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Trends
British Library digitises Greek manuscripts Prof Yash
Pal This universe |
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Mystery of solar tsunami Solar activities like sunspots and solar flares on the Sun’s surface are a continuous phenomenon and these activities usually ebb and flow on a fairly predictable cycle. A solar flare is an explosion on the Sun that happens when energy stored in twisted magnetic fields, usually above sunspots, is suddenly released. Flares produce a burst of radiation across the electromagnetic spectrum, from radio waves to x-rays and gamma rays. The amount of energy released is the equivalent of millions of 100-megaton hydrogen bombs exploding at the same time. The first solar flare was recorded in astronomical literature on September 1, 1859. Typically, a cycle lasts about 11 years, taking roughly five years and five months to move from a solar minimum, a period of time when there are few sunspots, to peak at the solar maximum, during which sunspot activity is amplified. The last solar maximum occurred in 2001, but it was particularly weak and long lasting. These eruptions occur when immense magnetic structures in the solar atmosphere lose their stability and can no longer be held down by the Sun’s huge gravitational pull. Solar tsunamis were discovered in 1997 by the Solar and Heliospheric Observatory (SOHO). In 1997, a Coronal Mass Ejections (CME) came blasting from an active region on the Sun’s surface, and SOHO recorded a tsunami rippling away from the blast site. The technical name is “fast-mode MagnetoHydroDynamical wave” or “MHD wave” or “Moreton wave” for short. Solar tsunami is a tsunami-like shock wave that forms on the Sun. These waves generally roll across the hot surface of the Sun, destroying or sweeping away filamentary material. These waves are infrequent yet very powerful. The one STEREO saw reared up about 100,000 km high, raced outward at 250 km/second (560,000 mph), and packed as much energy as 2.4 million megatons of TNT (1029 ergs). While almost everyone knows about tsunami that refers to destructive waves of the sea, the news of solar tsunami heading towards the Earth has left the world jittery of the relatively new and unknown phenomenon. Solar tsunami is a towering wave of hot plasma racing across the Sun’s surface. It has suddenly grabbed the attention of the inhabitants of the Earth as the news of the waves heading towards it (Earth) hit the headlines worldwide. According to a NASA press release, the Coronal Mass Ejections (CME) clouds, usually emitted from the Sun over several hours, can carry up to 10 billion tons of plasma. They usually move away from the Sun at about 1.6 million km/h, allowing them to travel 150 million km to the Earth in only three to four days. Once they arrive at the Earth, they interact with the planet’s magnetic field, which may lead to a geomagnetic storm. According to a report, auroras happen when energised particles from the Sun interact with the Earth’s magnetic field. The particles flow down the field lines that run toward Earth’s poles, banging into atoms of atmospheric nitrogen and oxygen along the way. The charged solar particles give Earth’s atmospheric atoms an energy boost, which then gets released as light, producing the shimmering curtains of greens, reds, and other colours. Recently, the Sun’s surface erupted and blasted tons of plasma—ionised atoms—into interplantary space. This eruption is directed right at us and it’s the first major Earth-directed eruption in quite some time. It took two days for the atoms to travel the 93 million miles to the Earth. The NASA captured images of the event, called a coronal mass ejection, from the Solar Dynamics Observatory (SDO), a spacecraft launched in February. SDO provides better-than-HD quality views of the Sun at a variety of wavelengths. This first image, which is false-colour, shows hot solar plasma at temperatures ranging between one to two million kelvins. The dense golden swirl on the left is a solar flare and a coronal mass ejection, which sent a billion-ton cloud of particles hurtling towards the Earth. The most recent solar eruptions are the signs that the Sun is waking up and heading towards another solar maximum expected in the 2013 time frame. According to scientists, the possible implications of solar tsunami and required preparations from them are highlighted as: Possible implications: One of the biggest concerns is the potential for a major blackout. The major impacts would be on the power grid. A major storm could cause immense damage to world communication system through satellites. It remains unclear, however, how much damage the eruption will cause the world's communication tools. It could cause major blackouts that could last for weeks, possibly months or even years. Preparations: Scientists are working together to prepare for space weather events, and will soon be launching probes to monitor radiation belts. On individual basis, a little bit of extra water, a couple of flashlights and a transistor radio are a few good things to have. However, according to scientists, there is nothing to worry about as the consequences and effects of solar tsunami would just be limited to blackouts, disruption in communication systems and a rather desirable effect of brighter auroras or the northern lights. Scientists are assured enough that the solar tsunami poses no direct threat to the Earth and life on the planet. On the other hand, solar tsunami waves can also improve our forecasting of space weather. The writer teaches at the
