Ice skating
From Wikipedia, the free encyclopedia
Outdoor ice skating in Austria
Ice skating is traveling on ice with skates, narrow (and sometimes parabolic) blade-like devices moulded into special boots (or, more primitively, without boots, tied to regular footwear). It is mainly done for recreation and as a sport.
It is possible on canals and lakes,
etc. after it has been freezing for some time, and at indoor and
outdoor skating tracks and areas with artificial cooling. The skating rink regarded as the world's longest (about 8 kilometres long) is the Rideau Canal located in Ottawa, Ontario, Canada.
In some countries with a temperate climate, e.g. the Netherlands, frozen canals and lakes are fairly rare, but skating is popular where these are encountered.
History
Prehistory
The exact time and process by which humans first learned to ice
skate is not known, though archaeologists believe the activity was
widespread. The convenience and efficiency of ice skating to cross
large, icy areas is shown in archaeological evidence by the finding of
primitive animal bone ice skates in places such as Russia, Scandinavia, Great Britain, Germany, and Switzerland.
The runners were made from bones of cattle. They ground down until they
formed a flat gliding surface, and thongs tied them to the feet. [1]
Earliest historical documentations
The first concrete mention of ice skating is found in a book written by William Fitzstephen, a monk in Canterbury. In his book about Thomas Beckett, he writes the following, a description of a scene taking place below the northern city walls of Canterbury during the winter:
...if the moors in Finsbury and Moorfield freeze over, children
from London play. Some of the children have attached bones to their
ankles, and carry well-worn sticks. They fly across the ice like birds,
or well-fired arrows. Suddenly, two children will run at each other,
sticks held high in the air. They then attack each other until one
falls down. Often, the children injure their heads or break their arms
or legs...
The sticks that Fitzstephen refers to were used for movement, as the
primitive bone-made ice skates did not sharp gliding edges like modern
ice skates.[1]
The first depiction of ice skating in a work of art was made in the 15th century, by the Dutch artist Johannes Brugman. The picture, of Saint Lidwina, patron saint
of ice skaters, falling on the ice was the first work of art by a major
artist to feature ice skating as a main theme. Another important aspect
of the painting is a man seen in the background, who is skating on one
leg. This means that the ice skates the man was wearing must have sharp
edges similar to those found on modern ice skates.[1]
Development of skates
Adding edges to ice skates was invented by the Dutch in the 13th or 14th century. These ice skates were made of steel,
with sharpened edges on the bottom to aid movement. The construction of
modern ice skates has remained largely the same. The only other major
change in ice skate design came soon after. Around the same time period
as steel edges were added to ice skates, another Dutchman, a table
maker’s apprentice,
experimented with the height to width ratio of the metal blade of the
ice skates, producing a design that remains almost unaltered to this
day. The user of the skates no longer needed to use sticks for
propulsion, and movement on skates was now freer and more stable.
Social status of ice skating
In the Netherlands, ice skating was considered proper for all
classes of people to participate in, as shown in many pictures by the Old Masters. However, in other places, participation in ice skating was limited to only members of the upper classes. Emperor Rudolf II of the Holy Roman Empire enjoyed ice skating so much he had a large ice carnival constructed in his court in 1610 in order to popularize the sport. James II of England,
came to the Netherlands in exile, and he fell for the sport. When he
went back to England, this "new" sport was introduced to the British
aristocracy. King Louis XVI of France brought ice skating to Paris during his reign. Madame de Pompadour, Napoleon I, Napoleon III, and the House of Stuart were, among others, royal and upper class fans of ice skating. It is said that Queen Victoria got to know her future husband, Prince Albert, better through a series of ice skating trips.
How it works
Ice skating works because the metal blade at the bottom of the ice skate shoe can glide with very little friction
over the surface of the ice. However, slightly leaning the blade over
and digging one of its edges into the ice ("rockover and bite") gives
skaters the ability to increase friction and control their movement at
will. In addition, by choosing to move along curved paths whilst
leaning their bodies radially and flexing their knees, skaters can use
gravity to control and increase their momentum. They can also create
momentum by pushing the blade against the curved track which it cuts
into the ice. Skillfully combining these two actions of leaning and
pushing - a technique known as "drawing" - results in what looks like
effortless and graceful curvilinear flow across the ice.
Research in materials has come up with a number of theories
explaining the true nature of skating. The issue is that the precise
mechanism by which the low-friction is generated is not fully
understood, though a number of plausible theories abound usually
involving explanations of air-ice boundary holla layer water and/or
friction generated through the skate bottom.
The boundary layer of water being the cause of slipperiness has been
disputed when measurements of the boundary layer water with an atomic
force microscope found the boundary layer to be too thin to supply
sufficient friction reduction. Nevertheless, a popular theory of this
is that because the molecular structure of ice is a crystalline structure, it turns out that having this structure abruptly stop when it reaches the top of the ice is not the most entropically favorable form. Instead, there is always a thin film
of liquid water ranging in thickness from only a few molecules to
thousands of molecules on top of the ice. This allows a smoother
transition from the structured ice to the completely random structure
of the air molecules. The thickness of this liquid layer depends almost
entirely on the temperature of the surface of the ice (higher
temperatures give a thicker layer), and the liquid layer disappears
around −20°C (−4°F). However, skating is still possible at temperatures much lower than −20°C. Experiments show that ice has a minimum of kinetic friction at −7°C (19°F), and many indoor skating rinks set their system to a similar temperature.
Sports based on ice skating
A number of sports, and recreational activities are based on the principle of ice skating:
- Figure skating is a sport in which individuals, mixed couples, or groups perform spins, jumps, and other moves on ice, often to music.
- Ice hockey
is a team sport played on ice, where the objective of the game is to
score goals by shooting a puck into the opponent's goal using a long
stick with a blade that is commonly curved at one end.
- Speed skating is a sport in which the competitors attempt to travel a certain distance as quickly as possible on skates.
- Tour skating is a recreational activity where participants travel large distances by ice skating on natural ice.
- Rousette skating is a recreational event based on ice skating.
References
External links
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