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R.N. 70269/98ISSN : 0972-169X

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May 2011 Vol. 13 No. 8 Rs. 5.00

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Inside

Robert Wilhelm Bunsen

(Pioneer of chemical spectroscopy and

the inventor of the Bunsen burner)

(1811-1899)

Editorial : Can Hindi Make a

Difference?

Robert Wilhelm Bunsen: Pioneer ofchemical spectroscopy and theinventor of the Bunsen burner

The story of laser

Conversation with Dr. Prakasam Tata

Antibiotic effectiveness: What You

Can Do to Safeguard it?

Recent Developments in Scienceand Technology

VP News

Editorial : Can Hindi Make a

Difference?

Robert Wilhelm Bunsen: Pioneer ofchemical spectroscopy and theinventor of the Bunsen burner

The story of laser

Conversation with Dr. Prakasam Tata

Antibiotic effectiveness: What You

Can Do to Safeguard it?

Recent Developments in Scienceand Technology

VP News

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Editorial

Editor : Er Anuj Sinha

Address for Vigyan Prasar, C-24,

correspondence : Qutab Institutional Area, New Delhi-110 016

Tel : 011-26967532; Fax : 0120-2404437

e-mail : info@vigyanprasar.gov.in

website : http://www.vigyanprasar.gov.in

Vigyan Prasar is not responsible for the statements and opinions

expressed by the authors in their articles/write-ups published in

Dream 2047

Articles, excerpts from articles published in Dream 2047 may

be freely reproduced with due acknowledgement/credit, provided

periodicals in which they are reproduced are distributed free.

Published and Printed by Dr. Subodh Mahanti on behalf of Vigyan Prasar, C-24, Qutab Institutional Area, New Delhi - 110 016 and Printed at Aravali

Printers & Publishers Pvt. Ltd., W-30, Okhla Industrial Area, Phase-II, New Delhi-110 020 Phone: 011-26388830-32 Editor: Er Anuj Sinha

o Anuj SinhaE-mail: sanuj@vigyanprasar.gov.in

Indian engineers and scientists can be justifiably proud of their achievements in sectors as complex asspace, agriculture, nuclear energy and defence. There were controls imposed on transfer of knowhowand developments were required to meet difficult time schedules and severe cost constraints. Thesuccess in the IT sector is just as spectacular with supercomputing power now available to meteorologistsand other researchers developed indigenously.

Of course there are challenges, often cross-sectoral, requiring scientists to work with sociologistsand economists to be able to find acceptable solutions. These are issues of rural employment, urban

dwellings, energy efficiency in generation and utilisation and many more. New problems are emerging including reduction of carbon

dioxide emissions from industries and transport, water and energy conservation, and adaptation of agriculture practices even as

climate change impacts forcefully on the small farmer.

One is optimistic that a new generation of scientists and engineers will address these issues more effectively. They will require

high levels of problem solving skills and a well-developed capacity for critical and logical thinking. The best minds will need deep

understanding of their chosen field of science or engineering from world class institutions. They will also have to be equipped with

imagination, intuition and capacity for team work.

Inventive thinking, semi-guided exploration, entrepreneurship and creativity need to be nurtured and these are likely to best

develop if students learn to work and think in their mother tongue. Mind games, puzzles, team games and projects are used by leading

corporations (Xerox, Motorola, Kodak, GM and others) for their most creative teams to hone their skills in the above faculties.

Can higher education in science and engineering be transformed from English to Hindi? What will be the challenges and

implications? Is it desirable? These questions were examined at a discussion recently and some of these questions were viewed in a

new light.

Students who enter leading universities and colleges represent a national spectrum with mother tongues from across several

regions. Their medium of instruction in schools also varies. The first few months in college are spent in improving social skills,

staying abreast with the subjects and learning English language that is the medium of instruction. When they graduate, these

youngsters are ready for a career in research, teaching, or industry in India or abroad. They meet their and the societies aspirations

as they spread their wings.

Have they lost the edge that they would have if their instruction was in Hindi? Small European nations have demonstrated

that teaching and research at any level in the national language is feasible and equips the students with skill sets needed and expected

by the employers. They use English as a link language and often do so without the fluency that our scholars demonstrate.

Books, notes, assignments and other curriculum based work may continue as per agreed standards and in the accepted mediumof instruction. Can some topics in the existing curriculum be delivered in Hindi? Is it possible to encourage Solutions Research

as a skill set in the mother tongue? Would it be possible to provide societal exposure and comparisons in the local language? After

all medical internees learn to interact with patients from third year onwards and this has to be in the local language. Would this be

beneficial to the desired skill development?

Popular magazines in science and engineering need encouragement to help in developing vocabulary and interest in these

subjects. Articles in newspapers and features on radio and television will help in creating dialogue on local, national and international

issues. The opportunities on the digital medium are mind boggling. Science and engineering communicators have an important

responsibility to fulfill if Hindi has to find place as a instruction medium in institutions of higher learning and research. They will

have to move away from rituals that are witnessed in several institutions at present. Higher skill sets for creative thinking and problem

solving in the new generation are worthwhile goals.

Can Hindi Make a Difference?

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Robert Wilhelm Bunsen was one ofthe most versatile chemists of thenineteenth century. He was pre-eminently anexperimentalist with little interest in theory.He was a pioneer of chemical spectroscopy.

Bunsen, jointly with Gustav RobertKirchhoff (1824-1887), discovered the useof spectroscopy in chemical analysis in 1859and within two years they discovered twonew elements, viz., caesium and rubidiumwith its aid. His first major research helpedestablish the radical theory developed largelyby Jean Baptiste Andre Dumas (1800-1884) and Justus von Liebig (1803-1873),a theory according to which organic groupsor compound radicals correspond, in part, tothe simple atoms of inorganic compounds.He devised the Bunsen cell, a zinc-carbonprimary cell. This invention made it possibleto replace the expensive platinum plate ofthe Grove cell by a cheap carbon rod. Hewas a master of gas analysis. His studies ofIcelandic volcanoes led to explaining thephenomenon of geyser. He helped improvethe English blast-furnaces. He inventedmany laboratory devices, including thefilter pump and Bunsen burner. Theburner which has immortalized the nameof Bunsen was not actually invented by

him but an improvement was made on theburner devised by Michael Faraday at thesuggestion made by Bunsen. It was Bunsensconcept to premix the gas and air prior tocombustion in order to yield the necessaryhigh temperature, non-luminous flame. Itwas Bunsens thorough understanding of theprinciples of combustion that enabled him to

suggest the improvement. The actual designand manufacture of the burner was madeby his technician Peter Desaga. Even todayBunsen burner can be found everywherefrom the kitchen to laboratory.

Bunsen was a pioneer inphotochemistry and jointly with Britishchemist Henry Roscoe devised a photometerand an actinometer. Bunsen was a greateacher and his lecture courses were famous

He attracted students from all over the worldto study in his laboratory. Bunsen was greatlydevoted to his students. Among his studentswas Dimtri Ivanovich Mendeleef.

Bunsen was born at GottingenGermany, on 13 March 1811. His fatherChristian Bunsen was Chief Librarianand Professor of Modern Philology at theUniversity of Gottingen. After completing hischool education in the city of HolzmindenBunsen entered the Gottingen Universityin 1828. He received his PhD at the ageof 20. For his PhD he produced a Latin

dissertation on hygrometers. After his PhDhe went on a long study tour (1830-33); firshe visited different cities of Germany andthen went to Paris and Vienna. This helpedhim to establish a network of contacts withwell-known chemists of the time and hecultivated these contacts throughout hiprofessional life.

In 1834, he became a Privatdozent atthe University of Gottingen. At Gottingenwhile investigating the insolubility of metasalts of arsenious acid he discovered the useof iron oxide hydrate as precipitating agentwhich remains the best known antidoteagainst arsenic poisoning till today.

In 1836, he joined the PolytechnicSchool of Cassel as a teacher of chemistrywhere he succeeded the famous Germanchemist Friedrich Wohler (1800-1882). In1839, he became a professor of chemistryat the University of Marburg and where heremained until 1851. At Marburg Bunsenundertook studies of the highly toxicorganometallic compounds known as cacody

Each of the physical and natural sciences will probably always be likened to an unfinishedstructure. But in the case of chemistry we have good reason to think that the structure hasat least reached the point where its foundations have been completed. If these foundationswere begun by Lavoisier and Dalton, then Bunsen may be thought of as the last of thatremarkable group of men, including Wohler, Liebig, and Dumas, by whom this structurewas completed.

Henry Crew in The Astrophysical Journal

The Bunsen burner, simple, inexpensive, and effective, immediately displaced itspredecessors. The easily adjusted flame burned hot and clean, and was perfectly suited tolaboratory operations. The present form of the Bunsen burner, familiar to every science

student today, has scarcely changed from the original of 1855.A.J. Rocke in The Oxford Companion to the Modern History of Science

Bunsen was a great experimentalist, an expert in gas analysis and glass blowing, and apioneer of photochemistry and spectroscopy. He also worked in electrochemistry, devisingan improved version of the Grove cell.