Department of Physics, Sant Longowal Institute of Engineering and Technology (SLIET), Longowal
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Trends WASHINGTON: Magma has worked its way up to just under the surface in a remote region of northwest Saudi Arabia, causing a flurry of small to moderate quakes and threatening to form a new volcano, researchers. A swarm of 30,000 quakes shook the region of Harrat Lunayyir from May to June last year and opened an 5-mile long rift. British scientists say cuts will cripple research LONDON: Looming spending cuts in science will endanger Britain's fragile economic recovery, drive away foreign talent and do untold damage to the nation's competitive edge, leading academics warned on Friday. Six of the country's top scientists joined forces to spell out the risk posed by chopping funding in science and technology. Canadian ornithopter achieves Da Vinci's dream VANCOUVER: Leonardo Da Vinci would be proud: the Snowbird has flown. Centuries after the Renaissance inventor sketched a human-powered flying machine, Canadian engineering students say they have flown an engineless aircraft that stays aloft by flapping its wings like a bird. NASA layoffs showdown looms CAPE CANAVERAL, Florida: With more than 1,500 space shuttle workers facing layoffs this week, legislators say they will take a final shot at passing a blueprint for the U.S. human space program before adjourning ahead of the November 2 congressional elections. "We're teetering right on the edge," U.S. Senator Bill Nelson, a Florida Democrat,said at a space policy symposium at the University of Central Florida in Orlando.
— Reuters
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British Library digitises Greek manuscripts
The British Library in London has posted over a quarter of its Greek manuscripts, equating to more than 280 volumes, online, the latest step towards digitising important ancient documents. The manuscripts, freely available at
www.bl.uk/manuscripts, are part of what the library calls one of the most important collections outside Greece for the study of more than 2,000 years of Hellenic culture. The library holds a total of over 1,000 Greek manuscripts, over 3,000 Greek papyri and a comprehensive collection of early Greek printing. They contain information for scholars working on the
literature, history, science, religion, philosophy and art of the Eastern Mediterranean in the Classical and
Byzantine periods. "This is exactly what we have all hoped for from new technology, but so rarely get," said Mary Beard, professor of classics at the University of Cambridge. It opens up a precious resource to anyone-from the specialist to the curious-anywhere in the world, for free. Highlights of the digitised manuscripts include the highly illustrated Theodore Psalter produced in Constantinople in 1066 and Babrius's fables, discovered on Mount Athos in 1842, which contains 123 Aesopic fables and was corrected by the great Byzantine scholar Demetrius Triclinius. The initiative, funded by a grant from the Stavros Niarchos Foundation, is the latest by the library to make ancient, fragile and rare documents available to a wider public. Other digital projects include a 16th century notebook by Leonardo Da Vinci and the 4th century Codex Sinaiticus, containing the earliest surviving copy of the
complete New Testament. — by arrangement with The Independent
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This universe Why does a battery get depleted if it is not used for a long time? This happens mainly because a charged body loses charge through leakage into the atmosphere. This is particularly so if the air is moist. Besides this, the terminals also get oxidised with time That batteries have a finite life is also due to occurrence of the unwanted chemical or physical changes to, or the loss of, the active materials of which they are made. This might happen if the membranes that separate different chemicals erode or lose their character.
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WASHINGTON: Magma has worked its way up to just under the surface in a remote region of northwest Saudi Arabia, causing a flurry of small to moderate quakes and threatening to form a new volcano, researchers. A swarm of 30,000 quakes shook the region of Harrat Lunayyir from May to June last year and opened an 5-mile long rift.
