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| SCIENCE TRIBUNE | Thursday, January 11, 2001, Chandigarh, India |
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Radioisotopes serve us too! Innovations in computing
Science Quiz |
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Over-speeding in space FOR all of us the biggest fantasy for high speed travel would be to “travel at the speed of light”. But perhaps there is a way ..... to skip the yet “untouched” — light barrier — and to find your speedometer’s needle showing
super-luminoul velocities, faster than light (FTL)! The first (unsuccessful) outdoor attempt to measure the speed of light was made by famous Italian scientist Galileo Galilei in the 17th century. But it was the French physicist Fizeau, who calculated the speed of light (He arrived at the result ‘C’ = 300,000 km/sec), inside the laboratory — for the first time in the world! After comparing the great number of independent measurements from all over the world, today’s best available estimate, of speed of light through space is C = 299,776 km/sec or 186300 miles/sec. According to Einstein theory of special
relativity, nothing can travel faster than light, and light’s speed itself is invariable (i.e. constant) But we have already moved beyond Einstein and relativistic physics is not the end of the story. There is quantum physics too, which Einstein loathed because it introduced an element of uncertainty... and quantum physics does not forbid faster than light travel. Before discussing the FTL travel we must first consider the situation of sub-luminoul (slower than light) travel. Taking ‘C’ invariable, we have a factor called ‘tau’ by which mass, length and time vary as a body is accelerated towards the light speed: Supposing our spaceship is travelling at the speed of one million kmph, “tau” only drops to 0.9999996 and ship’s mass will be divided by “tau” and thus will increase to 1.000004 of its “rest-mass”. At approximately half the velocity of light, “tau” = 0.866 and ship’s mass will increase by 15%. Now much more energy is needed to propel this extra mass being continuously added with acceleration! In fact, much of the energy of the ship is being converted into mass! And at near the light speed “tau” equals 0.01414 and ship’s mass has increased 71 times. But what will happen to “tau” if we travel faster than light: Taking any value of VØC the “tau” becomes a multiple of Ö-1, which means mass, length and time became imaginary! But this does not mean that FTL travel is a silly talk. Imaginary numbers are often used in mathematical shortcuts that lead to real answers. According to currently popular theory these imaginary numbers are justified by taking into account a new set of particles which are considered to be travelling faster than light! These “yet to be discovered” particles have been given the name “tachyons” which represent an exact mirrors image in properties of our ordinary slower than light particles (tardyonic particles) with which our present universe is composed of. In this case they are considered to be travelling at infinite velocity and infinite energy is required to slow them down to light’s speed (which is the minimum possible speed at which they can travel)!! It is believed that “tachyons” were created moments after Big Bang, but might have become isolated from our own universe and have formed their own “tachyonic universe” which we can never reach unless God performs some miracle. According to some scientists, if tachyons continue to be created in our own universe, they may be detectable, say in cosmic ray showers. In 1973, a few Australian researchers became confident of having found evidence of some mysterious FTL warnings received in their photographic plates, until the case was repeatedly studied by other fellows... only to be declared dubious. And now the (controversial news of the) claims of Dr Lijun Wang of NEC Research Institute in Princeton, that he had accelerated the light particles up to 300 times faster than their normal velocity of 186,300 miles/second-would revolutionise physics if proven. If it has any relation with time travelling tachyons then bang goes the law of causalty (which says “cause” occurs first, “effect” happens later) and the chief obstacle to space (and time) travel of all kind has been removed!! High-speed space travel has always been one of the best tools for a science fiction film’s hero to become master of the universe. And every fan of TV serial “Startrek” gets energised when Captain Kirk orders to engage the propulsion drive of the “USS-Enterprise” at velocity factor: Warp 6 (six times the speed of light) though they never explain how they do it. It may seem fanciful today but imagination is the prime requisite for the advancement of mankind; and there are still many men who are interested in science for the sake of putting it to good use. A single new invention — a single new discovery — may change the entire space travel picture overnight. We wish it would happen soon. |
