attractedleavemealone

leavemealone  时间:2021-03-16  阅读:()
KINDERGARTEN'OPTICSManuelF.
M.
Costa,JúliaCampos,MadalenaLira,SandraFrancoUniversidadedoMinho,DepartamentodeFísicaTel.
+351253604070;Fax.
+351253678981e-mail:mfcosta@fisica.
uminho.
pt4710-057BRAGAPORTUGALABSTRACTTheintroductiontoourschool'studentsofthewondersoflightandopticsanditsunderstandingcanandshouldbemadeasextensivelyaspossible.
Assoonasatkindergartenlevel!
Ahands-onapproachleadingthestudentstoobserveexperimentanddiscoverthemselvesinacriticalcommittedandactivewaythedifferentaspectsoflightandopticsshouldbeemployedatallschoollevelsandmustbethemaindrivingpedagogicalpracticeofalllearningprocessofscienceandtechnology.
Inthiscommunicationwepresentaseriesofexperimentsandsupportmaterialdesignedinthishands-onperspectivetobeusedtointroducethestudyofopticstokindergartenandearlybasicschoolstudents.
Acriticalevaluationofthefirstresultsoftheapplicationofthesematerialwithstudentsaged4to10yearswillbepresented.
1.
IntroductionYoungchildrenarealwayseagertolearntoseenewthingsbutalsotoknowandtounderstandtheworldthatsurroundthem.
Withreduced"pre-knowledge"usually,therearenopreviouslyacquiredmisconceptionsorevenprejudices.
Alsotherenoexamstostudyfor…"just"theinnatesurvivalneedtoknow.
However,sincetheywerebornapermanentlearningprocesstakeplaceatanextremelyfastpace.
Childrenlearnfromtheenvironmentfromwhattheyfeelfromwhattheylive.
Aswecouldseewhencontactingchildreninthisagerange,4to10yearsold,aconstantreferencetotheireverydaylifeandpreviousexperiencesismade.
Hands-on[1,2]activitiesarefundamentalandthe"natural"approachfortheseyoungstudents.
Thefirstconcernoftheeducatorshouldbe,withthisclearperspectiveinmind,toshow…orbetter…toletthechildrento"see",toobserve,toconfrontthemselveswithnewobjectsprocessesandsituations.
Timeisfundamentalandshouldbegenerouslygiventotheyoungstudents.
Ofcoursesome"pressure"canbeuseful…induetime…respectingeachonespace.
Fromearlykindergartenyearsthechildrenshould"learn",shouldbeleadtoworkingrouptointeractandcooperatewithpeerstowardsacommongoal.
Carehowevershouldbetakenbytheeducatorinordertoensurethateachstudentwillhave,inthesegroupactivities,theneededtimetoestablishtheirown"knowledge"whileguarantyingthatnochildren,apparently"faster",feelsuncomfortable"waiting"fortheothers.
Nosenseofsuperiority,orinferiority,orevenofcondescendence,inthiscompetitionprocessthatalwaysappearsinthesesituationsattheseages,shouldberewarded.
Yetfundamentalitisthattheeachchildunderstands,stepbystep,theimportanceof"cooperation",oflisteningtheotherlettingtheotherstoknowofourfindings,helpingandacceptingtobehelpedinthesakeofacommongoal.
Howtodothat…aPortuguesepopularsaying(certainlywithequivalentsthroughouttheword!
)"wordsaresilver,silenceisgold"…bepatientgivetimetothestudents,andtoyourself…,openwidelyyoureyesandleadthewaysmoothlyaffirmativelyanddiscreetly.
Wordsmightbemadeofsilverbutitisfundamentalthatthechildisabletoverbalisecoherentlytheirfeelingstheirfindingstheiropinions.
Hands-onshouldbecomplementedwithaconstructivist[3]approachandotherslikeconstrucionism[4]andconceptuallearning[5].
"Always"hands-onbutnotblind/mechanically…"…dothisandthenthatandthatand…"Learningisdiscovering…bythestudent…himself…activelyandreflexively.
2.
LightandopticsatthekindergartenBeingrelatedtooneofourmainsenses,beingtheeyesamajorgatewaytotheworldthatsurroundus,lightrelatedphenomenaareratherappealingtoyoungchildren[6].
