- Ice skating
Ice skating is
traveling on icewith skates, narrow (and sometimes parabolic) blade-like devices moulded into special boots [cite web|last = van Voorbergen | first = Bert | title = The virtual ice Skates museum - Ice skates and their history (1) | url = http://www.iceskatesmuseum.com/museum-e/e-historie-1.htm | accessdate = 2006-09-18 [http://www.iceskatesmuseum.com/museum-e/e-historie-1.htm] ] A study by Federico Formenti of the University of Oxford suggests that the earliest ice skating happened in Southern Finland about 4000 years ago. [cite web|url = http://www.blackwell-synergy.com/doi/abs/10.1111/j.1095-8312.2007.00991.x|title=The first humans travelling on ice: an energy-saving strategy? | coauthors=Federico Formenti, Alberto E. Minett]
Development of skates
Skating originates in Scandinavia from around 1000 BC. Originally, skates were strapped to the bottom of the foot. They used a flattened bone as the original blade. Skaters did not actually skate on the ice, but glided on top of it. When they started to uses a steel blade with sharpened edges, true skating emmerged. Skaters now cut into the ice, not glide on top of it. 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 stayed 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,Major international competitions are sanctioned by the ISU. These include the Winter Olympic Games, the World Championships, the World Junior Figure Skating Championships, the European Figure Skating Championships, the Four Continents Figure Skating Championships, and the ISU Grand Prix of Figure Skating.
ocial 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. James II of Englandcame 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, and was soon enjoyed by people from all walks of life. It is said that Queen Victoriagot to know her future husband, Prince Albert, better through a series of ice skating trips; meanwhile Fenland agricultural workers became masters of speed skating. However, in other places, participation in ice skating was limited to members of the upper classes. EmperorRudolf II of the Holy Roman Empireenjoyed ice skating so much he had a large ice carnival constructed in his court in 1610 in order to popularize the sport. King Louis XVIof Francebrought ice skating to Parisduring his reign. Madame de Pompadour, Napoleon I, Napoleon III, and the House of Stuartwere, among others, royal and upper class fans of ice skating.
How it works
Ice skating works because the metal blade at the bottom of the ice skate shoe can glide with very little
frictionover 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 while 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.
How the low-friction surface develops is not exactly known, but a large body of knowledge does exist. These are explained below.
Experiments show that ice has a minimum kinetic friction at −7°C (19°F), and many indoor skating rinks set their system to a similar temperature. The low amount of friction actually observed has been difficult for physicists to explain, especially at lower temperatures. On the surface of any body of ice at a temperature above about −20°C (−4°F), there is always a
thin filmof liquid water, ranging in thickness from only a few molecules to thousands of molecules. This is because an abrupt end to the crystalline structureis not the most entropically favorablepossibility. The thickness of this liquid layer depends almost entirely on the temperature of the surface of the ice, with higher temperatures giving a thicker layer. However, skating is possible at temperatures much lower than −20°C, at which temperature there is no naturally occurring film of liquid.
When the blade of an ice skate passes over the ice, the ice undergoes two kinds of changes in its physical state: an increase in pressure, and a change in temperature due to kinetic friction and the heat of melting. Direct measurements [Colbeck et al., American Journal of Physics. vol. 65, no. 6; June 1997; p.488-92; abstract at http://www.skridsko.net/klubbar/data/science.html] show that the heating due to friction is greater than the cooling due to the heat of melting. Although high pressure can cause ice to melt, by lowering its melting point, the pressure required is far greater than that actually produced by ice skates. Frictional heating does lead to an increase in the thickness of the naturally occurring film of liquid, but measurements with an atomic force microscope have found the boundary layer to be too thin to supply the observed reduction in friction.
The first main danger in ice skating is falling on the ice, which is dependent on the quality of the ice surface, the design of the ice skate, and the skill and experience of the skater. While serious injury is rare, a number of (short track) skaters have been paralyzed after a fall when they hit the boarding. An additional danger of falling is injury caused by the skater's own metal blades or those of other skaters. Falling can be fatal if a
helmetor Ice Halo is not worn to protect against serious head trauma.
The second, and more serious, danger is falling through the ice into the freezing water underneath when skating outdoors on a frozen body of water. This can lead to serious injury or death due to shock, hypothermia or drowning. It is often difficult or impossible for skaters to climb out of the water back onto the ice due to the ice repeatedly breaking, the skater being weighed down by skates and thick winter clothing, or the skater becoming disoriented under water.
ports based on ice skating
A number of sports are played while ice skating:
Ice hockeyis 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 to accommodate the shooter's handedness.
Bandyis a team sport played on ice, with sticks, a small ball and rules similar to those of field hockey.
Figure skatingis a sport in which individuals, synchronized skating (group skating),mixed couples, or groups perform spins, jumps, and other moves on ice, artistically to music.
Ringetteis a team sport played on ice, where the objective of the game is to score goals by shooting a ring into the opponent's goal using a long bladeless stick.
Speed skatingis a sport in which the competitors attempt to travel a certain distance as quickly as possible on skates.
Tour skatingis a recreational activity where participants travel long distances by ice skating on natural ice.
Communal games on ice
A number of recreational activity games can be played on ice.
Rousette skatingis a recreational event based on ice skating.
* Various tagging games with different rules.
In recent years, a new surface made of plastic has been commercialised. Sheets of interconnected polyethylene panels covered with a thin film of grease allow skating with the same blades used for ice skating. [http://www.dunedinicehockey.co.nz/forum/index.php?topic=99.0]
[http://jeb.biologists.org/cgi/content/abstract/210/10/1825 Formenti F. and Minetti A.E. (2007) Human locomotion on ice: the evolution of ice skating energetics through history]
[http://www.blackwell-synergy.com/doi/abs/10.1111/j.1095-8312.2007.00991.x Formenti F. and Minetti A.E. (2008) The first humans travelling on ice: an energy saving strategy?]
* [http://www.skridsko.net/klubbar/data/science.html Scientific Papers]
* [http://www.berkeley.edu/news/media/releases/2002/05/10_somorjai.html Gabor Somorjai, the father of modern surface chemistry]
* [http://www.nhl.com NHL US Website]
* [http://www.sportsites.be/ijshockey Icehockeylinks]
* [http://www.queensfinestskaters.co.uk Queens Finest Skaters, A UK run ice skating community site with hockey skate reviews and a forum]
* [http://www.tapuz.co.il/blog/ViewEntry.asp?EntryId=1148142 Ice Skating shown in maximum card from Israel]
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