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Parachuting
Parachuting and skydiving are methods of descending from a high point in an atmosphere to the ground or ocean surface with the aid of gravity, involving the control of speed during the descent using a parachute or multiple parachutes. For human skydiving, there is often a phase of free fall (the skydiving segment), where the parachute has not yet been deployed and the body gradually accelerates to terminal velocity. In cargo parachuting, the parachute descent may begin immediately, such as a parachute- airdrop in the lower atmosphere of Earth, or it may be significantly delayed. For example, in a planetary atmosphere, where an object is descending "under parachute" following atmospheric entry from space, may occur only after the hypersonic entry phase and initial deceleration that occurs due to friction with the thin upper atmosphere. History The first parachute jump in history was made on 22 October 1797 by Frenchman André-Jacques Garnerin above Parc Monceau, Pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parachute
A parachute is a device designed to slow an object's descent through an atmosphere by creating Drag (physics), drag or aerodynamic Lift (force), lift. It is primarily used to safely support people exiting aircraft at height, but also serves various purposes like slowing cargo, aiding in space capsule recovery, and stabilizing vehicles or objects. Modern parachutes are typically made from durable fabrics like nylon and come in various shapes, such as dome-shaped, rectangular, and inverted domes, depending on their specific function. The concept of the parachute dates back to ancient attempts at flight. In 852 AD, Armen Firman, in Córdoba, Spain, made the first recorded jump with a large cloak to slow his fall. Renaissance figures like Francesco di Giorgio Martini and Leonardo da Vinci later sketched designs resembling modern parachutes, but it wasn’t until the 18th century that the first successful jumps occurred. French Louis-Sébastien Lenormand made the first public jump i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Airborne Forces
Airborne forces are ground combat units carried by aircraft and airdropped into battle zones, typically by parachute drop. Parachute-qualified infantry and support personnel serving in airborne units are also known as paratroopers. The main advantage of airborne forces is their ability to be deployed into combat zones without a land passage, as long as the airspace is accessible. Formations of airborne forces are limited only by the number and size of their transport aircraft; a sizeable force can appear "out of the sky" behind enemy lines in merely hours if not minutes, an action known as ''vertical envelopment''. Airborne forces typically lack enough supplies for prolonged combat and so they are used for establishing an airhead to bring in larger forces before carrying out other combat objectives. Some infantry fighting vehicles have also been modified for paradropping with infantry to provide heavier firepower. Protocol I of the Geneva Conventions protects parachutis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Smokejumpers
A smokejumper is a specially-trained Wildfire suppression, wildland firefighter who provides an initial attack response on remote wildfires. They are inserted at the site of the fire by parachute. This allows firefighters to access remote fires in their early stages without needing to hike long distances carrying equipment and supplies. Traditional terrestrial crews can use only what they can carry and often require hours and days to reach fire on foot. The benefits of smokejumping include the speed at which firefighters can reach a burn site, the broad range of fires a single crew can reach by aircraft, and the larger equipment payloads that can be delivered to a fire compared to pedestrian crews. Once arrived on site, smokejumpers utilize similar strategies to hotshot crews and terrestrial crews to extinguish fires. Primarily, firefighters use axes to dig trenches around the fire's perimeter to isolate the flames from further fuel sources - nearby trees and shrubs. By tilling ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extreme Sport
Action sports, adventure sports or extreme sports are physical activity, activities perceived as involving a high degree of risk of injury or death. These activities often involve speed, height, a high level of physical exertion and highly specialized gear. Extreme tourism overlaps with extreme sport. The two share the same main attraction, "adrenaline, adrenaline rush" caused by an element of risk, and differ mostly in the degree of engagement and professionalism. Definition There is no precise definition of an 'extreme sport' and the origin of the term is unclear but it gained popularity in the 1990s when it was picked up by marketing companies to promote the X Games and when the Extreme Sports Channel and Extreme International launched. More recently, the commonly used definition from research is "a competitive (comparison or self-evaluative) activity within which the participant is subjected to natural or unusual physical and mental challenges such as speed, height, depth or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
André-Jacques Garnerin
André-Jacques Garnerin (31 January 1769 – 18 August 1823) was a French balloonist and the inventor of the frameless parachute. He was appointed Official Aeronaut of France. Biography André-Jacques Garnerin was born in Paris. During the first phase of the French Revolutionary Wars (1792–1797), he was captured by British troops. Subsequently, he was turned over to the Austrians and held as a prisoner of war in Buda, Hungary, for three years. Balloons and parachutes Ballooning André-Jacques Garnerin was a student of the ballooning pioneer Professor Jacques Charles. Garnerin was heavily involved in the flight of hot air balloons, and worked with his older brother, Jean-Baptiste-Olivier Garnerin (1766–1849), in most of his ballooning activities. His significant contributions to ballooning and his expertise led to his appointment as the Official Aeronaut of France. Garnerin began experiments with early parachutes based on umbrella-shaped devices and carried out the firs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vaud
