Chandigarh, Thursday, March 4, 1999
Chandigarh, Thursday, March 4, 1999 |
A secret encryption code Infinite uses of polymers |
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New unit
to measure an angle PRACTICALLY used units of length and mass have simple mathematical relation. For example, 1 kilometre has 1000 metres, and I metre has 1000 millimetres. Similarly, 1 kilogram has 1000 grams and 1 gram has 1000 milligrams. However, no such simple relation exists amongst various practical units of angle and time. For measuring an angle, three units are in use. The routinely used unit of angle is degree, which is one ninetieth (1/90) part of a right angle. Each degree has 60 minutes and each minute has 60 seconds. A complete angle has 360 degrees. This unit, thus, is in accordance with sexagesimal system and is not in harmony with units of length and mass. Another unit of angle is grade which is one hundredh (1/100) part of a right angle. Each grade has been divided into 100 minutes and each minute is further divided into 100 seconds. A complete angle has 400 grades. This unit again is not in complete harmony with the units of length, and mass. The third unit of angle is a radian which has been adopted in the international system of units and is defined as the angle subtended at the centre of the circle by an arc equal in length to the radius of the circle. One complete angle has 2p (pie) radians i.e. 6.2857 radians. Thus, the unit radian doesn’t have a simple relation with one complete angle. Radian is a very big unit, especially for astronomers, limiting its practical use. Neither sexagesimal nor decimal system is applicable in this unit making mathematical calculations difficult. We had earlier proposed a decimal unit for time (The Tribune, Nov 26, 1998) and hereby suggest a new unit for angle also which will have a simple relation with complete angle. The application of decimal system would be feasible, in this unit. The proposed unit of angle may be called “vritansh” a Hindi word meaning part of a circle. A “vritansh” may be defined as two fiftieth (1/250th) part of a right angle (Fig. 1) 1 vritansh (1v ) = 1 right angle = 250 Accordingly, 1 right angle = 250v 1 straight angle (1800) = 500v 1 complete angle (3600)= 1000v One vritansh, thus, would equal 0.36 degree (i.e. 21 minutes and 36 seconds). Similar to the pattern of units of length and mass, different units of angle will be as follows: 10 vritansh= 1 decavritansh (1dav) 10 decavritansh= 1 hectovritansh (1hv) 10 hectovritansh= 1 kilovritansh (1kv) 1 complete angle = 1kv = 10hv = 100dav = 1000v Smaller units of angle will be as follows: 1/10 vritansh = 1 decivritansh (1dv) 1/10 decivritansh = 1 centivritansh (1cv) 1/10 centivritansh = 1 millivritansh (1mv) 1 vritansh = 10dv = 100cv = 1000mv One complete angle (Fig. 2) will, thus, have 10 hectovritanshes, 1,000 vritanshes, 1,00,000 centivritanshes or 10,00,000 millivritanshes. Presently one complete angle has 12,96,000 seconds but as per proposed system it will have 10,00,000 millivritanshes. Interconversion: Relationship between present units (degree, grade and radian) and proposed unit (vritansh) of angle is given below: 1 degree = 2.7777v 1 minute = 0.046296v = 4.6296cv = 46.296mv 1 second = 0.00077v = 0.07716cv = 0.7716mv 1 hectovritansh = 36o 1 vritansh = 0.36o = 21 min 36 sec = 1296sec 1 centivritansh = 0.00036o = 12.96 sec 1 millivritansh = 0.00036o = 1.296 sec 1 grade = 2.5v 1 min = 2.5cv 1 sec = 0.25mv 1 vritansh = 0.4 grades 1 centivritansh = 0.4 min 1 millivritansh = 4 sec 1 radian = 159.08873v p radian = 500v 2 p radian = 1000v 1 vritansh = 0.0062856 radians 1 kilovritansh = 6.2857 radians Interconversions of present units and proposed unit of angle can be made by using conversion tables (Table 1a, 1b, 2a and 2b). By using Table 1a we can convert degrees into vritanshes. For examples, we are to convert 200° into vritanshes. Now 200 can be fractioned as 180+x, where x=20. Vritansh equivalent to 200°can be located in the table under the column 180 + x corrseponding to row x = 20. This value comes out to be 555v. Now add fractional vritansh value from the last column of the table corresponding to the same row (x=20) i.e. 0.555v. Hence 200o is equvalent to 555.555v. This table can, similarly, be used for converting degrees from 1 to 360 into vritanshes. For conversion of fractions of degrees i.e. minutes and seconds into mili and centi vritanshes Table 1b can be used. For converting vritanshes into degrees we will use Table 2a. Suppose we want to know degree equivalent of angle 130 vritanshes. Now 130 can be fractioned as 125 + x, where x = 5. Degree equivalent to 130v can be located in the table under the column 125 + x corresponding to row x = 5. This value comes out to be 46o. Now add fractional degree value (i.e. min and sec) from the last column of the table corresponding to the same row (x=5) i.e. 48 min 00 sec. Hence, 130v is equivalent to 46 degree and 48 min. This table can similarly by used for converting vritanshes from 1 to 1000 into degrees. For conversion of fractions of virtansh i.e. milli/centi vritanshes into min and sec, Table 2b can be used. Table for natural sines and cosines in reference to new angle unit vritansh can also be prepared by