Contents:

Quick Reference Sheets:• Intro: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .page2• Experiment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .page3• EquipmentList:Bending Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .page4• Story,Part1:Minions with Laser Beam Eyes . . . . . . . . . . . . . . . . . . .page5• Story,Ending . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .page6

Video Transcript:• Intro: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .page7• Story,Part1:Minions with Laser Beam Eyes . . . . . . . . . . . . . . . . . .page9• Experiment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .page12• StoryEnding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .page16

Teacher’s Guide for:

Bending LightNote: All activities in this document should be performed with adult supervision. Likewise, common sense and care are essential to the conduct of any and all activities, whether described in this document or otherwise. Parents or guardians should supervise children. Rock-it Science assumes no responsibility for any injuries or damages arising from any activities.

Note: All activities in this document should be performed with adult supervision. Likewise, common sense and care are essential to the conduct of any and all activities, whether described in this document or otherwise. Parents or guardians should supervise children. Rock-it Science assumes no responsibility for any injuries or damages arising from any activities.

BendingLightARock-itScienceLessonFilmedOctober,2009

Title Page of Video

NOTE: This is the transcript of a lesson that was videotaped during an actual Rock-it Science class with real students, not actors. The students’ brainstorming comments are included on the video but are not transcribed here because they’re not part of the lesson presentation.

Rock-it Science2110 Walsh Ave, Unit FSanta Clara, CA 95050www.rockitscience.org

(c) 2012 Rock-it Science Educationally Useful Programs. All Rights Reserved

Rock-it Science Teacher’s Guide Bending Light -- Page 2

Intro Quick Recap:• Lightusuallytravelsstraight .Lightfromastarwillusuallytravelstraightthroughspace .

• Einsteinsaidifthere’samassiveobjectnearthelight,likethesun,thelightcangetbentorshootoffinadifferentdirection .

• It’slikeatrampolinewithabowl-ingballinthecenter .Thesurfacebendsalittle .Asmallerballwouldnormallyrollstraightacrossthetrampoline,butwiththebowlingballthere,itgoesalittlebitcrooked .

• Anotherwaytomakelightbendistoshineitthroughwater .Ifyouputapencilinaglassofwa-ter,itlookscrookedunderwater .

• Askstudentswhereourdatacomesfrom .Theymaysay,“computers,internet,servers,”etc .Keepnarrowingitdownuntilyougettofiberopticcables .

• Datausedtobepulsedthroughcopperwires .Butyoucan’tgetalotofpulsesthroughthesamewirebecausetheyinterferewitheachother .Youalsolosealotofsignalwithdistance .

• Ifyoushinelightthroughaglassfiber,abunchofitshootsoutthewalls .Butifyougetjusttherightsizefiber,thelightwillbounceoffthewallsinsideanditwon’tloseanyenergy .Itcangoformiles,andboosterscanmakeitgoevenfarther .

• FiberopticcablesareusedforalmostallthedatatransmissionintheUSA,andinmostoftheworld .

• There’saplaceneartheSuezCanalwhereawholebunchoffiberopticcablespassthroughanarrowspot .Awhileback,somebodycutthem,andawholesectionoftheworldlosttheirinter-netconnection .

• Today’sexperimentwillmakesunlightgothroughsomefiberoptickindofmaterial .• Laserpenscanbedangerous .Theoneswe’reusingwon’tpermanentlyblindyou,butyou’llgetadarkdotinyourfieldofvisionforawhile .Sodon’tshinethematpeople’sheads .

• Prisonguardsuselaser-sightedrifles,sotheydon’tevenhavetoaimthroughascope .Theyjustpointthereddotatthetarget .Huntersusethese,too .Soyoushouldn’tpointalaseratsomeonebecausetheymightthinkyou’repointingagunatthem .

• Don’tpointalaseratanairplane,becauseyoucouldblindthepilot .Andthepolicehavewaysoftrackingyoudown .

Light bounces off the insides of the fiber optic cable.

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Experiment Quick Recap: “Stethoscopes”• We’regoingtouselaserpensandfindoutifwecanmakethebeambendalittlebit .Studentsworkingroupsoftwo .

• Instructorexplainswhatstudentsaregoingtodo:• First,justshinethelaseraroundandseewhatitdoes,butdon’tshineitatpeople’sheads .Pointitatyourfingerandseeifyoucanseeanythinginsideyourfinger .

• Second,studentsholdasmalllensinfrontofthelaserandshinethebeamthroughthelens .Thelenseshaveimperfections,sotrytofindaspotthat’snottoomessedup .

