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English: Volcano-like thistle growth

Common knowledge about plant growth on urban streets is that it exerts strong forces upon solid covers to rip them up. The herbal turgor (hydraulic cell pressure) is able to achieve the level of truck wheels. But this is not complete truth. Surprisingly, the physics of small scale growth process is the same as in the case of volcanic edifice self-organization. Two images of asphalt crushing by thistles, which are weeds of outstanding stamina, give the details of the phenomenon. During initial growth thistle stems play the role of magmatic flow. They enlarge themselves and multiply cover cracks to destruct solid cover in the final run. Before volcanic eruption the pressure of inner magmatic chamber makes fluids/gases to migrate and to expand preexisting cover cracks. The latter in turn stimulates the former and the synergy of the processes arises due to positive feedback. Thus instability develops and sometimes leads to volcano’s cap throwing out and formation of its caldera. The nonlinear processes like this were firstly described by the founder of computer and artificial intelligence sciences Alan Turing in his work devoted to biological morphogenesis. There he mathematically theorized on proposed diffusion-reaction instability. The approach explains features of periodic Belousov-Zhabotinsky chemical reactions, zebra black-white lines, feline fur spots, etc.

Two images acquired in late summer prove the above analyses. Left image depicts the location of a crater with young thistle formed on asphalt surface. Long and strong roots of mother plant (right down corner of the image) allowed the young noxious weed to form crater far from asphalt stripe borders. Pay notice to the crack bunches’ direction approx. 45° to the borders, being the maximal shear stress one of the asphalt cover. Right image shows the young thistle inside the fresh crater depression with a part of its overturned cover nearby. Closer look at magnified image proves that stems were grown inside the cracks crossing the crater. Despite the consistency of results the above analyses of natural harmony are far from being final.

English: Volcano-like thistle growth Common knowledge about plant growth on urban streets is that it exerts strong forces upon solid covers to rip them up. The herbal turgor (hydraulic cell pressure) is able to achieve the level of truck wheels. But this is not complete truth. Surprisingly, the physics of small scale growth process is the same as in the case of volcanic edifice self-organization. Two images of asphalt crushing by thistles, which are weeds of outstanding stamina, give the details of the phenomenon. During initial growth thistle stems play the role of magmatic flow. They enlarge themselves and multiply cover cracks to destruct solid cover in the final run. Before volcanic eruption the pressure of inner magmatic chamber makes fluids/gases to migrate and to expand preexisting cover cracks. The latter in turn stimulates the former and the synergy of the processes arises due to positive feedback. Thus instability develops and sometimes leads to volcano’s cap throwing out and formation of its caldera. The nonlinear processes like this were firstly described by the founder of computer and artificial intelligence sciences Alan Turing in his work devoted to biological morphogenesis. There he mathematically theorized on proposed diffusion-reaction instability. The approach explains features of periodic Belousov-Zhabotinsky chemical reactions, zebra black-white lines, feline fur spots, etc. Two images acquired in late summer prove the above analyses. Left image depicts the location of a crater with young thistle formed on asphalt surface. Long and strong roots of mother plant (right down corner of the image) allowed the young noxious weed to form crater far from asphalt stripe borders. Pay notice to the crack bunches’ direction approx. 45° to the borders, being the maximal shear stress one of the asphalt cover. Right image shows the young thistle inside the fresh crater depression with a part of its overturned cover nearby. Closer look at magnified image proves that stems were grown inside the cracks crossing the crater. Despite the consistency of results the above analyses of natural harmony are far from being final.