Muslim

A Muslim (Arabic: مسلم‎; /ˈmʊslɨm/ MOOS-lim or English pronunciation: /ˈmʌzlɨm/ MUZ-lim) or Moslem is an adherent of the religion of Islam. Literally, the word means "one who submits (to God)". Muslim is the participle of the same verb of which Islam is the infinitive. All Muslims observe Sunnah, but differences in the definition of what is and what is not Sunnah has led to the emergence of sectarian movements. The well-organised and cohesive community of Muslims who accept the Sunnah as defined within one of the traditional Maliki, Hanafi, Shafi or Hanbali madhabs are the classical Sunni Muslims.Other Muslims, for example the Ahmadiyya Muslim Community, are also well known as being an organised and a disciplined community

Muslims believe that there is only one God, called Allah in Arabic. Muslims also believe that Islam existed long before Muhammad though it was not called Islam until the revelation of Surah al-Ma'ida. Muslims believe that this religion had evolved with time from the time of Adam until the time of Muhammad and was completed with the revelation of verse 3 of Surah al-Ma'ida:

This day have I perfected your religion for you, completed My favour upon you, and have chosen for you Islam as your religion.

The Qur'an describes many Biblical prophets and messengers as Muslim: Adam, Noah (Arabic: Nuh), Moses and Jesus and his apostles. The Qur'an states that these men were Muslims because they submitted to God, preached his message and upheld his values. Thus, in Surah 3:52 of the Qur'an, Jesus’ disciples tell Jesus, "We believe in God; and you be our witness that we submit and obey (wa-shahad be anna muslimūn)."

Muslims consider making ritual prayer five times a day a religious duty (fard) (see the section on Ismāˤīlīs below for exceptions); these five prayers are known as fajr, dhuhr, ˤasr, maghrib and ˤishā'. There is also a special Friday prayer called jumuˤah. Currently, the most up to date reports from an American think-tank and PBS have estimated 1.2 to 1.57 billion Muslims populate the world, or about 20% of an estimated 2009 world population of 6.8 billion,[4] with 60% in Asia and 20% of Muslims living in the Middle East and North Africa

Etymology

S-L-M#Islam "Piety, Faith"

Arabic muslimun is the stem IV participle of the triliteral S-L-M "to be whole, intact". A literal translation would be "one who wants or seeks wholeness", where "wholeness" translates islāmun. In a religious sense, Al-Islām translates to "faith, piety", and Muslim to "one who has (religious) faith or piety". According to the Quran, Abraham was ancestor of the Muslims by his covenant with God. Current use of "Muslim" is defined in the Amman Message.

The feminine form of muslimun is muslimatun (Arabic: مسلمة‎) and a female adherent is a Muslimah. Mu'min (Arabic: مؤمن‎) is an Arabic Islamic term frequently referenced in the Qur'an, meaning "believer", and denoting a person that has complete submission to the will of Allah

Other words for Muslim

The ordinary word in English is "Muslim", pronounced /ˈmʊslɪm/ or /ˈmʌzləm/. The word is pronounced [ˈmʊslɪm] in Arabic. It is sometimes transliterated "Moslem", an older, possibly Persian-based spelling. This can be felt to be an abuse of the word.“Submitter” is the English equivalent of the Arabic word “Muslim”.

Until at least the mid-1960s, many English-language writers used the term Mohammedans or Mahometans. Although such terms were not necessarily intended to be pejorative, Muslims argue that the terms are offensive because they allegedly imply that Muslims worship Muhammad rather than God.

Variant forms of this word are still used by many Indo-European and Turkic languages. These words are similar to the French, Spanish, Portuguese, Italian, Russian, Turkish, Bosnian, Persian, Kurdish, and Hindi words for "Muslim".

In spite of that, the Polish word for Muslim almost certainly does come directly from the Turkish. While it appears as if it came directly from the Arabic, in "Muzułmanin", the "ł" sound is close to either the English "w", or to the "l" in Allah, when pronounced by the Turkic peoples.

