About growth of riverbed networks and rock patterns

The waves of the sea, the little ripples on the shore, the sweeping curve of the sandy bay between the headlands, the outline of the hills, the shape of the clouds, all these are so many riddles of form (…) and all of them the physicist can more or less easily read and adequately solve – wrote D'Arcy Wentworth Thompson in his monumental work On Growth and Form published for the first time exactly one hundred years ago. Since that time, physics has much advanced along the way pointed out by Thompson. Now we understand much better the mechanisms governing spontaneous organization of the matter and know how to describe systems, in which interactions between components produce some ordered structures or give rise to quantitatively new physical behaviour. Two examples of self-organization of inorganic matter presented during the seminar include: how cave germs are born, and how riverbed networks are growing on sandy grounds. In particular I will try to physically explain why an initially planar crack between rocks can non-uniformly evolve into a system of karstic caves/corridors, and why streams supplying the Apalachicola river in Florida merge at the 72 degrees angle.

All interested persons are invited,
M. Kowal, W. Piechocki, L. Roszkowski, J. Skalski, L. Szymanowski