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Home , Brahmasphutasiddhanta, Children of the West End, Jantar Mantar, Orbits (sculpture), Rainbow (sculpture), Tip (sculpture)

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Jantar Mantar contents

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Children’s ScienceObservatory

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March -April2018 otn tot29 21 32 30 23 25 11 20 18 12 Sunflowers followtheSun! 14 9 About ProfJoséDinneny Rooting itout Do You Know?- Answers -Moondistance What keepstheMoonupinSky Sweet birthdaysinmathexams! 4 Beauty andtheFibonacciSequence Do You Know?-Questions Bases in Arithmetic The spreadingofarithmetic NASA’s Twins StudyExploresGeneExpression Contents z Year-18No2Issue104 website :http://hsb.iitm.ac.in/~jm

X X Children’s Science X March - April 2018 X Jantar Mantar X Children’s Science Observatory X March - April 2018 genetic, orDNAlevel.Infact,itwasagreat travel andzerogravityatthemolecular, opportunity tostudytheimpactofspace Kelly, remainedonEarth.NASAusedthis Station. Hisidenticaltwinbrother,Mark space livingontheInternationalSpace home lastMarchafternearlyoneyearin so howdidthishappen? identical twinshavesetsofDNA, two differentsetsofDNA.Weknowthat twins; bothareretiredastronauts,butwith Gene Expression S NASA astronautScottKellyreturned Study Explores NASA’s Twins cott KellyandMarkareidentical There weremanychangesthathadbeen stone toathree-yearmissionMars. Scott Kelly’sone-yearmissionisastepping aboard theInternationalSpaceStationbut standard-duration six-monthmissions what happenstothebodyafter one yearinspace.NASAhasagraspon happens tothehumanbodyafterspending accomplish onegoal:discoverwhat teams fromaroundthecountrytogetherto preliminary findings. but recentlyNASAreleasedsome Additional researchanalysisisinprogress, times. Thesestudiesarefarfromcomplete. affected bylivinginspaceforextended knowledge isgainedastohowthebody after Scott’smission.Fromthesesamples, taken fromeachtwinbefore,duringand researchers aresharingbiologicalsamples ground-based controlsubject,ten Mark, aretiredNASAastronaut,as Thus theTwins Studywasformed.Using opportunity totestNatureversusNurture. The Twins Studybroughttenresearch 4 5 regulate bloodsugarafter meals. help maintainnormalinsulin activityto also anincreaseofsomeproteins which during andafterScott’smission.Therewas was anincreaseingroupsofcytokinesboth markers thatindicateinflammation.There that haveaneffectonwell-knownblood the levelsof lesser inflammation.Theyalsomeasured ground, Mark’sdataindicatedsimilarbut inflammation whileinspace.Onthe (lipids arefats)inScottindicated reported thatalteredlevelsofalipidpanel Inflammation great detail. and theteamstostudythesechangesin that hehadanidenticaltwinallowedNASA two inchestalleronhisreturn.Butthefact observed before.Forinstance,Scottwas One teamthatwasapartofthestudy cytokines , whichareproteins is permanentorreversible. Mark. Itisnotclearyetwhether thischange mission, butnochangeswere observedin Scott duringandimmediatelyafterhis The carotidarterywallwasthickenedin throughout thedurationofmission. and theyprovidedbloodurinesamples arteries wereexaminedwithultrasound function ofbloodvessels.Thetwins’ spaceflight influencesthestructureand tell howinflammationandstressduring Hardening ofarteries effective asitisontheground. vaccine givenaboardthespacestationisas leading totheconclusionthatflu similar immuneresponsesineachtwin, on thegroundandinspace.Therewere Effect ofvaccines Hardening andthickeningofthearteries Both brothersweregivenfluvaccines, z

X Jantar Mantar X Children’s Science Observatory X March - April 2018 X Jantar Mantar X Children’s Science Observatory X March - April 2018 , butbecamesimilar afterhereturned while inspaceweredifferent thanpre- human health.Scott’smicrobial species gastrointestinal tractand playamajorrolein (entire communities)liveinthe Gut bacteria Many thousandsoftypesbacteria the stressesofspacetravel, whichcan “cell-free DNA”.Thisisthought tobefrom after spaceflight,circulating inthebloodas than expected,andsomewerefoundonly unique mutationsintheirgenome,more showed thateachtwinhashundredsof genome ofbothtwinswassequenced.It so theyhaveidenticalDNA.Theentire Genetic changes lengthening telomeres. healthier lifestylecouldhaveresultedin oftelomerelengthening:the the findings mass declineandfolateincreaseagreewith from thespacefoodsystem.Kelly’sbody space, perhapsduetobetterfoodchoices before flight,buthisfolatewentupwhilein during flight.His found thatScottKelly’sbodymassdropped Biochemical Profile intake whileonthespacestation. exercise regimeandrestrictedcaloric investigation, butmaybefromhisrigorous Scott’s telomeresinspacearestillunder stay. nearly thesamelevelsasbeforehisspace 48 hoursoflanding,thenstabilizedto telomeres shortenedinlengthwithinabout space. OncehereturnedtoEarth,his increased inaveragelengthwhilehewas telomeressignificantly that Scott’s person ages.However,oneteamreported Telomeres usuallydecreaseinlengthasa DNA whichcarrygeneticinformation. ends ofchromosomes,whicharemade Study onTelomeres to Earth. Identical twinsaregeneticallyindentical, One teamthatwasapartofthestudy The reasonsforthelengtheningof Telomeres areaprotective“cap”on the folate statuswaslow 6 7 missions: These responsesareimportantforfuture pathways inScottduringhistimespace. biological were foundforatleastfive responses cellular function.Significant also turngenesonandoff,whichchange new molecules,likeafatorprotein.Itcan Such actionscantriggertheassemblyof pathways andejectionofDNARNA. cause changesinacell’sbiological gravity); formation (likelyfromfluid shiftsandzero restriction); DNA repair(likelyfromradiationandcaloric of cells”); (indicating damagetothe“powerhouses levels ofmitochondriaintheblood and highCO z z z z collagen, bloodclotting,and bone telomere length,DNAdamage,and mitochondrial stressandincreased hypoxia (likelyfromlackofoxygen 2 levels); lasts sixtoeightmonths), orevenfarther. (where theone-wayoutwardjourneyitself space travel,suchasajourneytoMars realise variouspossiblilitiesforlong-term the humanbodyinspace.Thiswillhelp opportunity tounderstandpotentialrisks months. landing, whileafewpersistedaftersix returned tobaselinewithinhoursordaysof nearly hispreflightstatus.Somechanges experienced inspacequicklyreturnedto Most ofthebiologicalchangeshe the processofreadaptingtoEarth’sgravity. nutrient shiftsthataffectgeneexpression. increased inflammation,anddramatic associated withoxygendeprivationstress, researchers learnedthatspaceflightis metabolites, cytokines,andproteins, The Twins Studywasanamazing After returningtoEarth,Scottstarted Source: NASA

