Amazing physics hides behind numerous everyday things. felt for many years Hans Joachim Schlichting investigates these phenomena and explains them in his column to the readership of »Scientific Spectrum«. Schlichting is a professor of physics didactics and worked at the University of Münster until he retired.
If you take a closer look at the pieces of wood, you will discover that each individual hair sprouts out of a tiny opening in the material. One gets the impression that a liquid substance would be pushed through nozzles, similar to the production of spaghetti, and would immediately harden in the air. This notion is not entirely far-fetched because, according to relevant research, the holes are the exit openings of so-called wood rays. These are tiny channels that run radially through the vascular tissue from the middle to the bark and are used to transport water and nutrients in the living tree. The individual ice hairs are rooted at the mouths of the wood rays and have the same diameter as these. In addition, the ice always sprouts from the sections of deadwood that have been freed from the bark. Sometimes it even oozes out of the cracks between partially detached pieces of bark.
For a long time it was unknown how the frosty revival of the dead pieces of wood came about. Alfred Wegener (1880–1930), who later became famous for his hypothesis of continental drift, had already gained important insights in 1918. At first he thought that the hairy ice was one of the fungi that attack dead wood. After realizing that it was ice, he suspected that tree fungi played a key role in the formation of hairy ice.
Recent scientific research have shown the connection with fungi. If you treat pieces of wood that have been freed from ice, which under the right meteorological conditions are then clothed again in the crystalline wool, with heat, alcohol or fungicides, the effect is lost. In addition, melted hair ice is slightly brownish in color, which indicates organic residues. All the hairy branches were infested with a type of fungus typical of deciduous trees, the pink-tinged gelatinous crust (Exediopsis effusa).