Chandigarh, Thursday, August 5, 1999
Chandigarh, Thursday, August 5, 1999 |
Celestial spectacle: darkness at noon by D.P. Singh A TOTAL eclipse of the Sun is a phenomenon unique to our planet in the Solar System. It happens due to a remarkable coincidence of size and distance between heavenly bodies. Our Moon is 400 times nearer to us than the Sun. This makes both appear almost of the same size from the Earth. When the Moon happens to be right between the Sun and us, it blots out the bright face of the sun. The result is a total solar eclipse. “Steel”
from spider’s web Cybersurfing with Amar Chandel The
evening of the shadow Science
Quiz
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Celestial spectacle: darkness at
noon A TOTAL eclipse of the Sun is a phenomenon unique to our planet in the Solar System. It happens due to a remarkable coincidence of size and distance between heavenly bodies. Our Moon is 400 times nearer to us than the Sun. This makes both appear almost of the same size from the Earth. When the Moon happens to be right between the Sun and us, it blots out the bright face of the sun. The result is a total solar eclipse. As far as eclipses go, a total eclipse of the Sun is a rare spectacle. The total solar eclipse of 11 August, 1999, offers a good opportunity of photographing this rare celestial event that is repeating over India after a lapse of about four years. The eclipse on August 11 begins at 9:30:57 UT in the North Atlantic, when the umbral shadow of the Moon touches the Earth. Moving east the shadow cone will touch England at 10:10 UT. After crossing France, Germany, Austria and Hungary, the shadow cone enters Romania. Total solar eclipse of the longest duration of 143 seconds occurs here at 11:03:04 UT. The umbra reaches Turkey at 11:21 UT. At 12:22 UT the shadow enters Pakistan. Due to being on the central line of the totality path, the Karachi residents can see the total solar eclipse for 73 seconds. From Karachi, racing at a speed of 2km/sec., the shadow cone enters India at 12:28 UT (17:58 IST). Calcutta gets to see 87.9% totality. The shadow reaches Vishakhapatnam at 12:36 UT (18:06 IST). It leaves the earth over the Bay of Bengal 0.36 seconds later. The total solar eclipse of August 11 is the 21st eclipse of the Saros Series no 145, which started on January 4, 1639. The series began with 14 partial eclipses. The first total solar eclipse of the series occurred on June 17, 1909, and was seen in the Arctic Ocean. The totality lasted for 24 seconds. The total solar eclipse with the longest duration of totality of this Saros Series will take place on June 25, 2522. The duration of the totality in this eclipse will be 7 minutes and 12 seconds. In next three and 9 half centuries, 20 partial eclipses in this Saros series will take place. Basically, solar eclipses can be divided into three types. (1) Partial: Observer sees the moon partially obscure the sun. (2) Annular: The lunar disc covers only the central portion of the sun. So the observer gets a view of a bright ring. (3) Total: The entire sun is obscured by the Moon. The “Diamond ring” can be seen only during a total solar eclipse. A total solar eclipse is a fantastic sight to look at, provided proper protection is taken. For comfortable viewing of the Sun, a filter of suitable density, which can bring down the brightness to tolerable levels, should be used. The filter should also have the capacity to block ultraviolet and infrared radiation up to the safe limit. You can make a suitable filter at home for safe viewing of the eclipse. Take a small plain mirror and a piece of thin black paper. Cut a hole of around 1 cm diameter at the centre of the paper. Paste the paper on the surface of the mirror. The paper at the edge of the hole should not bulge out nor should the adhesive spill out on the mirror surface within the exposed area. Place the mirror in a sunny area so that the image of the Sun is reflected on the wall or any surface under shadow. A circular image of Sun will be seen there. The progress of the eclipse can be easily monitored as the circular image changes to a crescent and then to circular shape again. One of the most
uncertain factors of the August 11 eclipse would be the
local weather, which is not good at all for the path of
totality in the Indian segment. Even with the poor
weather prospects it would be worthwhile taking a chance
and prepare for the great eclipse day. If luck is on your
side, it may be an unforgettable experience. If you miss
it, you’ll have to wait for July 24, 2009, as the
next total solar eclipse will be visible from India only
then. |
“Steel” from spider’s
web IS IT a new version of a spider’s web or “biosteel” made of terse, light material similar to that which a spider weaves to create its web — a new material that presages a 21st century revolution? Recent discovery of this new material called “biosteel” by a Canadian company creates one of the most amazing substance adapted from what nature produces, say Western scientific sources. This material is nothing else than what the spider’s spin out which we know as web. It is light, flexible, yet incredibly strong, that a spider uses to catch unsuspecting flies and other insects. Now this company is on the verge of manufacturing “biosteel” in quantities, and by a most surprising method — in the milk of transgenic goats. If the project succeeds, which seems highly likely, the product christened “Biosteel” may soon be used for a variety of applications, from medical sutures to bulletproof vests to supportive material for space stations. The process may also mark a step towards the production of other bio-materials — and the beginning of a new kind of industrial revolution, based on the use of organic processes instead of minerals. Spiderweb has a tensile strength of 300,000 pounds per square inch, and is both stronger and lighter than compounds based on steel or petrochemicals. Its impressive properties have been known for a long time, and