For 200 years, #ice was thought to be slippery because a thin liquid #water layer forms under pressure and friction under the weight of the footstep.

But this idea of frictional melting appears to have defied direct experimental verification.

Now it also has been shown to be wrong.

A new paper presents molecular simulations of ice interfaces that reveal that ice surfaces liquefy without melting thermodynamically but predominantly by cold, displacement-driven amorphization.

Despite effective self-lubrication, very small ice friction is found to require water to slip past a hydrophobic counterface—or an excess amount of water, produced by, e.g., extreme sliding velocities.

#physics #science
https://journals.aps.org/prl/abstract/10.1103/1plj-7p4z

As we listen to a piece of music, our ears perform a calculation.

The high-pitched flutter of the flute, the middle tones of the violin, and the low hum of the double bass fill the air with pressure waves of many different frequencies.

When the combined sound wave descends through the ear canal and into the spiral-shaped cochlea, hairs of different lengths resonate to the different pitches, separating the messy signal into buckets of elemental sounds.

Amid the chaos of revolutionary France, one man’s mathematical obsession gave way to a calculation that now underpins much of #mathematics and #physics.

The calculation, called the #Fourier transform, decomposes any #function into its parts.

https://www.quantamagazine.org/what-is-the-fourier-transform-20250903/