A Dictionary of Scientists,Oxford University Press, 1999

Robert Wilhelm BunsenPioneer of chemical spectroscopy and

the inventor of the Bunsen burner

Dr. Subodh MahantiE-mail: smahanti@vigyanprasar.gov.in

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Robert Wilhelm Bunsen

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compounds. He discovered the first memberof cacodyls. Cacodyl is tetramethylarsine(CH

3)

2As

2(CH

3)

2.The name cacodyl was

derived from the Greek kakodhsmeaningstinking. Describing one of the cacodylcompounds Bunsen wrote: the smell ofthis body produces instantaneous tingling ofthe hands and feet, and even giddiness andinsensibilityIt is remarkable that when oneis exposed to the smell of these compoundsthe tongue becomes covered with a blackcoating, even when no further evil effects are

noticeable.Bunsen prepared various derivativesof cacodyls including the chloride, iodide,fluoride and cyanide. Bunsen demonstratedthat cacodyl was an oxide of arsenic thatcontained a methyl radical. Bunsens workwas a significant contribution towards theconfirmation of the theory of radicals andalso the idea put forward by Henri Berzeliusthat the concept of radical in inorganicchemistry is equally applicable to organicchemistry. Before the work of Bunsen, Gay-Lussac isolated the radical cyan in 1815

and Liebig and Wohler had published theirwork on the radical of benzoic acid. Duringhis investigations on cacodyls compoundsBunsen lost one eye in an explosion andtwice he nearly killed himself through arsenicpoisoning.

To concentrate on his work on spectralanalysis Bunsen took a sudden decisionto discontinue his work on quantitativephotochemistry in collaboration with theBritish chemist Henry Roscoe (1833-1915).

Explaining the reason for terminating hisalmost ten-year-long collaboration Hewrote to Roscoe: At present Kirchhoff andI are engaged in a common work whichdoesnt let us sleepKirchhoff has made awonderful, entirely unexpected discovery infinding the cause of the dark lines in the solarspectrumthus a means has been found to

determine the composition of the Sun andthe fixed stars with the same accuracy aswe determine sulphuric acid, chlorine, etc.,with our chemical reagents. Substances onthe earth can be determined just as early ason the Sun, so that, for example, I have beenable to detect lithium in twenty grams of seawater.

The origin of spectral analysis couldbe traced to the work of the Germanphysicist and optician Josef von Fraunhofer(1787-1826). While breaking the Sunswhite light into the colours of the spectrumby using a prism, Fraunhofer noticed somestrange black lines that seemed to punctuatethe solar spectrum. Fraunhofer markedthe position of the prominent lines in thespectrum, labeled them A through K. Hecalculated the wavelength of each line and hefound out that the positions of these lines inthe spectrum remained the same, as if theselines represented a kind of code. Fraunhoferworked with different sources of light, thedirect light of the Sun, reflected light of theMoon and the planets and starlight. He

found that each different light source leave adifferent pattern of the lines in its spectrum,a different code or a different thumbprint.These lines are named Fraunhofer lines.

Fraunhofer died in 1826 at an early age o39 without cracking the code or finding outhe significance of unique pattern of lines inthe spectrum of a light source.

Bunsen and Kirchhoff finallyunderstood the significance of the spectrapattern. They developed an instrumentwhat they called spectroscope, which passedlight through a narrow slit before passingit through a prism. The slit controlled thesource of the light and in this way it wapossible to display different wavelengthdifferently, and viewing against a scale i

became easier to differentiate and interpretThey used the burner devised by Bunsento heat various chemicals to incandescenceor glowing heat, the heat at which thechemicals gave off light. The Bunsen burneitself gave off very little light. Bunsen andKirchhoff observed that each chemical gaveoff its own distinctive pattern of colouredlines. For example sodium vapour produceda double yellow line, as its thumbprintToday we know the thumbprints of all theknown elements and the components of anysubstance could be analysed by analysing

its chemical spectrum. The classic paperof Bunsen and Kirchhoff titled Chemicaanalysis through observation of the spectrumpublished in 1860 ushered in era of chemicaspectroscopy.

Commenting on Bunsens contributionto the field of spectroscopy Americanphysicist Henry Crew wrote: The peculiarmerit of Bunsen in the field of spectroscopyis then that he perfected a simple methodwhich is capable of detecting the presence

International Year of Chemistry 2011

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Gustav Robert Kirchhoff Jean Baptiste Andre Dumas

Henry Roscoe

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of an element by the use of quantities vastly

smaller than are required by any other knownmethod. It opened to chemists, therefore,an entirely new field of investigation andone which, as the sequel has proved, is notconfined to our own planet or even to thesolar system.

Bunsen and Kirchhoff, by using thetechnique of spectral analysis, discoveredtwo alkali metals. Their first discoverywas caesium, named after its distinctiveblue spectral line. They announced theirdiscovery in the following way: Supported

by unambiguous results of the spectral-analytical method, we believe we can stateright now that there is a fourth metal in thealkali group besides potassium, sodium, andlithium, and it has a simple characteristicspectrum like lithium; a metal that showsonly two lines in our apparatus: a faint blueone, almost coinciding with Srd, and anotherblue one a little further to the violet end ofthe spectrum and as strong as clearly definedas the lithium one. After a few months theydiscovered rubidium, another alkali metal,named after the red line that announced

its existence. Following their footsteps fivenew elements were discovered by othersthallium (the name thallium was derivedfrom the Greek word thallos, which meansa new green branch) by the British chemistWilliam Crookes (1832-1919) in 1861,indium (named after indigo, a bright bluedye) by F. Reich and his assistant Th. Richterin 1863; gallium by Paul Emile Lecoqde Boisbaudran in 1875 (named after itsinventor, Lecoq means rooster in French

and which is gallus in Latin), scandium(named after Scandinavia) by L. Nilsonin 1879 and germanium (named afterGermany) by C. Winkler in 1886.

Bunsen liked to travel. In fact travellingwas one of his favourite relaxations. It wasthis pastime which led him to explain thephenomenon of geyser. In 1846, he visited

Iceland where he came across geysers. Heinvestigated the composition of the gasescoming off from the fumaroles and theiraction on the rocks with which they came incontact among other things.

Bunsens outstanding contributionswere given due recognition by the scientificworld. He was elected to the ChemicalSociety of London (1842) and the Academiedes Sciences of France (1853). He was electeda foreign Fellow of the Royal Society ofLondon (1858). Bunsen was elected a foreignmember of the Royal Swedish Academy ofSciences (1860). Awards received by Bunsenincluded the Copley Medal (1860) andthe first Davy Medal (1877) of the RoyalSociety of London, the Albert Medal (1898).Bunsen was too modest to be influenced byawards and once he remarked: Such things(recognitions) had value for me only becausethey pleased my mother, she is now dead.

Bunsen died at Heidelberg on 16August 1899.

References1. Trifonov, D. N. and V. D. Trifonov,

Chemical Elements: How they wereDiscovered, Moscow: Mir Publishers,1982.

International Year of Chemistry 2011

2. Crew, Henry, Robert WilhelmBunsen, The Astrophysical JournalVol. X, No.5, pp.301-303, 1899(available on the Internet)

3. Spangenburg, Ray and Diane KMoser, The History of Science in theNineteenth Century, HyderabadUniversities Press (India) Pvt. Ltd1999.

4. Heilbron, J. L. (Ed.), The Oxfordcompanion to the History of ModernScience, Oxford: Oxford UniversityPress, 2003.

5. The Cambridge Dictionary of ScientistsCambridge: Cambridge UniversityPress, 2001.

6. A Dictionary of Scientists, OxfordOxford University Press, 1999.

7. Chambers Biographical DictionaryNew York: Chambers HarrapPublishers Ltd., 1997.

8. The Hutchinson Dictionary of Science(Edited by Peter Lafferty and JulianRowe), Oxford: Helicon PublishingLtd., 1993.

9. Available sources on the Internet.

(The article is a popular presentation of thimportant points of the life and work of Rober

Wilhelm Bunsen available in the literature. Thidea is to inspire the younger generation to knowmore about Bunsen. The author has given thesources consulted for writing this article. Howeverthe sources on the Internet are numerous and havenot been individually listed. The author is gratefuto all those authors whose works have contributedto writing this article and the sources of the picturesreproduced here.)

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Paul Emile Lecoq de Boisbaudran

William Crookes

Josef von Fraunhofer

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39

The laser, considered to be one of thegreatest inventions of the 20th century,has now virtually permeated almost all walksof life. For instance, scanning of bar codeson packets of food items and consumer

products or recording and playing of audio/video contents on CDs and DVDs is donewith the help of a laser. The hologramstickers used for security purposes on credit/debit cards, books, mobile batteries, etc.are recorded with the help of a holographictechnique that uses laser. A laser printer canprint data fast with excellent print quality.Laser has other applications too in a plethoraof fields like communication, industry,medicine, defence, space science and soon. Laser has indeed changed our lives in adramatic manner.

