*Why is so much slippery on the ice?*

For more than two centuries, scientists had to struggle to tell why the snow is really slippery and why the skates can move so well on it.

The ice skating game only depends on the fact that ice is slipping on the ice at the Winter Olympics. Speedkiters can reach 35 miles per hour on ice, skaters can rotate and glide up to 40-pound curling stone because the friction of snow is low.

But for the last two centuries, scientists had to struggle to tell why the snow is really slippery and why the skates can move so well on it.

But now it is not so. The secret of slipping on ice has come out.

What is the snow?

You know that ice is solid water. But what happens when it becomes solid and looks attractive. Most of the substances in the universe are more dense than solid liquids. When a substance is coolly cooled, its molecules are very close together. But the snow is different. When it falls below 32 degrees Fahrenheit, a special hydrogen bond between water molecules forces the empty space between each other's water molecules.

Solid snow is actually less dense than liquid water. This is the reason that ice fragments float in the ocean. Scientists used it as a clue to find out the secret of ice darning slippery and make some guesses.

Hypothesis 1:
Pressure melts ice (it is mostly wrong, but still interesting). Since the 19th century, the most common answer to the question "Why is snow slipping" is because ice melts under pressure. " This idea is from James Thompson's work, which works in mathematics in the 1850s, which describes a very strange property of ice: 'Under high pressure, ice turns into water. Solid ice is less dense than water. If you squeeze the snow, it becomes less stable and melts. As Kenneth Chang of the New York Times explained, a 150-pound person on a blade will reduce the melting point of 32 ° C to 31.97 ° Fenuite, while the ice rinks for figure skating is usually kept at 24 degrees Fahrenheit. Simply put: Skaters can put enough pressure to melting snow.

Hypothesis 2:
Friction melts ice. So the pressure of a thin blade on the ice can not explain why skates slipped. But what about friction? Do not have enough heat to melting ice at the speed of sliding ice skates on the surface? This is definitely a part of the answer, but it does not explain why the snow starts to move so abnormally.
While skating ice, drivers are so fast that ice does not give friction time.

Hypothesis 3:
There is a very small layer of liquid water over the ice. James Thompson, a few years ago, told that the pressure melts ice, physicist Michael Faraday discovered another attractive property of ice: thin, liquid layer on the surface, his use was so easy that you can do it at home.

Bring all three hypotheses together -

So what happens when the ice skate made of aluminum or steel touches the ice? The small liquid layer is the reason that skate may start running on ice immediately. And as the blades move faster and faster through the ice, friction is generated, which melts the water. This causes more friction, and more melting. All those skaters move in a channel like a hydroplane on a thin, thin film of water, and it all happens in one moment.