Vaud ( ; , ), more formally Canton of Vaud, is one of the Cantons of Switzerland, 26 cantons forming the Switzerland, Swiss Confederation. It is composed of Subdivisions of the canton of Vaud, ten districts; its capital city is Lausanne. Its coat of arms bears the motto "Liberté et patrie" on a white-green bicolour. Vaud is the third-largest Swiss canton by population and fourth by size. It is located in Romandy, the partially French-speaking western part of the country, and borders the canton of canton of Neuchâtel, Neuchâtel to the north, the cantons of Canton of Fribourg, Fribourg and Canton of Bern, Bern to the east, the canton of Valais to the south, the canton of canton of Geneva, Geneva to the south-west, and France to the west. The geography of the canton includes all three natural regions of Switzerland: the Jura Mountains, the Swiss Plateau, and the Swiss Alps, (Swiss) Alps. It also includes some of the largest lakes of the country: Lake Geneva and Lake Neuchâtel. It ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypersonic
In aerodynamics, a hypersonic speed is one that exceeds five times the speed of sound, often stated as starting at speeds of Mach 5 and above. The precise Mach number at which a craft can be said to be flying at hypersonic speed varies, since individual physical changes in the airflow (like molecular dissociation and ionization) occur at different speeds; these effects collectively become important around Mach 5–10. The hypersonic regime can also be alternatively defined as speeds where specific heat capacity changes with the temperature of the flow as kinetic energy of the moving object is converted into heat. Characteristics of flow While the definition of hypersonic flow can be quite vague and is generally debatable (especially because of the absence of discontinuity between supersonic and hypersonic flows), a hypersonic flow may be characterized by certain physical phenomena that can no longer be analytically discounted as in supersonic flow. The peculiarities in hyperso ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Forest Firefighter
Wildfire suppression is a range of firefighting tactics used to suppress wildfires. Firefighting efforts depend on many factors such as the available fuel, the local atmospheric conditions, the features of the terrain, and the size of the wildfire. Because of this wildfire suppression in wild land areas usually requires different techniques, equipment, and training from the more familiar structure fire fighting found in populated areas. Working in conjunction with specially designed aerial firefighting aircraft, fire engines, tools, firefighting foams, fire retardants, and using various firefighting techniques, wildfire-trained crews work to suppress flames, construct fire lines, and extinguish flames and areas of heat in order to protect resources and natural wilderness. Wildfire suppression also addresses the issues of the wildland–urban interface, where populated areas border with wild land areas. In the United States and other countries, aggressive wildfire suppression aim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Special Operations
Special operations or special ops are military activities conducted, according to NATO, by "specially designated, organized, selected, trained, and equipped forces using unconventional techniques and modes of employment." Special operations may include reconnaissance, unconventional warfare, and counterterrorism, and are typically conducted by small groups of highly trained personnel, emphasizing sufficiency, stealth, speed, and tactical coordination, commonly known as ''special forces'' (SF) or ''special operations forces'' (SOF). History Australia In World War II, following advice from the British, Australia began raising special forces. The first units to be formed were independent companies, which began training at Wilson's Promontory in Victoria in early 1941 under the tutelage of British instructors. With an establishment of 17 officers and 256 men, the independent companies were trained as "stay behind" forces, a role that they were later employed in against the Japa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Parachute Association
The United States Parachute Association (USPA) is a private sports governing body for the sport of skydiving in the United States. Its headquarters are located in Fredericksburg, Virginia Fredericksburg is an Independent city (United States), independent city in Virginia, United States. As of the 2020 United States census, 2020 census, the population was 27,982. It is south of Washington, D.C., and north of Richmond, Virginia, R .... The USPA's roots go back to the National Parachute Riggers-Jumpers, Inc., which was formed in the 1930s. Functions USPA performs the following functions: * Issues sport skydiving licenses * Publishes and maintains skydiving training manuals and course guidelines from which instructional ratings are issued * Serves as legal advocate and political lobbyist for skydiving * Provides third-party insurance for skydivers * Maintains the Basic Safety Requirements (BSRs) as a set of voluntarily followed safety guidelines * Coordinates skydiving competiti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sport
Sport is a physical activity or game, often Competition, competitive and organization, organized, that maintains or improves physical ability and skills. Sport may provide enjoyment to participants and entertainment to spectators. The number of participants in a particular sport can vary from hundreds of people to a single individual. Sport competitions may use a team or single person format, and may be Open (sport), open, allowing a broad range of participants, or closed, restricting participation to specific groups or those invited. Competitions may allow a "tie" or "draw", in which there is no single winner; others provide tie-breaking methods to ensure there is only one winner. They also may be arranged in a tournament format, producing a champion. Many sports leagues make an annual champion by arranging games in a regular sports season, followed in some cases by playoffs. Sport is generally recognised as system of activities based in physical athleticism or physical de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Recreation
Recreation is an activity of leisure, leisure being discretionary time. The "need to do something for recreation" is an essential element of human biology and psychology. Recreational activities are often done for happiness, enjoyment, amusement, or pleasure and are considered to be "fun". Etymology The term ''recreation'' appears to have been used in English first in the late 14th century, first in the sense of "refreshment or curing of a sick person", and derived turn from Latin (''re'': "again", ''creare'': "to create, bring forth, beget"). Prerequisites to leisure People spend their time on activities of daily living, Employment, work, sleep, social duties and leisure, the latter time being free from prior commitments to physiologic or social needs, a prerequisite of recreation. Leisure has increased with increased longevity and, for many, with decreased hours spent for physical and economic survival, yet others argue that time pressure has increased for modern people, as the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