Youngstudentsreadilyrealizetheimportanceofseeingandtheroleoftheireyesandoflightsources.
Theyareparticularlyattractedtothecolourphenomena,toreflectionandtransparency,toshadeandchangesinluminosity…Belowwepresentasetofsimpleexperimentsthatwedesignedfor4to10yearsoldstudentsandthatmayserveasbasisforteachersandeducatorstouseintheirclassroomsandininformalactivities[7].
Wedividedtheexperimentsinthreeparts.
Afirstoneintendstointroducetheroleoftheeyeand…weneedlighttoseeobjects.
Atthesecondpartweintendtoshowusingasimplemodelhowtheeyeworks.
Finallythethirdpartdealswithlightandcoloursandisbythemostattractiveoneforouryoungscientists.
3.
Lightandopticsexperimentsinthekindergartenandelementaryschools3.
1Part1.
Themainconceptbehindthisfirstsetofexperimentswas:weneedlighttoseeobjects.
Theexperimentsweredesigntoshowthat:Weseeanobjectbecausethelightfromtheobjectenterstheeyethroughthepupil.
Constrictionofthepupillimitstheamountoflightenteringtheeye,anddilatingofthepupilallowsmorelighttoentertheeye.
So,inbrightlight,thepupilconstricts,andindarkness,thepupildilates.
(Experiment1)Thereareobjectsthatemitlight(ie,lightsources)andothersthatreflectlight.
(Experiment2)Lightisreflectedfromthesurfaceofobjects.
Darkobjectsreflectlittlelightwhilewhiteobjectsreflectmorelight(Experiments3and4.
Figure1.
).
Experimentn.
1.
PupilobservationBackground:Thelightenterstheeyethroughthepupil.
Thepupilhastoadapttodifferentlightintensities.
Method:Thechildrenaredividedintogroupsof2or3.
Theroomlightisdimmedandpenlightsaredistributedtoeachgroup.
Itisaskedtooneofthechildrentoilluminatehis/hereyeswhiletheothersobservethepupilclosingdown.
Experimentn.
2.
Luminousandnon-luminousobjectsBackground:Thereareobjectsthatemitlightandothersthatreflectlight.
Method:Theroomisdimmed.
Lightemittingobjects(ofdifferenttypes)andnon-luminousobjectsareavailableandareshown.
Thesimilaritiesanddifferencesbetweenthevarioustypesoflightsourcesandobjectsarediscussed.
Experimentn.
3.
BrighteranddarkerobjectsBackground:Thelightisreflectedfromthesurfaceoftheobjects.
Thedarkobjectsreflectlittlelightwhilewhiteobjectsreflectmorelight.
Method:Severalobjectsofdifferentcoloursareplacedinablackboxwiththefrontfaceopen.
Theroomlightisdimmedleavingonlyasmalllampbehindthebox.
Thepositionofthelampisgraduallychangedtoallowsomelighttoreachtheobjectsinsidethebox.
Astheinsideoftheboxbecomesmoreilluminatedthedarkerobjectsbecomeprogressivelymorevisible.
Experimentn.
4.
LightreflectedbyobjectsBackground:Thelightisreflectedfromthesurfaceofobjects.
Thedarkobjectsreflectlittlelightwhilewhiteobjectsreflectmorelight.
Method:Inaverydarkroom,eachchildplacehimselfinfrontofamirror.
Onehandholdsapenlightononesideofthefaceinordertolightenthenose.
Thechildisaskedtoobservehis/herfaceinthemirror(figure1.
).
Figure1-Thelightreflectedbytheobjects'experiment.
Theexperimentisrepeatedbyholdingawhitecardboardwiththeotherhand,paralleltothesidenotilluminated.
Theprocedureisthenrepeatedbyreplacingthewhitecardboardbyablackoneandthenbycardboardsofdifferentcolours.
Finallythestudentreplacethecardabyasecondmirror.
Childrenrecordanddiscusswhattheysawhappeningonthenon-illuminatedpartoftheirfacewhenusingthedifferentcoloursorthesecondmirror.
