Ice is a tricky thing. It seems to be a solid surface. But if you take a careless step, you are already flying in an unknown direction. But why does this happen? Secret of slippery ice: what the winter surface hides? The answer seems obvious: water! However, it is not that simple. Let’s figure it out.
What’s going on underfoot anyway?
Imagine stepping on ice and suddenly your sole slips. Why? Ice itself is not super slippery. If you take a piece of ice and run your finger across it, you will notice the friction. But when we step on ice or glide on skates, an interesting thing happens – under the action of pressure and friction, a very thin layer of water forms on the surface of the ice. It acts as a lubricant, making the surface surprisingly slippery.
There are two key factors: pressure and mechanical friction. When body weight is concentrated on a small contact area, such as the tips of skates or the soles of shoes, the pressure increases and with it the likelihood of localized melting. Even if the ambient temperature is well below freezing, the ice at the point of contact can partially soften, creating a thin film of water.
Add friction to this: as you move, heat is generated, further facilitating melting. As a result, a microscopic layer of liquid appears between the ice surface and your shoe, reducing resistance. The faster you move, the more active this effect is. This is why skating at high speeds feels even more slippery than simply standing on the ice.
Importantly, the force of pressure and the speed of movement can affect the thickness of this film, changing the level of slip. That is why car tires have a tread to break the water film, and hockey skates have sharp edges for better grip on the ice.
Temperature matters!
The warmer the ice, the easier it is to melt when it comes into contact with your feet, tires, or skate blade. Around -1°C to -3°C, the ice is at its slipperiest. The film of water is thin, but thick enough to provide minimal friction. But at -20°C, it’s a different story. The ice is hard and dry, making it much harder to glide on. Have you ever noticed that indoor skating rinks. Where the temperature is not so low, are much more enjoyable than skating on a lake on a frosty day?
Precipitation, humidity and nature’s surprises
Have you ever noticed how ice can be even more dangerous after rain or sleet? The moisture on the ice surface turns into another slippery layer, increasing the sliding effect. Or another option – when snow hides an ice trap, and suddenly you test how durable your winter clothing is. It can be even worse: when there is a thaw during the day and frost at night – the road turns into a perfect skating rink.
Natural ice, on lakes and rivers, often contains microcracks, air bubbles and impurities that can affect its sliding properties. It can be uneven, brittle or even “puffy” due to uneven freezing. But artificial ice, on skating rinks or sports arenas, is usually created in layers and is almost perfectly smooth. This makes it more predictable for athletes and ordinary people going out on the ice.
The Secret of Slippery Ice: Is This What Scientists Are Investigating?
Glaciologists, physicists and even winter sports engineers are grappling with the mystery of slippery ice. They are using ultra-sensitive sensors to measure the thickness of the water film on the ice. They are also creating computer models of how shoes, skates and car tires interact with the winter surface.
For example, in 2018, a team of researchers from Europe (France) conducted an experiment. In which they used an atomic force microscope to study the molecular structure of the ice surface. It turned out that even at very low temperatures, a thin layer of water molecules remains on the ice. They are in constant motion. This discovery not only confirmed ancient theories. It helped to better understand how the properties of ice can be influenced to improve safety in cities and roads.
In addition, NASA studies the structure of ice in extreme conditions. This helps not only in sports, but also in the design of spacecraft. Scientists also experiment with different shoe sole materials to find the least slippery options.
Why is this important in everyday life?
Understanding the nature of slippery ice helps us create better soles for winter shoes, safer tires for cars, and even more efficient technologies for winter sports. For example, figure skates and hockey blades are designed differently. This is precisely because of how they interact with ice. And anti-icing agents? They don’t just melt the ice, they change its structure, making the surface less slippery.
So why is it so slippery?
It turns out that this is a complex of factors: temperature, pressure, humidity, surface features. The warmer the ice, the more likely it will have a thin layer of water. The higher the humidity, the more likely it is to slip unpredictably. And even pressure plays a role. A light person may not melt the ice under their feet, while a heavier person will create the same slippery water film.
Here’s another amazing fact: in 2018, scientists from the Netherlands proved that water molecules on the surface of ice are not organized chaotically. But in certain structures resembling liquid crystals. This discovery can help in the development of new anti-slip coatings and even explain some anomalies in the behavior of ice in nature.
Read also:
What is the minimum temperature a human can withstand?
Why you’re always cold: 7 possible reasons and tips