"Amigo"
2016-02-29
Astronomy picture of the day - 2016 February 29 - Julius Caesar and Leap Days
Image Credit: Classical Numismatic Group, Inc., Wikimedia
Explanation: Today, February 29th, is a leap day - a relatively rare occurrence. In 46 BC, Julius Caesar, featured here in a self-decreed minted coin, created a calendar system that added one leap day every four years. Acting on advice by Alexandrian astronomer Sosigenes, Caesar did this to make up for the fact that the Earth's year is slightly more than 365 days. In modern terms, the time it takes for the Earth to circle the Sun is slightly more than the time it takes for the Earth to rotate 365 times (with respect to the Sun -- actually we now know this takes about 365.24219 rotations). So, if calendar years contained 365 days they would drift from the actual year by about 1 day every 4 years. Eventually July (named posthumously for Julius Caesar himself) would occur during the northern hemisphere winter! By adopting a leap year with an extra day every four years, the calendar year would drift much less. This Julian Calendar system was used until the year 1582 when Pope Gregory XIII provided further fine-tuning when he added that leap days should not occur in years ending in "00", unless divisible by 400. This Gregorian Calendar system is the one in common use today.
A herdeira ultimamente nascida: Haize!
Haize - 28-02-2016
(My last little baby... e o carimbo de "fabrica" esta na vista direita mais pequena...)
(My last little baby... e o carimbo de "fabrica" esta na vista direita mais pequena...)
2016-02-28
Astronomy picture of the day - 2016 February 28 - IC 1848: The Soul Nebula
Image Credit & Copyright: Roberto Colombari
Explanation: Stars are forming in the Soul of the Queen of Aethopia. More specifically, a large star forming region called the Soul Nebula can be found in the direction of the constellation Cassiopeia, who Greek mythology credits as the vain wife of a King who long ago ruled lands surrounding the upper Nile river. The Soul Nebula houses several open clusters of stars, a large radio source known as W5, and huge evacuated bubbles formed by the winds of young massive stars. Located about 6,500 light years away, the Soul Nebula spans about 100 light years and is usually imaged next to its celestial neighbor the Heart Nebula (IC 1805). The featured image appears mostly red due to the emission of a specific color of light emitted by excited hydrogen gas.
2016-02-27
Astronomy picture of the day - 2016 February 27 - Northern Pluto
Image Credit: NASA, Johns Hopkins Univ./APL, Southwest Research Institute
Explanation: Gaze across the frozen canyons of northern Pluto in this contrast enhanced color scene, imaged last July by the New Horizons spacecraft. Currently known as Lowell Regio, the region has been informally named for Percival Lowell, founder of the Lowell Observatory. Also famous for his speculation that there were canals on Mars, in 1906 Lowell started the search that ultimately led to Pluto's discovery. Pluto's North Pole itself is above and left of center in the the frame. The pale bluish floor of the broad canyon on the left is about 70 kilometers (45 miles) wide, running vertically toward the south. Higher elevations take on a yellowish hue. New Horizon's measurements have determined that in addition to nitrogen ice, methane ice is abundant across northern Pluto's Lowell Regio.
2016-02-26
Astronomy picture of the day - 2016 February 26 - The Tarantula Nebula
Image Credit & Copyright: Processing - Robert Gendler, Roberto Colombari
Data - Hubble Tarantula Treasury, European Southern Observatory
Explanation: The Tarantula Nebula is more than a thousand light-years in diameter, a giant star forming region within nearby satellite galaxy the Large Magellanic Cloud, about 180 thousand light-years away. The largest, most violent star forming region known in the whole Local Group of galaxies, the cosmic arachnid sprawls across this spectacular composite view constructed with space- and ground-based image data. Within the Tarantula (NGC 2070), intense radiation, stellar winds and supernova shocks from the central young cluster of massive stars, cataloged as R136, energize the nebular glow and shape the spidery filaments. Around the Tarantula are other star forming regions with young star clusters, filaments, and blown-out bubble-shaped clouds In fact, the frame includes the site of the closest supernova in modern times, SN 1987A, at the lower right. The rich field of view spans about 1 degree or 2 full moons, in the southern constellation Dorado. But were the Tarantula Nebula closer, say 1,500 light-years distant like the local star forming Orion Nebula, it would take up half the sky.
2016-02-25
Texto - E a minha tia Celeste cantava o Fado - 1957
Naqueles belos anos todos cantavam ; o João
Maria Tudela, a Emissora Nacional, o Rádio Clube… Beatriz Costa, Maria de
Lurdes Rezende…e quando cansados de tanto cantar na Rádio, vinham alguns reclames tipo, “Tide a lavar e eu a descansar”…
E chegava, enfim, o que mais ansiávamos: Os Parodiantes de Lisboa! “Patilhas e Ventoinha”
marcaram para sempre a minha meninice…
Televisão, Internet, tecnologias que hoje nos
são habituais, nem sequer imaginar…
Telefone não existia para a nossa classe; íamos
a casa de uns e outros sem prevenir nem hora marcada; éramos recebidos com a
naturalidade dos familiares bem-vindos…
De quando em vez, ouvia-se cantar o fado; por
vezes numa rara telefonia… Mas, na maioria dos casos, eram vozes bem conhecidas;
a minha tia Celeste era uma delas!
E eram as incessantes corridas entre putos;
partiam da avenida da Bélgica, davam a volta ao quarteirão, passando pelo Beco
da Adega e, por vezes, atravessavam a “avenida” sem carros. Cruzavam por vezes
velhas carrossas com rodas em “cauthcu” que as tornavam um pouco mais
silenciosas.
Ao fim do dia, quase ao anoitecer, era tempo de começar as
partidas: tocar às campainhas, atirar lixo contra as montras, desafiar capicuas
(guardas republicanos a cavalo), levar de “cavalo marinho” para alguns, “curtir”
como se diz hoje em dia.
Foi a minha meninice no Barreiro; tinha então
todos os seres amados, entretanto desaparecidos, de que tenho todas as saudades do Mundo!
Bordeaux, 25 de Fevereiro de 2016
JoanMira
Astronomy picture of the day - 2016 February 25 - Highest, Tallest, and Closest to the Stars
Image Credit & Copyright: Jeff Dai, O Chul Kwon, Stéphane Guisard (Los Cielos de America), TWAN
Explanation: Fans of planet Earth probably recognize its highest mountain, the Himalayan Mount Everest, on the left in this 3-panel skyscape of The World at Night. Shrouded in cloud Everest's peak is at 8,848 meters (29,029 feet) elevation above sea level. In the middle panel, stars trail above volcanic Mauna Kea forming part of the island of Hawaii. Festooned with astronomical observatories, its summit lies a mere 4,168 meters above sea level. Still, measured from its base starting below the ocean's surface, Mauna Kea is over 10,000 meters tall, making it Earth's tallest mountain from base to summit. At right, beneath the arc of the Milky Way is the Andean mountain Chimborazo in Ecuador. The highest equatorial mountain, the Chimborazo volcano's peak elevation is 6,268 meters above sea level. But rotating planet Earth is a flattened sphere (oblate spheroid) in shape, its equatorial diameter greater than its diameter measured pole to pole. Sitting nearly on top of Earth's greatest equatorial bulge, Chimborazo's peak is the farthest point on the planet's surface from the center, over 2,000 meters farther from the center of the Earth than Everest's peak. That makes Chimborazo's summit the place on Earth's surface closest to the stars.
2016-02-24
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