Emergent Phenomena

A relatively new concept that would be very difficult to study if not for simulation is the idea of emergent phenomena. In fact, this idea is very important to the creators of StarLogo, so many of the development of StarLogo went hand-in-hand with building simulations where emergent phenomena appear.

So, what is it? The idea is that if you have a bunch of entities (ants, people, cars, atoms, whatever) interacting according to some simple rules (after all, how smart is an ant or an atom), you will sometimes see some interesting global effects that you wouldn't expect just by looking at the simple rules. In other words, some global phenomenon emerges from the interactions of many entities following simple rules.

We can only get so far with an abstract description like this, so the goal of today's lab is to see some examples of emergent phenomena. Go to

http://education.mit.edu/starlogo/

• Termites. You can load this from Sample Projects / Biology / termites.slogo from the StarLogo folder. It's not a really fast simulation, so you may have to watch it for several minutes before the pattern starts to emerge.
• Firefly. You can load this from Sample Projects / Biology / firefly.slogo from the StarLogo folder. This is a reasonably quick simulation, so try it with different numbers of fireflies and the other sliders.
• Bees. Don't run this one, because it is way too slow. However, it's interesting to read about.
• DLA. You can load this from Sample Projects / Physics / dla.slogo from the StarLogo folder. This simulation is intermediate in speed, so you might have time to try 2-3 scenarios.
• Traffic. You can load this from Sample Projects / Social Systems / traffic.slogo from the StarLogo folder. The traffic jams can take a while to develop, so you'll probably only have time for 1-2 of these.

These phenomena are real. These aren't just toy simulations. Scientists are really studying how phenomena like traffic jams and fireflies using simulations of this sort.

The goal today is primarily to look at these examples to gain some intuition about what is meant by "emergent phenomena." Just have fun with it.

Why is this topic in CS199? Because without simulation, it would be incredibly hard to investigate emergent phenomena. No one has the time and industry to do the zillions of calculations for the individual entities that would be necessary to see the phenomena emerge. So, this is really about motivation: why simulation is such a necessary part of modern understanding of the world. Prior to the availability of the computer, scientists, social scientists, engineers and researchers of all sorts had to do their work with simple equations. Now, thanks to the computer, they can investigate all sorts of things.