What is laser?Laser is an acronym for Light Amplificationby Stimulated Emission of Radiation. It is apowerful source of light having some uniquecharacteristics not found in the normal lightsources like tungsten bulbs, mercury lamps,etc. A unique property of laser is that it containswaves of a single colour or wavelength. Thisproperty is known as monochromaticity orspectral purity. The ordinary light has manycolours or wavelengths and is, therefore, not

monochromatic.Another unique property of laser isthat it has high degree of directionality; i.e.,it can travel very long distances with verylittle divergence, which can be less than 10-5radians. In contrast, a beam of ordinary lightspreads out very quickly; in fact, it spreads toabout a kilometer across for every kilometretraversed. Hypothetically, if a narrow beamordinary light could travel to the Moon,which is at a distance of 3,84,400 km fromEarth, it would have spread to such an extentthat the diameter of the light on the Moon

would be about 3,84,400 km. In contrast,the spread of a laser beam would be hardlya few kilometres. This unique characteristicof laser was used for measuring the distanceof the Moon from Earth when astronauts ofApollo-11 mission of 1969 mounted a retro-reflector (a special kind of reflecting mirrorthat sends the light back to the source alongthe same direction) on the surface of theMoon. When a laser beam was sent from theEarth to the retro-reflector on the Moon, it

was reflected back to Earth. By measuring thetime taken by the laser beam to travel fromEarth to the mirror and back, the distance ofthe Moon from Earth was calculated with anaccuracy of 15cm.

Laser light is highly coherent; i.e., itswaves are exactly in step with each otherand thus have a fixed phase relationship. Infact, the high degree of directionality andmonochromaticity of laser is responsible forits coherence. The high monochromaticityof laser light endows it with a property calledtemporal coherence while the high degreeof directionality of laser endows it withanother property called spatial coherence.Thus, high degree of both temporal andspatial coherence exists simultaneously in

laser light.Another remarkable feature of laseris its high intensity. This means that a largeamount of energy can be focused on to a verysmall spot. This has important applicationsin industry for cutting, welding, etc., and inthe field of laser fusion.

Thus, laser light has high degreeof directionality, is monochromatic andcoherent and has high intensity. Laser lightcan be compared to a group of soldiers wearinguniforms of the same colour and marchingtogether in step in the same direction.

Ordinary light, on the other hand, is like acrowd of people wearing clothes of differentcolours, walking generally out of step withone another in different directions.

Invention of laserLaser was invented by Theodore HaroldMaiman on 16 May 1960. He obtained itby stimulating the atoms, molecules, or ionsof an active medium. This led to stimulatedemission that finally resulted into theamplification of light.

The principle of stimulated emission

was proposed by Albert Einstein in 1917.However, for more than three-and-a-halfdecades this principle remained on paper,as it could not be put to any practicalapplications.Maser the longer-wavelengthpredecessor of laserThe invention of laser became possible onlyafter the invention of maser (acronym forMicrowave Amplification by Stimulated

Emission of Radiation). The idea for theinvention of maser is said to have struckCharles Hard Townes while he was sitting onthe bench of a park. Townes, who was withColumbia University in USA, was workingin the field of microwave spectroscopy. Hewas trying to build a short-wave oscillatowhich could work at frequencies as high athe infrared.

Townes had tried several ideasHowever, none seemed to work. He wasalso chairman of a committee for navy thatwas examining ways to develop very shortwave oscillators. In 1951, the committeewas having its meetings in WashingtonThe members of the committee could nocome out even with a single plausible ideafor the development of short-wave oscillator

This had greatly disappointed Townes. Onlythe last meeting of the committee was duewhich was to be held the next day.

Next morning Townes got up earlyHe got dressed and moved out of his hotelPlenty of time was left for the meeting tostart. Being too early in the morning, nocaf or restaurant was open. Moving aheadTownes suddenly found himself outside theentrance gate of the famous Franklin Park. Aif guided by some inner instinct, he entered

The story of laser

Dr. P.K. MukherjeeE-mail: pkm_du@rediffmail.com

Charles Townes

Theodore Maiman with a ruby laser

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the park and sat on a bench. The beautifulflowers of azaleas caught his attention.

While admiring the natural beauty ofthe park his mind was also focussing on theproblem that had bogged him down for quitesome time. Suddenly, as if by flash, an ideastruck him. Earlier also he had consideredmolecules that oscillate at high frequencies.

However, he had dismissed them becausein equilibrium such molecules are boundby certain laws of thermodynamics. But,molecules do not have to obey such lawsif they are not in equilibrium, thoughtTownes. This was precisely the idea thatstruck Townes while sitting on the bench.He immediately took out a piece of paperfrom his pocket and started writing someequations on it. He wanted to see if selectionof excited molecules by molecularbeam methods could produceenough molecules to providea feedback oscillator. It verymuch looks possible, sighedTownes. He seemed to have got asolution to the problem that washankering him.

Using the principle ofstimulated emission proposedby Einstein, Townes in 1954succeeded in constructing amicrowave amplifier device calledmaster. It is a mere coincidence thattwo Russian scientists, Alexender

Mikhailovich Prokhorov andNicolai Gennedieyevich Basov,working in Lebedev Institute inMoscow were also simultaneouslyand independently thinking alongthe same lines. However, Townes was thefirst to produce the maser. For the inventionof maser Townes, Basov and Prokhorovshared the 1964 Nobel Prize in Physics; halfof the prize was awarded to Townes and theother half jointly to Basov andProkhorov.

The developmentof laserIn 1958, Townes jointly with (hissisters husband) Arthur LeonardSchawlow published a paper inPhysical Review wherein theypresented the idea that the maserprinciple could be extended tooptical frequencies. In effect, thismeant that like microwaves, lightwaves could also be amplified

using a device which they called opticalmaser (later to be named laser).

About the same time, Gordon Gouldwas also working on the same problem. Heis supposed to be the first to have introducedto the public the term laser in his 1959conference paper. However, TheodoreHarold Maiman, working with the HughesResearch Laboratory in California, USA,was the one who made the first laser operateon 16 May 1960. For this, Maiman used acylindrical rod of ruby crystal that producedlaser light in the visible red region.

Principle of laser actionIn order to understand the principle of laseraction we first need to clearly understandthe concepts of stimulated emission and

population inversion. These are technicalconcepts which we will try to explain insimple terms.

According to quantum theory,emission or absorption of radiation is not

a continuous process.Rather, it takes placein the form of discrete

packets or bundles ofenergy, each packet orbundle being called aquantum. A quantum oflight radiation is calledphoton.

An atom can bothabsorb and emit energy.When an atom absorbsenergy it gets excited.The process is known as

absorption. The excited state of the atomhowever, lasts for a very short duration of 108seconds after which it returns to its origina(unexcited) state. This process, which isaccompanied by the emission of radiationby the atom, is known as spontaneousemission.

Besides the above two processes, a

third process is also possible. An outsidephoton interacting with an excited atom maystimulate it to emit a photon. This process iknown as stimulated emission. Howevera necessary condition for this to happen isthat the outside photon should have energythat is equal to the difference between theenergies of the atom in its excited and thelowest energy state (ground state).

An important characteristic ostimulated emission is that theemitted photon has exactly thesame wavelength (or frequency)as the outside photon and thathe two photons are in the samephase.

If the process is repeatedmore and more atoms will beforced to emit photons therebyinitiating a chain reaction. Thiswould result in rapid buildupof radiation of one particularwavelength travelling coherentlyin a precise, fixed direction. Thiprocess is called amplification

by stimulated emission which ifundamental for laser action.

However, besides stimulatedemission another condition, calledpopulation inversion, is also

necessary for laser action. Under the normacircumstances, the number of atoms in thelowest energy state (ground state) is greatethan that of the excited energy state. Ifsomehow the situation could be reversed, iwould be possible to achieve what is knownas population inversion.

If an intermediate state, called

metastable state having a lifetime higherthan that of the excited state, is presenbetween the ground state and excited statethen the atoms could pause at the metastablestate for more time. This would result intoa higher population of atoms in the upperenergy (metastable) state relative to thatin the ground state, leading to populationinversion which is an essential condition forlaser action. The lifetime of the metastablestate may be about a millisecond (10-3s)

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The story of laser

Principle of laser

Arthur Leonard Schawlow

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which is fairly large compared to thelifetime of the excited state of theatom (10-8s).

Main componentsof a laserA laser generally requires three maincomponents for its operation: (i) the

active medium, (ii) the pumpingsource; and (iii) the optical or cavityresonator. The active medium maybe a solid, liquid, gas, or semiconductor. Thepumping source may be a xenon or kryptonflash lamp; electrical energy or energyobtained from chemical reactions may alsobe used as pumping source. The optical orcavity resonator consists of two mirrors onehaving full reflectivity while the other having90% or less reflectivity. It may benoted that different types of lasers canhave different configurations of theoptical resonator. While some cavityresonators may use plane mirrors (asused by Maiman) others may usespherical, hemispherical, confocal, orconcave-convex mirrors.

The pumping source pumpsenergy into the active mediumto achieve the state of populationinversion. The radiation emitted inthe form of photons as a result ofstimulated emission multiplies bybouncing back and forth between

the two mirrors and passing throughthe active medium. As a result, theradiation gets amplified and finally the laserlight comes out in the form of a narrow beamthrough the partially transparent mirror.