people have dreamt of being able to produce it for their own uses, perhaps the way the ancient Chinese learned to produce silk from silkworms. But spiders are aggressive and are not as easily domesticated as the amiable silkworm. More recently, various biotechnology researchers have tried producing spider silk the way they produce medically useful proteins such as human insulin. This involves inserting the gene for the desired material into bacteria, and then producing larger quantities of it through fermentation. But that produced only a gooey substance with little similarity to the natural product, and no commercial value. Researchers at Nexia Biotechnologies in Montreal, Canada, thought there might be a better way — putting the spider-silk gene into milk animals. From spider to cow or goat may sound like a huge leap, but in a way it was logical, since there are close anatomical similarities between the silk-producing glands of spiders and milk-producing glands of ruminant animals. When evolution figures out a way to do something, it often does it with different variations in many different species. The scientists’ first efforts in the laboratory involved splicing the spider-silk gene into cells taken from the mammary glands of large animals. The silk genes worked with amazing efficiency in the mammary cells, and Nexia scientists were soon producing high-quality spider silk through cell culture. They then produced a line of transgenic mice to see how it would work in living animals. That experiment also succeeded. The next step was to get the gene into some full-size milk-producing animals. They selected a type of African goat known for its ability to begin reproducing and lactating at an early age — as early as three months after birth. The first transgenic goats will be born this year. If the goats perform as expected when they mature, Nexia will have the beginnings of a breeding stock, and a working spider-silk dairy early next year. Then the challenge will be to extract the pure silk protein from the milk and spin it into fabric by processes roughly comparable to the way artificial fabrics are manufactured from petro-chemical solutions. Nexia’s CEO,
Jeffrey Turner, thinks the first uses of Biosteel will be
in medicine; for sutures, possibly for artificial tendons
or ligaments. Farther down the line, it might be the
stuff of bulletproof vests lighter and stronger than
those currently in use, for the coatings of space
stations, perhaps even in bridges or other structures. (IPA) |
Cybersurfing with
Amar Chandel The century’s last solar eclipse on August 11 has generated tremendous interest. Several websites have made elaborate arrangements to give the visitors a minute-by-minute account of the celestial event, along with photographs. Among the most promising ones is www.eso.org ,which is the fruit of wide international collaboration. The European Association for Astronomy Education (EAAE) will be showing the eclipse live from France, Romania etc. It also informs the viewers about aurora, meteors and previous eclipses. On the other hand, the European Space Agency’s site, http:// sci.esa.int/ , will be showing the latest pictures from the SOHO spacecraft, besides guiding the viewers regarding the progress of the eclipse. * * * * With an ever-increasing interaction between the people of various countries, it is but natural that commerce between them is growing. This requires the change of one currency into another. Doing the calculation to find out how many dollars or pounds your rupees will fetch is rather simple. The conversion becomes more difficult if you have to convert to less popular currencies. The first problem is that you have to find the rate for that day. And even then you have to first find the value of your money in some international currency and then convert it into the currency of your choice. One website provides tremendous help. Go to www.xe.net and just fill the column as to how many rupees (or any other currency) you want to convert and into which currency. The exact amount is calculated in a jiffy. For instance, I tried to find out how much one lakh rupees will fetch in Malaysian ringgits. My money (if I happened to have it, that is) was worth 9,792.23 MYR. It would have fetched me 21,772.33 Mexican pesos. The currency conversion rates are updated every hour. Hundreds of currencies are listed. The site boasts of several other services also. * * * * There are any number of sites which let you send free e-mail greetings. But if your intention is to send funny greetings, there are few to match www.virtualinsults.com. As the name suggests, it stores cards with barbed comments, which you can send only to either a very close friend or a sworn enemy. They are sharp, they are witty and they are pungent. If you have friends (or enemies) who can take your message in the right spirit, you can give it a try. * * * * It is not for nothing that India is called a sleeping giant. Even pygmies have been rushing ahead while the giant remains static. The hosts of www.Indiaforward.com are convinced that the problem lies with our leaders, who have taken the country for a ride for the past 50 years. It promises to put the country among the richest by the year 2025. How? Simple. It raises various vital issues and asks the public to speak out on them. The hope is that soon enough a pressure group will develop and with the help of the media, it would be possible to persuade the leaders to mend their ways. Even if the miracle may
not come about, the site is a wonderful medium for
letting off one’s steam. |