X Jantar Mantar X Children’s Science Observatory X March - April 2018 X Jantar Mantar X Children’s Science Observatory X March - April 2018 chapatis andhowmuchfruitdoyoueat every dayoftheexaminations,howmany school, andsixchapatissevenplums chapatis andascoreofgrapeseveryday bananas athomeeverydayofholiday,five days? examinations, howwouldyouaddupthe then twoweeksandthreedaysof months, oneweekanddayofschool, month andthreedaysofholiday,thenfour mind? ? Perhapsyoucandothatallinyour score offruitinall.Howwouldyoudothe is twenty).Youwouldknowtherearefour and sevengrapes(whichis67,sinceascore three bananas,ortenplums,score the arithmeticthatyoustudiedinschool? not knowhowtousedecimalnotationand H If youeattenchapatisandthree For somewhatlargernumbers,saya Of courseyouwouldknowhowtocount ow wouldyoudocalculationifdid The spreadingofarithmetic The Institute of Mathematical Sciences, ofMathematical Chennai The Institute Kamal Lodaya wires. AbacuseswerecommoninChina, abacus todayitprobablyusesbeadson on awoodenboard.Ifyouhaveseenan was theuseofanabacus.Thisusedpebbles calculation ontheirhands. andthendothe 60 usingtheirfingers they wereabletorepresentnumbersupto who wereverygoodatcalculation.Possibly counting time)andtheyhadexpertscribes system withbase60(westilluseitfor Sumerians decimal systembecamepopular,the subtract andmultiplythem.Beforethe andtoadd, numbers usingyourfingers, ways havebeendevisedtorepresentlarge ortoe.)Very clever “digit” meansfinger (ActuallytheEnglishword on yourfingers. over allthedays? How tocount Another methodwhichdevelopedlater The mostcommonmethodiscounting and Babylonians inIraqhada 8 9 Africa Africa From BrahmatoArabiaand From BrahmatoArabiaand CE hewrotethe (then in Gujarat, nowinRajasthan).In628 was bornin598CE.Helived inBhinmal Africa From BrahmatoArabiaand arithmetic welearntinschool. keep recordsofcalculationsthatledtothe ships toseveralports.Itwastheneed many markets.PerhapsIsendgoodsouton the same.ThenIpayyouandtakemyfruit. thatthecostis abacuses, calculateandfind accountant andtheybothsitwiththeir (my abacusexpert)andyoucallyour prices. Icomewithmytrustedaccountant bananas, plumsandgrapes,allatdifferent buy severalthingsfromyou.Maybe start trading.Iamamerchantwhowantsto it out? the number6,302,715,408.Canyoufigure board. Thepictureshowsaxuanpanwith around todoveryfastcalculationsonthe base isused)andmovingthepebbles representing numbers(usuallyadecimal are expertswhoverygoodat where theyarecalledxuanpan.Againthere Africa Africa From BrahmatoArabiaand From BrahmatoArabiaand The Indianmathematician But Icouldbeatraderwhotradesin comeaboutwhen people Difficulties and geographyunderthe patronageofthe produced worksinmathematics, astronomy 850 CE.HewawasaPersian scholarwho Khiva, inUzbekistan)livedaround800to of Musa) Arabic numerals. much sothattheyareoftenknownas do arithmeticusingIndiannumerals,so to ,Muslimmerchantslearnthow the spreadofIslamallwayfromAfrica the (roughly, “GreattablesfromSindhind”)and Arabic asthe translated the Ibrahim) astronomer as partofanembassyfromSindh.TheIraqi of Brahmagupta’sworks,cametoBaghdad an astronomerfromtherewithknowledge he wrotethe (nowinMadhyaPradesh).In665CE 776 CE)invadedSindhand Gujarat. al-Mansur merchants about700CE.TheIslamiccaliph make atoughsubjectsweeterforstudents. name itsoundsasthoughwasmeantto food”), onpracticalastronomy.Fromthe Abu AbdallahMuhammadibnMusa These methodswerelearntbyArabian . addition, subtractionand which younowuseinschoolfor about them),andthetechniques earliest bookknownwhichtalks and negativenumbers(thisisthe Along theway,heintroduceszero and rewritestheminhisownway. a bookwhichstudiesearlier (“Doctrines comingfromBrahma”), al-Fazari al-Khwarizmi inBaghdad(ruledfrom754to Later Brahmaguptamovedto Muhammad ibnIbrahim al-Sindhindal-kabir Khandakhadyaka Brahmasphutasiddhanta inthecourtofal-Mansur, (texts),criticisesthem asthe (fromKhwarizm, Arakhand (“Sweet Kanaka (sonof . With into (son ,

X Jantar Mantar X Children’s Science Observatory X March - April 2018 X Jantar Mantar X Children’s Science Observatory X March - April 2018 the (modern Iraq).Hewrotehisownversionof Caliph Al-Ma’munoftheAbbasidCaliphate word “algorithm”,named aftertheperson numbers”), fromwherewe gettheEnglish indorum CE usingthename was translatedintoLatininthe13thcentury Hindi Base 10isalsocalledthe common usethatusesdecimalnumbers. 1000. Thefactorof10 number 1actuallyrepresents1x10 relevant powerof10.So,inthisexample,the number isgivenbytheentrytimes in anyofthepositions.Thevalueof Only tennumbers(from0to9)canbeentries thousands positions).WhyisitcalledBase10? hundredths, tenths,tens,hundreds,and entries 6,5,4,3,2,1respectivelyinthe based onpowersoften(e.g.,1234.56has The placesorpositionsofthenumbersare value rangingfrom0to9(10possibilities). position ofanumbercanhaveaninteger denary system.Inbase10,eachdigitina system 1) inanyposition,wegettheso-called Similarly, ifweallowonlytwonumbers(0and the countinginnexthighestposition. Exceeding thenumber9inapositionstarts (1x10 point. Sothenumber1234.56equals the 4th(3=4-1)placetoleftofdecimal Base 10referstothenumberingsystemin Sindhind (“BookofIndianaccounting”),which Bases inArithmetic Bases inArithmetic Bases inArithmetic Bases inArithmetic Bases inArithmetic 3 +2x10 , whichispopularincomputers.Here (or“Al-Khwarizmi’sIndian , calledtheKitab 2 +3x10 Algorithmi denumero 1 +4x10 3 cameinbecauseitwas decimal system 0 +5x10 al-Hisab al- -1 3 , whichis +6x10 binary or -2 ). know! to 7minutesand30seconds,asyoualready in sexagesimalis7,30so1/8thofanhourrefers a decimalpoint:forinstance,thefraction1/8 Here thecommaistobereadlike the figure. 5, and6.TowritefractionsinBase60,see it isthelowestcommonmultipleof1,2,3,4, divisible byeverynumberfrom1to6;thatis, 1 minute.60isthesmallestnumberthat minutes, 432and minutes, 121065 sections of30minutes,2015 60 minutes,canbedividedevenlyinto Forexample,onehourwhichis simplified. involvingsexagesimalnumbersare numbers. Withsomanyfactors, 20, 30,and60,ofwhich2,3,5areprime twelve factorsnamely1,2,3,4,5,6,10,12,15, means thatithasmanyfactors.Infact, 60 isahighlycompositenumber,which power of60. involves multiplyingtheentriesbycorrect (1x2 must write10,whichcanbereadas 0 and1referto1,butwrite2,we Base 60(alsocalled who describedthemethods! side toanotherinthe“contest” between title describes“forcing”numbers fromone quadratic equations.More colloquially,its spreadsheet), andalsosolvingsimple methods forsolvinglinearequations(asina restoration andcompensation”)has What issospecialabout60?Thenumber His 1 +0x2 Kitab aljabrw’al-muqabala 0 =2). Itisobviousthatcountingin sexagesimal system (“Bookof ) 10 11 A toweringfigurefromPisa A toweringfigurefromPisa smelted ironandsilver,tools, weapons, exported Tuscan wine,oil,hemp,flax, the islandsofElbaand Giglio. Thecity shipbuilding, barsofcrudeironcamefrom camebybargefromupriverfor Timbers wool wereimportedandusedfortextiles. used inleathermanufacture.Dyesand East, andsoon.Alumwasimported from ProvenceinFrance,spicesthe from NorthAfrica,furHungary,horses Sardinia, squirrelskinsfromSicily,goatskin grain fromotherItaliancitystates,salt thriving withbusiness.Itsportwouldimport In the12thcenturyCE,statewas little insidefromtoday’ssea-portofLivorno. in themiddleages.ItisonriverArno,a A toweringfigurefromPisa translated intoLatinin1145by the twosidesofanequation.Itwas Chester English word“algebra”. et almucabala A toweringfigurefromPisa A toweringfigurefromPisa Pisa inTuscany (todayinItaly)wasaport , whousedthename , fromwherewegetthe Liber algebrae Robert of Bonacci), andheismostly knowntodayas be called explaining thesemethods. Helatercameto “book ofcalculation”inLatin, mathematicians. Butthenhealsowrotea Khwarizmi andperhapsalsobyotherArab clear thathereadthebooksbyAl- to thoseusedbyhiscountrymen. Arabian merchantswhichwerefarsuperior learn themethodsofcalculation HeurgedLeonardo to customs officer. Algeria innorthAfricaasatradeand was postedatBugia(todayBejaia)in Bonacci wasaprosperousmerchant.He about 1170CE.Hisfather Guilielmo (William) pence)! solidi of differentkindsthatwereused: and othergoods.Imaginethekindsofcoins Arabs, Libyans,sellingsilks,carpets,vases Turks, armour. Intheportonecouldfind Leonardo didlearnthem,anditseems Leonardo Pisano , denarii Leonardo Fibonacci (justlikepounds,shillings,and spiral aloeplantwith5spirals. bracts. Thepictureshowsa arrangement ofapinecone’s apple, anuncurlingfernandthe stem, thefruitsproutsofapine- the arrangementofleavesona example, inbranchingtrees, naturally inseveralsettings,for very interestingandappears two numbers.Thesequenceis tained byaddingtheprevious ... whosenextnumberisob- ending series.Itis1,2,3,5,8, Fibonacci Sequence? This sequenceisanever (fromPisa)wasborn What isthe (familyof Liber abbaci, librae ,

