessarily! Check out Conway's "Game of Life" (not to be confused with the board game of the same name. This is something different), for example:
http://en.wikipedia.org/wiki/Conway's_game_of_life
