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Why Is Ice Slippery? A New Hypothesis Slides Into the Chat.www.quantamagazine.org/why-is-ice-slippery-a-new-hypothesis-slides-into-the-chat-20251208/
67 sats \ 3 comments \ @0xbitcoiner 8 Dec science
A newly proposed explanation for the slipperiness of ice has revived a centuries-long debate.
The reason we can gracefully glide on an ice-skating rink or clumsily slip on an icy sidewalk is that the surface of ice is coated by a thin watery layer. Scientists generally agree that this lubricating, liquidlike layer is what makes ice slippery. They disagree, though, about why the layer forms.
Three main theories about the phenomenon have been debated over the past two centuries. Earlier this year, researchers in Germany put forward a fourth hypothesis(opens a new tab) that they say solves the puzzle.
But does it? A consensus feels nearer but has yet to be reached. For now, the slippery problem remains open.
  • Hypothesis 1: Pressure
  • Hypothesis 2: Friction
  • Hypothesis 3: Premelting
  • Hypothesis 4: Amorphization
  • A Consensus Kept on Ice
...read more atquantamagazine.org
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22 sats \ 1 reply \ @SimpleStacker 8 Dec
I'm, uh, kinda surprised that this is an open question
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0 sats \ 0 replies \ @0xbitcoiner OP 8 Dec

+1

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0 sats \ 0 replies \ @noknees 5h
This was really an interesting read! I remember this discussion by my own physics teacher.
  • Earlier theories proposed that pressure from a skate or foot lowers ice's melting point, creating a water film, as suggested by James Thomson in the 1800s.
  • Frictional heating from motion was another idea, where rubbing generates enough warmth to melt the surface slightly. Experiments, like those by Lord Kelvin, supported friction's role by showing higher friction with heat-conducting materials. We also have the theory of pre-existing quasi-liquid layer (QLL) on ice surfaces, formed by weaker bonding of surface molecules exposed to fewer neighbors
But I think we already have a reasonable solution to this problem through dipole interactions which says molecular dipoles in ice align and disrupt with those in contacting surfaces like shoe soles, disordering the ice into a slippery, amorphous state without needing heat or pressure. This viscous, oil-like film resembles crushed ice in snow cones, enabling low friction. Although the explanation for regelation of ice still remains unattended in this case. [EXPLANATION]
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