Islam

The majority of Muslims accept as a Muslim anyone who has publicly pronounced the Shahadah (declaration of faith) which states,

Ash-hadu an laa ilaha illa-lah

Wa ash-hadu anna Muhammadan rasulullah

"I bear witness there is no deity worthy of worship except Allah and I bear witness, Muhammad is His messenger".

The Amman Message more specifically declared that a Muslim is one who adheres to one of the eight schools of Islamic legal thought.

Currently, there are between one billion and two billion Muslims, making it the second largest religion in the world.

Muslim and mu'min

One of the verses in the Qur'an makes a distinction between a mu'min, a believer, and a Muslim:

The Arabs of the desert say, "We believe." (tu/minu) Say thou: Ye believe not; but rather say, "We profess Islam;" (aslamna) for the faith (al-imanu) hath not yet found its way into your hearts. But if ye obey [God] and His Apostle, he will not allow you to lose any of your actions: for [God] is Indulgent, Merciful ('The Koran 49:14, Rodwell).

According to the academician Carl Ernst, contemporary usage of the terms "Islam" and "Muslim" for the faith and its adherents is a modern innovation. As shown in the Quranic passage cited above, early Muslims distinguished between the Muslim, who has "submitted" and does the bare minimum required to be considered a part of the Muslim community, and the mu'min, the believer, who has given himself or herself to the faith heart and soul. Ernst writes:

"The Arabic term Islam itself was of relatively minor importance in classical theologies based on the Qur'an. If one looks at the works of theologians such as the famous al-Ghazali (d. 1111), the key term of religious identity is not Islam but iman (faith), and the one who possesses it is the mu'min (believer). Faith is one of the major topics of the Qur'an; it is mentioned hundreds of times in the sacred text. In comparison, Islam is a less common term of secondary importance; it only occurs eight times in the Qur'an. Since, however, the term Islam had a derivative meaning relating to the community of those who have submitted to God, it has taken on a new political significance, especially in recent history."

For another term in Islam for a non-Muslim who is a monotheist believer (usually applied historically in a pre-Islamic context), see hanif.

(source:wikipedia)

Jet aircraft

A jet aircraft is an aircraft propelled by jet engines. Jet aircraft generally fly much faster than propeller-powered aircraft and at higher altitudes – as high as 10,000 to 15,000 meters (about 33,000 to 49,000 ft). At these altitudes, jet engines achieve maximum efficiency over long distances. The engines in propeller powered aircraft achieve their maximum efficiency at much lower altitudes. Jet aircraft can move faster than sound.

Two engineers, Frank Whittle in the United Kingdom and Hans von Ohain in Germany, developed the concept independently during the late 1930s. The concept had already been discussed as early as August 1928 by Frank Whittle at Flying School, Wittering, but Hans von Ohain also wrote in February 1936 to Ernst Heinkel, telling him of the design and its possibilities. However, it can be argued that A. A. Griffith, who published a paper in July 1926 on compressors and turbines, which he had been studying at the RAE, also deserves priority credit.

History

Heinkel He 178, the world's first aircraft to fly purely on turbojet power

Caproni Campini N1 in flight

A number of jet powerplants were suggested from the first instances of powered flight. René Lorin, Morize, Harris proposed systems for creating a jet efflux.

The "turbojet", the most common type of jet in use today, was invented in the 1930s, independently by Frank Whittle and Hans von Ohain. The first turbojet aircraft to fly was the Heinkel He 178 prototype of the German Air Force, the Luftwaffe, piloted by Erich Warsitz on August 27, 1939.

The first flight of a jet engined aircraft to come to popular attention was the Italian Caproni Campini N.1 motorjet prototype that flew on August 27, 1940. Test pilot Major Mario De Bernardi of the Regia Aeronautica was at the controls. It was the first jet aircraft recognised by the Fédération Aéronautique Internationale (at the time the German He 178 program was still kept secret). Campini had proposed the motorjet in 1932.