X Jantar Mantar X Children’s Science Observatory X March - April 2018 X Jantar Mantar X Children’s Science Observatory X March - April 2018 Fibonacci sequenceinthisissueofJM! Fibonacci the 1870s.Lookforarticleon American mathematicianEdouardLucasin sequenceby immortalized astheFibonacci examples, involvingrabbits,was having manymoreexamples.Oneofhis of Al-Khwarizmiandisdistinguishedby Hisbookissimilarinspirittothat Fibonacci. first Englishtranslationof first took evenlongerthanAl-Khwarizmi’s.The material inLatinandItalian. calculation, makingcopiesofsomethe writers wrotetheirownbooksof 1240. AlmostimmediatelymanyItalian reference wehavetoLeonardoisabout wrote manyotherbooks.Thelast which 14copiessurvivetoday.Healso 1202. Therewasasecondeditionin1228,of The first editionof The first Translation ofthesevoluminousbooks Liber abbaci Liber abbaci wasin was Popular writingonarithmetic Popular writingonarithmetic the 13thand16thcentury. “books ofcalculation”,publishedbetween 1450, andtodayweknowabout400Italian completed onlyin2002. all Italians. The printingpressmadethemaccessibleto spread fastamongtheItalianmerchants. were quicklytranslatedintoItalian,and inLatin, written although theywerefirst European scholars.Leonardo’sbooks, languages remainedinthehandsof Latin. Eventhetranslationsintomodern Al-Khwarizmi’s booksweretranslatedinto Khwarizmi’s whichwerealreadyavailable? popular inEurope,muchmoresothanAl- Popular writingonarithmetic Popular writingonarithmetic Popular writingonarithmetic The printingpresswasinventedaround The Arabicarithmeticmethods,andalso Why didLeonardo’sbooksbecomeso 12 13 inheritance, legacies,dowries,andlegal example problems,dealingwith is displayed,anditsrecordremains. Leonardo’s methodsthewholecalculation calculation itselfmaygeterased.In out,therecord ofthe answerwritten final calculation canbedoneveryfastandthe crossing outnumbers.Thusalthough the Indianones,involvewritingoverand but whydidnoplanetsform there? move soslowlythataflycan’tdetectthemovement andactuallygetit? Al-Khwarizmi’s bookshavemany 4. Whyistheresuchabig ‘gap’betweenMarsandJupiter?Thereisanasteroid belt, 3. Howdoelectriceelsgettheirenergy? 2. Genetically, whoareweclosestto—ourparents,chidren,orsiblings? toswatbecausetheyaresomuchquickerthanus.Butcan’t we 1. Fliesaredifficult Do YouKnow? adopted, andeventuallyenteredschools. business. Theseteachingswerewidely these practicesbecamecommonto trade andmanufacturewasgrowing interest. ThiswasthetimewhenItalian work withquarterlyandannualcompound occur ateverystop.Theyexplainhowto where expense,withdrawalandprofit accounting forasequenceofbusinesstrips fair way.Theyexplainhowtodo contributions frompartnerscanbesplitina fromajointventurewithunequal profit share market.Thebooksexplainedhow market, liketoday’sstockbrokersdoina commodities (likesaffronorpepper)inthe who couldcalculatetherelativevalueof books gavetheadvantagetomerchants Goetzmann merchants. have immediatelymadesenseto alloying ofmoney.Hisexampleswould quantities andcurrencies,minting valueofmerchandiseindifferent finding adapted todividingcapitalamongpartners, issues. Leonardo’sexampleswereeasily American finance professor American finance Answers onanotherpageof thisissue wrotein2004thatLeonardo’s Finding Fibonacci by KeithDevlin William Based on

X Jantar Mantar X Children’s Science Observatory X March - April 2018 X Jantar Mantar X Children’s Science Observatory X March - April 2018 The FibonacciSequence The FibonacciSequence context ofhowrabbitpopulations multiply numbers togetthenextnumber: starting with1andaddingtheprevioustwo of Arithmetic Fibonacci Sequence. Fibonacci century, whichnowgoesbythenameof noted byIndianmathematiciansinthesixth today. Healsopopularisedasequence for themoderndecimalsystemweuse the book,“ popularising theHindu-Arabicnumeralsin Mediterranean coast.Heisfamousfor whom hemetwhiletravellingalongthe a lotofarithmeticfromArabmerchants twelfth centuryandlearnedformalised born sometimeinthelaterpartof The FibonacciSequence The FibonacciSequence The FibonacciSequence Beauty andthe Fibonacci discussedthis sequenceinthe Fibonacci 1,1,2,3,5,8,13,21,34,55,89,144,... It isasimplesequenceobtainedby A s wesawinthearticleon“ Sequence Fibonacci Liber Abbaci” ”, Leonardo Fibonacci , whichisthebasis was Spread Golden Ratio Golden Ratio value) tothegoldenratio. sequence converges(thatis,tendstothe that theratioofsuccessivenumbersin maynothaveknown so rapidly.Fibonacci by anirrationalnumber, most pleasingtotheeye.Thisratioisgiven sides inthegoldenratiolooksaesthetically Golden Ratio successive ratiosgiveyou thegoldenratio. 1.618, 1.681,... Veryquicklythe will get1,2,1.5,1.67,1.625, 1.615,1.619, successive numbersinthesequence.You sequence?Try dividingthe with Fibonacci also beexpressedasacontinuedfraction. get thevaluegivenabove.Thisratiocan ,youcansolvethisto golden ratio.Ifyouknowhowtosolvea the (a+b) and(a)sothat(a+b)/a=a/b=f, number istheratioofarectanglewithsides look pleasingtotheeye.Thismysterious rectangle areinthisratio,thewill Golden Ratio Golden Ratio f = (1+ f = Architects believethatarectanglewith What doesthegoldenratiohavetodo That is,ifthelengthandbreadthofa \ sqrt (5))/2=1.618... 14 15 Fibonacci Spiral Fibonacci Spiral entry ofthesequence).Nowyouhavea adjacent toitofthesamesize(second entryofthesequence).Placeone (first these numbers.Drawasquareofunitsize Fibonacci Spiral Fibonacci Spiral Fibonacci Spiral The Fibonacci spiralcanbedrawn using The Fibonacci Shells Shells the mostfamousexampleofsequence Sequence.Shellsareprobably Fibonacci progressive proportionalincreaseofthe in theboxexampleabove,shellsfollow Shells Nature. spiralappear everywherein Fibonacci drawn intoshowthespiralclearly. Thearcshavebeen seen inthefigure. larger andsquaresthat‘spiral’outas longer sideoflength2.Keepgoing,toget 2 (thirdentry)sothatitistouchingthe rectangle ofsides2:1.Placeasquaresize Shells Shells As youmayhaveguessedbythecurve Both the Fibonacci sequenceandthe Both theFibonacci

