Cirrus clouds are atmospheric clouds characterized by thin, wispy
strands, often bunched into tufts. They range in color from white to
faint gray and form when water vapor undergoes deposition at altitudes
above 5,000 m (16,500 ft) in temperate regions and above 6,000 m
(20,000 ft) in tropical regions. They also form from the outflow of
tropical cyclones or the anvils of cumulonimbus clouds. Since these
cirrus clouds arrive in advance of the frontal system or tropical
cyclone, they indicate that the weather conditions may soon deteriorate.
While they can indicate the arrival of precipitation, cirrus clouds
themselves produce only fall streaks (falling ice crystals that
evaporate before landing on the ground). Jet streams can stretch cirrus
clouds across continents, but the clouds will remain only a few
kilometers deep. When visible light interacts with the ice crystals in
cirrus clouds, it can produce glories, sun dogs, and fire rainbows.
Read more: <https://en.wikipedia.org/wiki/Cirrus_cloud>
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Today's selected anniversaries:
1911:
Mexican president Porfirio Díaz and the revolutionary
Francisco I. Madero signed the Treaty of Ciudad Juárez to end
hostilities between each other's forces, concluding the initial phase of
the Mexican Revolution.
<https://en.wikipedia.org/wiki/Treaty_of_Ciudad_Ju%C3%A1rez>
1927:
Aboard the Spirit of St. Louis, American aviator Charles
Lindbergh completed the first solo non-stop transatlantic flight, flying
from Roosevelt Field near New York City to Paris–Le Bourget Airport.
<https://en.wikipedia.org/wiki/Charles_Lindbergh>
1946:
While working with a mass of plutonium known as the demon core,
Manhattan Project physicist Louis Slotin accidentally exposed himself to
a lethal dose of hard radiation.
<https://en.wikipedia.org/wiki/Louis_Slotin>
2014:
A Taiwanese man carried out a stabbing spree on a Taipei Metro
train, killing four people and injuring 24 others.
<https://en.wikipedia.org/wiki/2014_Taipei_Metro_attack>
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Wiktionary's word of the day:
orature:
The oral equivalent of literature: a collection of traditional folk
songs, stories, etc., that is communicated orally rather than in
writing. […]
<https://en.wiktionary.org/wiki/orature>
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Wikiquote quote of the day:
In his own way each man must struggle, lest the moral law become
a far-off abstraction utterly separated from his active life.
--Jane Addams
<https://en.wikiquote.org/wiki/Jane_Addams>