The British experimental Gloster E.28/39 first took to the air on May 15, 1941, powered by Sir Frank Whittle's turbojet, and piloted by Glosters test pilot Flt Lt PG Sayer. After the United States was shown the British work, it produced the Bell XP-59A with a version of the Whittle engine built by General Electric, which flew on September 12, 1942, piloted by Col L. Craigie.

The first operational jet fighter was the Messerschmitt Me 262., made by Germany during late World War II. It was the fastest conventional aircraft of World War II – although the rocket-powered Messerschmitt Me 163 Komet was faster. It had first flown in 1941 but mass production started in 1944 with the first squadrons opeational that year, too late for a decisive effect on the outcome of the war. About the same time, mid 1944, the United Kingdom's Gloster Meteor was being committed to defense of the UK against the V1 flying bomb – itself a jet powered aircraft – and then ground-attack operations over Europe in the last months of the war. USSR tested its own Bereznyak-Isayev BI-1 in 1942, but the project was scrapped by Stalin in 1945. The Imperial Japanese Navy also developed jet aircraft in 1945, including the Nakajima J9Y Kikka, a crude copy of the Me-262.

The US introduced the North American B-45 Tornado, their first jet bomber, into service in 1948. Although capable of carrying nuclear weapons it was used for reconnaissance over Korea.

On November 8, 1950, during the Korean War, United States Air Force Lt. Russell J. Brown, flying in an F-80, intercepted two North Korean MiG-15s near the Yalu River and shot them down in the first jet-to-jet dogfight in history.

The UK put the English Electric Canberra into service in 1951. Designed to fly higher and faster than any interceptor it carried no defensive armament.

BOAC operated the first commercial jet service, from London to Johannesburg, in 1952 with the de Havilland Comet jetliner. The Comet was initially ahead of rivals, but a series of crashes gave time for the Boeing 707 to enter service in 1958 and dominate the market for civilian airliners.

The fastest military jet plane was the SR-71 Blackbird at Mach 3.35 (2,275 mph, 3,661 km/h). The fastest commercial jet plane was the Tupolev Tu-144 at Mach 2.35 (1,555 mph, 2,503 km/h).

Modern jet aircraft

Bahrain Royal Flight Boeing 747SP

Modern airliners cruise at speeds of 0.75 to 0.85 Mach, or 75% to 85% of the speed of sound.

Other jets

Most people use the term 'jet aircraft' to denote gas turbine based airbreathing jet engines, but rockets and scramjets are both also propelled by them.

The fastest airbreathing jet aircraft is the unmanned X-43 scramjet at around Mach 9–10. The fastest manned (rocket) aircraft is the X-15 at Mach 6.85.

The Space Shuttle, while far faster than the X-43 or X-15, is not regarded as an aircraft during ascent. During re-entry it is classed (like a glider) as an unpowered aircraft.

The shape of most airliners is usually designed to have nearly the same cross-sectional area at each point along its length as the Sears-Haack body

Aerodynamics

Many jet aircraft fly at high speeds, either supersonic or speeds just below the speed of sound ("transonic"). Aerodynamics is therefore an important consideration.

Jet aircraft are usually designed using the Whitcomb area rule, which says that the cross-section of the aircraft at any point must be approximately the same as the Sears-Haack body. This minimises the production of shockwaves which would waste energy.

Jet engines

Main article: jet engine

Jet engines come in several main types:

turbojet

turbofan (which come in two main forms low bypass turbofan and high bypass turbofan)

rocket

The types are used for different aircraft. Turbojets are seldom used, but was used on Concorde; it has a high exhaust speed and low frontal cross-section, and so is best suited to high-speed flight. Low bypass turbofans have a lower exhaust speed than turbojets and are used for transonic and low supersonic speeds. High bypass turbofans are used for subsonic aircraft and are quite efficient and are widely used for airliners.

Rockets have extremely fast exhaust speeds and are mainly used when high speeds or extremely high altitudes are needed.

(ource:wikipedia)