• Thentapethelensontotheendofthelaserpen,sothatthebeamdoesn’tshinethroughthetape .Seeifthelightspreadsoutwhenyoushineitatthewhiteboard .

• Thenholdapieceofwindowscreeninfrontofthelensandshineitatthewhiteboard .Seeifyoucanmaketheimagereallybig .

• Gouptotheboardandlookcloselyatthelinesonthescreenimage .(Don’ttellthemwhatthelinesshouldlooklikeyet .Aftertheyfinish,drawadiagramoftheshadowydiffractionlinesthatappearwithinthescreenpattern .)

• Thenputawaythescreenandplaceamicroscopeslideinfrontofthelensandshinethebeamontothewhiteboard .Seeifyoucangetthemicroscopicimagetoenlarge .(Slidesusedinthislessonwerethingslikeabutterflyscale,beeantenna,flyleg,etc .)

• Thentakethelensoffthepenandgetaclearplasticcupofwater .Shinethelaserthroughthewatertoseeifitbendsorlookscrooked,butdon’tputthepeninthewater .

• Thenstudentsshinethebeamthroughflexibleacrylictubingtoseehowthelightbendsasitpassesthroughthetubing .

• Instructorreleasesaburstofstagefogandstudentsshinebeamsthroughthefog .Iftheymovethebeamveryfast,theyshouldbeabletoseeturbulenceinthefog .

• Duringthecourseoftheexperiment,thelightsareonwhilestudentsareassemblingthingsorsuppliesarebeingpassedout .Oncethey’reready,thelightsareturnedoutsotheycanseethebeamsbetter .

Tape lens onto laser pen.

Diffraction pattern from screen. Diagram of diffraction pattern.

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Equipment List: “Bending Light”Items needed for Instructor:

• Fogmachine• Stagefogsolution

Items needed for Students:

Consumables (per student):

• Water,about6oz .• Tape,cellophane,about6”Other:

• Laserpens,0 .5milliwattredpens• Windowscreen,approx .2”x2”• Acrylicrod,flexible,1/8”diameter,fromTAPplastics• Lens,convex,withafocallengthofabout1/2to1inch(takenfromoldcheapcameras)

• Microscopeslidesofobjectssuchasinsectparts• Cup,clearplastic,16oz .

Prep Work:

• Cutscreensto2”x2”squares .• Checkbatteriesinlaserpens(TwoAAAbatteriesperpen) .

• Checkfogmachinetomakesureit’sworking .

Flexible acrylic rods.

Microscope slides.

Laser pens.

Lens.

Screen.

Story Recap: “Minions with Laser Beam Eyes”

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Part 1:

• EvilMisterFredwantedtoimprovehisarmyofminions,sohefoundanoldmagicbookandusedanincantationononeofthem:“Eeny-meeny-chili-beany-hear-the-spirits-speak .”Itgavetheminionredeyes .

• Heusedtheincantationonalltheminionsandgavethemallredeyessothey’dscarepeople .• Onedayhegotmadataminionandstartedhittinghisfootwithabaseballbat .TheminiongotmadandlaserbeamsshotoutofhiseyesandsetEvilMisterFred’smustacheonfire .

• EvilMisterFredputelectricdogcollarsontheminions,whichwoulddeliverashocktothemwhenhewantedthemtogetmadandshootlasers .

• Inordertogetthemtoallshootthesameway,heembeddedcompassesintheirheads,andtheshocksonlystoppedwhentheyallpointedthesameway .

• NearbywasalakewhereNessie,theLockNessMonster,lived .JackandJilllivedinabigsteelchamberatthebottomofthelake .Theywerebreathingoxygenandheliumsotheywouldn’tgetnitrogennarcosis .Breathingitmadetheirvoiceshigh .

• JackandJillweretheretotakecareofNessie .NoonehadeverfoundherexceptforJackandJill .Nessieislikeanamphibiousdinosaurwithfinsandshinyscales .

• EvilMisterFredsawNessieandwantedtocaptureher .ButfirsthehadtogetridofJackandJill .• TheminionslineduparoundthelakeandwaitedforJackandJilltocometothesurface .WhenJackcameup,hesawtheminionsgoofingaround,andoneofthemshotanotheronewithlaserbeams .

• JackwentdowntotellJill,butshedidn’tbelievehim .SoshewentuptothesurfaceandEvilMisterFredsawher .Hemadetheminionsshootbeamsather,andherhaircaughtfire .Sheswambackdown .NowJackandJillaretrappedinthelake .