3.
2Part2.
ThemaingoalofthesesetofexperimentsistoillustratehowoureyeworkTheexperimentsweredesigntoshowthat:Howtheimageofanobjectisfocusedontheretina.
(Experiment1)Whatisaccommodation.
(Experiment2)Seeing"bad"…Whatismyopiaandhyperopia.
(Experiment3)Thesesetofexperimentswereperformedwithamodelofthehumaneye(figure2.
).
Figure2-HowtheeyeworksexperimentsExperimentn1.
Usingabrightlightsource(acandlemaybeusedunderteacherssupervision),imagescanbefocusedonthemodel'sretinasimulatingthehumaneyeimagingmechanism.
Experimentn2.
Todemonstratetheaccommodationthelenscanturnthickerorflattertofocustheimageontheretina.
Thelensisachamberconstructedofopticallyclearsiliconeelastomerconnectedbytubingtoawater-filledsyringe.
Waterforcedintothelensincreasesitsthicknessandcurvature;withdrawalflattenstheprofileofthelens,changingitsfocus.
Experimentn3.
Theeyemodelcansimulaterefractiveproblems(thatsomechildrenmaysufferfrom).
Myopiaandhyperopiacanbesimulatedbychangingtheeyes'shape(length).
Itisalsopossibletousecorrectivelenses.
Wheneverthereisachildusingspectaclesitmaybeusedtoillustratethecorrectioneffect(iftheteacher/educatorisnotconfidentenoughwiththeprocess,isprobablybettertoskipthisstepunlesssomestudentspointsitout(whichoftenhappens…fortunately…).
3.
3Part3.
Colouristhemainconceptaddressedatthislastsetofexperiments.
Theexperimentsweredesigntoshowthat:Itiseasytoseparatewhitelight'colours(Experiments1and2).
Wegetwhitelightbyaddinggreen,redandbluelight(Experiment3).
Gettingyellow,magentaorcyancolours(Experiment4).
Object'colourdependsonthelightreflectedfromthem(Experiment5).
Experimentn.
1.
Whitelightdecomposition1.
Background:Whitelightis"composed"ofallthecoloursintherainbow.
Method:Usingabrightwhitelightsource(placingaslitinfrontmayhelp),abeamofwhitelightisprojectedontoawhitesmoothsurface(target).
Withadiffractiongratingand,or,aprism,thelightisdecomposed,projectingthelightspectrumonthetarget(itmaynotbeeasytogetallcoloursclearlyvisible…childrenmustlearntobepatientandresilient).
Colourfiltersareplacedinfrontthebeamand,asalways…,discussed.
Experimentn.
2.
Whitelightdecomposition2.
Background:Whitelightis"composed"ofallthecoloursintherainbow.
Method:CDsaredistributedtothechildren.
Theyobservethedecompositionofsunlight(theceilinglamporeventhelightemittedbyacomputerscreen)intotherainbow.
Theexperimentisthenrepeatedwithapocketspectrometer.
Experimentn.
3.
and4.
Mixinglightwithdifferentcolours.
Background:Addinggreenredandbluelightallowsustogetwhitelight.
Method:Threelightsourcesareused-onered,onegreenandoneblue(simpleflashlightswithcolourfilter–theteachermustcheckaheadhowredisthered,howgreenisthegreen…).
Thethreebeamsaredirectedtoonepointofasmooth,notpolished,whitewallorboard.
Childrenarealsoaskedtomakeshadowswiththeirhands(figure3.
)andnoticeallthecoloursobserved.
Theexperimentisrepeatedwithonlytwolampsconnectedatatime.
Theconceptofsubtractivecolourmissingmayalsobeaddressed.
Figure3–Colourshadows.
Experimentn.
5.
Background:Thecolourofobjectsdependsonthelightreflectedfromthem.
Method:Thisexperimentisdoneusingthesamelightsourcesusedbeforeandatthesamepositions.
Severalcardboardpicturesofdifferentcolours(thecardboardshouldnotbeshiny)areplacedonablackboard(figure3).
Thosecolourcardsareilluminatedwithoneofthelampsandrepeatedwitheachoneoftheotherlampsandcombinationsofthem.