Different types of laserMaiman used ruby crystal for developingthe first laser. Subsequently, gas, liquid,semiconductor, etc., have also been used asmaterials for production of laser. Althoughinnumerable types of laser are now available,based on their production technology

seven broad categories of lasers have beenidentified. These are solid-state lasers, gaslasers, liquid or dye lasers, semiconductorlasers, chemical lasers, gas dynamic lasers,and free electron lasers.

The ruby laser developed by Maimanemits red light which lies in the visible rangeof the spectrum. However, besides visiblelight some lasers emit light in the ultravioletregion while others emit light in the infraredregion also.

Scientists have also succeeded inproducing X-ray lasers that produceradiation in the X-ray region. Raman lasers,based on the Raman Effect discovered by theIndian Nobel laureate physicist C.V. Raman,have also been developed. It may be notedthat Raman lasers are different from the

conventional lasers as laser action is possiblein them even without population inversion.Scientists are currently busy in developingstate-of-the-art lasers such as nano lasers,quantum dot lasers etc. Some success hasalready been achieved in thisdirection.

Applicationsof laserLasers have wide ranging

applications in various fields.In the field of medicine,laser is used for performingcataract operations and in theLasik surgery for correctingthe refractive errors ofeyes. Laser is also used forwelding of detached retina.It also finds application indentistry and for clearing ofthe blocked arteries by way

of a procedure called laser angioplastyAlso, it is used for the treatment ovarious kinds of cancer.

In fibre-optic communicationlaser is used for transfer of vasamounts of data with faster speedIt has applications in industry forcutting of metals and for welding o

even dissimilar metals. Laser is alsoused for drilling of holes in such hardmaterial as diamond.

Laser has important applicationin metrology, surveying and seismology. Iis also used for the study of environmentapollution. In defence and warfare too, laserhas important applications. Laser systemcan be used to track down and destroyenemy missiles. Underwater ranging using

laser makes possible detection osubmerged submarines.

Lasers are being used fortesting the validity of some basicscientific theories. For instance, thevalidity of Einsteins special theoryof relativity has been tested usinghelium-neon laser. Lasers can alsobe used for isotopic separationmeasurement of impurities presenin materials and study of ultrafaschemical reactions in chemistry. Inphysics, lasers play a significant rolein the fields of spectroscopy andthermonuclear fusion. Application

of laser even extend to agricultureUsing laser the rate of sproutingof seeds can be increased and even the cropscan be reaped relatively early. Many moreapplications of laser are expected to emergein the near future. Today, laser is greatlybenefitting the human society at large.

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The story of laser

Diagram of a ruby laser

A scientist experimenting with laser

A patient undergoing laser eye surgery

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Dr. Prakasam Tata, a well knowncivil engineer and environmentalscientist is associated with the Centrefor Transformation of Waste Technology(CTWT) as Executive Director since itsinception and he is the man behind thesuccess of this Centre which attracts policymakers and environmentalists.

The primary mission of the CTWTis to use wastes as a resource to generaterevenue on a sustainable basis. Therevenue is to be used to finance waterreclamation and reuse projects and otherenvironmental improvements. The Centreexplores opportunities to implement

waste transformation technologies andparticipate in the process of commercialisingcommodities, products and energy convertedfrom municipal wastes and the residuals ofindustrial and agricultural activities, and theemerging green industries.

Dr. Prakasham Tata persued hisprofessional interests at the State University ofNew Jersy and has been outstanding teacherand researcher in Chicago for the past fivedecades. His empathy for the downtroddenhas drawn him to The Rotary InternationalMovement and he is active in Naperville,

USA. He resurrected Bharathi Teertha topromote Indian Culture and continues togive it leadership & vision.

Dr. Prakasham Tata who was bornin Vizianagaram, Andhra Pradesh, is alsoworking for his childhood dream of doingsomething to improve public health inVizianagaram to provide the city a betterenvironment. He played an importantrole in the construction of a wastewatertreatment system in Vizianagaram, to bringinto focus the whole gamut of issues relatingto clean water availability, conservation,

management, waste water disposal andrecycling. According to Dr Tata, modernliving was leading to more water toxicitylevels and more energy consumption forwater management. Urban areas faced anincreasing sewage disposal problem, andwater was being increasingly polluted.

Recently Er Anuj Sinha, Director,Vigyan Prasar and Consultant, Departmentof Science & Technology, Government ofIndia interacted with Dr. Prakasam Tata on

challenges faced by him to create a successstory of Vizianagaram.

Prof Ashok Lal, a well known author,also joined in the discussion. Prof AshokLal began his career as an executive in StateTrading Corporation and specialized inInternational Marketing. He moved overto academics and found his true calling in

interpreting the works of Galib and reflectingthoughts of the Buddha. His interestspans from radio scripting to street playsand other forms of direct communicationon developmental issues. Prof Lal was atVizianagaram to release his book on Galiband Buddha which was published byBharathi Teertha Trust.

Here are excerpts of the conversation.Er Anuj Sinha: In any social

engineering project it is not only the

technology that determines the successor failure but it is also factored by thecommitment of the people the users of aparticular service and the promoters. Sowhat are the lessons that one learns from thisexperiment that could be useful to otherswho may be equally committed to try andsee whether they can make contribution toa project of that type the you took up andcompleted in Vizianagaram?

Dr. Prakasam Tata:There is nothing

that cannot be done. I have been living in theUnited States for last 48 years and I could

complete the project in my home town in2003-04, with the cooperation of some locapeople I found that majority of the masseswere not interested in doing it. It is a senseof apathy that I observed because there isno support from the government or fromactivists concerned about the environmentThey talk about all kinds of different thingsbut they rarely discuss local problems otry to identify a solution. Even if I offereda solution they said it cannot be doneunless the government is involved. So whalessons did I learn from it? The government

supported the project. Almost Rs. 2.5 crorewas spent on this project and it was taxpayers money. But once the regime changethe priorities change.

I must comment on the toilet complexthat was completed recently. I have seen thefrustration of villagers there and as per myscientific estimations I know this project haspotential benefit of about Rs. 1.5 to 2 lakhper year after paying for the arrangementsand also the salaries of four people workingin this complex. But what I heard from thevillagers is a little bit disappointing. This

project was not funded by the governmentrather and it is a project of the RotaryInternational. But, by motivating the massesby sitting with them and telling them thathis is their project, they agreed to pitch in.

Now I am not happy over the moneyspent over there simply because it is themoney of the people being spent and nobodyseems to be caring about that money. It habeen happening for last 3.5 to 4 years. Everyyear I come and ask the authorities why theyare not taking interest. I have documentedit in films and articles also. This is a real storyand you can see my frustration.

AS:May I draw a parallel from Punjabwhich has had a different outcome? Therewas a religious leader in Punjab who waconvinced that the stream of river flowingnext to his ashram was really neglected withsewer discharges from neighbouring villagesHe managed to raise this issue among thedevotees and they jumped in on the offerand over a period of five weeks they hadconstructed aeration ponds for all discharges

Dr. Prakasam Tata,a pioneer in transformation of waste

Dr. Prakasam Tata

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Conversation

in to the river and made it alive again.Perhaps the people of Punjab do kar-seva -as a matter of faith and religion, whereas thepeople of this community here are not thatsocially inclined and ask the government todo everything!!

Prof Ashok Lal:Can I interrupt you?What Er Sinha is saying is of great significance

but there is a problem here of attachingreligion. I am very glad that it worked inPunjab. But, what will work here is somekind of symbology, because we know whatwe mean by religion in the present time. So,I personally I am very much for promotingspirituality only. But iconic representationin terms of a religion where problems wouldarise is another story.

PT: Anuj ji, you raise a very goodpoint. I am not talking about religion,about spirituality. We do nothave to deal with religion per

se. All the Hindus, ashrams,must act together; must sayto their devotees unless youact, things will never change.They should urge the peoplenot to spread pollution. Thereare religious leaders who havelots of followers; when theysay something their followerswould implement it. In thesame manner, when somemullah calls upon his followers

to clean the mushy river, theywould be keen to do it.There are common good

things for the entire populationto share for livelihood andsustainability of the region. Sowe can bring all the mullahs, all Buddhistpriests and Hindu pundits and also scientiststogether to demand service to society forthe common goal. So finally we have anobligation to save the planet Earth for thecoming generations.

AS:May I come back to the experiment

you carried out in Vizianagaram. How couldwe have done the things differently? Nowyou go back 9-10 years; could it happen ina different form so that it would have beenmore successful?

PT: I think it is very difficult foradministrators posted every 6 months or oneyear, taking charge and trying to understandthe problems that had been previously triedto be rectified. One problem I see is that bythe time they understand the problem and

come to a stage where they try to think ofsolving the problem their tenure is over. Atleast this is what I found in the few yearsof my exposure of solving the problem inVizianagaram! I dont blame them becausethe system is so inefficient, any new personwill take time to understand what theproblem is.

So we have to create awareness amongthe public and actually demonstrate that theycan solve the problems, without dependingon the government, because governmentscannot do much. This is a kind of feelingthat is needed to be developed in society.

AS: Coming to other functioningof Bharathi Teertha, where you have beenpromoting art music, and traditional culture.Of course we admire the commitment andgenerosity that you donated your ancestral

home. How and what sort of vision orchange you see in the future?