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Radioisotopes serve us too! INDIA is one of the largest producers of radioisotopes in the world. Production of radioisotopes as a part of
peaceful uses of atomic energy is as valuable a service as production of power for a nation. Varieties of radioisotopes find applications, which are of direct concern to people. Radioisotopes are used in medicine, agriculture and industry. Radioisotopes technology finds large-scale applications in agriculture and food technology. Using various radioisotopes, Bhabha Atomic Research Centre (BARC), Mumbai has produced several important mutants of new food grains and pulses such as pigeon pea, mung bean, black gram, groundnut, jute and long slender rice. The high yielding crops or tissue culture raised plants have been provided to the farmers. About 500 metric tonnes of certified seeds of crop varieties have already been developed in BARC. These high yielding varieties are being widely used in the fields of Maharashtra, Bihar, Andhra Pradesh and Madhya Pradesh. Almost 5000 plants produced through tissue culture and micro-propagated banana plants were issued to the farmers in Maharashtra for field planning. Thus the use of radioisotopes has helped us to increase the food production and to increase the shelf life of perishable food items. They are also being used to study
plant soil interaction, thereby leading to better understanding of the role of fertilisers. A major woe of our farmers has been that a large part of the food produced by them is lost in the post-harvest storage. The scientists at the Department of Atomic Energy (DAE) have successfully demonstrated that the sprouting and perishing of onions and potatoes can be prevented by irradiation with gamma rays. This method of storing food materials is safe. The materials can be stored for a longer time to improve distribution throughout the year. Irradiation is found to be useful in delaying ripening of mangoes and bananas, disinfection of wheat and extending the shelflife of fish, poultry and meat. The method is also used to elininate pathogens from the frozen seafood. The bio-pesticides produced by radioactive techniques are not only free from dangers of chemical pesticides, but are also effective and friendly to the soil and environment. A special biological insecticide “Bacillus Thuriginesis” has been developed by BARC for use in destroying various caterpillars. Radioisotopes have also helped in monitoring the fate and persistence of pesticides in soil, ground water and environment. In the area of food preservation also the radioisotopesn have come to our rescue. India has the traditional supremacy in export of spices. The microbial decontamination of spices and related prevention of loss by irradiation has helped the country to maintain high quality in many of these items. Today food irradiation of various export items such as spices, seafood, onions and potatoes is being done successfully in the country. Health is another major field where radioisotopes have made their presence felt in India. The radioisotopes produced from the reactors are used
both for diagnostic and therapeutic purposes. Radioimmunoassay (RIA) is now conducted in the country in more than 80 hospitals.
Development of Technetium-99m generator gave special thrust to nuclear medicine in India. Technetium-99m is used for scintigraphy of body organs and investigations of disorders connected with bone, kidney and other vital organs such as heart, lungs, brain etc. In India the Variable Energy Cyclotron Centre is generating Gallium-67 which is used for the early detection of tumour and abscess. Today
nuclear cardiology is also made accessible to common man. Almost about a lakh of cancer patients derive the benefit of radioisotopes sources supplied by DAE for therapeutic
applications. Another application of radioisotopes towards the health care is their use in radiation sterilisation services. A number of products such as disposable syringes, surgical sutures and dressing etc. are sterilised by irradiation. Three such radiation sterilisation plants are already in operation in Trombay, Bangalore and New Delhi. The Board of Radiation and Isotopen Technology (BRIT) supplies nearly 60,000 consignments of radiopharmaceuticals that help over six lakh patients’ investigations and various radioisotopes to about 400 user institutions. In addition to this, it carries out sterilisation of 9000 cubic metres of medical products per annum. With the installation of well-equipped radioactive laboratories, India has been producing a variety of isotopes and making them available in medicine, agriculture, and industry. Every day several thousands of men and women get hope to live with smiles on their faces as they are redeemed from the monstrous diseases. |