using these conversion tables and already existing tables of natural sines and cosines. It would be worthwhile to mention here that the authors have earlier proposed decimal unit for time termed as “kaal”. ‘Kaal’ will be 1/1000th part of a day. Accordingly, a day will have 10 hectokaals or 1000 kaals or 1,00,000 centikaals instead of having 24 hours or 1440 minutes or 86,400 seconds, respectively. If the proposed units of time and angle are adopted, these will be much simpler and convenient for calculations. New units will be in harmony with the unit of length and mass and will make applicability of decimal system possible. These would be more practical and there won’t be need for depiction of angle in minutes and seconds. Interestingly, as per the proposed system of unit, earth will rotate around its axis through an angle of 1 viratansh in 1 kaal. In one day i.e. in 1000 kaals it will complete one complete angle i.e. 1000 vritanshes. As per existing system earth complete 2 p radian angle i.e. 6.2857 radians in one day or 1 degree in every 4 minutes. So it is clear that if proposed system is adopted, we can have wonderful, natural, simplest relation between units of time and angle with respect to rotation of earth around its axis. Astronomers, physicists, geophysicists, space scientists and scientists of other related fields would be fascinated to have such a simple relation between units of time and angle. Through this article authors want to emphasise upon the scientists and authorities to analyse the merits and demerits of the proposed system for its adoption. The authors are
Assistant Professors at Krishi Gyan Kendra, Mahendragarh
of Chaudhary Charan Singh Haryana Agricultural
University, Hisar (India). |
A secret
encryption code IF you have an uneasy feeling about the security of Internet commerce, you have probably reassured yourself that the hi-tech security schemes which safeguard your privacy are written by the world’s best cryptographers. Think again. Victor Shoup, a cryptography researcher at IBM’s Zurich laboratory, has come up with a world first: a practical encryption technique that has provable security. You might be surprised to learn that it may never make it onto the market. Unfortunately for the public, quality and security are near the bottom of the priority list when it comes to turning a scheme into a product. The spoils go to the fastest. “If you’re first, you win, and it doesn’t really matter if the product is crap,” Shoup explains. “A lot of what’s out there is not the best that could be done, even without sacrificing any practicality.” The upshot is that cryptographers have minimal say in the development of new products. “I have marginally more influence than if I was at a university,” says Shoup. “Much of the cryptography software that’s out there is written by software engineers who don’t know too much about the theory of cryptography — and you can really hang yourself if you don’t know what you’re doing.” Shoup developed his encryption technique with Ronald Cramer of the Swiss Institute for Technology. It is making slow progress through the IBM production machine. Shoup is working with IBM’s engineers to see where it fits into their plans. “In principle it’s moving forward: it could take a year, or it might be derailed,” he says. In the end it might just come down to marketing; can IBM market something that needs three times as much computing time, but offers “provable security”? Shoup seems somewhat disinterested. “If they can, good. If they can’t, fine.” He is dissatisfied with an industry that, in his view, takes security much less seriously than it should. “I would like to see more of what’s available commercially being directly influenced by the cryptographic research community,” he says. “Then we could have more up-to-date, solid algorithms: by applying the knowledge available in the cryptographic research community we could make better products.” But, he says, there’s generally a huge gap between engineers and the crypto-theory people. “They don’t talk to each other; they don’t even like each other for the most part.” He would not be at all surprised if the Cramer-Shoup system doesn’t replace much less secure systems. The attitude in the industry, he claims, is “if it cain’t broke, don’t fix it”. Last February the most widely used encryption technique — RSA — had to be fixed: it was broken into by a researcher at Bell Labs. The wounds have been patched up, but RSA is still not — and can never be — “provably secure”; you can’t know there isn’t a scheme that will tear it to shreds waiting just around the next corner. Shoup is amazed that RSA changed their set-up only when it was left with a gaping hole. “RSA knew about alternatives to what they were using,” he says. “Several years ago they could have switched to a more secure system but they didn’t. They should be embarrassed — it’s really not supposed to get broken — but they maintain that they’re not.” He was also surprised that this attack on RSA didn’t get more media attention. “The attacks that get reported in the media are mostly bugs on obscure bits of software; they’re rarely a head-on attack on cryptography itself. I thought it was quite a serious thing, but all the major players in the field — including IBM — played it down.” The reasons are obvious. There is an enormous vested interest in the apparent security of online transactions; all the companies want the public to use e-commerce. “They don’t want to scare people off,” says Shoup. “Anyway, they all license RSA software.’” He believes that the more companies play down security problems without solving them, and the more their online business grows, the richer the pickings will become for those who can beat the encryption systems. In the end, he believes, a provably secure technique should be implemented, regardless of whether it is quite neat or fast enough. “We can do it, so we should do it,” he says. —