Story Recap (cont.): “Minions with Laser Beam Eyes”

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Ending:

• Nessieisafire-breathingmonster,andherscalesareasshinyasmirrors,andhertailislikeafiber-opticcablethatcanhavelightgoinoneplaceandcomeoutsomewhereelse .

• JackandJilltoldNessietogoandtalktotheminionsontheshore .WhenEvilMisterFredsawhim,hedidn’twanttokillthemonster .

• ButwhenJackcameup,EvilMisterFredpushedthebuttonfortheshockcollars,andthemin-ionsstartedshootinglaserbeams .

• Butitwashardforthemtoaimbecausetheywerejumpingaroundscreamingfromtheshock .Solaserbeamsweregoingallovertheplace .

• Nessieabsorbedsomeofthemwithhertailandshotthemback,settingsomeminions’mustachesonfire .Someofthebeamsbouncedoffherscalesintotheair,andshewasalsoshootingsomeflamesjusttokeeptheminionsjumpingupanddown .

• ThenNessiejumpedoutofthewater .SheconcentratedawholebunchofthelaserbeamsthroughhertailandshotthematEvilMisterFred .Shesethismustacheonfireandmadethecastlered-hot,andEvilMisterFredwentrunningandjumpingoverthehorizon .

Rock-it Science Teacher’s Guide Bending Light -- Page 7

Transcript: Intro Todaywe’regoingtobedoingsomethingwithlight .Lightusuallygoesprettymuchstraight .Ifyouhaveastaroutthere,andlightiscomingfromthestarthroughspace,andifyou’refloatingthereinaspacesuit,youcanprettymuchdependonthelightbeingstraight .However,aguynamedEinsteinsaidthat’snotalwaysthecase .Einsteinsaidifthere’sabigmassiveobjectnearthatlight,likethesun,thatthelightcanactuallygetbentasitgoesby .Anditcanshootoffinadifferentdirection .

Andsomepeoplesayit’skindoflikeifyouhaveatrampo-lineandyouputabowlingballonthetrampoline,youkindofbenditdownalittlebit .Andifyourollaballacrossitwith-outthebowlingballinthere,theballwouldrollstraight .Butwhenyouputthebowlingballinthereandyourollthelittleballbyit,itmakesitgocrooked .

Well,itturnsoutthere’sanotherwaytomakelightbend .Andyou’vealldoneitbefore .Ifyoulookatsomebodythroughaglassofwater,they’lllookweird .Whenlightgoesthroughaglass,itbends .Ifyoustickapencilinthere,thepencillookscrookedunderthewater .Itlookslikeitgotsuddenlybentatthesurface .

There’sotherwaystomakelightbend,too .Nowadaysallofourdatacomesthrough . . .what?[Student: Computers.]Computers .Howdoesacomputergetit?[Student: Internet.]Internet .Howdoestheinternettransferitfromoneplacetoanother?[Student: Servers.]Servers .Andserversareconnectedtootherservers .Throughwhat?Isittransmittedbyhamstersthatrunfromplacetoplace?[Stu-dent: Satellite.]Oh,yeah .Itcouldgobysatellite .Doesitgothroughtelephonewires?[Student: Waves.]Waves?Yeah,lightwaves .Whatdoesthelighttravelin?What’sundertheground?Well,theyusedtotransmitalldatathroughcopperwires .Anditwaspulses--pulse,pulse,pulse,pulse,pulse--reallyfastthroughthecopperwire .Andit’skindofhardtogetalotofpulsesthroughthesamewirebecausetheyinterferewitheachother,andyoulosealotofthesignalwithdistance .

Well,somebodyelsehadabetteridea .Theysaid,“Let’sputthelightthroughglassfibers .”Soifyouhaveaglassfiberandyoushinelightthroughit,thelightcangothroughthefiber .Butabunchofitshootsoutthewallsofthefiber .Andsoforafibertenfeetlong,you’dhavelittlebitoflightattheend,but

notverymuch .Thensomebodyelsesaid,“Well,you’vegottogetjusttherightsizeoffiber .Ifit’stoobig,itmightnotwork;ifit’stoolittle,itmightnotwork .Ifyougetonethat’sjusttherightsize,thelight,

insteadofshootingthroughtheedges,willbounceinside--boing,boing,boing,boing,boing--anditwon’tloseanyenergyasithitsthewalls .”Itturnsout,itworked .Sowehavefiberopticcablesthatcan

Light from a star can bend as it passes the sun.

Trampoline and bowling ball.

Pencil in glass of water.

Light shoots out through walls of fiber.

