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The dynamics of ant swarms share an uncanny similarity with the movement of various fluids (video above). Micah Streiff and his team from the Georgia Institute of Technology in Atlanta captured writhing groups of ants behaving just like liquids. You can watch them diffuse outwards from a pool, tackle jagged surface like a viscous fluid or flow from a funnel (from NewScientist | 2010 best videos).

[…] Fire ants use their claws to grip diverse surfaces, including each other. As a result of their mutual adhesion and large numbers, ant colonies flow like inanimate fluids. In this sequence of films, we demonstrate how ants behave similarly to the spreading of drops, the capillary rise of menisci, and gravity-driven flow down a wall. By emulating the flow of fluids, ant colonies can remain united under stressful conditions. […], in Micah Streiff, Nathan Mlot, Sho Shinotsuka, Alex Alexeev, David Hu, “Ants as Fluids: Physics-Inspired Biology,” ArXiv, 15 Oct 2010. .


Figure – Subcritical Turing bifurcation: formation of a hexagonal pattern from noisy initial conditions in the two-component reaction-diffusion system of Fitzhugh-Nagumo type. From left to rigth:a) Noisy initial conditions at t = 0. b) State of the system at t = 10. c) Almost converged state at t = 100. (source link)

Figure – Other patterns found in the above two-component reaction-diffusion system of Fitzhugh-Nagumo type. From left to rigth: a) Rotating spiral.b) Target pattern. c) Stationary localized pulse (dissipative soliton). (source link)

When an activator-inhibitor system undergoes a change of parameters, one may pass from conditions under which a homogeneous ground state is stable to conditions under which it is linearly unstable. The corresponding bifurcation may be either a Hopf bifurcation to a globally oscillating homogeneous state with a dominant wave number k=0 or a Turing bifurcation to a globally patterned state with a dominant finite wave number. The latter in two spatial dimensions typically leads to stripe or hexagonal patterns. [p.s. – a related lovely beach bay!.. state-phase diagram; Reaction-Diffusion by the Gray-Scott model: Pearson’s Parameterization (link) ]

Video – “BIG BANG BIG BOOM”: an unscientific point of view on the beginning and evolution of life … and how it could probably end. Direction and animation by BLU / production and distribution by / sountrack by Andrea Martignoni.

[…] It is suggested that a system of chemical substances, called morphogens, reacting together and diffusing through a tissue, is adequate to account for the main phenomena of morphogenesis. Such a system, although it may originally be quite homogeneous, may later develop a pattern or structure due to an instability of the homogeneous equilibrium, which is triggered off by random disturbances. Such reaction-diffusion systems are considered in some detail in the case of an isolated ring of cells, a mathematically convenient, though biologically, unusual system. The investigation is chiefly concerned with the onset of instability. It is found that there are six essentially different forms which this may take. In the most interesting form stationary waves appear on the ring. It is suggested that this might account, for instance, for the tentacle patterns on Hydra and for whorled leaves. A system of reactions and diffusion on a sphere is also considered. Such a system appears to account for gastrulation. Another reaction system in two dimensions gives rise to patterns reminiscent of dappling. It is also suggested that stationary waves in two dimensions could account for the phenomena of phyllotaxis. The purpose of this paper is to discuss a possible mechanism by which the genes of a zygote may determine the anatomical structure of the resulting organism. The theory does not make any new hypotheses; it merely suggests that certain well-known physical laws are sufficient to account for many of the facts. The full understanding of the paper requires a good knowledge of mathematics, some biology, and some elementary chemistry. Since readers cannot be expected to be experts in all of these subjects, a number of elementary facts are explained, which can be found in text-books, but whose omission would make the paper difficult reading. […], A. M. Turing, “The Chemical Basis of Morphogenesis“, in Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences, Vol. 237, No. 641. (Aug. 14, 1952), pp. 37-72. (link)

“Chaos theory has a bad name, conjuring up images of unpredictable weather, economic crashes and science gone wrong. But there is a fascinating and hidden side to Chaos, one that scientists are only now beginning to understand. It turns out that chaos theory answers a question that mankind has asked for millennia – how did we get here?

Over this 2010 BBC 4 documentary “The Secret Life of Chaos“, Professor Jim Al-Khalili sets out to uncover one of the great mysteries of science – how does a universe that starts off as dust end up with intelligent life? How does order emerge from disorder? It’s a mind bending, counter-intuitive and for many people a deeply troubling idea. But Professor Al-Khalili reveals the science behind much of beauty and structure in the natural world and discovers that far from it being magic or an act of God, it is in fact an intrinsic part of the laws of physics. Amazingly, it turns out that the mathematics of chaos can explain how and why the universe creates exquisite order and pattern. The natural world is full of awe-inspiring examples of the way nature transforms simplicity into complexity. From trees to clouds to humans – after watching this film you’ll never be able to look at the world in the same way again.” (description at YouTube).

[1 hour documentary in 6 parts: Part I (above), Part II, Part III, Part IV, Part V and Part VI. Even if you have no time, do not miss part 6. I mean, do really not miss it. Enjoy!]

[...] People should learn how to play Lego with their minds. Concepts are building bricks [...] V. Ramos, 2002.

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