X Jantar Mantar X Children’s Science Observatory X March - April 2018 X Jantar Mantar X Children’s Science Observatory X March - April 2018 Trees Trees utilizing thispattern. existence today, majestic treesarein larger. Sometruly becomes tallerand grow asthetree the trunkandspiral Sequence evolveoutof see theFibonacci If youdid,would the treeandeachother? branches growoutof the structureofhow do youlookandanalyse them everywhere,but Trees own littlepieceofmath. display. Andthen,thereyouhaveit!Your shown. Theyarealsofuntocollectand to see,asinthepictureofnautilusshell because thelinesareverycleanandclear Trees Trees Trees —wesee obvious andclear,likewiththeshell.The aren’t spreadoutandthespiralismore Sequencebecausethepetals Fibonacci but rosesareanexcellentexampleofthe Flowers ofallkindsfollowthepattern, Flower Pistils Flower Pistils Flower Petals Flower Petals particularly complex. Sunflower pistilsare intricate design. produces alovelyand creates usedrepeatedly the curvesequence The patternformedby incredible pieceofart. the resultisan pieces ofnature,but intensely thanother Sequence muchmore follows theFibonacci the petals(thepistil) flower inthemiddleof Flower Pistils Flower Petals Flower Pistils Flower Pistils Flower Petals Flower Petals The partofthe 16 17 vertical imaginaryline.Butthesixthpetal number oneandsixwillbeonthesame 5-spiral. Thismeansthatpetal a Fibonacci ‘ rose’.Rosepetalsarearrangedin (and soismath).Thefrontcovershowsa sequence increases.Rosesarebeautiful petals unfoldmoreandthe Storms Storms beautiful anddestructive. could saythisexampleprovesmathcanbe at least,cycloneslookcool.Iguesswe Sequence.Onamap, follow theFibonacci tornadoes) andmanyotherstormsystems Storms company locatedinHolland. de Werken The techniquewasdevelopedby the cleanseparationbetweencolours. obtained. However,itisnoteasytoachieve spiral. That’showthecoverphotowas the dyedependingontheirpositionin with colouredwater,thepetalswilltakeup and transfereachendintoadifferentglass cut thestemverticallyintofourequalparts occurs aftertwofull‘rotations’.Whenyou Storms Storms Cyclones (alsocalledhurricanesor fromRiverRoses,aflower Adapted fromthearticleby http://theodysseyonline.com Victoria McGraw, Victoria Peter van

X Jantar Mantar X Children’s Science Observatory X March - April 2018 X Jantar Mantar X Children’s Science Observatory X March - April 2018 sweets, sotheprobability ofpickingan That’s easy:thereare6orange outof first probability. Whatistheprobability ofthe Probability Analysis this problem? the examiners.Howdoweactuallysolve children did,missingthequestionaskedby of thevalue offinding if itwassimplyamatter and hersweets.Itwouldbesomucheasier hence puzzledbyallthefussaboutHannah ‘solving thequadraticequation’andare children simplyseethisasfactorization,or Class XintheUK): examination inJune2015(equivalentofour asked inthe GCSE mathematics greatly afewyearsago.Itwasproblem question?” andsoon. or “Whateverdidtheymeaninthat easy!”, or“Whataweirdquestionpaper!”, hearing childrenexclaiming,“Ohthatwas H this toprovethatn sweets oneaftertheotherisone-third,use chances ofHannahpickingtwoorange of nsweets,which6areorange.Ifthe Sweet birthdays in mathexams! annah’s Sweets The Institute of Mathematical Sciences, ofMathematical The Institute n The informationgivenisabout How doesonereasonwiththis?Many · Here isaquestionthatstirreduppeople These areexamtimesandwekeep . Andapparentlythatiswhatmost sweetHannahpickedbeing orange? Hannah hasabagcontainingtotal R. Ramanujam Chennai 2 -n-90=0. n get theequation: it istheproductoftwoprobabilities: two eventsare happening, oneaftertheother?Since is theprobabilityofthesetwoevents being orange,soweget5/( ( picked wasorangeaswell?Nowtherewere probability thatthe following conversationtakes place separately month ofherbirthdayand andBernard orange sweetis Cheryl’s Birthday equation. you don’tknowhowtosolveaquadratic you willget list of10possibledates: when herbirthdayis.Cherylgivesthema friends ofCheryl,andtheywanttoknow logic. the world.Thiswasanexerciseinpure caused agreatdealofdiscussionallover question for14yearoldsinSingapore months earlier,inApril2015,anOlympiad n- 1) sweetsleftover,with5amongthem (30/( Simplifying, wehave Cheryl thentellsAlbert (6/ But thisisgiventobeone-third.Sowe (6/ in in in Before Hannahtherewas If youreallywanttosolvethisequation, Hence wegetthegivenequation. in Albert 90 = = 90 July June May August n n : 14or16; : 15,16or19; and : 17or18; ) x(5/( ) x(5/( thedayofherbirthday.The n n 2 n 2 : 14,15or17. - - =19. Substituteandcheckif n Bernard n )) =(1/3),or independent . 6/n. n n - 1)). - 1))=(1/3). second Wellthen,whatisthe friendsarenew separately sweetHannah n- ofeachother, 1). Nowwhat Cheryl . Afew the 18 19 between AlbertandBernard. know Cheryl’sbirthday,butIitnow! it either. birthday is,butIknowthatyoudon’t birthday! Albert Albert Bernard Such questionsrequireyou tothink So whenisCheryl’sbirthday?” : Idon’tknowwhenCheryl’s : ThenIalsoknowCheryl’s : Beforeyousaidthis,Ididn’t in themonthisherbirthday. course hedoesnotknowwhichofthedays there ismorethanonepossibility,soof reason outthepossibilities. calmly aboutthegiveninformationand cracking theirBoardexaminations! fromreading JantarMantarfor benefited puzzles. ChildreninSingapore wouldhave has carriedarticlesonhimandsuch puzzle-maker (1914to2010). Martin Gardner “sum—product” puzzlespopularizedby birthday mustbeonJuly16. it wasthe15thor17th.)HenceCheryl’s August. (Ifsohewouldbeunsurewhether birthday too,sohecouldnothaveheard conclude thisaswell. 16, orAugust17.ButthensocanAlbert conclude thatthebirthdayisAugust15,July he musthaveheard15,16,or17.Sowe be unsurewhetheritwasJulyorAugust,so 15, 16or17.Hadheheard14,wouldstill the birthdaynow.Clearly,Bernardheard14, well! August. ButsocanBernardconcludethisas conclude thatAlbertwastoldeitherJulyor be sureofBernard’signorance.Hencewe to ruleout18or19andhencehecouldnot told MayorJune,therewasnowayforhim does notknowthebirthday.Ifhehadbeen it hastobeMay19. that itisJune18.Similarlyifheweretold19, but ifitis18thenheimmediatelyknows told 14,15,16or17,hewouldbeuncertain, dates 18and19donotrepeat.Soifhewas Bernard istoldthe Albert istoldthe This lineofproblemsfollowsthefamous But thenAlbertsaysheknowsthe Notice thatBernardsaysheknows Albert saysthatheknowsBernard , thegreatAmerican month day . Noticethatthe . Ineachofthem Jantar Mantar z

