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.

Figure skating

Figure skating is a sport and activity in which individuals, duos, or groups perform on figure skates on ice. It was the first winter sport included in the Olympics, in 1908. The four Olympic disciplines are men's singles, ladies' singles, pair skating, and ice dancing. Non-Olympic disciplines include synchronized skating and four skating. From intermediate through senior-level competition, skaters generally perform two programs (short and long) which, depending on the discipline, may include spins, jumps, moves in the field, lifts, throw jumps, death spirals, and other elements or moves.

The blade has a groove on the bottom creating two distinct edges — inside and outside. In figure skating, the skater should glide on one edge of the blade and not on both at the same time, which is referred to as a flat edge. During a spin, skaters use the "sweet spot" of the blade, which is the roundest portion of the blade, just behind the pick and near the middle of the blade. Skates used in single and pair skating have a set of large, jagged teeth called toe picks on the front of the blade. Toe picks are mainly used in the take-off for jumps. Ice dancing blades are an inch shorter in the rear and have smaller toe picks.

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.