Why Is The Ice So Slippery?
From the Fall 2019 edition of Learn to Skate USA The Magazine
When you step on the ice, you do more than just glide. You become a rocket on frozen water. You’re a modern gladiator battling to find the back of the net, be the first to cross the finish line or launch yourself high into the air.
But have you ever wondered why the ice is so slippery? If ice is what happens when water becomes solid, why isn’t it a solid surface we can easily walk across? One thing is for sure — there’s a lot more than just skating happening in the rink.
First Theories
Before ice was thoroughly studied, scientists thought that the friction caused by your blades ever-so-slightly raised the temperature at the surface of the ice (like when you rub your hands together and create friction to warm your fingers during your skating lessons). Then the warm spot produced a microfilm of water, which made you slide before the ice froze over again.
Sounds plausible, right? Even though that explanation was assumed to be correct for years, and the wetness of the surface DOES make it slippery, the theory of friction actually falls short of explaining the science of skating.
It’s All in the Molecules
Have you ever noticed that ice floats on water? Even the biggest icebergs sit effortlessly on top of the ocean. That’s because solid water is less dense than liquid water — which is the key to unlocking the mystery of that slippery surface.
Water is made up of billions and billions of molecules. When it freezes, those molecules cling to each other through something called hydrogen bonds. The molecules hold each other in place to form the crystalline structure of ice. But the molecules on the surface of that structure have fewer other molecules to cling to, which makes them more disorganized. The structureless space between molecules creates a lack of density, which makes the surface of the ice more wet than the core — and ultimately makes the ice surface more slippery.
Maybe one day you’ll score a hat trick. Maybe one day you’ll land a triple jump. Maybe tomorrow you’ll be faster than you were today. But the next time you enter the rink, just remember there’s a lot more happening on the ice than skating.