GUARDIAN |
Infinite
uses of polymers PLASTIC goods that we so commonly use for household and industrial purposes are synthetic polymers made of carbon, hydrogen and oxygen. Polyethylene, or polythene as it is familiarly termed, is a long chain of carbon-hydrogen molecules crosslinked to give it strength and plasticity. Newly developed polymers can be very smart, with properties that find use in a vast variety of applications from biology to electronics. The first polymer that was made in the laboratory in the 1850s was celluloid, a mixture of nitrated cellulose and camphor. It became universally popular for a number of applications from shirt collars to movie films, boxes and toys. However, it is highly flammable and so gave way to bakelite, discovered in 1909. Bakelite is still used as an electrical insulator which does not catch fire. Just before World War II, the accidental discovery of nylon led a revolution in textiles and so spurred research in polymers. Since then a whole range of polymers like nylon, polyester, polystyrene, polythylene, polyviny1 chlofide, perspex, teflon, and polypropylene have been synthesised. These new materials have replaced metals and ceramics to a large extent, becoming kitchen sinks, buckets and bowls, and they are now replacing abrasives as in kitchen and industrial scourers. Polymers are not all man made, and they do occur in nature. We are made of polymer since the monomer of DNA, the very staff of life, is a long chain of carbon and other atoms, which twist around each other to form a double helix linked by bonds between them. Polymers acquire unique properties when chosen monomers are cross linked in a particular way. They can be shaped, extruded, machined or moulded. The shampoo as well as the bottle that contains it, the non-stick coating on cooking pots, the sticky coating of lables as well as components of utomobiles are all polymers of various kinds. Polymer science is expanding every day as new products and uses are being uncovered. It has become an interdisciplinary science where chemists are helped by physicists, engineers and biologists. The field is so immense that luck still plays a part in discovery. Discovery of light emitting polymers was one such chance discovery. In tryint to make semi-conducting polymers that might replace expensive single crystal silicon, scientists coated a thin layer of PPV (polyphenylene vinylene) over a large area. A voltage applied across it made the film glow with a bright yellowish green light and LEDs (light emitting diodes) were born! The discoverers at once formed a small company and transferred the process to a television company which then manufactured flat screen TV sets. Now polymers have since been developed that promise a full colour flat screen television display less than a centimetre thick. Light emitting polymers are more economic than any other display methods with their distinct advantages of bright light, high resolution and distortion free-viewing at any angle. Made by standard ink jet technology as used by computer printers, they are easy and cheap to produce. This allows great freedom of design and one can visualise a car dashboard where the meters blend into the bodywork. Polymers are versatile, durable and cheap but they suffer from the grave disadvantage that they are almost indestructible. These two factors will determine the feasibility of a new polymer — its cost of production and the cost of waste disposal after use. Plastics, as we know, litter the world, leaking the oil from which they were made. Work is, therefore, in progress to make biodegradable plastics. Two such strange products are plastics made from bacteria and polymer products made from potatoes. Such is the promise of polymers that funds to develop them are freely available in Europe and the USA in spite of a recession. The spider’s web is a natural polymer that is the toughest fibre on earth. Industry would like to make similar fibres from common materials, for instance paints from common starch. Such polymers would be biodegradable and so eco-friendly. European technology is actively funding such clean technology. One such instance is the use of carbon dioxide under pressure instead of toxic solvents to dissolve paint. An interesting new area of application is biodegradable surgical thread for suturing in operations. As the sutures heal, the polymer thread would disintegrate and be absorbed by the body. Such polymers could also make capsules that are implanted in the body for then the drug within the capsule is released slowly and more evenly