X Jantar Mantar X Children’s Science Observatory X March - April 2018 X Jantar Mantar X Children’s Science Observatory X March - April 2018 external force. or acceleratewhenacted uponbyan states thatobjectschange theirmomentum Newton’s secondlawofmotion,which object speeduporaccelerate.Thisisasper the samedirection,forcemakes since theforceandobject’svelocityarein diagram. Letthisforcebeconstant.Then, pushing inthesamedirection.See object ismovingtotheleftwithaforce the velocityofobject. forces. of theobject. you cansaythatforces into theEarth?Theanswerisalso,gravity. aswell,whydoesn’tthefall up, itfallsdownagain.Ifgravityactsonthe of gravity.That’swhywhenwethrowaball T 1. Let uslookatthreedifferentcasesfor What doforcestoanobject?Inshort, Types offorces up intheSky the Moon What keeps Force pushinginthesamedirectionas he Earthattractseverybodybecause change Supposean themotion put onthebrakesofacar. is referredtoasdeceleration,likewhenyou there isacceleration,buttheslowingdown the left. moving totherightforcewouldbe the samecaseasabove,butforanobject as thevelocityofobject Here theobjectslowsdown.Again, 2. Force pushingintheoppositedirection . Thisisalmost 20 21 not subjecttogravity?Or, isit?Letusfirst called centripetalforce. is pointingtothecentreofcircle it andchangesdirection.Suchaforcethat with astring),theballhascentralforceon in thedirectionofstring(youcan’tpush on theball.Butsincestringcanonlypull Why doesitmovethisway?Thestringpulls attached. Swingtheballaroundinacircle. or maybeayoyosincethestringisalready example. Take aballattheendofstring- direction astheobjectturns.Hereisan force wouldhavetopointinadifferent to exertacontinuouscentralforce,the circle; hencethename.Ofcourse,inorder and itdoesn’tslowdown.Itjustturnsina “central” force. velocity oftheobject. days of with eachotherthroughgravity.Fromthe forces. Anybodiesthathavemassinteract between twomasses,m school, youmighthavereadthattheforce outmoreaboutgravity.In trying tofind distance meansthatifyoumovethe dependence onthe“inversesquare” are, thelesserforce,and greater theforce.Thefurtherapartthey the distancebetweenthem. and inverselyproportionaltothesquareof proportional totheproductoftheirmasses What abouttheMoon,then? Whyisit Trajectories In thiscase,theobjectdoesn’tspeedup 3. Gravity isoneoftheearliestknown This meansthatthelargermass, Force pushingperpendiculartothe Isaac Newton Gravity Gravity Gravity Gravity Gravity Letuscallthisa , scientistshavebeen 1 andm 2 , isdirectly of gravityisthatit farapart. are infinitely force goingtozeroonlywhentheobjects very farapart,withthegravitational experience gravityeveniftheyareplaced Japan. Lookatthe‘angleofattack’.The 31, 2007attheNagaiStadiuminOsaka, World AthleticsChampionshipsonAugust ondaysevenofthe11thIAAF Throw Final the goldmedalinWomen’sJavelin the CzechRepubliconherwaytowinning javelin throw). sideways. (Oryoucanthinkofashotputor look attheactionofaballwhenitisthrown and 1/3 become four(eight)timessmaller(1/2 the gravitationalforcebetweenthemwill masses twice(thrice)thedistanceapart, and thatiswhytheballfallsbackonEarth. always bringsbodiesclosertooneanother, different. Hencethegravitationalforce charges (orpoles)arethesameor attractive dependingonwhetherthe for instance,whichcanberepulsiveor is incontrasttoelectricormagneticforces, However, themostimportantproperty The pictureshowsBarboraSpotakovaof 3 =1/8). Thismeansthattheobjects always

attractive . This 2 =1/4

X Jantar Mantar X Children’s Science Observatory X March - April 2018 X Jantar Mantar X Children’s Science Observatory X March - April 2018 travel fartherand(andhencewin The horizontalforcewhichallowsitto it istheverticaldownwardforceofgravity. javelin hasbeenreleased,theonlyforceon important thingtonoteisthatoncethe The as canbeseenfromthefigure. angle atwhichitwaslaunchedorthrown, distance thejavelintravelsdependson earth, itwouldtravel119kmbeforehitthe fromaballoon34kmabovethe were fired before ithitstheground.Ifsamerifle bullet, itwouldtravelalmost1km(0.84km) about 1.4km/s,whichisreallyfastfora 1.7 mabovetheground).Foravelocityof byatallman(about of abulletbeingfired The figure inpage23showsanexample The figure farther theobjecttravels. larger theinitialvelocity, of thewaterfountains.The can beseenfromthepicture trajectory likeaparabola,as upon onlybygravityhasa zero velocityandisacted that issentupwardswithnon- called aparabola.Anyobject shown hasaspecialname:itis trajectory the javelintravelsiscalledits hands. athlete whenitleavesher distant throw)isgivenbythe the goldmedalformost The shapeofthepaththat . Thetrajectory 22 23 27,600 km/hr.Ifthe about 7.6km/sor mean velocityof orbiting theEarthata Station International Space the samething.The fact, allsatellitesdo actually misses!In Earth sofastthatit falling towardsthe the samething:itis the Earth. goes intoorbitaround ground. Atthiscriticalvelocity,itsimply and farther,untilitstartsto“miss”the and more,thebulletwouldtravelfarther ground. Asthevelocityisincreasedmore where themoonisonly1/5 drawn toscale,asinthesecondfigure tosee.Sothepictureisusuallynot difficult drawn thiswayintextbooksbecauseitis the EarthandMooninpicture.Itisnot moon weremovinginaperfectcircle,the gravitational forceonthemoon.If size). is supposetobe(butthecorrectrelative The moondoes Look attheactualsizesanddistancesof In the figure, thearrowrepresents In thefigure, Earth-Moondistance Earth-Moondistance Earth-Moondistance Earth-Moondistance Earth-Moondistance (ISS)is th thedistanceit and justcauseittochangeitsdirection. “central” (towardsthecentreofcircle) gravitational forcewouldalwaysbe are launched.Thisescapevelocityisabout and enterspace.Thatishowspaceships object can“escape”fromEarth’sgravity velocity isincreasedevenmorethenthe

