September 16, 2025
Slippery When Not Wet
Timothy Birdnow
We've all fallen on ice after a deep freeze, and if we haven't we've had other encounters with the slippery substance. But why is ice slippery?
New Research offers a possible answer:
So what are dipoles? No, they aren't two strippers plying their trade at the same time. Rather,they are:
And it is these dipoles that cause ice to be slipperier than Gavin Newsome:
So it's dipole on dipole eh? Wonder if the snowwomen wear pasties or are they fully in the buff?
This article concludes:
That last sounds like a description of Joe Biden's Presidency, does it not?
At any rate this is something everyone experiences and hardly anyone gives any thought to - and yet it involves some rather rowdy science.
Next time you fall and break a hip on the ice take comfort in the fact that you were injured by dipoles!
(BTW years ago the wife and I were out to eat and we were walking in a parking lot and she was struggling with the ice. I shot my mouth off "why are you having so much trouble; I'm not - look at me!" and immediately I hit a patch of ice and landed on my gluteous maximus. Right on cue! Teach me to shoot off my mouth!)
We've all fallen on ice after a deep freeze, and if we haven't we've had other encounters with the slippery substance. But why is ice slippery?
New Research offers a possible answer:
For more than a century, students around the world have been told that pressure and friction make ice melt. The familiar winter slip on a frozen sidewalk is often blamed on body weight pressing through the sole of your (still warm) shoe. New research from Saarland University indicates this view is incomplete, finding that slipperiness stems from interactions between molecular dipoles in the ice and those in the contacting surface, such as a shoe sole, rather than from pressure or friction.
The study by Professor Müser and colleagues Achraf Atila and Sergey Sukhomlinov challenges a model put forward nearly two hundred years ago by the brother of Lord Kelvin, James Thompson, who suggested that pressure and friction, along with temperature, cause ice to melt.
"It turns out that neither pressure nor friction plays a particularly significant part in forming the thin liquid layer on ice,” explains Martin Müser. Instead, computer simulations by the team reveal that molecular dipoles are the key drivers behind the formation of this slippery layer, which so often causes us to lose our footing in winter.
The study by Professor Müser and colleagues Achraf Atila and Sergey Sukhomlinov challenges a model put forward nearly two hundred years ago by the brother of Lord Kelvin, James Thompson, who suggested that pressure and friction, along with temperature, cause ice to melt.
"It turns out that neither pressure nor friction plays a particularly significant part in forming the thin liquid layer on ice,” explains Martin Müser. Instead, computer simulations by the team reveal that molecular dipoles are the key drivers behind the formation of this slippery layer, which so often causes us to lose our footing in winter.
So what are dipoles? No, they aren't two strippers plying their trade at the same time. Rather,they are:
But what exactly is a dipole? A molecular dipole arises when a molecule has regions of partial positive and partial negative charge, giving the molecule an overall polarity that points in a specific direction.
And it is these dipoles that cause ice to be slipperier than Gavin Newsome:
To get a better understanding of what is going on, it helps to know how ice is structured. Below zero degrees Celsius, water molecules (H₂O) arrange themselves into a highly ordered crystal lattice in which the molecules are all aligned neatly with one another creating a solid, crystalline structure.
When someone steps onto this orderly structure, it’s not the resulting pressure or friction of the shoe that disrupts the top layer of molecules, but the orientation of the dipoles in the shoe sole interacting with those in the ice. The previously well-ordered structure suddenly becomes disordered.
"In three dimensions, these dipole-dipole interactions become ‘frustrated,'” says Müser, referring to a concept in physics where competing forces prevent a system from achieving a fully ordered stable configuration.
When someone steps onto this orderly structure, it’s not the resulting pressure or friction of the shoe that disrupts the top layer of molecules, but the orientation of the dipoles in the shoe sole interacting with those in the ice. The previously well-ordered structure suddenly becomes disordered.
"In three dimensions, these dipole-dipole interactions become ‘frustrated,'” says Müser, referring to a concept in physics where competing forces prevent a system from achieving a fully ordered stable configuration.
So it's dipole on dipole eh? Wonder if the snowwomen wear pasties or are they fully in the buff?
This article concludes:
At the microscopic level, the forces between the dipoles in the ice and those in the shoe sole material disrupt the orderly crystalline structure at the interface between ice and shoe, causing the ice to become disordered, amorphous, and ultimately liquid.
That last sounds like a description of Joe Biden's Presidency, does it not?
At any rate this is something everyone experiences and hardly anyone gives any thought to - and yet it involves some rather rowdy science.
Next time you fall and break a hip on the ice take comfort in the fact that you were injured by dipoles!
(BTW years ago the wife and I were out to eat and we were walking in a parking lot and she was struggling with the ice. I shot my mouth off "why are you having so much trouble; I'm not - look at me!" and immediately I hit a patch of ice and landed on my gluteous maximus. Right on cue! Teach me to shoot off my mouth!)
Posted by: Timothy Birdnow at
07:35 AM
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1
You mean it doesn't have anything to do with G-g-g-global Warming? B-but, Greta and I were all set to crack open a bottle of bubbly and discuss this! She was gonna bring the wine, too... if the Israelis left her any (she said). Yes, it'll probably be a box, not a bottle.
Posted by: Dana Mathewson at September 16, 2025 10:12 PM (qL1rE)
2
Does Maneshevitzmake wineina box Dana? Somehow I see her drinking Pina Coconetta.
Posted by: Timothy Birdnow at September 17, 2025 06:26 AM (9QPil)
3
Dunno. She didn't show anyhow. I heard somebody told her Republicans were female abusers. I didn't even know she was female!
Posted by: Dana Mathewson at September 18, 2025 12:11 AM (qL1rE)
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