Light bounces inside the walls of the fiber, if it’s the right size.

Rock-it Science Teacher’s Guide Bending Light -- Page 8

transmitlightformiles .Andthentheyhaveboostersthatcanmakeitgofurtherandfurther .AndalmostalloftheUnitedStatesnowsendsdatathroughfiberopticcables .Andalmostalltheworlddoes,too .

Ifsomebodycutsthecables,likeataplacewheretheygoalltogethertocoverawholebigarea,liketheSuezCanal . . . Thishappenedlastyear,Ithink .There’saplacehere[points to the Suez Canal on a globe]betweenEgyptandSaudiArabiawhereawholebunchofthefiberopticcablesallgotogetherthroughthatlittlespot .Somebodywentandcutthem .That’snotcool .Andawholebunchofthissectionoftheworldlosttheirinternetconnection .Andwe’regoingtomakesunlightgothroughsomefiberoptickindofstufftoday .We’reluckythatwegotsomenewlaserpenstouseforthis .

Laserpenscanbedangerous .Ifyoushinealaserpenatsomebody’sfaceandtheyturnaroundandlookatyouandtheygetitintheireye,itcantemporarilyleaveablindspotontheireye .[Student: Can it blind you?]It’shardtogetapermanentblindspot .Aclerkatoneofthestoressaid,“Oh,they’renotdangerous .See?”Andheshotitrightinhisowneye .Andhesaid,“Oh,well,maybetheyare .”Haveyoueverhadaflashcameragopoof!rightinyourface?Andthenforawhileyouseethisdot?Whereveryoulook,there’sthedot .Well,that’swhathappenswithalaserpen .Andit’susuallynotpermanentdamage,butyoudon’twanttodoit .Soduringtheexperiment,whenwe’reusinglaserpens,don’tbeshiningthemonotherpeople’sheadsorfaces .Ifyouhappentobounceitoffonsomeone,itisn’tgoingtohurtthematall,buttheyjustdon’tlikeit .

Ifyougotoprisonforsomereason,andyou’reoutintheexerciseyard,justbeingcool,tryingtokeeptheotherguysfrombeatingyouup,andyounoticeareddotonyourchest,theguardshaverifleswithlasersightsonthem .Theydon’thavetolookthroughthelittlebeadsanymore .Theyjustpointthedot .Areddotonyourchestmeansthere’sariflepointedatyou .Andifyou’reoutinthewoodsandyouseeareddotsomewhere,telltheguy,“I’mnotadeer!!”Soit’snotgoodtopointlasersatsomebodybecausetheymightthinkit’sagunpointedatthem .

Ifyoupointalaserintheskyatanairplaneandsay,“Oh,lookitthere!Icanholditontheairplane!”AguyinCampbelldidthis .Ittooktenminutes,andthepolicewereathisdoor .Andtheywon’ttellhowtheyfoundout .Somehowtheycantrackyoudown .Soit’snotagoodideatopointlasersatairplanes .

Well,weneedacrazystory .Thenwe’lldosomeexperiments .[Student: How high up does the plane have to be?]You’vegottobeabletoseeit .You’llfindoutlaterhowharditistoholdalaserinyourhandandaimitatsomething .[Student: How is it dangerous to point a laser at a plane?]Ifthepilotlooksdownatit,andithappenstobeoneofthepowerfulgreenones,you’llblindthepilot .Nowyouhavethisplanegoing [moves hand in a chaotic swerving motion].

The Suez Canal, where cables were cut.

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Story: “Minions with Laser Beam Eyes”Onceuponatime,EvilMisterFredwasonamissiontoimprovehisarmy .Theminions,ofcourse,aren’tverygoodsoldiers .Theydon’twanttoobeyorders,they’renotverysmart,andtheyhavenoarms .Kindofhardtomakegoodsoldierswithnoarms .AndEvilMisterFredhadgiventhembaseballbats,andtheycouldbangeachotherontheheadwiththeirbaseballbatswiththeirmustachesbecausetheyhaveverystrongmustaches .Buthestillwasn’tsatisfiedwiththat .

SohecalledtheAcmeStoreofEverythingandhesaid,“Whathaveyougottomakemyminionsstrongerandmorepowerful?”Andtheysaid,“Oh,isthistheEvilMisterFredspeaking?”Andhesaid,“Yeah,theveryoneandonly .”Andtheysaid,“Nothing .“Hesaid,“Awww,that’snotgood .”Andtheysaid,“Whydon’tyougolookinthelibrary?”SoEvilMisterFredwenttothelibrary .