X Jantar Mantar X Children’s Science Observatory X March - April 2018 X Jantar Mantar X Children’s Science Observatory X March - April 2018 would bothspeedup of thevelocity.Inthiscase,object perpendicular toaswellinthedirection centre. Sotheforcehasacomponent pointing tothecentreoforbitbutisoff- arises whentheforceisnotexactly circle, calledanellipse.Suchatrajectory ) isnotexactlycircular,butasquashed (and infacttheEarth’strajectoryaound 11.2 km/s. Moon thatoccurredalittle whileago. This ispartofthereasonbehindSuper away fromtheEarth,oppositehappens. speeds upasitdoesso.Asthemoonmoves Earth. not haveaconstantvelocityasitorbitsthe directions. Becauseofthisthemoondoes One lastpoint.Themoon’strajectory Circular versusEllipticalTrajectories This isshowninthepicture ofNewton’s Newton’s Cannon The moonmovesclosertotheEarthand and change moon-crash-into-the-earth/ www.wired.com/2012/11/why-doesnt-the- article inTheWired,https:// Cool, isn’tit? the centerofthiscircleisinsideEarth. that theEarthmovesaroundissosmall moves inamuchsmallercircle.Thecircle greater thanthemassofmoon,soit it does.However,Earth’smassis81times make theEarthmoveinacircle?Essentially, magnitude offorce.Wouldn’tthisalso Earth towardsitselfwiththeexactsame should dothesamething:itpull pulls themoontowardsitself, different bodies.ThismeansthatifEarth reaction areequalandoppositeacton Earth, asseenintrajectoryE. (greater thantheescapevelocity,itleaves path (D)andgivenevenmorevelocity little morevelocity,itgoesinanelliptical velocity forittogoinacircularpath.With with trajectoryCjustabouthasorbital hit theEarth(trajectoriesAandB),one cannon. Whilebulletswithlowervelocities Sources: Newton’s thirdlawstatesthatactionand What aboutMoon’sgravity? Wikipedia,NASA,RhettAllain’s z 24 25 fly untilitstartswashing perfectly stillandwatchthe out equationsdescribingthis! scientists haveevenworked it astakesoff.Some just abovetheflytointercept slapping it,clapyourhand speed and,insteadof approach theflyatnormal makes thejobeasier.You fly withaclapofthehands long. not stayinoneplaceforvery characteristic offlies,theydo pastures. Thatisanother up, ortheflyjusttakesoffforgreener slowly thateitheryougetboredandgive sensitive thatyouwouldhavetomoveso confuse thefly. triggers theflytoflee,soaslowhandcould expand relativetothefly’svisioniswhat slowly. Howfasttheedgesofyourhand you cantricktheflybyjustmovingvery very fast,andsoyouareright.Inprinciple, 1 You couldalsohold Apparently, confusingthe But thentheflymotionvisionisso Ans: detect themovementandactuallygetit? can’t wemovesoslowlythataflycan’t they are somuchquickerthanus.But . Fliesare difficulttoswatbecause Flies processmotioninformation Do YouKnow? Answers to middle finger. effectively crushitwhenyoureleaseyour to anapproachinghand,soyoucan enough tonottakeoffasitnormallywould directions itapparentlygetsconfused the flyisbeingapproachedfrommultiple oncetheflyisinrange.Since cocked finger towards theflyandquicklyrelease slingshot whileyouslowlyslideyourhand backlikea and pullyourmiddlefinger wideonthesamesurfaceasfly fingers the shower. distracted, justlikejumpingonsomeonein itself, thenstrikequicklywhileitis One othersolutionistospreadyour

X Jantar Mantar X Children’s Science Observatory X March - April 2018 X Jantar Mantar X Children’s Science Observatory X March - April 2018 50% relatedtothem children. Whenitcomesto siblingsyouare parents andyouare50%related toyour science. Youare50%relatedtoyour complicated, asisusuallythecasein obviously theirchildren. when youaskadults,theythinkitis question, theytypicallysayparents,and question. Whenyouaskchildrenthis capture .... fun scientistsarehavingplottingtheir The shortansweristhatitalittlebit Ans: siblings? our parents, ourchidren, orour 2. Genetically, whoare weclosestto— Poor fly!Iffliescouldknowhowmuch Now thisisareallyinteresting on average . In children inheritanXchromosome from chromosome pairwhilemales haveXY.All chromosome. Femaleshave XXsex 50% onaverage. completely differentparts.Thatiswhyit you tobetakingthesamepartsor that chromosomeandsoitispossiblefor sisters) theycouldtakedifferentpartsof comparing differentsiblings(brothersand However, thereissomemixing.Ifyou pairs ofchromosomesfromoneparent. from yourparents,yougeteachof23 parents. share ourgeneticmaterialequallywith mother andhalffromourfather,sowe particular, wegethalfourDNAfrom Of the23pairs,lastoneissex The reasonisthatwhenyouinheritDNA 26 27 share theirentireDNAexactly. isbasedon. Identicaltwins fingerprinting actually unique.ThisiswhatDNA genetic mixinghappens,soweareall recombination inwhichsomeamountof differences becauseofaprocesscalled share only25%.Therearealwayssmall genetic material,whilebrotherandsister the average,sistersshare75%ofthis chromosomes oftheirmother.Henceon while theymayinheriteitheroftheX the sameXchromosomefromtheirfathers, complicates theissue.Alldaughtersinherit presence ofmitochondrialDNA) the child!).Thesexchromosome(and it isthefatherwhodeterminessexof while boysinherittheYchromosome(yes, their mother;girlsinheritXfromfather to theminusofanothervoltagesadd and youconnectedtheplusofonebattery endtoend, Ifyouconnectedabattery fish. (like onanecklace)alongtheinsideof electrocytes andtheyarestrungtogether musclecells.Theyarecalled use modified generators? Theansweristhatelectriceels Ans: energy? 3. Howdoelectriceelsgettheir Perhaps theyhavebuiltin energy thanthatbecause itscurrentflows milliseconds. Aneelgenerates muchless current mustbeflowinginto itfor50 cause anarmtospasm,200milliampsof same dimensionsasanadultman’sarm.To comparison, aneel’sbodyhasroughlythe given areaofthebody.Forpurposes duration ofthecurrentflowingthroughany electric shockdependsontheamountand explanation isthattheseverityofan without shockingthemselves.Onepossible clear whytheycanshockotheranimals other? Apparentlyscientistsarenotentirely nucleus. matter howfartheyarefromthecommand thousands ofcellsactivateatonce,no array ofnervesmakessurethatthe When thecommandisgiven,acomplex decides whentheelectricorganwillfire. does thisthroughacommandnucleusthat of theseelectrocytes.Thenervoussystem system thathascansynchronizetheactivity hundreds ofvolts. thousands ofcells,adduptomake which together,overthecourseofthese these cellstogeneratethosetinyvoltages of sodiumandpotassiuminout accumulator orbattery.Itispumpingions and thereforesmall.) voltage, thecurrentgeneratedisdivided, current. Sothoughgeneratealarge which providesadditionaloutletsforthe eel anditstail.(Notethateelsliveinwater, discharged fromjustbelowthechinof you maybeget500voltsandtheyare accumulate voltageandoveraverybigeel too.Theseelectrocytecellsslowly fish together. Thesamethingshappentothe Why don’telectriceelsshockeach The eelhasahighlyspecializednervous So yes,theeelisbasicallyagiant

