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| SCIENCE & TECHNOLOGY |
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| Transit
of Venus Neelam Gulati Sharma The major celestial event i.e. Transit of Venus, will take place on June 8, 2004. None alive today has seen this sight as this has happened only twice during this century. For the first time since 1882, Venus will cross the face of the Sun. It will take 6 hrs 12 minutes to complete its journey.
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Transit
of Venus The major celestial event i.e. Transit of Venus, will take place on June 8, 2004. None alive today has seen this sight as this has happened only twice during this century. For the first time since 1882, Venus will cross the face of the Sun. It will take 6 hrs 12 minutes to complete its journey. The entire transit shall be visible from Europe, Africa (except the far West), the Middle East, and Asia (except the far East). In case of Eastern and central North America, the Sun will rise with the transit in progress. Dr Fred Espenak, NASA/GSFC has provided with the date on transit contacts, but for some important cities. The same for Chandigarh and Delhi is as follows: This rare and inspiring event will occur after a gap of nearly 121 years and hence is a great occasion to witness. Pt. Samanta Chandrasekhar of Orissa was a well known astronomer of the century. He made some observations and predictions of the 9th December, 1874 Transit of Venus, completely uninfluenced by the western schools of astronomy. This rarer event was visible from India and many other parts of the world. The next Transit of Venus was in 1882 which was not visible from India. Hence, this event has created a lot of excitement amongst amateur astronomers and educators as this event shows the possibility of recreating historical measurements of Earth-Sun distance by students worldwide, through observations of the timings of this transit. Samanta’s observations were completely non-telescopic and made with handmade instruments — and the accuracy achieved seems extraordinary. Viewing of the Transit of Venus directly requires sufficient safety measures, so that there is no damage caused to the eyes temporarily or permanently. Smoked glass or sunglasses are not at all safe. Also it is not at all safe to look at the Sun without safety filters. Chorioretinal burns are most usually produced when booked at the Sun directly. In most of the cases, nothing abnormal is noticed immediately except the dazzling sensation; but it is only thereafter that a defuse cloud floats with irregular undulations before the eyes, associated usually with irritating after-images, photophobia (feat of light), and occasionally photopsia (flashes of light) and chromatopsia (disturbance in colour vision). After 24 hours, this diffuse cloud contracts into a dense scotoma (a blind spot or area of depressed vision) which may last for weeks or months or even permanently.
The writer is Principal
Scientific Officer (POS), Punjab State Council for Science &
Technology, Chandigarh. |
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Will
ocean ever get extinct due to deposition of decayed particles on the
seabed? Over long time scales oceans and mountains are continuously changed and transformed. There was a time, a few hundred million years ago, when the landmass of India was in the Southern Hemisphere. There was a big ocean where most of India is now located. Himalayas did not exist. This mountain range came into existence when India collided with the Asian continent. This collision is still in progress; we are moving North-North-East about 5 cm a year, mostly going under China. (In the last million years the distance covered would be more than 50 kilometers. The birthplaces of Gods and early humans in our land must have moved through a distance of this order or more!). Sea fossils are found on top of high mountains, all over the world, showing that nothing is permanent on long time scales. The earth is continuously transforming. Large oceans have mid-ocean ridges where matter comes out from inside the earth as hot lava, sometimes making islands that rise tall - or not so tall - above the sea surface. This matter is transported along the ocean bottom to edges of continents where it is subducted back into the earth mantle. Such subduction zones lie along the West Coast of North America and along the eastern edge of Asia. There is continuous change. What will happen in millions of years can only be surmised. Dead matter of living things does change the morphology of the oceans. For example many coral islands and reefs are nothing but accumulations of coral skeletons growing on hills and mountains under the sea whose tops come close to the sea surface for sunlight to penetrate. Coral mountains jutting out of water cannot exist because coral needs seawater and sunlight together. Though qualitatively significant, this phenomenon also rides on the much larger basic elements of the drama that keeps altering the surface of the earth. If the universe is expanding then what is the space into which it is expanding? One answer to your question could be that this is one of those
questions that have no validity. One cannot define space without the
universe. In this sense the universe expands into space that it itself
creates! I know this appears confusing. But I do not know how else to
answer this. Part of the problem stems from the fact that we cannot
get away from images of a three dimensional non-relativistic space.  |
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NEW PRODUCTS AND DISCOVERIES Groovy pictures Songs and words preserved on antique vinyl records and wax cylinders become more precious with each passing day. They also grow increasingly fragile and are especially vulnerable to damage if played. Now, researchers using optical-scanning equipment have made exquisitely detailed maps of the grooves of such recordings. By simulating how a stylus moves along those contours, the team has reproduced the encoded sounds with high fidelity. Food display matters a lot Variety may be the spice of life — and a key contributor to an expanding waistline. Research by Brian Wansink, a professor of marketing and nutritional science at the University of Illinois at Urbana-Champaign, challenges the conventional notion that a person’s ability to control eating and stick to a successful diet has solely to do with willpower. Little-understood contextual cues — such as how food is displayed and its variety of colours — can lead people to overindulge and unknowingly bulk up, he says in an article he wrote that has been published in the Journal of Consumer Research. Smooth-talking appliances A smooth-talking washing machine may not be savvy enough to keep a user from mixing whites and darks, but it can open doors that the digital revolution has closed to the blind. New generation appliances are sleek, high-tech — and incomprehensible if the user can’t see the dazzling array of LED displays. But it’s a problem that can be talked through, literally. A team of engineering students at Michigan State University have figured out a way to cheaply modify household appliances to be easily used by the blind or those who have trouble seeing. The washer clearly announces each function as it’s selected, and can also run through the full range of selections. "Cosmic bullets" In a desolate corner of Argentina, scientists are using a network of observatory stations spread over an area 10 times the size of Paris to uncover one of the universe’s deepest secrets. Researchers have littered 3,000 square km with hundreds of UFO-like containers to scour the heavens for mysterious, rare and powerful cosmic rays that bombard Earth. Subatomic particles known as "cosmic bullets" are one of science’s great unknowns. They pack more energy than any known particle in the universe, and determining what propels the "cosmic bullets" could challenge the laws of physics, such as the theory of relatively. — Reuters |