AL:This is of great interest to me, butbefore that I want to ask a question. I wantto know your trigger, what made you take upthis endeavour in spite of your profession,and in spite of your several concerns that you

may have in Chicago and elsewhere?PT: Well I think its a personal

element of mine because, when I made acommitment that I promised to somebodyI wanted to make sure that I have tried mybest to make it happen. I sincerely believe,whatever I said to anybody in my life I havetried my best to fulfill that commitment.

I know my limits; I also know myweaknesses. But if I made a commitment,that always keeps bothering me in some

respect and compels me to do somethingSo that when I retired from my active jobI could take other opportunities. Now I wilgo to the question of Er Sinha; I will telyou the best way, when I went to the firstlecture in the college, my professor told mean engineer who knows the history can do abetter job. So I know the history of Bharath

Teertha - which had its glorious days inAndhra Research University, this is what theycalled it at that time. When the UniversityGrants Commission came, it lost its statusas a research university and it has becomeBharathi Teertha! And the benevolence othe maharaja is diminished; only passionatepeople like Suryanarayana Murti were leftMr Murti passed away in 1999, but I madea promise to him that I will do somethingfor our place. So when I retired in 2002,

wanted to do something andto work for the benefit oVizianagaram.

After many yearof professional career onecan become a good oratorand can give good lecturesBut what is next? Is there atransformation of peoplethere? I think music is such amedium. Many people wanto sing and dance and hence Iwant to give them a platformwhere music and culture wil

go hand in hand.AS: My point here i

that Prof Prakasam Tata iin a unique position to tryand integrate these two greahuman endeavors science

and culture. Can that commitment todevelopment and integration of science withart happen because of the Bharathi Teertha?

PT: I am 75 years old. Let me bepragmatic about it. I do not know, but iat all anything will happen. I always teltwo things, one is committed people and

the other is finances. I am now findingmore committed people. While givingdemonstrations I say you are right peoplewho can do it. In doing this, I requestedmany people and one of them is you AnujWhile undertaking the Vizianagaram projecI met administrators in India and also in theUnited States. After sharing my views peoplehave started to believe and started to supporme. We have reached the fifth year now ocelebrating the World Water Day.

Dr. Prakasam Tata delivering a talk.

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Conversation

AS: Can I take you back to yourformative years when you were in Nagpur,spending time in LIT campus? I spent fiveyears there after you left. How did it shapeyour personality?

PT: There are several people whohave made my life. Prof A. Nath, Head,Department of Bio Chemistry was a great

philosopher. I believe in the Vedas andAyurvedas and he pulled out so many slokaswhich motivated me to do the best. Beforethat there were many teachers who impressedme in a way.

I was 17 years old when I was admittedto Nagpur. I did not know Hindi or Englishwell. I just had Rs 10 with me and I wentwith the hold-all that time. At the station therikshawala asked me three rupees. That timeI did not know what is he saying. I said Oh

God, why I am here! By hearing me he said,are you a Telugu man? At the same momentI recognised God. Because I know God willnot come with 10 hands and all. I said yes,and then he gave me such a treatment thathe even carried my hold-all. After reachingto the hostel I was giving him 3 rupees andone extra for the efforts but he refused to

take the money. It is great that I have met somany different people. Even in the UnitedStates I met many good people.

AS:In another aspect of your character,you spotted something in Prof Ashok Lal.And probably he did it like that. What isthat you spotted? Was it an intuition onlyor logical type decision that this guy has thatspark?

PT:I was told by my friend Prof AjitPant that he has a friend here and he is good.

I said I want to listen to this man. Both ous along with his wife Kumkum had a goodtime talking to each other. I found that if anysingle man can change the way we perceivethings it could be Ashok Lal. And thats itI agreed to print his thesis on Buddha andGalib that was released yesterday.

AS: It has been a positive expressionabout a Bharathi Teertha. We have interactedin searching and locating unifying effortin reducing tension, interpreting differenchange of thought.

PT: Definitely, that is one of ththings to join more people in this efforand then have trust in Bharathi Teertha. AI have always said, I am finding myself inthis effort. As an endeavour, as a consumeor producer, all that I can say.

AS:Thank you Sir.

Vigyan Prasar invites applications for participation in a 5-day capacity buildingNational Workshop onScience Broadcasting

May 2 to 6, 2011Venue: Indian Institute of Mass Communication (IIMC),

Aruna Asaf Ali Marg, JNU New Campus, New Delhi

The workshop will focus on improving the skills needed to quickly locate scientific content relevant to specific target audiencesand to structure the content in comprehensible and engaging ways. The workshop will provide tools, tricks and tips for covering

issues related to health, agriculture, environment and technology. The workshop will use power point presentations, discussions,demonstrations, exercises and games to orient the producers to the best practices used in attracting audiences in a competitivemedia environment.

ObjectivesThere has been an explosive growth of TV and Radio channels in India. After a period of more-of-the-same, where channelsimitated each other, media channels are now struggling to specialize and to capture niche audiences. As the media landscapedevelops, the ability to handle content that meets the information needs while satisfying the entertainment values of the viewersand listeners will ultimately determine the survival of most of the existing channels. This workshop provides an opportunity to trainthe content producers and to build their capacity to handle diverse contents efficiently and effectively.

Who can participate?Producers from private channels, production houses, community radio stations, FM stations; Producers from Public sector(Doordarshan, EMMRCs, IGNOU, CIET, etc), faculty members from Science Journalism / electronic media courses, scriptwriters

and freelance producers and academicians with a minimum of three years experience; not more than 40 years of age.

Expected outcome of the workshopBy the end of the 5 days, the participants will have worked out the concepts, done research, worked out a treatment for producingprogrammes which they can produce easily after the workshop. In other words, the output will be story ideas which are executable,backed by reasonable amount of research and pitched at the right level for specific audiences.

The outcome will be programmes with scientific content produced by the participants in the following months, enriched bythe inputs from the workshop. Networking among participants and between the participants and trainers is also an expected followup action.

For more details for the workshop please visit Vigyan Prasars website www.vigyanprasar.gov.in

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Antimicrobials and antibiotics are the icons of modernmedicine. Of the many proud sagas that colour the world

of medicine, they easily rate among the biggest miracles. Yet,through their widespread misuse, today a stage has been reachedwhen they are losing their efficacy. Antimicrobial resistance alsoknown as drug resistance is rendering these pills ineffective. Thethreat is real.

Should you think antibiotic resistance isnt a problem ordoesnt affect you, think again. Infections caused by resistantmicroorganisms failing to respond to conventional treatment,resulting in prolonged illness and greater risk of death are on a steeprise. About 440,000 new cases of multidrug-resistant tuberculosis(MDR-TB) are emerging annually, causing at least 150,000 deaths.Resistance to earlier generation antimalarials such as chloroquineand sulfadoxine-pyrimethamine combination is nearly global. Thenotorious methicillin-resistant Staphylococcus aureus (MRSA) once a concern only for people in the hospital is raising its ugly headand is causing infections among healthy people in the community. Ifthis isnt alarming, think about this: resistance is on the rise againstthe antiretroviral drugs (ARV) used in the treatment of the humanimmunodeficiency virus (HIV).

The writing is clearly on the wall: inappropriate and irrationaluse of antimicrobial drugs has spawned the emergence of resistantmicroorganisms, which threaten to spread far and wide among thehuman race and turn into killer illnesses. Regular antibiotics nolonger work against them. These infections are very difficult to treat,

mean longer layoffs, extended hospital stays, and the need for moreexpensive and toxic medications. Some resistant infections can even

cause death.A global health concern, the only way to tide over the crisi

would be to use antibiotics wisely.

What makes antimicrobials ineffective?If antibiotics are used too often for conditions they cant treat like colds, flu or other viral infections they become less effectiveagainst the bacteria theyre intended to treat. Not taking antibioticexactly as prescribed also leads to problems. For example, if you takean antibiotic for only a few days instead of the full course the antibiotic may wipe out some but not all of the bacteria. Thesurviving bacteria become more resistant and can be spread to othepeople. When bacteria become resistant to first line treatments, therisk of complications and death is increased. Each year, thousands opeople die each year of antibiotic-resistant infections they contractedin the hospital.

The failure of first-line antibiotics also means that doctors haveto resort to less conventional medications, many of which are morecostly and associated with more serious side effects. For instance, thdrugs needed to treat drug-resistant forms of tuberculosis (TB) aremuch more expensive than are the drugs used to treat non-resistantTB. The course of treatment is long up to two years and theside effects can be severe.

Other consequences are the increased costs associated with

Antibiotic effectivenessWhat You Can Do to

Safeguard it?Dr Yatish Agarwal

e-mail: dryatish@yahoo.com

33

Hailed as the wonder drugs of the 20th century, antibiotics easily rate among the best ofthe miracles worked by modern medicine. Before their birth, teeny-weeny bacteria tooksuch heavy toll of human lives that the average life expectancy of the human race onearth was less than 25 years. With the advent of these miracle drugs, it has nearlytripled in many parts of the world and several scourges caused by microorganismsstand decimated. Yet, today, the human race is on the verge of squandering thisbig advantage. Due to their widespread misuse, antibiotics are rapidly losingtheir efficacy. New microorganisms often referred to as superbugs are becomingresistant to them, and are threatening to kill, spread to others, and return us tothe pre-antibiotic era. Unless quick measures are initiated both by individualsand society, the future generations may again be left exposed to the evil wrathof microorganisms. Recognising the threat, the World Health Organization(WHO) has decided to send out a clarion call to its member nations to intensifymeasures to safeguard these wonder drugs for future generations. The centraltheme of the World Health Day 2011 is to call on governments and stakeholders toimplement the policies and practices needed to prevent and counter the emergence ofhighly resistant microorganisms.