X Jantar Mantar X Children’s Science Observatory X March - April 2018 X Jantar Mantar X Children’s Science Observatory X March - April 2018 than thedischargingeelitself. animals closetotheeelgetshocked,rather smaller involume.Therefore,thesmall length thananeelisabout1,000times system orheart.Aprey10timessmallerin current evenmorenearthecentralnervous through theskin.Thisprobablyreduces part ofthecurrentdissipatesintowater for only2milliseconds.Additionally,alarge outwards toJupiterandbeyond. This material allthewayfrom near theSun growing wheretheasteroidsnoware. was Jupiterthatstoppedanyplanet Ans: form there? asteroid belt,butwhydidnoplanets between MarsandJupiter?There isan 4. Whyisthere suchabig‘gap’ There clearlywasplanet-forming Scientists seemtoconsiderthatit culprit! scarcely benoticeable. times themassofEarth,sothiswould gobbled upbyJupiter.NowJupiteris318 Mercury, anddoubtless,somehasbeen hit MarsandtheEarthVenus material scatteredinwardsandwouldhave scattered outofthesolarsystem.Some system? Mostofthematerialhasbeen down onusintheearlyphasesofsolar Have theybecomeasteroidsthatrained belt. though therearethousandsofbodiesinthe This isasurprisinglysmallamounteven about ahundredthofanEarthmassintotal. asteroids together.Theywouldmakeonly So yes,theverdictisclear: Jupiteristhe Where hasallthatmaterialgone,then? Source: ScientificAmerican and now ifwestuckallthe We couldnotmakeaplanet been lostbecauseofJupiter. of thematerialhas,infact, they arestirredupandmost 1,000 kilometresacross.So today arelessthanabout large bodiescannotgrew. to clumptogether.Sovery energetic toallowmaterials such bodiestobetoo cause collisionsbetween asteroid beltis.Thiswould orbit, whichiswherethe such bodiesjustinsideits would stiruptheorbitsof close toJupiter,itsgravity -sized bodies.But larger bodies,eventually together intolargerand should haveclumped Cambridge ScienceforKids. The largestbodiesthere 28 29 Park, andtheUniversityof Nottinghamin Pennsylvania StateUniversity, inUniversity Jonathan Lynch huge crisiswefaceasaspecies,” says for water. interested inhowtherootsofplantshunt shapes. Withthatbackground,he’snow of howplantsdeveloptheirpartsand food. Hestartedhiscareerstudyingdetails waystogrow better be usefulinfinding plants work.Whathelearns,though,could He conductsprojectsjusttodiscoverhow research group“runsoncuriosity,”hesays. explore howrootssearchforwater.His discovering plants’alienwaysdriveshimto California, USA.Hesaysthethrillof Carnegie InstitutionforScienceinStanford, on ourownplanet.” Dinneny. Yet,heargues,“Wehavealiens and thegalaxyforextraterrestriallife,”says odd theyreallyare. They’re sofamiliarit’seasytoforgethow salads andpotsonasunnywindowsill. touch. waterwithoutsightor Plants alsofind information andcanmakegooddecisions. system. Yettheytakeindifferentkindsof strange. Theyhavenobrainandnervous feed Earth’sgrowingpopulation. under stress.Whathelearnscouldhelpto J These questionsareimportantin“this The rootofthematter Dinneny isaplantbiologistatthe “We’re outsearchingthesolarsystem They areeverywhereinourlives:lawns, José Dinnenywantsustoseeplantsas Rooting itout osé Dinneny . Heisarootbiologistat studieshowplantsgrow roots arespecial:Theyglow whenvarious intheground.Butthese that rootsfind dirt. It’slikeminiversions oftheconditions among airpockets,microriversandclotsof between twoclearplates.Therootsweave their rootsinslimsandwichesofsoilheld depending onthewateravailability. get expressed(turnedonoractivated) Activated CellSorting name fortheprocessis special viewofrootsinsoil.Thetechnical a systemcalled realism, Dinnenyandhiscolleaguescreated from howplantsgrowinreallife.Formore of plantsinthelab.Butthisisverydifferent This letsresearchersexperimentwithlots dishes withanutrientgelinsteadofsoil. biologists oftenstartseedlingsinpetri makes thismorecomplicated. question. AndEarth’schangingclimateonly boost theircropsandkeepupishuge — andfast.Whetherfarmerswillbeableto England. Thehumanpopulationisgrowing In the GLO-roots system,plantsgrow To studyhowplantsgrowthoseroots, GLO-Roots . Itshowshowgenes Fluorescence . Itcreatesa

X Jantar Mantar X Children’s Science Observatory X March - April 2018 X Jantar Mantar X Children’s Science Observatory X March - April 2018 happening inroots. outwhat’s Now he’sfocusingonways tofigure places. studied plantstryingtogrow indifficult the geneticsofplantdevelopment.Later,he University ofCalifornia,SanDiego.Hestudied captivated him.ForhisPhD,hewenttothe of California,Berkeley.There,plantscience a straight-Astudent,andhewenttoUniversity thought.” but “you’regoingtodobetterthanyouever effort andsuccess.”Noteverygoalgetsmet, says. “Thereisamagicalrelationshipbetween inherently Or they’redoingwellbecausejust ‘OK, I’mgoodatthis,’or‘I’mnotthat.’ government accountant. raised himasasinglemomworking working hard.Thatincludedhismother.She examplesof academic ,buthehadfine studying. Dinnenydidn’tcomefroman advanced classes.Hebegantoapplyhimself biology. Helobbiedhardtotransfer to realizehehadatalentforunderstanding factoid,” heremembers. wondering whocouldpossiblyhaveknownthat “Everyone lookedaroundtheroomsortof hand.” Theanswer:aphospho-diesterbond. in DNA.“Iwastheonlypersonwhoraisedhis when histeacheraskedabouta changed. Hestillremembersapivotalmoment Placement biologyclass.Suddenly,things In 10thgrade,though,hetookanAdvanced The schoolhewenttohadahighdropoutrate. in classesthatweren’tparticularlychallenging.” California’s SanFernandoValley.“Iwasplaced About ProfJoséDinneny About ProfJoséDinneny About ProfJoséDinneny About ProfJoséDinneny About ProfJoséDinneny By his final yearofhighschool,Dinnenywas By hisfinal “Often wekindofcubbyholeourselvesinto, He evensurprisedhimself.Dinnenybegan Dinneny spentmuchofhischildhoodin betteratdoingthisthanIam,’”he chemical bond tissues shouldbeabletosense order tobeablesense this, root’s is morewaterinacertain direction?In to grow?Howdotheyknowthatthere How dotheydecideinwhichdirection branches intheirsearchforwater. formed. more recentlythelittlerootlets the colourationgetstowhite, days aftersowingaseed.Thecloser images ofagrowingrootstarting11 photo showsthisbycombiningdaily of aseedlingexplorethesoil.The researchers tovisualizehowtheroots environment. how rootsarerespondingtotheir And thatgivesresearcherscluesto analyze wherethatglowshowsup. underground observatory.Computers genes turnoninthistwinkling We knowthatrootsgrowoutside The GLO-roots set-upallows 30 31 “hydropatterning.” tissues. Dinnenycallsthis this byanalyzing/hormones/intheroot apart). Dinnenyandhiscolleagueslearned are onlyabout100micronsapart(0.1mm tissues cansensedifferencesatpointsthat surrounding soil.Itturnsoutthattheroot differences inthewetnessof needs tosurvive. what it determine whetheraplantcanfind the manytinydirectionalchoicesthatwill out tosearchforwater.Thisisjustoneof root. Theroothasformedabranchpoking grow outintodryorhostilesoil. automatically ensuresthatrootsdonot roots tooptimisesoilexploration.It genetic level.Itallowstheplanttogrowits found theansweratveryfundamental question, Howdotheythis?Andhe timeDinnenyaskedthe for thefirst early classesthatrootsgrowthisway.But strange. Afterall,wehavelearnedfrom tissue develops. candrasticallychangethewayroot Changes intheliquidavailabilityatroot liquid) orairdeterminesthetissuegrowth. contact ofaroottipwithwater(orany every aspectofrootdevelopment.The The photoshowsacrosssectionofrice this On onehandwemaynotfind Hydropatterning mayregulatenearly Hydropatterning www.sciencenewsforstudents.org/ Adapted fromScienceNews for Students, https://

