Flow: Nature's Patterns: A Tapestry in Three Parts
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From the swirl of a wisp of smoke to eddies in rivers, and the huge persistent storm system that is the Great Spot on Jupiter, we see similar forms and patterns wherever there is flow - whether the movement of wind, water, sand, or flocks of birds. It is the complex dynamics of flow that structures our atmosphere, land, and oceans.
Part of a trilogy of books exploring the science of patterns in nature by acclaimed science writer Philip Ball, this volume explores the elusive rules that govern flow - the science of chaotic behavior.
Lord Kelvin ﬁrst proposed in the nineteenth century that vortex walls could develop these wavy instabilities. Vatistas thinks that, since the rotating clouds of gas and dust in spiral galaxies are comparable to vortices in ﬂuids, the existence of these many-lobed vortex cores might explain why some 46 j NATURE’S PATTERNS: FLOW Fig. 2.17: Vortices in a spinning tub of ﬂuid may be roughly polygonal, with several ‘corners’. (Photos: Georgios Vatistas, Concordia University.) PATTERNS DOWNSTREAM
see switches between stone holes, islands, stripes, and polygons as these factors change (Fig. 3.19). The patterns are highly reminiscent of the animal markings examined in Book I. And, curiously, polygonal networks seem to follow rules for polygon-wall junctions analogous to those found Fig. 3.19: The model of ‘sorted ground’ devised by Kessler and Werner generates a wide range of stone patterns. In the top image, the ratio of stones to soil decreases from left to right; in the middle, the
objects in your vision at once, but may have to turn your head from one to the other once you get closer). When this divergence exceeds the critical angle of 1208, then the group chooses to head for one target or the other. In any event, the main conclusion is that the model shows how a group of interacting individuals can respond to the information gathered by just a few, and can reach a collective decision about how to use that information even without any sophisticated means of assessing and
schooling, of ﬁsh, see ﬁsh, schooling Schreckenberg, Michael 155, 158 second law of thermodynamics 94 segregation, of grains 91–101, 110–113 self-organized criticality 101–110 self-propelled particle model 131–133, 139 Shapiro, Ascher 37, 38 shear instability 34 Shinbrot, Troy 118 Smithson, Robert 17 social insects 125 solar ﬂares 105 solar granules 75, 76 Sommeria, Joel 43 spinodal decomposition 101 splashes 21–25 Stanley, Gene 93 Starry Night (Van Gogh) 176–178 Stavans, Joel 100, 101 Stokes,
probably the most memorable of Edgerton’s images was copied straight from Worthington: he ﬁlmed milk droplets as they splash into a smooth liquid surface. Edgerton’s drop is tidier, somehow more regular and orderly, a true marvel of natural pattern (Fig. 2.2a): each prong of the crown is more or less equidistant from its neighbours, and each of them disgorges a single spherical globule.* This is the secret structure of rainfall, reproduced countless times as raindrops fall into ponds and puddles.