Andupthereinthelowestdepthsofthelibrary,hefoundsomedustyoldbooks .Heopeneduponeofthebooks,andtherewasalltheseincantationsandstuff .Andhesaid,“Aw,thisiswhatIneed .Yeah!”Andhewasturningthepages .Heturnedoneofthepagesandabighandcameoutandstartedtochokehim .Andhesaid,“Yeah,Ilovethisbook!”Sohecheckeditout .

Hetookithometohiscastle,andhewassittingtherelookingthroughthepages,andoneoftheminionswaswatchinghim .Andhesaid,“Oh,here’sagoodone .It’sallwritteninlatinorsomethinglikethat:Eeny-meeny-chili-beany-hear-the-spirits-speak .”Andhepointedattheminionandhesaid,“Poof!”Andtheminion’shairjustwentpsssshhhh[hair stands on end], andhishairsatbackdown .Andthentheminionlookedathimandhelookeddifferentthanhedidbefore .Hehadredeyes .AndEvilMisterFredsaid,“Whoa,that’sanicetouch .Ilikethat .”

Sohegotawholebunchofminionstogetherandhedidtheeeny-meeny-chili-beanything .Andnowhe’sgotawholebunchofminionswithredeyes .Andhesaid,“Well,atleasttheylookcool .Maybethey’llscareeverybodyaway,andwecanstealtheirmoneythatway .”

Well,hewasouttheregoofingaroundwiththeminions,andtheywerebeingtheirusualbadselves .Hegotreallymadatoneofthem .Andhegrabbedtheminion’sbaseballbatandstartedhittinghimonthefoot--whack!whack!whack!Andthatmadetheminionreallymad .Theminionwastryingtorunaway .AndtheminionlookedatEvilMisterFredandwent,”Arrrrrgggghhh!”Likethat .LaserbeamsshotoutofhiseyesandcaughtEvilMisterFred’smustacheonfire .AndEvilMisterFred,ofcourse,didtheooh-ah-ooh-ahdanceandputhismustacheout .Andthenhesaid,“Nowwe’vegotsomething!Thisisgreat .IfIcangettheminionsmad,they’llusetheirlasereyesandshootwhateverItellthemtoshoot .Ho,ho,ho!”

Evil Mister Fred and minions.

Army of red-eyed minions.

Mustache on fire.

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Sohetriedsomepracticethings .Heendedupwithholesinhiscastle,intheground,minionswithallkindsofflamingbaseballbatsandburnedparts .Sohehadtofindawaytocon-trolthem .Sowhathedidwasheputontheminionsthekindofdogcollarsthatgiveryouashock .Youknow,ifadogbarksordoesthewrongthing,itgiveshimanelectricshock .Andhesays,“Okay,I’vegotitallworkedoutnow .Whenallthemin-ionsarepointedintherightdirection,I’lljustpushthebuttonandpzzzhoom!--laserbeamswillshootoutoftheireyes,andI’lldefeatmyenemy .”Andhehadtojustgetthemtopointalltherightway .Soheembeddedacompassintheirheads,andtheywouldalwaysgetshocksuntilthecompassespointedthesameway,whateverwayhetoldthemtopoint .Nowhehadthisthingworkedout .Hehadtheinvinciblearmy .There’snowayitcouldfail .

Now,overherewe’vegotalake,andthere’sacreaturethatlivesinthelake .It’snameisNessie .Andthere’speoplelivingnearthelakeinacity,likethat .Anddownatthebottomofthelake,there’sabigsteelchamberwithaholeinthebottom .Andthere’ssomewaterinit .AndJackandJillarelivinginthisthing .Theywanttoseehowlongtheycansurviveunder-water,withthepressuredownthere .Theydon’tgettobreatheregularair,becauseifyoubreatheregularair,thenitrogengetsinyourblood,andprettysoonyoustartactingdrunk .Theycallitnitrogennarcosis .AndsoJackandJillarebreathingacombinationofoxygenandheliumgas .Youknowwhathap-penstoyourvoicewhenyoubreatheheliumgas?Yougetarealhigh-pitchedvoice .

SoJackandJillaredowntheretalkinginareallyhighvoicetoeachotherandlookingoutthewindows .Andtheycanjumpthroughtheholeinthebottomandswimaroundinthisbiglake .Andthere’sNessiedownthere .TheytakecareofNessie .[Student: Doesn’t Nessie have a body in the water?]Yeah,Nessiehasabigbodyinthewater .Nessie’sahugedinosaur-lookingthing,andhe’sgotfins . [Student: Like the Loch Ness monster.]Yeah,theLochNessmonster .AndNessieiskindoflikeanamphibian,likeafrogoranewt,butNessiehasscales,likeasalmonorotherkindoffishthathasscales .Andthescalesarereallyshiny .AndeverybodyhasheardaboutNessie,butnobody’sfoundhim,exceptJackandJill .