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Mediscape

prolonged illnesses, including expenses for additional tests, treatmentsand hospitalisation, and indirect costs such as lost income.

What you can do to safeguardantibiotic effectiveness?Repeated and improper use of antibiotics is the primary cause of theincrease in the number of drug-resistant bacteria. Heres what youcan do to promote proper use of antibiotics:

Understand when antibiotics should be usedDont expect to take antibiotics every time youre sick. Antibioticsare effective in treating most bacterial infections, but theyre notuseful against viral infections, such as colds, acute bronchitis or theflu. And even some common bacterial ailments, such as mild earinfections, dont benefit much from antibiotics.

Dont pressure your doctor forantibiotics if you have a viral illnessInstead, talk with your doctor about ways to relieve your symptomsfor instance, a saline nasal spray to clear a stuffy nose or a mixtureof warm water, lemon and honey to temporarily soothe a sorethroat.

Take antibiotics exactly as prescribedFollow your doctors instructions when taking medication.Dont stop treatment a few days early because yourefeeling better. Taking the full course of antibiotics isthe only way to kill all of the harmful bacteria.A shortened course of antibiotics, on theother hand, often wipes out only themost vulnerable bacteria while allowingrelatively resistant bacteria to survive.

Never take antibiotics without a prescriptionIf you didnt complete a full course of antibiotics, you might betempted to use the leftover medication the next time you get sick orto pass it along to someone else. But this isnt a good idea. For onething, the antibiotic might not be appropriate for a future illnessAnd even if it is, youre not likely to have enough pills to combat thgerms making you sick, which can lead to more resistant bacteria.Prevent the spread of germs

Good hygiene goes a long way inpreventing infection. Wash yourhands thoroughly with soap andwater, especially after using thetoilet, changing a diaper, or beforehandling food. Keep food preparationareas clean. Although antibacteriacleaners and soap are widely availablethey arent necessary. Plain soap andwater work fine to kill germs in mossettings.

Understanding the new type of antibioticresistance labelled as NDM1

l NDM1 is an enzyme that confers resistance to one of the mostpotent classes of antibiotics, known as carbapenems. Manydifferent types of bacteria have now been reported to harbour thisnew resistance machinery. At least one in 10 of these NDM1-containing strains appear to be pan-resistant, which means thatthere is no known antibiotic that can treat it.

l This is ominous since this particular resistance machinery isgoverned by a set of genes that can move easily from one bacterium

to another.l Equally damning is the fact that NDM1 has been found in the

most commonly encountered bacterium in the human population,E. coli, which is the most common cause of bladder and kidneyinfections. Of the two drugs potentially capable of treating aninfection due to these new multi resistant strains, one of them,colistin, causes toxic effects to the kidney in about a third of people,and hence, is not safe.

l Currently, there is no significant new drug development whichpromises to offer a major breakthrough against this problem.

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Protect yourself and othersAntibiotic resistance is a global health problem. Nearly all significantbacterial infections in the world are becoming resistant to commonlyused antibiotics. When you misuse antibiotics, you help createresistant microorganisms that can cause new and hard-to-treatinfections. Thats why the decisions you make about using antibiotics unlike almost any other medicine you take have far-reachingconsequences. Be responsible in how you use antibiotics to protectyour health and that of your family, neighbours and community.

Recognise the ills of antimicrobial resistanceAntimicrobial resistance is a ruthless killer. Infections caused byresistant microorganisms often fail to respond to conventionatreatment, resulting in prolonged illness and greater risk of death.

Antimicrobial resistance challenges control of infectiousdiseases. Antimicrobial resistance hampers the effectiveness oftreatment because patients remain infectious for longer, thuspotentially spreading resistant microorganisms to others.

Antimicrobial resistance threatens a return to the pre-antibioticera. The risk of many infectious diseases is becoming uncontrollableand could derail progress made towards reaching the targets of thehealth-related United Nations Millennium Development Goals setfor 2015.

Antimicrobial resistance increases the costs of health careWhen infections become resistant to first-line medicines, moreexpensive therapies must be employed. The longer duration of illnessand treatment, often in hospitals, also increases health-care costs andthe financial burden to families and societies.

Antimicrobial resistance jeopardizes health-care gains tosociety. Antimicrobial resistance is threatening to jeopardize the

achievements of modern medicine. Without effective antimicrobialsfor care and prevention, success rates for treatments such as organtransplantation, cancer chemotherapy and major surgery would behampered.

Antimicrobial resistance is a compromise to health securityand can seriously damage trade and economies. The growth ofglobal trade and travel allows resistant microorganisms to promptlyspread to virtually any part of the world. Any society that fails totake adequate steps to safeguard against antibiotic resistance poses athreat to the entire human population.

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50 years of human space flightFifty years ago, on 12 April 1961, the Russian air force pilotYuri Gagarin became the first human to orbit the Earth.He went into space in a capsule called Vostok-1, which waslofted into orbit by a rocket from the Baikonur launch padin Kazakhstan. The Vostok-1 spacecraft blasted off fromthe Baikonur launch site at 06:07 UTC (11.37 IST). Thepayload included life-support equipment and radio forcommunication and television cameras to relay informationon the condition of the pilot. Gagarins flight lasted 108minutes, including 89 minutes in space. He completed oneorbit of the Earth, travelling at 27,400 kilometres per hour.At the highest point, the spacecraft was 327 kilometres above mean sea level. Gagarin

ejected after re-entry and descended under his own parachute, as was planned.In his post-flight report, Gagarin recalled his experience of spaceflight, having

been the first human in space: The feeling of weightlessness was somewhat unfamiliar compared with Earthconditions. Here, you feel as if you were hanging in a horizontal position in straps. Youfeel as if you are suspended. Gagarin was killed in the crash of a two-seat jet aircraft on 27 March 1968, whileon what was described as a routine training flight.

[A detailed article on Gagarins historic flight will be published in a forthcomingissue of Dream 2047.]

A useful magazineDream 2047 is a very popular magazine inIndia. It is read everywhere in the country. Ialso aread it regularly and find it very useful. Ithink all youth and students should read thispopular magazine.

Mukund KumarS/o Shri Ramjee Tiwari

P.O/Via Piprahi, Distt. Sheohar, Bihar 843334

*****

Creating scientific temperamentI belong to a backward area (Dist: Kulgam) of

Jammu and Kashmir, facing much difficultyin getting comprehensive and basic study

material for physics that could help removemy misconceptions. I thank you for yourmission to create innovative and scientifictemperament among the youth throughDream 2047. Your endeavour is going tobring about a scientific revolution throughoutour country.

Nadeem ManzoorS/o Shri Manzoor Ah. Naikoo

R/o Damidulla, Teh./Distt. : KulgamPost Office : Yaripora

Jammu & Kashmir 192232

*****

Letters to the editor

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Recent developmentsin science and technologyMESSENGERin orbitaround MercuryOf the planets visible to the naked eye,Mercury is probably the most elusive. Beingclosest to the Sun, it is almost always hiddenin the glow of sunrise or sunset, beingvisible only when its orbit carries it furthestaway from the Sun in the sky as seen fromEarth. Even when Mercury is visible on the

horizon just after sunset or before dawn,it is mostly obscured by the haze and dustin the atmosphere. For this reason littlecould be learnt about the planetthrough telescopic observationfrom Earth, although fly-bys by aspacecraft in the 1970s did revealsome surface feature. But it wastoo little. Now, for the first timehistory a spacecraft has gone intoorbit around Mercury. NASAs

MESSENGER spacecraft achievedthe distinction on 18 March 2011after a nearly seven-year journeyfrom Earth.

MESSENGER standsfor MErcury Surface, SpaceENvironment, GEochemistry, andRanging. Launched in August 2004the spacecraft covered nearly eightbillion kilometres and included anumber of planetary flybys before

reaching Mercury orbit. Before going intoorbit, the spacecraft had made three fly-bys

of Mercury in January and October 2008and September 2009. MESSENGERs orbitaround Mercury is highly elliptical, 200kilometres above the surface at the lowestpoint and 15,193 kilometres at the highest.

BeforeMESSENGER,Mariner-10 wasthe only spacecraft to have visited Mercury.

It did not go into orbit,but successfully flewby the planet on threedifferent occasions:29 March 1974, 21September 1974, and 16March 1975. Mariner10 took a total of 3,500images. Unfortunately,Mariner-10 ended upcapturing images of thesame side of Mercuryeach time.MESSENGERis intended to explorethe sides never seenbefore. MESSENGERstasks during its one-year primary science

mission include makingtopographic maps of the

entire surface of Mercury and characterisingthe planets magnetic field and geologichistory, including the role of volcanism in its

relatively recent past.There are six key questions NASA

hopes to answer duringMESSENGERs yearlong orbit of Mercury: why is Mercury sodense; what is the planets geological historywhat is the nature of Mercurys magneticfield; what is the structure of Mercurys corewhat are the unusual materials at Mercurypoles; and what volatiles are important at

Mercury? It will also attempt to confirmradar studies that hint at the presence of icewithin permanently shadowed craters neathe north and south poles of the planet.