X Jantar Mantar X Children’s Science Observatory X March - April 2018 X Jantar Mantar X Children’s Science Observatory X March - April 2018 tiny flowerscalled head ismadeofhundreds to 30cminwidth.Theflower flower headthatcangrowup up to3meterstall,witha stem oftheflowercangrow the endofstem.The annuus sunflower plant( food, seedsandoil.The grown almosteverywherefor America, nowsunflowersare though itisnativetoNorth- turn towardtheSun.Even name becausetheflowers flowers. Sunflowerhasgotits compared tomanyother and brightincolour easily visibletoinsectsand pseudanthium “false flower”alsocalled Together theymakeupa follow theSun! The Institute of Mathematical Sciences, ofMathematical The Institute I t iseasytospotasunflower—itbig ) hasalargeflowerat Sunflowers . Itisvery M.V.N. Murthy Helianthus Chennai florets . Sun. Thisiscommonmisconception, sunflowers followthemovementof California atDavisintheUSA. fromUniversity of research findings of themovementhelpedbysomerecent surely beginningtounderstandthemystery internal clock?Scientistsareslowlybut east againnextmorning?Doesithavean does thesunflowergreetSunin then whathappensaftertheSunsets?How day untilitsetsinthewest-wellalmost.But the movementofSunthroughout the Sunineasteachmorningandfollow sunflowers, asthenameindicates,greet sunflower canproduceupto1,000seeds.\ birds whichhelppollinateit.Atypical Some observations first: Itisnotthatall Some observationsfirst: It hasbeenknownforalongtimethat Is thereaninternalclock? 32 33 beings. rhythm likehumansandmanyotherliving Sunflower appearstofollowthiscircadian influences importantbodilyfunctions. rhythm thatyourbodyalsofollowsandit what isknownas“ of day-night24hourcycleissaiddisplay biological processthatfollowsthisrhythm sunflowers duringtheirgrowingphase.Any day-night rhythmfollowedbyyoung it fullsizeandfacesthesamedirection. comes toastopastheflowermatures the Sun.Thismovementslowsdownand sunflowers thatfollowthemovementof day. Itistheyoung,notfullymature, follow thedailyrhythmbutfaceseastall actually afullygrownsunflowerdoesnot The nextquestionisthen howdothey The scientistswereinterestedinthe Circadian rythms Circadian Rhythm ”. Itisa by aninternalcircadianclock? Inorderto changing distancebetweenthedots. time-lapse video,theycouldmeasurethe themwithavideocamera. Ona filmed this? Theyputinkdotsonthestemsand the daynightcycle.Howdidtheymeasure sunflower torhythmicallymovealongwith eastern edgeandwesternallowsthe The differentialgrowthofthestemon left andtheoppositewhileturningright. lesser distancethantheouterwheeltoturn like acarwheelclosetothecurbcovers Sun againinthemorning.Itissomething flower totheoriginalpositiongreet than thewesternedge,bringingback the nighteasternedgegrowslonger the flowercanfollowSun.Andduring grows morethantheeasternedgesothat the daywesternedgeofstem Is thegrowthpatternthen determined Is theclockinternalorexternal? peculiar way.During growing thestemina They dothisby shorter thanthenight. if thedayislongeror day. Itdoesnotmatter same processthenext at nighttobeginthe plant rearrangesitself have observedthatthe morning. Infactthey position inthe return totheoriginal Sun’s progressand sunflower followsthe day theyoung found thatduringthe top. Scientistshave single sunfloweratthe sunflower planthasa do it:Thestemofthe

X Jantar Mantar X Children’s Science Observatory X March - April 2018 X X X Chennai true tothebestofmyknowledgeandbelief. I, C.S.Venkateswaran,herebydeclarethattheparticularsgivenaboveare than onepercentofthetotalcopital Jantar Mantar T partners shareholdersholding Children’s : : who ownthenewspaper 6. Name&AddressofIndividuals Science Observatory5. Editor'sName : : March4. Publisher'sName - April : 20183. Printer'sName 2. PeriodicityofPublication drs : : : Address of origin) (If foreignerstatethecountry Whether CitizenofIndia : : Address (If ForeignerstatethecountryofOrigin) Whether citizenofIndia : Address country ofOrigin) (If Foreignerstatethe Whether citizenofIndia .Paeo ulcto : 1. PlaceofPublication Children’s ScienceObservatory Jantar Mantar Form -IVRule8 130/3,AvvaiShanmugamSalai, & oeGopalapuram,Chennai-600086 more Chennai -600036 IMSC, Tharamani, Indian D.Indumathi Gopalapuram, Chennai-600086 Indian C.S.Venkateswaran Royapettah, Chennai-600014 Print Specialities,186,VMStreet, Indian S.Vaidyanathan Bi-Monthly Gopalapuram, Chennai-600086 amilnadu ScienceForum 130/3 130/3 , Avvai , Avvai Publisher Signature of

S S hanmugam Salai, hanmugam Salai, light andthecircadianrhythm. growth isdrivenbygenes thatrespondto ‘growth’ atthemolecular levelwherethe relationship betweenthe‘clock’and provides aniceexampletounderstandthe responsible for for the connectionbetweengenesresponsible molecular biologists,theyhadearliershown environment,” asthescientistssay.As modulating thegrowthinanatural example ofaplant’sinternalclock “first sunflower isbecauseitseemstobethe environmental factors,butinternalinorigin. had aperiodof24hoursandarenotdueto accurately measuredthattheserhythms a plant.Afternearlycenturyitwas Mairan noticedthedailyleafmovementsof 1729 whentheFrenchastronomerde the researchoncircadianrhythmsbeganin dramatic asinthecaseofsunflower;fact as inthecaseofanimals.Itmaynotbe is widelyobservedinmanyvarietyofplants among plants?Actuallythecircadianrhythm pollination. in attractingthebeeswhichhelp warming oftheflowerthatfacedeasthelps photosynthesis. Furthermore,theearly to growlargermaximisingthe Apparently facingtheSunhelpsplants incredible internalclockmechanism. rhythm showingthatindeedtheyhavethis path oftheSunmaintainingcircadian sunflower seemedtofollowanimaginary 30 hoursinsteadof24hours.However,the different lightanddarkcyclesgoingupto lightwith plants insidewithartificial out,scientistsgrewthesunflower find The importanceofthestudyon Is thispeculiartosunflowerplantalone Why dotheseplantsbehaveinthisway? rhythm andtheplanthormone growth . Sunflowerplant z 34 Advisory Board Dr. R. Ramanujam (IMSc, Chennai) Dr. Kamal Lodaya (IMSc, Chennai) Dr. P. B. Sunil Kumar, IIT-Madras, Chennai. Dr. S. Krishnaswamy, MK University, Madurai Editor Dr. D. Indumathi, (IMSc, Chennai)

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March - April 2018 Cover X A rainbow rose. Photo by Ryan Amos. Technique developed by Peter van de Werken; based on fact that rose petals are arranged in a Fibonacci spiral. Back Cover: Pansies are the most cross-bred flowers that are available in hundreds of colours. Children’s Science Observatory X Jantar Mantar

X 2 March - April 2018 X Children’s Science Observatory

Schematic showing the orbit of the International Space Station which is a satellite in low Earth orbit (about 400 km X above Earth). It completes about 15.5 per day and can often be seen with the naked eye. Its first component was launched in 1998, the last module was fitted in 2011, and it is expected to be in use till 2028! Jantar Mantar

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