Wikipedia:Main Page history/2019 September 30

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From today's featured article

IFF Mark II was the first operational identification friend or foe system, developed by the Royal Air Force just before World War II. The Mark I, its predecessor, amplified the signals of the British Chain Home radar systems, triggering a radar display blip. It required manual tuning, and operators could not always distinguish between an enemy aircraft and a friendly one with a maladjusted IFF. The Mark II, deployed at the end of the Battle of Britain in late 1940, fixed this problem with an automatic gain control and three automatic tuners that covered a wider selection of radars. The Mark II's frequencies were sufficient for the early war period, but by 1942 many more radars were in use, including incompatible ones based on the cavity magnetron. The IFF Mark III eliminated the multiple tuners and operated on a single frequency that could be used with any radar; it entered service in 1943 and quickly replaced the Mark II. (Full article...)

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Did you know...

Euro-sign sculpture

... that a monumental euro-sign sculpture (pictured) is installed at the Willy-Brandt-Platz in Frankfurt, which was named in 1992 after the former chancellor?
... that Finland's minister of science and culture Hanna Kosonen is a world champion in ski orienteering?
... that falguera, a plant known from only one valley in Spain, is threatened by rock climbers and by road maintenance?
... that after the U.S. Supreme Court struck down its racial quota, the management of Starrett City left apartments empty, in an attempt to rent them at market rate, instead of renting them to black and Hispanic families?
... that a few months after Lü Peijian was appointed China's auditor general, he announced the discovery of more than US$1.6 billion worth of tax evasion, fraud, and waste?
... that the silk made by webspinners is produced from glands on their forelegs?
... that before he wrote Areyo Hoshikuzu, a manga about demobilized soldiers in occupied Japan, series creator Sansuke Yamada was best known as a gay manga artist?
... that funeral dinners are regularly attended by up to a quarter of the residents in Darrington, Washington?
... that the Jewish Democratic Committee and the Romanian Communist Party together sent Romanian Jews to Israel, hoping to make it a communist ally?
... that Patricia Swallow led the Wrens, served on the Heron, and was vice president of the Royal Naval Bird Watching Society?

In the news

Middlesex Guildhall

During a prolonged period of haze over Southeast Asia, more than 800,000 people endure respiratory diseases.
An earthquake in Kashmir kills 38 people and injures more than 700 others.
The Supreme Court of the United Kingdom (building pictured) unanimously rules that the September 2019 prorogation of Parliament was unlawful and void.
Astronomers announce that 2I/Borisov is the first verified interstellar comet, ahead of its closest approach to the Sun on 7 December.

On this day

September 30: First day of Rosh Hashanah (Judaism, 2019, AM 5780)

Hotel Ambacang, destroyed by the 2009 Sumatra earthquake

737 – Muslim conquest of Transoxiana: Türgesh tribes attacked the exposed baggage train of the Umayyads, which had been sent ahead of the main force, and captured it.
1551 – Sue Takafusa, a military leader for the Ōuchi clan in western Japan, led a coup against the daimyō, Ōuchi Yoshitaka, leading to the latter's forced suicide.
1882 – The Vulcan Street Plant, the first hydroelectric central station to serve a system of private and commercial customers in North America, went on line in Appleton, Wisconsin.
1939 – NBC broadcast the first televised American football game, between the Fordham Rams and the Waynesburg Yellow Jackets.
2009 – A 7.6 M_W earthquake struck off the southern coast of Sumatra, Indonesia (damage pictured), killing 1,115 and impacting an estimated 1.2 million people.

Honorius of Canterbury (d. 653) · Lucinda Hinsdale Stone (b. 1814) · Catie Ball (b. 1951)

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From today's featured list

Five-time winner Allyson Felix

The Jesse Owens Award is an annual track and field award that is the highest accolade given out by USA Track & Field. As the country's highest award for the sport, it bears Jesse Owens's name in recognition of his significant career, which included four gold medals at the 1936 Olympic Games. First awarded in 1981 to hurdler Edwin Moses, it was created to recognize the season's top American performer in track and field competitions. In 1996, the award was divided into two categories, with both a male and female winner. The 1996 winners, Michael Johnson and Gail Devers, each won two gold medals at that year's Olympics in Atlanta. The winners of the award are typically announced in late November or early December after the end of the outdoor track and field season. A number of athletes have received the award on more than one occasion: Jackie Joyner-Kersee was the first to do so with back-to-back wins in 1986 and 1987, while Carl Lewis won his second award in 1991. Sprinter Allyson Felix (pictured) has won the award on five occasions, more times than any other athlete. (Full list...)

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Today's featured picture

The gentoo penguin (Pygoscelis papua) is a penguin species in the genus Pygoscelis, most closely related to the Adélie penguin and the chinstrap penguin. The earliest scientific description was made in 1781 by Johann Reinhold Forster with a reference point of the Falkland Islands. They call in a variety of ways, but the most frequently heard is a loud trumpeting which the bird emits with its head thrown back. The gentoo penguin is easily recognized by the wide white stripe extending like a bonnet across the top of its head and its bright orange-red bill. It has pale whitish-pink webbed feet and a fairly long tail – the most prominent tail of all penguin species. Chicks have grey backs with white fronts. As the gentoo penguin waddles along on land, its tail sticks out behind, sweeping from side to side, hence the scientific name Pygoscelis, which means 'rump-tailed'.

Photograph credit: Andrew Shiva

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