MESSENGER carries seven differenscience instruments as well as a radioscience experiment. The equipment includecameras, a laser altimeter, a magnetometerand a variety of spectrometers. Using theseinstruments, the spacecraft will be able todo many things, such as map the planetentire surface in great detail, gather dataon the composition of Mercurys crust and

investigate the nature of its magnetic fieldand thin atmosphere.

Because Mercury is so close to theSun, any spacecraft orbiting the planemust be able to withstand intense heat and

solar radiation. To protect it from thesearing heat of the SunMESSENGERis fitted with a sun-shade. The heat-resistant, highly reflective sun-shadesits on a titanium frame fixed to thefront of the spacecraft.

Interestingly, MESSENGERmission will last only two Mercury

days. This is because Mercury rotateson its axis so slowly that one Mercuryday is equivalent to about 176 dayhere on Earth. Mercury speeds aroundthe Sun very fast, taking just 88 daysto complete one orbit. So duringMESSENGERs 12 Earth-months oorbital observations, the spacecraf

will experience just two Mercury daysbut more than four Mercury years.

30

Biman Basue-mail: bimanbasu@gmail.com

Artists impression of MESSENGER orbiting Mercury.

The sun-shade can be seen on the left.

One of the first colour images of Mercury sent back byMESSENGER. (Credit: NASA/Johns Hopkins University

Applied Physics Laboratory/Carnegie Institution of Washington)

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Earths gravity revealedwith utmost precisionThat the Earth does not have a geometricallyperfect shape is well established, and the geoidis used to describe the unique and irregularshape of the Earth. A geoid is defined as

the surface within or around the Earth thatis everywhere normal to the direction ofgravity and coincides with mean sea levelin the oceans. However, only recently havethe more substantial irregularities in thesurface created by the global mean sea levelbeen observed. These irregularities are an

order of magnitude greater than experts had

predicted. Controlled by the gravitationalpotential of the Earth, these irregularitiesform very gentle but massive hills andvalleys. Recently, a new 3D map of Earthsgravity with unrivalled precision has beenprepared from the data gathered by ESAs

GOCE satellite. The new map shows themost accurate model of the geoid everproduced to further our understandingof how Earth works. The new geoid wasunveiled on 1 April 2011 at the FourthInternational GOCEUser Workshop hostedat the Technische Universitat Munchen in

Munich, Germany. The Gravity fieldand steady-state OceanCirculation Explorer(GOCE) is a unique satellitedesigned to measure gravity.The five-metre-long arrow-shaped satellite has none ofthe moving parts often seenin other spacecraft. Therefore,the satellite together with itsinstrumentation actuallyforms a single composite

gravity-measuring device.The spacecraft structure isbuilt largely of carbon-fibrereinforced plastic sandwichpanels to guarantee stableconditions under varyingtemperatures and at the sametime to limit mass.

Launched on 17March 2009 the satelliteorbits Earth as low as possible

to observe the strongest possible gravity-fieldsignal hence GOCEhas been designed toskim above Earth at a height of just 250km. Its slim elongated form enables it to cutthrough the wisps of atmosphere that arestill present at this height. An electric ionthruster at the back continuously generatestiny forces to compensate for any drag that

GOCE experiences along its orbit. GOCEhas now collected more than 12-monthof gravity data. Scientists hope GOCEwilprovide dynamic topography and circulationpatterns of the oceans with unprecedentedquality and resolution, which will helpimprove our understanding of the dynamicof world oceans.

According earth scientists the GOCEgeoid will help make advances in oceanand climate studies, and improve ourunderstanding of Earths internal structureFor example, the gravity data from GOCEare helping to develop a deeper knowledgeof the processes that cause earthquakessuch as the event that recently devastatedJapan. Since this earthquake was caused bytectonic plate movement under the oceanthe motion cannot be observed directlyfrom space. However, earthquakes createsignatures in gravity data, which could beused to understand the processes leading tothese natural disasters and ultimately help topredict them.

Indias tiger population risesFor the first time in decades, the tigerpopulation in India has shown a 20 percentincrease in their numbers in the wild overthe last five years, as evident from a surveyreleased by the Ministry of Environmenand Forests. According to the survey, Indiacurrent tiger population is 1,706, comparedwith 1,411 in 2006. India is home to abouhalf of the worlds wild tigers.

There were estimated to be around40,000 tigers in India at the time ofindependence from Britain in 1947. Their

numbers had declined sharply for decadeslargely because of poaching and the pressureof development encroaching on theirnatural habitat. However, even though tigernumbers have increased, the area occupiedby tigers has shrunk dramatically over thepast four years, from 93,000 hectares to just72,800 hectares, which is a cause of worryWith economy growing at nearly 9 percena year, mining, forestry and other types odevelopment are affecting wild habitats.

New Horizons

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ESAs GOCE mission has delivered the most accuratemodel of the geoid ever produced, which will be used

to further our understanding of how Earth works.

The GOEC satellite

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Your opinionDream 2047has been inviting your opinion on a specific topic every month. The reader sending the best comments will receive a popularscience book published by VP. Selected comments received will also be published in Dream 2047. The comments should be limited to400 words.

This months topic:Is the extensive use of technology in making umpire's decisions

killing the sporting spirit in the game of cricket?

Response should contain full name; postal address with pincode and email ID, if any; and should be accompanied by a recent passportsize photograph. Response may be sent by email (opinion@vigyanprasar.gov.in) or by post to the address given below. If sent by post,Response: Dream 2047May3 2011 should be clearly written on the envelope.

Vigyan PrasarA-50, Institutional Area, Sector-62, Noida 201 307 (U.P.)Phone: 91-120-240 4430/35 Fax: 91-120-240 4437Email: info@vigyanprasar.gov.in Website: www.vigyanprasar.gov.in

1. M.J. Lilly, PGTNLC GHSS, Block-II,Neyveli 3, Tamil NaduIn our country science text book at school level areupdated and designed to include new informationfrom time to time. While in teaching science studentsshould be made to understand the concepts rather

than memorising them, application of principles and concepts in reallife situation is very important. But, rote learning just to score markshas become the order of the day. Only when the concepts sharpen thereasoning ability of the students can they remove the superstitions andirrational beliefs existing in the society in a significant manner. Instead,teaching and learning has become examination oriented and the studentsare shaped into mark scoring machines. The joy of learning, understandingand appreciating the various concepts of science is missing, as teachersare in a hurry to complete the syllabus and prepare the students for theexaminations. As marks are the deciding factors at various levels, applicationof scientific skills finds no place in our society. Let us hope that the futuregeneration rectifies the existing scenario for the betterment of humanity by

wiping out the superstitions and irrational beliefs from our society.

*****

Puneeta Malhotra, Science CoordinatorK. R Mangalam World SchoolG.K. II, Delhipuneeta_krm@yahoo.co.inScience is taught as a compulsory subject up to class

X, but most of educated people are unable to apply thescience they learn to real life situations. The teachingof science lacks practical aspect thus observing, findingpatterns, linking observation to theory and predicting the method ofscience is not inculcated in the students. Experiments if conductedare more of verification experiments like finding the value of g using

simple pendulum, and if a student does not get the value as 9.8m/s2, theteacher marks that as incorrect. So the students often manipulate to getthe correct answer. A hidden message that goes across is there is onlyone correct answer, not that there can be other factors that affect the valueof g so that the student gives his answer and tries to find the reason forvariation. I am trying to put across the fact that we as teachers do notdevelop critical thinking in our students and therefore we are still tied

by the ropes of irrational beliefs and superstitions. Teaching science doescreate disequilibrium in our mind, and we start questioning the beliefs butto sustain this inquiry and to develop a habit of rational thinking, morestress needs to be laid on hands-on experience and activities which providescope for exploration. More emphasis on the method of science will helpin removing the scourge of superstitions and irrational belief.

*****

Dr. G.R. Prakash, Associate ProfessorRegional Institute of Education (NCERT)Mysore 570 006Teaching of science in most schools is in no waydifferent from rest of the subjects. India being a landof innumerable religions and cultures, there are lots of

beliefs and superstitions which cannot be even listed outcompletely. Moreover, in India religion and science havea happy blend. Religious beliefs, superstitions have no place in science.However, our constitution ensures right to religion to our citizens. Manybeliefs and superstitions have been forgotten. This may be the combinedinfluence of education, media and modern civilisation. However, it maytake another century to get rid of all vices. As a workable solution for thepresent all such beliefs and superstitions which do not harm/insult othersfeelings may be allowed to exist. Apart from overcoming blind beliefs,science should help one to develop rational thinking in ones daily life.

*****

Winners of Your Opinion contest for February 2011

Topic: Has the teaching of science in schools helped in removing the scourge ofsuperstitions and irrational beliefs existing in our society in any significant manner?

