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Ozone study dims Sun's global warming role Why people get ‘unfriended’ First dinosaurs walked on little cat feet Giant penguin fossil gives evolutionary clues Linguists discover new language Global Fund sees disease fight hampered by donors IVF pioneer wins medicine Nobel prize Discovery poses ethical dilemmas Scientists find way to refine Botox for new uses Prof Yash
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Ozone study dims Sun's global warming role Until now it was assumed that as solar activity – indicated by the number of sunspots on the Sun's surface – increases, then so does the amount of solar radiation coming to the Earth to heat the planet. However, a study based on satellite data of the Earth's atmosphere has shown there is a complicated interaction between the varying amounts of radiation from the Sun and the amount of ozone in the atmosphere. The investigation, which ran from 2004 to 2007 when the solar activity cycle was decreasing, found there was a rise in ozone that may have resulted in a corresponding increase in temperatures, which would have been indirectly due to the Sun rather than to increases in man-made greenhouse gases, the scientists said. The researchers emphasised the findings do not undermine the idea that carbon dioxide in the atmosphere is the main cause of global warming – but they do suggest the Sun's direct role in warming the planet has been overplayed in computer models. "These results are changing what we thought we knew about the Sun's effect on our climate. However, they only show us a snapshot of the Sun's activity and its behaviour over the three years of our study could be an anomaly," said Joanna Haigh, of the Grantham Institute for Climate Change, at Imperial College London. "We cannot jump to conclusions based on what we have found during this comparatively short period," Dr Haugh said."However, if further studies find the same pattern over a longer period of time, this could suggest that we may have overestimated the Sun's role in warming the planet." Although there is an 11-year solar cycle, the overall activity of the Sun has risen slightly over the past century, leading some climate "sceptics" to suggest the Sun rather then carbon dioxide is causing global warming. However, the authors of the latest study, published in Nature, said solar activity could account for at most about 10 per cent of the extra warming this century. But if the new findings can be supported, it would mean this greater solar activity may have kept global warming in check by lowering temperatures slightly and counteracting the influence of greenhouse
gases. — The Independent |
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Facebook
has become the best platform where friends meet to share photos, news and gossip, but when relationships sour, another phenomenon often occurs - unfriending. And now, in a first-of-its -kind comprehensive, a University of Colorado Denver Business School student has revealed the top reasons for Facebook unfriending, who is unfriended and how they react to being unfriended. “Researchers spend a lot of time examining how people form friendships online but little is known on how those relationships end. Perhaps this will help us develop a theory of the entire cycle of friending and unfriending,” said Dr. Christopher Sibona, a PhD student in the Computer Science and Information Systems program. After surveying more than 1,500 Facebook users on Twitter, Sibona found the number-one reason for unfriending is frequent, unimportant posts. “The 100th post about your favourite band is no longer interesting,” he said. The second reason was posting about polarizing topics like religion and politics. “They say not to talk about religion or politics at office parties and the same thing is true online,” he said. Inappropriate posts, such as crude or racist comments, were the third reason for being unfriended. The study showed 57 percent of those surveyed unfriended for online reasons, while 26.9 percent did so for offline behaviour. Sibona observed a sort of online hierarchy of dominant and subordinate relationships. For example, those making friend requests stood a much higher chance of being abruptly unfriended.
— ANI |
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First dinosaurs walked on little cat feet WASHINGTON: Tiny footprints from Poland show that
the first dinosaurs were extremely small animals that walked on four legs—and probably only came to rule the world after a mass extinction knocked out many big reptiles, scientists said on Tuesday. The 250-million-year-old footprints are the oldest evidence of dinosaurs, Stephen Brusatte of the American Museum of Natural History in New York and colleagues said. Giant penguin fossil gives evolutionary clues LIMA: The preserved feathers and scales of a giant fossilized penguin discovered on Peru’s central coast provide a glimpse of Peru’s Eocene period, and how the species evolved to its modern state, paleontologists say. The ancient version of the marine bird was about 1.5 meters (5 feet) tall and weighed almost 60 kg (132 lb), dwarfing today’s Emperor Penguin, the largest of the modern-day species. Linguists discover new language WASHINGTON:
Researchers looking for dying languages said on Tuesday they discovered a language previously unknown to science and spoken by just 800 people in northeastern India. The language, called Koro, belongs to the same family of languages as Tibetan and Burmese, linguists Gregory Anderson of Oregon’s Living Tongues Institute, David Harrison of Swarthmore College in Pennsylvania and Ganesh Murmu of India’s Ranchi University reported. Global Fund sees disease fight hampered by donors UNITED NATIONS/LONDON:
Donors pledged over $11.5 billion on Tuesday to fight AIDS, malaria and tuberculosis over the next three years but the head of the fund waging the battle said it was not enough to protect millions of people at risk. Announcing the figure raised by a two-day conference in New York, U.N. Secretary-General Ban Ki-moon said the pledges “send a powerful message” but that funding demands were “likely to outstrip even the impressive commitments made today.” STOCKHOLM:
British physiologist Robert Edwards, whose work led to the first “test-tube baby,” won the 2010 Nobel prize for medicine or physiology, the prize-awarding institute said on Monday. Sweden’s Karolinska Institute lauded Edwards, 85, for bringing joy and hope to the more than 10 percent of couples worldwide who suffer from infertility. Discovery poses ethical dilemmas PARIS:
In vitro fertilization (IVF), the pioneering technique that won Robert Edwards the 2010 Nobel Prize for medicine, opened up a wealth of scientific options and a Pandora’s box of ethical dilemmas. Edwards’s success in fertilizing a human egg outside of the womb led not only to “test tube babies” but also to innovations such as embryonic stem cell research and surrogate motherhood. Scientists find way to refine Botox for new uses LONDON:
British scientists have developed a new way of joining and rebuilding molecules and used it to refine the anti-wrinkle treatment Botox in an effort to improve its use for Parkinson’s, cerebral palsy and chronic migraine. Researchers at the Medical Research Council’s Laboratory of Molecular Biology said their results also open up ways to develop new forms of Clostridium botulinum neurotoxin, commonly known as Botox, which may be used as long-term painkillers.
— Reuters |
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This
universe
When we go up in the lift, our weight increases. When we come down in the lift, our weight decreases. Why? Gravity is a force that can accelerate a body. The force is usually expressed as Mass multiplied by g, the value of gravitational acceleration. When the lift starts to move up at a certain speed there is an acceleration of the floor of the lift in the upward direction. This adds to the felt weight. If the lift were to fall freely to the ground the floor of the lift will not feel our weight. If we descend at a smaller acceleration our weight as measure by a balance will reduce. There is an important principle, called the Equivalence Principle that states dynamical acceleration of a mass is proportional to gravitational acceleration. We say that light consist of electric and magnetic fields but both perpendicular to the path of propagation then there must be some component along the propagational path of light so as to make it propagate with such a large velocity which is it? Light is electric and magnetic components oscillating normal to each other and also normal to the direction of propagation of light. There is no component oscillating in the direction of propagation of light. When a ray of light scatters in interaction with a molecule of air, it direction is changed and the electric component of the scattered light is again required to be normal to the new direction of propagation of light, but the requirement would be that the electrical component, while oscillating normal to the direction of propagation is constrained in the direction of oscillation. This leads to polarisation of scattered light.
Readers wanting to ask Prof Yash Pal a question can e-mail him at
palyash.pal@gmail.com |
THE sun's role in climate change may have been overplayed, according to a study indicating that the Earth could actually get slightly cooler, rather than warmer, as the activity of the 11-year solar cycle increases.