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Innovations in computing IN a major breakthrough, a team of researchers at the University of California have developed a set of hair-thin chemical switches that could ultimately pave the way for the evolution of the so-called molecular computers, which not long back was in the realm of science fiction. According to James Heath, a member of the team of researchers, “A molecular computer will enable us to do things we cannot even imagine now. It could be million times more efficient than a silicon based machine.” Essentially, these innovative chemical switches are constituted of interlocked rings of atoms linked in a circle. By introducing electricity, these rings can be made to rotate around one another. In this way, these switches could be made to turn on and off and in the process provide memory to store and process an enormous volume of data. On the other hand, Chenming Hu, a Professor of Electrical Engineering and Computer Sciences at the University of California, has developed a revolutionary semiconductor transistor so tiny that a single computer chip can hold 400 times more devices than before. In the long run, this could lead to the development of a significantly faster and cheaper chip. According to Hu this breakthrough could change the design of switch on transistor which controls the flow of electric current in electronic devices. While previously this switch was a flat conductor that controlled only one side of the passage through which the current flows, Hu’s team has redesigned it as a fork shaped prong straddling both sides of the passage. Incidentally, this gives much better control and reduced current leakage. Professor Hu revealed that it was already about 10 times smaller than the standard semiconductor transistor now used by the industry. As envisaged now, the new transistors could help extend the success of the electronics industry which has profited by making transistors even smaller over the past three decades and delivering cheaper, better and faster computer brains”. In another significant development, researchers at the university of Roechester are currently working on designing a chip that reconfigures itself as it runs adapting to the needs of software while processing faster and using less power while doing so. The adaptable chip signals an effort to take full advantage of the massive processing power that chipmakers now deliver to desktops everyday. According to David Albonesi, Asst Professor of Electrical and Computer Engineering at the University of Roechester, “Today’s microprocessors are designed to work well overall but since they are all inflexible they can’t work as well as they could for any particular programme.” Going further Albonesi observes, “We are becoming a more and more wireless world with more and more processors draining batteries. While computing power has recketed forward, battery technology haunt kept pace. By making cellphones and portable computers more efficient, we will make them run faster while the batteries last longer.” |
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New products & discoveries Ice cool in the sun THIS solar-powered refrigerator for storing vaccines will provide a vital link in the World Health Organisation’s (WHO) fight to combat disease in the remote and inhospitable areas of the globe. The equipment was developed after BP Solar Systems of southern England learned that
unreliable or non-existent power supplies in some regions were a weak link in the WHO’s “Cold Chain” immunisation scheme which consists of a worldwide chain of vaccine storage centres to help fight diseases such as smallpox and polio. Following discussions with officials of WHO, a refrigerator chest was developed that provides 29 litres of cold space for vaccines at a storage temperature of +2 degree C to +6 degree C ambient. There is also a freezer compartment to accommodate six WHO standard ice packs. Power for the system comes from an array of nine 106cm x 45cm solar modules each containing 36 cells which convert light directly into electricity. It has an output of 12 volts 2 amps. A photovoltaic electronic unit and a storage battery to maintain power for up to five cloudy days completes the package. Field tests of the refrigerators are currently underway in the southern Sahara Desert, the Ghanaian and Ivory Coast jungles,Tanzania, Kenya, Pakistan and Algeria, although preliminary results are so encouraging that Nepal has already placeda firm order for five of the systems. A parallel project is also being implemented for refrigerated storage of veterinary vaccines. Trouble-free
artificial hip Researchers have developed new testing procedures which aim to realistically simulate the stresses their durability and ability to cope with extreme and shifting stresses. Each year, 150,000 people in Germany alone receive an artificial hip joint replacement but proper medical care is not the only consideration in ensuring long and trouble-free functioning of prostheses as they have to endure years of stress. Working with leading European hip implant and ceramics manufacturers, the Fraunhofer Institute for Mechanics of Materials IWM created laboratory conditions which simulate the stress during years of walking, running or dancing, and help to ensure that even after years of use, movement of the artificial hip remains smooth, a report in Fraunhofer Gesellschaftsays. “As artificial hip consists of three parts,” explain Roland Schafer from the IWM. “The shaft is surgically anchored to the thigh bone. A ball head is attached at the top end of this shaft, and a cup prosthesis is implanted in the pelvies. The ball and socket fit into one another and function like a natural hip joint.” All three parts, which have to remain functional for 20 or 30 years, are subjected to forces in the range of several kilonewtons. This is roughly equivalent to half a ton of weight. Ceramic has proven to be the ideal ball and cup material as it is extremely wear-resistant, well tolerated by the body and can withstand very heavy loads. Kits to detect