Attheendthethreelampsareswitchedon.
(Especiallyforthesetwolastexperimentsitisnecessarytodimsignificantlyroomlights).
4.
BriefdiscussionandconclusionWedecidedtoinviteagroupofelementaryschoolstudents(ages6to10yearsold)totheuniversityinordertoperformthesesetsofexperiments.
Theactivitywasrathersuccessfulpleasingtostudentsandteachers.
Althoughstatingtheirclearpreferencethatthecolourexperimentswerethemostpleasantones,theresultswereingeneralverypositive,duringtheexecutionitselfandinthefollow-upactivitiesundertakenbackattheschool.
Figure4.
Demonstrationsandvisitstomuseumsandsciencefairsmightbeveryusefulifafollowupworkispreparedbytheeducatorandconductedinclassroomcontext.
Follow-up,infact,shouldalwaysbeconsideredveryimportant.
Thesenon-formalorinformalactivities(visitstolabs,museums,sciencefairsorlectures,figure4.
)shouldalwaysbefollowedofworksessionsintheclassroomexploringthemotivationachievedanddevelopingandorstrengtheningtheknowledgetransmitted/acquired.
Attheendofouractivityaseriesofenquiriesandquizzesweredeliveredtotheteachersandaskedtobereturnedforanalysisandstatisticaltreatment.
Furthermorewedistributedtothestudentsmaterialandshortguidelinestobuild,ontheirown,akaleidoscopeandasimplepinholecamera(amuffinaluminumcup,arubberbandandasofttranslucentpapersheetisenough…).
Beingclearforusthatthestudentseasilyandcorrectlyareabletounderstandtheimportanceoftheeyeintheprocessofseeing,wedecidedtoexplorealittlebitthevisionprocess.
Weusedasimplemodeloftheeyewithapupil,arubberlensthatcouldbeinflatedusingawatersyringeandaretinalikedisplaceabletarget,whichcanbeeasilybuilt.
Weexpectedthestudentstohavedifficultiesinunderstandingtheprocessorevenacceptingit…wewereinsidetheeye…!
Infactonlyolderstudents,9to10yearsold,wereabletodealwithit.
Figure5.
Shapesandcolours.
Theagespancovered,4to10yearsold,isratherlarge(especiallyasdealingwithchildren).
Onemustcarefullycopewiththedifferences…beingflexiblebutalwaysobservingchild's'reactions.
Fromveryearlyagesyoungchildrenarestronglyattractedtocolours,inparticulartobrightprincipalcolours,arefascinatedbythewondersofcolourmixingandtheyseemmoreattractedtoadditivemixingoppositetowhathappenswithschoolstudentsthatbeforebeingpresentedtotheissuehadpreviousexperienceinmixinginkforpaintings(thesubtractiveprocess).
Thehands-onmanipulationofcolourcards(especiallyifbeingpartofgames)isparticularlyeffective(figure5.
).
Ingeneralthebasicconceptcoveredbytheseexperiments(speciallypart1and3)arereadilyunderstoodbytheyoungchildrenthatimmediatelyafterrealizingtheconceptpresentaseriesofexamplesrelatedtotheirownexperience(…whenelectricityfailedandlightswentoffIwasafraidmymamaleavemealoneinthedinnertable…).
Thistypeofreactionhappensquiteoften(normallyolderstudentsaremore"careful"expressingtheirfeelingsandideasandrestrainthemselves)andisagoodindicationthatsomelevelofunderstandingoftheconceptwasachieved.
References1.
"Hands-onScience";CostaMFM;SelectedPapersonHands-onScience(ISBN978-989-95336-2-2);CostaMF,DorríoBV,MichaelidesPandDivjakS(Eds.
);AssociaoHands-onScienceNetwork,Portugal;pp.
1-13(2008).
2.
GattS.
(ed.
),(2006)PrimaryScienceTeachersHandbook,EuropeanCommissionComenius3project:HandsonScienceNetwork,Malta.
3.
"Constructivism–AneffectiveTheoryofLearning";GattS;ConstructivistteachinginPrimarySchoolSocialStudies,Mathematics,Science,ICT,DesignandTechnology;GattSandVellaY(Eds.
