Revolution

A revolution (from the Latin revolutio, "a turn around") is a fundamental change in political power or organizational structures that takes place in a relatively short period of time when the population rises up in revolt against the current authorities. Aristotle described two types of political revolution:

Revolutions have occurred through human history and vary widely in terms of methods, duration, and motivating ideology. Their results include major changes in culture, economy, and socio-political institutions.

Scholarly debates about what does and does not constitute a revolution center on several issues. Early studies of revolutions primarily analyzed events in European history from a psychological perspective, but more modern examinations include global events and incorporate perspectives from several social sciences, including sociology and political science. Several generations of scholarly thought on revolutions have generated many competing theories and contributed much to the current understanding of this complex phenomenon.

Roller skating

Roller skating is the traveling on surfaces with roller skates. It is a form of recreational activity as well as a sport, and can also be a form of transportation. Skates generally come in three basic varieties: quad roller skates, inline skates or blades and tri-skates, though some have experimented with a single-wheeled "quintessence skate" or other variations on the basic skate design. In America, this hobby was most popular, first between 1935 and the early 1960s and then in the 1970s, when polyurethane wheels were created and "Disco" oriented roller rinks were the rage and then again in the 1990s when in-line outdoor roller skating, thanks to the improvement made to inline roller skates in 1981 by Scott Olson, took hold.

History

Rodney Mullen

John Rodney Mullen (born August 17, 1966) is an American professional skateboarder, entrepreneur, inventor, and public speaker who practices freestyle and street skateboarding. Mullen is credited with inventing numerous skateboarding tricks, including the flatground ollie, kickflip, heelflip, impossible, and 360-flip (also commonly known as the 'tre-flip' or '3-flip'). Mullen has appeared in over 20 skateboarding videos and has co-authored an autobiography, entitled The Mutt: How to Skateboard and Not Kill Yourself, with writer Sean Mortimer.

Early life

Mullen was born in Gainesville, Florida, United States, and began skateboarding at the age of ten, on New Years Day of 1977, after a neighborhood friend introduced him to a skateboard. He promised his strict father, a dentist, that he would cease skateboarding the first time he became seriously injured:

Mullen began practicing in the garage of the family home while wearing a comprehensive pads setup, a precaution that was part of the deal with his father, and spent time with his sister's surfer friends, who skateboarded on weekdays. Mullen became obsessed with the skateboard and practiced for many hours on a daily basis. As a child, Mullen slept in boots designed to correct a severe pigeon-toe condition. Despite Mullen's condition, "He had an incredible dexterity with his feet," in the words of Phil Chiocchio, former owner of the Florida skatepark, Sensation Basin.

Speed skating

Speed skating is a competitive form of ice skating in which the competitors race each other in travelling a certain distance on skates. Types of speed skating are long track speed skating, short track speed skating, and marathon speed skating. In the Olympic Games, long-track speed skating is usually referred to as just "speed skating", while short-track speed skating is known as "short track". The ISU, the governing body of both ice sports, refers to long track as "speed skating" and short track as "short track skating".

The standard rink for long track is 400 meters long, but tracks of 200, 250 and 333⅓ meters are used occasionally. It is one of two Olympic forms of the sport and the one with the longer history. An international federation was founded in 1892, the first for any winter sport. The sport enjoys large popularity in the Netherlands and Norway. There are top international rinks in a number of other countries, including Canada, the United States, Germany, Italy, Japan, South Korea and Russia. A World Cup circuit is held with events in those countries and with two events in Thialf, the ice hall in Heerenveen, Netherlands.

Ice skating

Ice skating is moving on ice by using ice skates. It can be done for a variety of reasons, including exercise, leisure, traveling, and various sports. Ice skating occurs both on specially prepared ice surfaces (arenas, tracks, parks), both indoors and outdoors, as well as on naturally occurring bodies of frozen water, such as ponds, lakes and rivers.

History

Early history of ice skating

A study by Federico Formenti of the University of Oxford suggests that the earliest ice skating happened in southern Finland more than 3,000 years ago. Originally, skates were merely sharpened, flattened bone strapped to the bottom of the foot. Skaters did not actually skate on the ice, but rather glided on top of it. True skating emerged when a steel blade with sharpened edges was used. Skates now cut into the ice instead of gliding 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 since then. In the Netherlands, ice skating was considered proper for all classes of people, as shown in many pictures by the Old Masters.