The evening of the shadow In India, Venus will be visible during totality while Mercury would have just set. Weather permitting, Vadodara (Gujarat) will be one of the best viewing sites in India, where totality will occur at around 18:02 hrs. Chandigarh will witness nearly 80% eclipse, when the sun will be nearly 15° above the horizon at around 17:52 hrs. There is no risk in seeing the eclipse with naked eyes when it is total. However, partial eclipse should never be seen without a filter. Particularly, when the bright disk re-emerges at the end of totality, the eyes get too less time to adjust. The best way to see the partial eclipse is through a welding glass. Otherwise, a fully exposed and developed black and white negative film (e.g., the starting limb of a roll) should be used. A colour negative should never be used as it does not effectively filter the IR component. A small telescope, with
aperture reduced and covered with a welding glass can be
very useful for a close-up view and photography. Adjust
it so that the final virtual image is formed at least 1-2
meters away. Thereafter, you can take photographs with a
small, fixed focus (28, 35 or 50mm) camera like
Kodak/Yashica. Remove the batteries and put the flash to
ON. This increases the aperture of the camera, making it
is easier for you to position the tip of the pencil of
light from the telescope, the eye-ring into the
camera’s aperture and click. An ISO 100 film (colour
or B/W) in a 35mm camera, behind a telescope with 25mm
aperture (covered with welding glass) at 25X
magnification can give very good results. B/W films have
a wider latitude and hence, are better suited for the
purpose. Otherwise, an uncovered small telescope can be
used for projecting the image on to a screen, which can
be watched by many people simultaneously. Even sun-spots
can be seen in such an image. Moreover, it is an
absolutely safe method. |
Science Quiz 1. Name the scientist who was awarded the Nobel Prize for both physics and chemistry and died of cancer because she worked for so long with radioactive materials. Name also her husband who was awarded the Nobel Prize for Physics. Which element was named after them? 2. Continuing on the subject, name their daughter and her husband who were jointly awarded the Nobel Prize for chemistry and both of whom died of cancer under similar circumstances. 3. Diamond is the hardest known substance. But scientists are trying to synthesise a compound experimentally, which, according to theoretical calculations, is harder than diamond. Which is this compound? 4. This animal holds a place between deer and antilope and is known for an exclusive natural product of high medicinal value. Name this animal, that has a pride of place as the state animal of Himachal Pradesh. 5. Name the technique that is generally used to separate a mixture into its components by slowly passing the mixture through on absorbent material. What is the modified form of this technique called that is used to separate charged molecules? 6. An ordinary mirror reflects rays of light. What is an arrangement called that can bounce back individual atoms or groups of atoms. 7. The TDS content of drinking water should be in the range of 150 to 400 milligram per litre. TDSM is an instrument to measure this content. What do the abbreviations TDS and TDSM stand for? 8. Green tea is already known to possess cancer-preventing and anti-inflammatory properties. Now it has been discovered that use of green tea may also prevent and reduce the severity of arthritis. Name the chemicals occurring naturally in green tea that have these protective properties. 9. Name a living object that eats dead skin of wounds and thus helps in quick healing of wounds. 10. What is “torr”? Why is it so named? ANSWERS 1. Polish Marie Curie
and French Pierre Curie; curium (atomic number 96) 2.
Irene Curie and Frederic Joliot 3. Carbon nitride 4. Musk
deer 5. Chromatography; electrophoresis 6. Magnetic
“mirror” 7. Total dissolved solids; total
dissolved salt metre 8. Polyphenols 9. Maggot 10. A unit
of pressure equal to pressure of one centimetre of
mercury column; named after the French physicist
Evangelista Torricelli who invented the first barometer. |
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e-mail Multi-level
computer memory devices “Flash memory” is a constantly charged, non-volatile semiconductor chip which retains information even when its power is switched off. It is commonly used to hold control codes in personal computers (PCs) such as Binary Input/Output System (BIOS), the programme used to start a computer and run attached devices like keyboard and mouse. The technology, being jointly developed by researchers of BTG International Ltd in London and Gerald Banks, a semiconductor firm, can be used in PCs and communication networking equipment with little additional cost and no increase in size of memory devices, reports London Press Service. It would help chip manufacturers overcome present performance problems with respect to speed and reliability without a steep increase in chip costs. BTG plans to commercialise the MLC technology through a number of leading chip manufacturers worldwide. Take-home
psychotherapy Psychologists who devised the programme say general practitioners (GPs) in future could keep libraries of similar CDs for patients to use on their own computers. Patients began by answering a series of questions designed to allow the computer to diagnose their condition. They were then recommended one or more treatment packages from a six-option menu. The menu includes relaxation techniques, controlling stressful thoughts and panic attacks, facing stress, hints on getting a good sleep and how to avoid worrying about future events. Three sessions were provided over three weeks, the first being an assessment and introduction with the subsequent two offering a progressive course of treatment, reports London Press Service. Drycleaning with
carbon dioxide The process, developed by researchers of University of North Carolina removes oily stains of grime, grease and fatty acids, as well as water-soluble stains like that of sweat, wine and syrups. It is an off-shoot of an
earlier process developed by the researchers to replace
water with carbon dioxide in paint manufacturing units,
according to a report in Environmental Science and
Technology. |
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