|
|
|
|
| SCIENCE & TECHNOLOGY |
|
|
|
The North Pole is moving Prof Yash
Pal THIS UNIVERSE Trends |
|
|
The North Pole is moving Scientists say that magnetic north, which for two centuries has been in the icy wilderness of Canada, is currently relocating towards Russia at a rate of about 40 miles a year. The speed of its movement has increased by a third in the past decade, prompting speculation that the field could be about to “flip”, causing compasses to invert and point south rather than north, something that happens between three and seven times every million years. Already the phenomenon is causing problems in the field of aviation. Tampa International airport in Florida has just spent a month renaming its three runways, which in common with those at most US airports are identified using numbers that correspond to the direction, in degrees, that they face on a compass. “Everything had to be changed; it was a huge project,” Brenda Geoghagan, a spokeswoman for the airport, said. The current rate of magnetic north’s movement away from Canada’s Ellesmere Island is throwing out compasses by roughly one degree every five years, prompting the US Federal Aviation Administration to re-evaluate runway names across the country every five years. Similar changes were recently made to runways at Fort Lauderdale and Palm Beach. Geologists believe that magnetic North Pole (which is different from the true North Pole, the axis on which the Earth spins) moves around due to changes in the planet’s molten core, which contains liquid iron. They first located it in 1831, and have been trying to follow its progress ever since. Records indicate that the pole’s location barely moved in the early decades, but in about 1904, it began tracking north-east at a rate of about nine miles a year. That speed increased significantly from about 1989, possibly because of a “plume” of magnetism deep below ground. The pole is now believed to be heading towards Siberia at about 37 miles each year. “Earth’s magnetic field is changing in time. And as far as we know, it has always been changing in time,” geophysicist Jeffrey Love of the US Geological Survey in Colorado told Discovery News, which investigated the issue last week. GPS systems, which rely on satellites, have replaced compasses as the means by which the majority of professional navigators orientate themselves. But compasses are still valuable, and are widely used by hikers and other amateur map-readers. In some environments, such as underwater or beneath ground, which cannot be reached by satellite signals, they remain the only option. The oil industry, which uses magnets to determine which angle it should drill into the earth, needs to keep track of the exact location of magnetic north. Birds that fly south for the winter, along with migratory sea creatures, could face confusion. Long-living animals, such as whales and turtles, may in future be required to recalibrate their navigational instincts. Despite the cost and inconvenience of altering runway names, not to mention the indignity of losing magnetic north to Russia, inhabitants of North America stand to benefit from the changes in at least one respect: it will give them more opportunities to observe the aurora borealis. No one can predict the impact of “polar reversal”, during which magnetic north and south reverse, since one hasn’t happened for 780,000 years, the longest stable period in the past 5 million years. Some geologists think we could be about to find out, though: they believe that the current changes to magnetic north could be the early stages of a “flip”. But Mr Love says we shouldn’t be too concerned. “Reversals typically take about 10,000 years to happen,” he said. “And 10,000 years ago civilisation did not exist. These processes are slow, and therefore we don’t have anything to worry about.”
— The Independent |
|
THIS UNIVERSE I am quoting below the answer I gave to this question five years ago: This is a truth about which I cannot give a very cogent and scientific explanation. What is more, I have not seen it in anything I have read. I do not know why we yawn. I can only guess. When we are tired and sleepy, most of us yawn. Do we have a need for gulping in more oxygen? Perhaps. Do we want to send a signal to friends and relatives around us that we have had enough of their company and we must take leave and go in for a shuteye? Perhaps. I do know that when we are listening to a particularly boring speech we become drowsy and begin to yawn? This particular yawn is especially contagious. This usually happens in late afternoon. The fact that it happens is indisputable. But there are lectures and speeches that wake us up and all yawing disappears. This shows that the origin of yawning is not only physiological. Intellectual and emotional engagement — or disengagement — also makes a difference. The contagious property of yawning is understandable, if the people who are simultaneously affected are together late in the day and listening to the same boring speaker. Perhaps disengagement of some in the audience, when noticed, leads to a similar disengagement of others. I have found that when I notice just one shining pair of eyes focused on the speaker, I also become more attentive. Besides physiology, social psychology is simultaneously at play. In spite of all these observations I still cannot tell you why yawning should be such a widespread symptom when some tiredness is combined with boredom. Only the young have the courage to pull out a novel or a short story book to overcome the boredom. Most others feel socially obligated to simulate attention with their eyes open and staring at the speaker — a stance not very conducive to an engaged presence at the event. Having said all this I might also point to another category of yawning that is perhaps better understood. Many of us get up in the morning after a restful sleep and shake away the last dregs of drowsiness by stretching our arms and a big yawn.This tendency perhaps helps to expand our lungs and fills them up with a large mouthful of air. I do not think this yawn is that contagious, partly because we seldom wake up at the same place at the same moment. Note: A truncated version of this item was printed in this column last week. This is the full answer. |
|
Trends
WASHINGTON: A NASA scientist reports detecting tiny fossilized bacteria on three meteorites, and maintains these microscopic life forms are not native to Earth. If confirmed, this research would suggest life in the universe is widespread and life on Earth may have come from elsewhere in the solar system, riding to our planet on space rocks like comets, moons and other astral bodies. Gene links to heart disease found LONDON: Scientists have found 13 new gene variants that increase a person’s risk of developing heart disease, the world’s number one killer, in a series of large-scale international genetic studies. The discovery of 13 previously unknown gene variations and the confirmation of around 10 more should offer clues about how heart ailments such as coronary artery disease develop, and lead to new and more effective treatments, the researchers said. Scientists grow viable urethras from boys’ cells CHICAGO: Researchers have used patients’ own cells to grow urinary tubes in the lab and have successfully used them to replace damaged tissue in five young boys, showing the potential power of cell-based therapies. Urine flow tests and tube diameter measurements show the tissue-engineered urethras are still working after six years, said Dr. Anthony Atala, director of the Institute for Regenerative Medicine at Wake Forest University Baptist Medical Center in North Carolina. How humans got big brains CHICAGO: Missing chunks of DNA responsible for turning genes on and off help explain some key differences between chimpanzees and humans-including why humans have big brains and why the human penis is not covered with prickly spines, U.S. researchers said. The study, published in the journal Nature, reinforces the notion that genes that control the activity of other genes play a big role in what makes humans so different from other mammals. —Reuters |
Strange life signs found on meteorites
I