over a control period and at a constant rate. To make such tailored polymers, the way polymerisation, usually done by gamma irradiation, proceeds and its ability to withstand sterilisation by heat and water should be investigated. Polymers can also carry drug molecules. Another application is of auxetic polymers that behave like the artery wall in a human body. Instead of thinning when stretched, these cells expand to take the increased pressure. Such properties make the increased pressure. Such properties make the polymer impact resistant and so useful to make sound absorbing panels or bullet proofvests. Doctors are looking for polymers for skin grafts, breast implants and joint replacements as well as for applications that would “grow” damaged body parts. The gap between synthetic and biological polymers is, therefore, narrowing in two directions — to make the biopolymer grow artificially and to make the synthetic polymer grow naturally like cells. But the question remains what would endow polymer with life. By putting the right synthetic polymers together, they might self organise and grow. This gives greater control over their growth. Ideally, one puts monomers into a vessel and they would organise themselves and produce material which would be very useful — or perhaps grow into a Frankenstein? Computer simulations can now model the behaviour of polymers, thereby, saving a lot of money to the developers. New and strange structures can be simulated, structures that might be dangerous to release in the realy world. There are thousands of monomers and they can be linked in infinite ways. Such polymers form an infinite set of objects which can be explored only by computer simulations, the ultimate polymer drawing board! For instance, carbon nanotubes were discovered in 1991. These are very fine tubes of carborn atoms with amazing properties. Their strength and other behaviour gives them applications as far ranging as disc brakes for jet aircraft and racing cars to tiny wires and transistors for miniature electronic equipment. Chemists find them to be great catalysts while metallurgists find that they modify the properties of other materials. They absorb amazing amounts of gases, specially hydrogen. —
PTI |
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Get your e-mail talking to you Of the millions of uses of Internet, perhaps the most popular is the e-mail. After all, it helps you send your messages across the globe in seconds, and at a very little cost. You can read a message sent to you almost in real-time. Read it? Why take the trouble of reading it when you can listen to it instead? Keep working on your computer while it reads out the messages to you. Software for this purpose is available free of cost (for a 15-day trial) and can be downloaded from www.4developers.com. Most e-mail programmes beep when a new message arrives. The more advanced ones play a sound file. In either case, if you are sitting in your living room and your PC beeps you don’t have any idea from whom and what is the e-mail you have just received. Talking E-mail instead enables you to listen to your incoming e-mail messages. For example, when a new message arrives from your friend “Ramesh”, Talking E-mail displays an animated cartoon figure which will say: “Message from Ramesh, Please contact me as soon as possible”. The programme uses the Microsoft Agent technology to read the messages. You can select from different cartoon characters (The ones used by MS Office), each with a unique voice and look. The programme works with your standard e-mail account and no special hardware is required other than a standard sound card. The current version has many improvements over the earlier one (1.0/1.1). The time announcement was changed so that it is announced on the hour without the extra zeros. Certain symbols like “>” or “*” are now filtered out. You can change the filtered symbols from the ‘Options’ screen. You can also position the character in any place on the desktop. Speech speed and pitch control have been added to the main screen.You can specify the font type and size. Not only that, you can drag and drop text from applications like MS Word on Talking E-mail so that the text is read. HTML messages sent from Netscape Messenger are now read correctly (bug fix). Version 1.2x reads messages in HTML and Rich text format while 1.1 had support for plain text messages only. A configuration wizard has been added to help users set up their e-mail account information. The pronunciation of the Hindi words can be funny but that of others is passable. *** A new catholic and spiritual website on the forthcoming tercentenary birth anniversary of the Khalsa (www.baisakhi1999.org.) depicts and portrays varied facets of the creation of the Khalsa and the Nectar of Immortality. This spiritual treat also includes the audio oration of a few holy incidents of the soul-stirring life of the Great Guru. Entrance to the holy mansion of the Beloved Lord is only open to those who love death and who pride in turning as the dust of everybody’s feet. That is what Humility Incarnate Guru Gobind Singh Ji taught the Khalsa. *** Slowly, the sites devoted to Clinton jokes are losing their popularity. But that does not mean that Clinton