Now,EvilMisterFred,beingkindofclever,hadsentminionsovertothislake,andtheydiscoveredJackandJill’ssecret:TheLockNessmonsterwasinthislake .AndhewantedtocapturetheLochNessmonster .Butfirst,hehadtogetridofJackandJill .Sohehadhisminionsmarchoverthereearlyone

Minions with dog collars and compasses.

Nessie swimming in the lake.

Jack and Jill’s underwater chamber.

Nessie has shiny scales.

Rock-it Science Teacher’s Guide Bending Light -- Page 11

morningandalllineuparoundtheedgeofthelake .AndhewasgoingtowaitforJackandJilltocometothesurface .Hewasgoingtohavehisminionsjustlookatthemandpzzzhoom!--burstintoflameswiththeirlaserbolteyes .

Now,Jackwasoutswimmingthere,andheswamupandgotonNessie’sneck,andhewasridingNessiearound .Andthemin-ionswereallthere .AndJacknoticedtheminions .Can’tmissthoseguys .Andhesaid,“Whoa!Redeyes!”Andtheminionsasusualweregoofingaround .LuckilyforJack,oneminionwashittinganothermin-ionwithabaseballbat,andlaserbeamsshotoutofhiseyes--pzzzhooom!--andhitthewater,bouncedoff,andintotheair,likethat .Jacksaid,“Whoa!”anddoveintothewaterandwentbackdown .

Hesaid,“Jill,there’sminionsoutthere .They’vegotredeyes,andtheycanshootlaserbeamsoutoftheireyes!”AndJillsaid,“Right,Jack .Whathaveyoubeeneating?”AndJacksaid,“Nothing .Yougolook .”AndJillswamtothesurface .AndEvilMisterFredspottedJill,andhesaid,“Ready,getset,fire!”Andpzzzhooom!--theycaughtJill’shaironfire .Itjustexploded .AndJillsaid,“Whoa!”andswambackdown .NowJackandJillaretrappedinthelake .IfyouwereJackandJill,whatwouldyoudo?

Jack riding on Nessie’s neck, while minion’s laser beam bounces.

Imagination and Brainstorming Time[Students make suggestions](THEREARENOWRONGANSWERS!Whatevertheysay,youshouldreply:“That’sagoodidea,”“Theymightdothat,”etc .Afterbrainstorming,proceedwiththeexperi-ments,thenfinishthestory .)

We’llleavethis“TobeContinued . . .”

Rock-it Science Teacher’s Guide Bending Light -- Page 12

Experiment: “Bending Light”Well,weneedtodosomeexperiments,andwe’vegotnewlaserpensthatactuallywork .They’renotreallypowerful,butasIsaid,youhavetoprotectyoureyesfromthem .Don’tshinethemonotherpeople’sfaces .Wewanttofindoutifwecanmakethelaserbeambendalittlebit .Andwealsowanttocreateamicroscopeoutofthelaserbeam .Andthatwouldbekindofodd .Alaserbeam,whenitgoesthroughair,staysrelativelysmall .Whenit’sclosetotheboard,it’sthatsize[shines beam on whiteboard from a few inches away].Asyougetfurtherandfurtherandfurtheraway,itdoesn’tgetmuchbiggerinsize[backs away from board, keeping beam shining at the same spot],butyoucanseethatitslowlygrowslarger .Wewantittogetbigfast .Ifyoushinethelaserthroughalens,it’llbendthelight .That’scalledrefraction[shines beam through a small lens toward the board, creating a larger area of light].Andanyimperfectionsthatareinthelenswillshowupontheboard .[Student: Would a fingerprint show up?]Let’ssee[puts his finger on the lens to leave a fingerprint, then shines the beam through it].Itkindoffuzzesitoutalittle,butthat’sitprettymuchthroughafingerprint .

Wewanttobeabletoexpanditsothatit’sbig .ItwouldshowupbetterifIturnedoutthelights .I’mgoingtoswitchoffthelights [lights off].Nowyoucanseetheimperfectionsintheglass .Youtrytofindaspotwhereit’snottoomessedup,andyou’regoingtotapethelensontothepenatthespotwhereit’sbestforyou .Ifyouhaveabiglenslikethis,tryingtotapeitontothelaserbeamisachallenge .We’regoingtogiveyousomescotchtapeandalaserpen .We’llgiveonelaserpentoeachgroupoftwo,andonelenstoeachgroupoftwo .