Your Opinion

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VP News

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National conference onConservation of Biodiversity

Dr. Parul R. Sheth

The National conference on Conservationof Biodiversity was organised jointly by

Vigyan Prasar (VP) and National Centrefor Science Communicators (NCSC),Mumbai on 20 and 21 November, 2010at Indian Institute of Science, Bangalore.The conference was attendedby science communicators,scientists and studentcommunity.

Prof P. Balaram, Director,Indian Institute of Science,Bangalore inaugurated the

conference. Keynote addresswas delivered by Prof. MadhavGadgil, eminent ecologistfrom Pune. Er Anuj Sinha,Director Vigyan Prasar briefedabout the varied activitiesof VP in creating awarenessabout biodiversity. Mr. A.P.Deshpande, Chairman,NCSCand Mr. Suhas Naik-Satam, Secretary,NCSC, Nehru Centre, Mumbai were presenton the occasion.

In his keynote address Prof Gadgil

spoke about the importance of conservationof biodiversity including assessment ofimpacts of any human interventions onenvironment. He stressed the importance ofEnvironmental Impact Assessment (EIA) bysaying that EIAs should be treated as seriousscientific exercises, which must be firmlyanchored on to the bedrock of facts, and likeall science be open to public scrutiny.

Prominent experts have presentedpapers on biodiversity conservation infour technical sessions: (i) Biodiversity inAgriculture; (ii) Presentation of projects

by students; (iii) Conservation Strategy;and (iv) Role of Science Communicators.Vigyan Prasar organised a posterexhibition on biodiversity during theconference.

Session on Biodiversityin AgricultureThe session on Biodiversity in Agriculturewas chaired by Prof Madhav Gadgil.Dr Anil P. Joshi pioneer of Himalayan

Environmental Studies & ConservationOrganisation (HESCO), Dehradun, whois involved with consistent development ofrural villages, said that loss of biodiversityis a major challenge for human race todayand the culprits are human choice and greed,

development factors, changing environment,etc. Rural India, which covers 90 per centof bioresources of the country, is the hub ofbioresources. Today, commercialisation has

set in in agriculture, horticulture and otherrelated fields and this has become the mainreason for depletion in diversity.

The importance of linkages between thechemical ecological profiles of bioresourcesand the physical niches they occupiedwas elaborated by Dr R. Gopichandran,Principal Research Scientist, Environment& Climate Change Wing, Gujarat Energy

Research & Management Institute; ResearchInnovation & Incubation Centre (GRIIC)Gandhinagar.

Dr R. N. Ray from NCSCT networkBhubaneshwar said that the involvemenof students in biodiversity conservation

would help mobilise a largeforce in the processes. Givingexamples of National ChildrenScience Congress of NCSTCDST and National Green Corpsprogramme of Department oEnvironment and Forest through

eco-clubs, Dr. Ray stressed theneed of involving students tospread the green movement inthe country.

Talking about EIA andEnvironment ManagemenPlan (EMP) preparation andimplementation, Dr. Shalin

Sharma, Chair Professor, Instituteof Engineers, Hyderabad, said that EIANotification 2006 provide the guidelinesfor obtaining the Environmental Clearance(EC) for any project. She stressed upon the

need for assessing the positive and negativeaspects of any new upcoming project. Thevalidation report should be prepared by theproject validator (PV), who should have noinvolvement with the project implementeror state/central environmental clearancecommittee member.

Loss of biodiversity can trigger largeunpredictable changes in an ecosystem and

some of these may adversely impactagriculture and human health. Theprime objective of Indias nuclear energyprogramme is the development and useof nuclear energy for peaceful purposesuch as power generation, applicationsof nuclear science, medicine, industryresearch and other areas. This was thesubject of Mr. Rupesh Gaikwad othe Institute of Chemical TechnologyMumbai who presented variousapplications of nuclear science in thefield of agriculture using radioisotopeand radiation technique.

The session was conducted by Ms

Speakers of technical session - Biodiversity in Agriculture

Prof Madhav Gadgil interacting withparticipants of the conference

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Kinkini Dasgupta Misra ,Scientistand Nimish Kapoor, Scientist of VP.

At the end of the session a setof recommendations were preparedwhich was discussed in the interactivesession with the experts and theparticipants.

Session on presentationof projects by studentsDr.Robert Singh, Associate Professor,Department of Biotechnology,Mizoram University, Aizwal, chairedthe session. The first presenter wasMs. Rita Zomuanpuii from Aizwal,Mizoram who spoke about thedistribution pattern, larval habitatsand per cent incidence of various Anophelesmosquito species from varied geographicallocations. Her results enlightened the role

of vector transmission ability, insecticidesusceptibility and genome status of theAnopheles mosquito in Mizoram.

Mr. Rajdeo Singh from St. XaviersCollege, Mumbai, gave an account ofmedicinal plants; the Global PositioningSystem (GPS) co-ordinates of about 250species. The study according to Mr. Singhwould be crucial for conservation measuresof important medicinal plant species andGPS will prove to be an efficient tool for in-situ conservation of important plant species.

Banana is the fourth most important

food after rice, wheat and maize in Mizoram.Ms Hrashel Lalremsiami from MizoramUniversity presented her work on applicationof tissue culture techniques for sustainableutilisation of banana in Mizoram.

The presentation by Mr. ArijitChatterjee from Kolkata, West Bengalincluded case studies done in West Bengal onconservation of monitor lizards and heronsby villagers. Despite common allegations onlocal people being ignorant and destructiveto wildlife, it was the villagers who activelyparticipated in conservation strategies of

wildlife.Mr. P. C. Lalrinfela, from the

Department of Biotechnology, MizoramUniversity presented his paper on the geneticdiversity of banana. Because of the seriousthreats for the loss of crop, conservationand sustainable utilisation of banana geneticresources needs to be taken up as a prioritythrough intervention of biotechnologicalapproaches.

The impact of synthetic chemical use

on biodiversity of crop fields was presentedby Mr. Soumya Sarkar from West BengalState University. Preliminary data analyses

suggested significant erosion and alterationof the wide diversity of crop field due toextensive use of pesticides and herbicides.

A paper on Medicinal plants of sub-tropical mountain forests in the easternpart of Mizoram was presented by Mr.R. Lalrinkima from the Dept of Forestry,Mizoram University. In order to preserveindigenous traditional knowledge ofmedicinal plants, field work was done indifferent villages.

Following the student presentations,Prof. C.D. Patil, former Secretary of

Karnataka Rajya Vigyan Parishad (KRVP)briefed on the working of KRVP, anorganisation working in the field ofscience popularisation and environmentalawareness.

Session on ConservationStrategyDr. A.P. Jayaraman, Vice Chairman,NCSC, Mumbai, chaired the session onConservation Strategy. Dr. T.N.C. Vidyafrom Jawaharlal Nehru Centre for AdvancedScientific Research, Bangalore spoke about

elephant migration.Studies from Arunachal Pradesh on

motivations for hunting, off-take rates,awareness of wildlife laws among tribalcommunities, potential impacts of huntingand the consequences for wildlife populationswere discussed by Dr. Aparajita Datta fromNature Conservation Foundation., Mysore.

Dr. S. Shivaji from Centre for Cellularand Molecular Biology, Hyderabad stressedon the need for conservation of wild life.

He briefed about the techniquesof molecular biology such asmicrosatellite analysis, mitochondrialgene analysis, etc. He also reviewedthe ongoing work at the Laboratoryfor the Conservation of EndangeredSpecies (LaCONES).

Landscape level biodiversity

mapping using remote sensing waspresented by Dr. M.S.R. Murthyfrom the National Remote SensingCentre, ISRO, Hyderabad. DrMurthy identified future challengesof Indian landscape level biodiversitystudies and conservation.

Dr. Scot Wrighton who isinvolved with the Lavasa Project at

Pune asserted that based on the experiencesto date in Lavasa, new cities can be placedin undeveloped areas where they can beexpected to grow and create viable urbanalternatives to Indias existing mega cities.To do this, extensive planning is requiredusing the best possible environment-friendlyurban development methods.

Session on the Role ofScience CommunicatorsThe session was chaired by Dr. D.Balasubramanian, Director, L.V.Prasad EyeInstitute, Hyderabad. Dr. Bal Phondke,former Director, National Institute ofScience Communication and Information

Resources, New Delhi delivered a talk on roleof media in conservation of biodiversity.

Talking about the role of sciencecommunicators in conservation ofbiodiversity, Ms Sumangala Mummigattifrom All India Radio, Bangalore, said thatcommunity participation becomes anessential requirement for conservation ofbiodiversity.

Mr. Shekar Dattatri, a freelance filmmaker who makes films for the NationalGeographic and the Discovery Channels,averred about the impact of film media in

communicating science and biodiversity.With the help of striking clipping from hisfilms on biodiversity he proved his point.

Dr. S. Jeelani, curator, ScienceCity, Kolkata presented the role of sciencemuseums to create mass awareness onBiodiversity.

The conference ended on aninspirational note to preserve whateverbiodiversity we have and make efforts tocreate awareness.

Participants at the Conference

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National Science Day is celebrated inIndia on 28 February every year tomark the discovery of Raman Effect by SirC.V. Raman. for which he was awardedthe Nobel Prize in 1930. National Science