plant disease New detection kits developed by scientists in United Kingdom have made it possible for farmers, growers, consultants and plant health specialists to diagnose presence of disease-causing pathogens in plants on-site, thus obviating the need to send samples to laboratories. The low-cost, simple-to-use pathogen detection kits, developedby Horticulture Research International’s scientists Dr Nigel Lyons and Dr Michael Clark, allow rapid and reliable on-site detection of important bacterial and viral plant disease in minutes. Horticulture Research International has plans to extend its initial range of detection kits which can detect over 20 bacterial and viral pathogens, according to a report in British Commercial News. The kits are available in two formats- the LF- series and SA- series, enabling the detection of important pathogens of plants (edible and ornamental), including plum pox virus, tomato spotted wilt virus (Erwinia amylovora), the cause of friability; Ralstonia (Pseudomonas) Solanacearum, the cause of brown rot in potatoes and bacterial wilt in a variety of other hosts; and Xanthomonas campestrispv compestris,the cause of black rot, a serious disease of brassicas. The LF- series contains four tests per pack, whereas the SA- series contains 50, 100 or 250 tests perpack, quantities which allow for the cost-effective screening of lasrge numbers of stock plants or similar. The LF- series kits incorporate a stick which is based on a sophisticated membrane technique similar to that employed in home pregnency- test kits.
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Science Quiz 1. “Of course, at one time people used to believe that God explained the universe. It seems now that these laws of physics are always playing the role of God — that they are omnipotent and omniscient”. Who said this? 2. Robotic surgery? Now a surgeon can sit in a room far away from the patient and by remote control “instruct” the instruments to perform surgery using a system called AESOP. What does AESOP stand for? 3. These water animals have highly developed senses of hearing and smell. They are also very sensitive to the electric fields surrounding their prey and can also detect magnetic lines of force in the earth’s magnetic field. All these characteristics make them very effective predators. Which are these animals that have been nicknamed the “ultimate killing machines”? 4. When some harmful substance enters our body through the mouth or some irritating substance enters our nose, the body tries to protect itself and reacts by coughing, vomiting or sneezing so as to expel the harmful substance. What general name is given to these automatic activities? 5. Plants keep on losing water vapour from the surfaces of their leaves or other parts so as to help transport water from the roots to the upper parts. What is this process called the rate of which depends on temperature, light, flow of wind, humidity of air, etc.? 6. This electronic instrument can display on a screen how electrical quantities like voltage and current vary with time. What is the name of this instrument? Which main device is used in it? 7. Recent researches have revealed that a natural body protein called AAT can prevent AIDS virus from infecting body cells and thus help fight AIDS. Can you tell the full name of this protein? 8. Scientists have now produced atoms from the inner orbits of which electrons have been removed while the outer orbits still retain electrons. What are such atoms called, which find applications in some new technologies? 9. In certain sets of chemically related elements (like lithium, sodium and potassium), the atomic weight of the middle element is found to be the arithmetic mean of those of the other two. What are such sets of elements called? 10. French and Kenyan scientists have recently discovered human fossils which are estimated to be about 6 million years old, thereby meaning that these are 1.5 million years older than the oldest human fossils that had been discovered so far. What name has been given to these newly discovered fossils? What name had been given to the 4.5 million years old human fossils discovered in 1974? Answers 1. American physicist Richard Feynman, who shared the 1965 Nobel Prize for Physics 2. Automated Endoscopic System for Optimal Positioning |
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