Self-Organization

Sometimes - espesially at bad times - it seems that science tells us that things are steadily falling apart. According to well proven results (in science such are a.k.a "laws of nature") from thermodynamics, disorder increases with time in any closed system. Happily enough, we are often enjoying the benefits of increasing, or at least maintained order in many of the open systems that we are a part of. What have science to tell about this? Do we have to resort to religion to display our gratitude over the splendid order of Nature?

I don't have anything in particular against religion, but it seems to me that the tendency things have to organize themselves around the exploitation of some resource is too strong for any God to control. Not in the most basic setting perhaps. In an ideal gas with particles (monoatomic molecules) only interacting through contact forces when they bounce into each other, disorder is the rule (in a neatly described kind of way). Even when heating and cooling is added it only produces a smooth, static and easily predictable (using some calculus) temperature gradient through the gas.

Now, add a second force; gravity: any "blob" or "bubble" in the gas now has the particle contact forces still acting on its surface, plus gravity working in all of its volume. We have hence created scale dependence, making a blob of gas (large volume to surface) doing different things than a single molecule (low volume to surface i.e. gravity negligeble), depending on its size and the averages over the molecules in it.

With heating from the top, nothing new is really achieved this way. But, with heating from the side, a nice little heat engine called natural convection cell is created, which helps the thermodynamic molecular diffusion to extract energy from the heater(-cooler pair), thereby keeping itself going! However interesting this is, the thing that really get me started on this is of course heating from below. Enough heating from below actually produces a tiny ecosystem of small convection cells. Looking at a video showing the development of these so called Benard cells seem to show that these cells spontaneously fall apart when too big, and promptly are put out of business by its greedy neigbors when too small. They have metabolism - are extracting energy from the area they are sitting on and dumping spill heat to the cool surface above them. They move. You might even say that they have some form of generation change looking at the large cells that fall apart in the video. Very life-like. Observe that the stable hexagonal pattern occurs only at specific levels of heating. For mild heating, long convection rolls result - for stronger heating, a rich turbulent specrum of vortices is produced.

Very life-like indeed, at least for just being a bunch of lose dead particles heated from blow!




The picture and video where taken from here, where more examples are available. See also some of these posts in my Furl-archive.