Firstyou’regoingtoshineitaroundandseewhatthelaserdoesonvariousthingsintheroomwhenIturnoffthelights .Then,whenyougetthatoutofyoursystem,you’regoingtoputthelensontheendofit,andthenwe’regoingtogiveyousomestuff .Andyou’regoingtoputstuffinthelightbeamandseewhathappens .

Shining the beam on the whiteboard from a distance, it’s only slightly larger.

Close up, the beam is small.

Shining the beam through a lens bends the light, making the beam wider . . . . . . like this.

Rock-it Science Teacher’s Guide Bending Light -- Page 13

Someofthestuffthatwehaveisapieceofscreendoorscreen .Andwehaveaboxofoldmicroscopeslides,someofwhichhavebecomedroppedbystudentssothatthere’ssomerazor-sharpedges .Thisisalwaysgood .Inthecenter,there’salittlepanelwithsomethingonit .Likeonehasalocustwing,onehasabeeantenna,onehasabutterflyscale,andyou’rego-ingtotrytomakethembigenoughsothatyoucanseethem .[Student: I didn’t know butterflies had scales.]Yeah,butter-flieshavescalesontheirwings .AndthereareguysinJapanwhomakepictures,elaboratebeautifulpictures,bytakingthescalesoffoneatatimeandstickingthemontoricepaper .Theproblemis,youcanonlyseethepicturesunderamicroscope .[Student: They take it off a live butterfly?]Adeadbutterfly .

Sofirstwe’llhandoutthelaserpens .Soyouguyschooseapartner[hands out pens to each group of two students].Andwe’llturnoffthelights[lights off]. [Students shine lasers on various objects in the room.]Andifyou’reholdingitinyourhand,nowhandittoyourpartner .

[After a few minutes]Trypointingitatyourfingerandseeifyoucanseeanythinginsideyourfinger .

[Lights on. Instructor passes out lenses, one for each pen.]Here’sthelens .Thesehaveafairlylargeradiusonthemsotheyspreadthelightwell .Now,justholdthelensupandtaketurnsshiningthelightthroughthelensandseewhatitdoes .[Lights out.]

Nowweneedtotapethelensesontothepens .[Lights on. Instructor passes out cellophane tape.]Trytotapeitoninsomewaysothelaserlightdoesn’thavetogothroughthetape .Itwoulddiffusethelight .

Nowwehaveapieceofscreendoorscreen .[Instructor passes out pieces of screen.]Haseverybodygotalensontheirpen?[Students: Yes.]I’llmakeiteasierforyou .[Lights off.]Trytomakethescreenbig .[Students shine the laser through the lens with the screen in front of it.]Nowsendyourpartneruptotheboardtolookatyoursandseeifthescreenlookssharpthatway .Ifyoulookcloselyatthelines,there’sapattern

betweenthelinesthatwewantyoutosee .Andthentradeplaces .Theonewhowentuptotheboardtolookatit,goholdit,andlettheotherpersongoupandlookatit .

[After a few minutes.]Okay,everybodysitdown .We’regoingtotradeyouamicroscopeslide .[Lights on.]Bytheway,whenyouwerelookingatthesquares,youprobablydidn’tseeperfectlyblacklines .Ifyoulookedcarefully,youwouldhaveseenshadowslikewavesbouncingoffofwallsinsidethelines .

Laser pens

Taping lens onto pen.Piece of window screen.

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[Draws diagram of lines.]Theseextrawavesarecalleddiffraction .Diffractioniswhensomethingelsehappensweird .

[Instructor passes out microscope slides, which include a leg of a honeybee, the antenna of a butterfly, a bee abdomen, a locust wing, a bee antenna, a butterfly wing, a praying mantis leg, a butterfly scale, a

butterfly leg, etc.]Ifyoudropitonthefloor,itwillbreakintosmallpieces,andthenitwillbehardtofind .Ifyouhavetodropit,dropitonthetable .Now,theobjectiveistomakewhatever’sontheslidelookreallybig . [Lights off. Students shine laser through lens and microscope slide, projecting image on whiteboard.]

[Lights on.]Okay,nowyoucantakethelensoff .Here’sacup .Haveonepersoninyourgroupcomeovertooneofthesebucketsandputwaterinthecup .Don’tputyourlaserpensinthewater .Theydon’tworkifthey’reallwet .[Lights off. Students shine lasers into the water.]Now,youshouldbeabletoseethebeaminthewater .Tryitfromdifferentdirectionsandseeifyoucangetittobendortocurve .Whileonepersonshines,havetheotherpersonlook,becausesometimesthelightlookscurved .Dependsonwhichdirectionyoulookfrom .