has been given up. The American President is too juicy a subject to be discarded. In fact, he has “graduated” to a higher level. His peccadillos have now even been turned into screensavers. You can download a lot many screensavers from www.screensavers.com but the Clinton one is the most popular. It shows Clinton playing his saxophone and singing while Hillary, Monica and Chelsea dance in step. “Hey Monica, you will go down in history/ … When I get up in the morning I don’t want no coffee or tea/ Just give me my Monica Lewinski/ I can break all the rules/ I am the President of the USA,” he croons. If that is your idea of humour, you can decorate your computer with this screensaver. *** And here is something for the lovers of Hindi movies. The website www.hindimovie.com is quite a treasure trove of both audio and video material. You can not only access the top songs of the week but also those of the year, the pervious year and even the decade. There are movie reviews, details on various actors and actresses, hits of Kishore, Rafi and Mukesh (most of which can be downloaded in the MP3 format), theatre info and even remixes. In short, you can immerse yourself in Hindi movie magic for several hours. *** And let me remind you to
keep sending us the details of the sites that you have
found particularly interesting, preferably with
photographs. Happy surfing. |
| H |
Smells jog memory PROOF that smell is a powerful memory cue which can aid the recall of events that occurred more than five years ago finally came after the first research of its kind was published last week. The study, carried out by John Aggleton and Louise Waskett of the University of Wales, in Cardiff, involved 45 people who were asked to remember features of the Jorvik Viking Centre in York, in the north of England, which recreates the city during the 10th century using not only sights and sounds but also highly distinctive smells. The researchers concluded that those participants who were exposed again to the museum’s smells could recall their visits more accurately than those who relied on memory alone. Three groups of 15 participants, who had not visited the centre in six years, were given a questionnaire about various displays in the exhibition. The first group was given a selection of seven odours to sniff, identical to those used at the museum, including “burnt wood”,”apples”, “fish market” and “rope/tar”. The control group was given seven different odours not used as part of the exhibition, including coffee, peppermint, coconut and maple. The third group were not given anything to smell. The results, published in the British Journal of Psychology, showed exposure to smells present on the last visit to the museum induced a significant improvement in recall. Those smelling these odours answered 11 of the 20 questions correctly. Those given no smells scored on average 9.5, while the control group scored 9 out of 20. Professor Aggleton said the smell was a particularly arousing sense because it has the most direct route into brain regions of all the senses. “The same brain structures involved in handling smell information are also involved in memory. Smells can also arouse emotions, which affect and modulate memory.” He believes this is the first study to ascertain the role of smell in the accuracy of memory in a real-life situation, rather than in laboratory conditions. “It is reassuring to know that we were not just making up the connection between smell and memory, because people can be very good at filling in the gaps in their recall. “But we were able to check people’s memories for an event that happened and verify how accurate those memories were.” (GUARDIAN) Yearbook in CD-ROM form Manorama Yearbook happens to be the largest selling yearbook in India, which is printed in five languages. For the first time, it has been made available in the CD-ROM form under the title Manorama Knowledge Adventure. Like the book, it contains a wealth of information. The entire database has been organised in a reference hierarchy that includes thousands of facts and items of interest on a variety of subjects. Comprehensive Time Lines let you explore world and Indian history from ancient times right up to 1998. It is also possible to take the search directly on the Internet using qualified and checked World Wide Web hyperlinks. The CD-ROM contains nearly a million words of reference information, hundreds of photographs and maps, and more than 30 minutes of video. It has India interactive maps, besides flashcards with over 4,500 competitive exam questions. Plane assembled from a kit It will now take a couple of hours to make a two-seater aeroplane at home. An aeroplane made of fibreglass having 650 components has been developed by a UK-based company Europa, that can be easily assembled and derigged. The kit-built aeroplane has a speed of 150 miles per hour and can run about 500 miles at a stretch. The aeroplane, which is being manufactured since last September, cost about the same as a Mercedes car, Joe Kerr, senior tutor, Royal College of Art in London, said at an exhibition in New Delhi. The plane has 15-feet
long wings and could use any petrol-driven car engine, he
said. |
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