For my fellow nerds, ICYMI:
What's Actually Happening on the Slippery Surface of Ice?
Ice is slippery not just because of pressure or friction—as we were taught for centuries—but because of a newly understood interaction between molecular dipoles in water. When a surface like a shoe or skate touches ice, it disrupts the orderly crystal structure of the ice at the molecular level. Water molecules have slightly positive and negative ends (dipoles), and when another material comes into contact, these dipoles become disordered. That disruption creates an ultra-thin, liquid-like layer on the surface—even in extreme cold—allowing us to slide.
The Old Theory
For nearly 200 years, scientists believed ice was slippery because:
• Pressure from our weight lowered the melting point, and
• Friction generated heat, melting the surface.
While both effects do occur, they can't fully explain why ice remains slippery at very low temperatures, where pressure-induced melting is minimal.
The New Understanding: Molecular Dipoles
• Dipoles: Water molecules have uneven charge distribution.
• Disruption: Contact with another material frustrates the ice's crystal lattice.
• Result: A thin, disordered, liquid-like layer forms on the surface—even well below freezing.
Why This Matters
Based on advanced computer simulations, this research overturns a long-standing explanation and finally explains why ice stays slippery in conditions where melting shouldn't happen at all.
Full article here:
https://interestingengineering.com/science/why-ice-is-slippery
I'll be thinking about molecular dipoles the next time I fall on my ass while skating or skiing.
Only on eLF.
And that dipole is also why water melts and boils at the temperatures it does.
If you compare the molecular weight of water (18) with comparable size molecules, you'd expect it to boil at a much lower temperature, like several hundred degrees below zero. But because of those dipoles and the hydrogen bonding that it causes, water boils at a temperature such that we have liquid water on Earth.
Another interesting fact: if the concentration of water in another liquid (e.g. liquid chlorine) is low enough, there's no hydrogen bonding and it behaves based on it's molecular weight.