),AgendaPublishers,Malta(2003).
4.
"AStudyofEducationalRoboticsinElementarySchools";RibeiroC,CoutinhoC,CostaMFMandRochaM;SelectedPapersonHands-onScience(ISBN978-989-95336-2-2);CostaMF,DorríoBV,MichaelidesPandDivjakS(Eds.
);AssociaoHands-onScienceNetwork,Portugal;pp.
580-595(2008).
5.
"TeachingPhysicsModellingwithGraphicSimulationsTools";ZamarroJM,MolinaGJandNúezMJ;SelectedPapersonHands-onScience(ISBN978-989-95336-2-2);CostaMF,DorríoBV,MichaelidesPandDivjakS(Eds.
);AssociaoHands-onScienceNetwork,Portugal;pp.
69-73(2008).
6.
"LearningOpticsatBasicSchoolsbyExperimentation";CostaMFM;SelectedPapersonHands-onScience(ISBN978-989-95336-2-2);CostaMF,DorríoBV,MichaelidesPandDivjakS(Eds.
);AssociaoHands-onScienceNetwork,Portugal;pp.
25-28(2008).
7.
ManuelF.
M.
Costa,Hands-onIntroductiontoOptics/Introduoàptica(bilingualedition),Hands-onScienceNetwork,ISBN9899509523,September2006.

轻云互联22元/月,美国硅谷、圣何塞CN2GIA云服务器,香港沙田cn2建站vps仅25元/月

轻云互联怎么样?轻云互联,广州轻云网络科技有限公司旗下品牌,2018年5月成立以来,轻云互联以性价比的价格一直为提供个人,中大小型企业/团队云上解决方案。本次轻云互联送上的是美国圣何塞cn2 vps(免费50G集群防御)及香港沙田cn2 vps(免费10G集群防御)促销活动,促销产品均为cn2直连中国大陆线路、采用kvm虚拟技术架构及静态内存。目前,轻云互联推出美国硅谷、圣何塞CN2GIA云服务器...

WHloud Date鲸云数据($9.00/月), 韩国,日本,香港

WHloud Date(鲸云数据),原做大数据和软件开发的团队,现在转变成云计算服务,面对海内外用户提供中国大陆,韩国,日本,香港等多个地方节点服务。24*7小时的在线支持,较为全面的虚拟化构架以及全方面的技术支持!官方网站:https://www.whloud.com/WHloud Date 韩国BGP云主机少量补货随时可以开通,随时可以用,两小时内提交退款,可在工作日期间全额原路返回!支持pa...

BuyVM($5/月)不限流量流媒体优化VPS主机 1GB内存

BuyVM商家属于比较老牌的服务商,早年有提供低价年付便宜VPS主机还记得曾经半夜的时候抢购的。但是由于这个商家风控非常严格,即便是有些是正常的操作也会导致被封账户,所以后来陆续无人去理睬,估计被我们风控的抢购低价VPS主机已经手足无措。这两年商家重新调整,而且风控也比较规范,比如才入手他们新上线的流媒体优化VPS主机也没有不适的提示。目前,BuyVM商家有提供新泽西、迈阿密等四个机房的VPS主机...

leavemealone为你推荐
微信回应封杀钉钉微信违规操作被封了,关键字关键字和一般标识符的区别porndao单词prondao的汉语是什么www.zjs.com.cn请问宅急送客服电话号码是多少?www.hhh258comwww.tx88d.com 有这个网站吗?www.se222se.comhttp://www.qqvip222.com/www.kaspersky.com.cn卡巴斯基中国总部设立在?kb123.net股市里的STAQ、NET市场是什么?www.175qq.com最炫的qq分组bk乐乐《哭泣的Bk》是Bk乐乐唱的吗?
免备案虚拟主机 windows虚机 php空间租用 10t等于多少g 青果网 web服务器架设软件 国外在线代理 最好的免费空间 789电视 phpmyadmin配置 电信虚拟主机 绍兴电信 银盘服务 跟踪路由命令 web服务器是什么 网购分享 万网空间 实惠 国外免费云空间 买空间网 更多