Why is ice is slippery? New study of the theory of physics with 200 years

A new study contradicts the theory generally accepted by physicists, which was initially proposed in the nineteenth century by James Thompson.

For almost two centuries, students have learned that ice becomes slippery because pressure and friction make it melt, leaving behind a thin liquid water film.

Now a new one from the University of Saarland published in Physical Review Letters challenges this explanation long accepted, suggesting that ice slip molecular interactions on its surface.

The study, led by physics teacher Martin Müser and his colleagues Achraf Atila and Sergey Sukhominov, shows that molecular dipoles, small positive and negative regions inside molecules, play the central role. When a surface, such as the sole of a shoe or skiing, comes into contact with the ice, the materials of the material interact with those of the ice, breaking their ordered crystal clear structure.

“It turns out that neither pressure nor friction play a particularly significant role in the formation of the thin liquid layer on ice,” Müser explained. Computational simulations revealed that these Dipolo-Dipolo Interactions are the true drivers Of the slippery effect, replacing a model proposed for the first time in the nineteenth century by James Thompson, brother of Lord Kelvin.

The ice at negative temperatures is typically composed of perfectly aligned water molecules, forming a crystalline network. At the moment when another material comes into contact, the guidance of its dipools interferes with the order of the ice, Creating a disorderly layer On the surface that behaves like a liquid, explains the.

This mechanism also pits another old belief: that skiing below -40 ° C is impossible because the cold prevents the formation of a lubricating film. According to Müser’s team, dipolar interactions persist even at extremely low temperatures, which means that there can still be a liquid -like film. At such temperatures, however, the film becomes so viscous that it slips on it would be virtually impossible in practice.

The discovery has important implications for physicsbecause it redefines the way scientists understand surface interactions and can influence future studies on friction, lubrication and material science.

“For someone who slips and falls in winter, the cause matters little,” Müser noted. “But for physics, distinguishing between pressure, friction and dipolar interactions is crucial.”