[Lights on. Instructor hands out fiber optic tubing.]Don’tbreakthemintopieces .Theyworkbetterifthey’rethesamesizeaswhenIhandthemtoyou .They’refragile .They’renotglass;they’replastic .[Students shine lasers through the tubing. Then they direct the light from the tubing through the glass of water.]

Diffraction patterns from screen. Diagram of diffraction patterns.

Microscope slides.

Projection from microscope slide.

Laser beam in water.

Flexible acrylic tubing.

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[Instructor turns on fog machine.]Ifthefogmachineshootsoutfog,don’tstanddirectlyinfrontofitbecauseit’shot .Okay,youcangooverthereandshineyourlaserbeaminthefog .[Students shine lasers through the fog.]Ifyouwiggleyourbeamreallyfast,youshouldseeturbulenceinthefog .

[Lights on.]Okay,youcanputthelaserpensbackinthebox . [Instruc-tor collects pens and tubing and has a student collect slides and tape dispensers.]Takeyourwateranddumpitbackintothewaterbucket .

Soyousawalittlebitabouthowfiberopticsworkandsawthelightstravelinsideofyours .Yourslookedbrightbecausealotofthelightwasgoingoutthroughthewalls .Regularfiberopticsdon’tletlightgooutthroughthewalls .Yousawthatitcanmagnifysomethingbyputtingalensonitandholdingitclosetothelens .Yousawhowlightcanbendwhenyouputitthroughwaterlikethat,andhowitcanlightupthefog .

Laser beam shining through flexible tubing.Laser beam showing turbulence in fog.

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End of Story * DO NOT * present this part of the lesson until after the experiments!Nowweneedacrazyendingforourstory .Itturnsout,theLochNessMonsterisafire-breathingmonster .Andhe’sgotscalesthatarelikemirrors,andhistailislikeafiberopticfiberthatcanhavelightgoinoneplaceandcomeoutsome-whereelse .SoJackandJillsaid,“Hey,Nessie,we’vegotajobforyou .Seethoseguysontheshorewithlaserbeameyes?They’dlikeyoutocomeandtalkwiththem,ormaybeplaygameswiththem .”AndNessiesaid,“Oh,boy,let’sseewhathappens .”

SoNessieswamupandsaid,“Hi,guys,howyadoing?”AndEvilMisterFredsaid,“Ah,themonster .Well,Ireallyshouldn’tshootthemonster .”AndthenJackpoppedupabovethesurfaceandhesaid,“Hey,what’sup?”Hewaswavinghishandaround .AndEvilMisterFredsaid,“Gettheguy!”Andhepushedtheircollars,andalltheminionswent,“Aaaahhhh!”andgotshockedlikethis .Theyweretry-ingtoshootlaserbeamsatJack .Well,it’shardtopointyoureyesstraightwhenyou’rescreaming,likethat .Andlaserbeamsaregoingallovertheplace,andNessieabsorbedsomeofthemwithhertailandshotthembackattheminions .Shehadminionswithmustachesonfire .Sheletsomeofthembounceoffofherscalesintotheair,andshewasshootingsomeflamesoutjusttokeepthemjumpingupanddown,justtoseewhattheywoulddo .

Sonowtheminionsarereallyunhappybecausethereareflamesonthem .Andshewasgoingwhoooom-mm!Andtheyweren’tpayingattentiontowheretheywerelooking,andshejustjumpedupoutofthewater .SonowyouhaveagiantNessieoutofthewater .She’sgotalongtail .Shehasfinslikeawalrus .Andthelaserbeamswereshootingalloverher,andsheconcentratedawholebunchofthemthroughhertailandshotthemoutstraightforwardatEvilMisterFred .AndthenshewarmedupEvilMisterFredwithsomeflamesjustbecausehe’ssuchaniceguy .Andthecastlebecamered-hot,andthelastthingtheysawwasEvilMisterFredrunningandjumpingandhoppingoverthehorizon .Andtheyalllivedhappilyeverafter,exceptEvilMisterFred .

End of LessonIf y0u have questions about this lesson, please ask them through the online Teacher Support Forum on our web site.

Nessie breathes fire.

Nessie jumps out of the water and shoots laser beams at Evil Mister Fred.

Beams bounce off Nessie’s scales and set minions’ mustaches on fire.