Contents: Quick Reference Sheets:

• Intro: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .page2• Demo: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .page3• Experiment:Polarized Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .page4• EquipmentList . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .page5• Story,Part1:Jack & Jill and the Minion Squids . . . . . . . . . . . . . . . .page6• Story,Ending . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .page7

Video Transcript:• Intro: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .page8• Story,Part1:Jack & Jill and the Minion Squids . . . . . . . . . . . . . . . . page9• Demo: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page11• Experiment:Polarized Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .page13• StoryEnding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .page14

Teacher’s Guide for:

Polarized 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.

PolarizedLightARock-itScienceLessonFilmedJuly,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) 2013 Rock-it Science Educationally Useful Programs. All Rights Reserved

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

Intro Quick Recap:

• What’sapole?Ifsomeonehitsyouwithapole,doyoubecomepolarized?• Youcanpolarizelight .• StudentandInstructorholdoppositeendsofalong,flexiblespring .Instructorrotatesitlikeajumpropetocreatewaveforms,goingfasterandfasterforthevariouscolors .

• Redlightmakesaslowwavewithonehump;Orangemakestwohumps;Yellowmakesthree;Greenmakesfour;bluemakesfive,etc .

• Lightisamixtureoftwokindsofenergy:magneticandelectrical .• Electricalenergygoesupanddown;magneticgoessideways;andwhenyouputthemtogether,itgoesroundandround .

• Blackhasnoenergy--itdoesn’tmove .Whiteisacombinationofallthecolors,soitmovesinalldirections .

• Polarizedlightisjustawaylightvibrates .Itcanbepolarizedsideways,tallways,andatanangle .• Whenwepolarizelight,itchangesthewayitacts .

Student holds one end of a long flexible spring while Instructor twirls it.

Rock-it Science Teacher’s Guide Polarized Light -- Page 3

Demo Quick Recap:

• Instructorholdsupaframewithsomekindofascreenmountedinitdiagonallyandwalksaroundsostudentscanseeitcloseup .Itjustlooksgrey .

• Instructorflipsthescreenover,anditstilljustlooksgrey .• Instructorholdsapolarizingfilter(“sunglassmaterial”)infrontofhisface .Asksifstudentscanseehim .Yes .

• Rotatesfilter90degrees,andstudentscanstillseehim .• Flipsfilterover,andstudentscanstillseehim .• Instructorputsthefilterinfrontoftheframeandwalksaroundsostudentscanseethattheframecontainsanimageofawomanwithastopsignandsomechildren .Ashewalks,hemovesthefilterupanddowntoshowtheimagewithandwithoutthefilter .

• Askstudentwhatcolorwasthewoman’sdress .Black .Walkpastagainsostudentscanverifyit .• Instructorclaimsthedressisreallywhiteandprovesitbyturningthefilter90degreesandput-tingitinfrontoftheimage .

• Holdthefilterinfrontofalaptopscreenandshowithidesorrevealsthescreen,dependingontheangleofthefilter .

• Instructorholdsafilterinfrontofhisfaceandstudentscanseethroughit .Thenheholdsasec-ondoneaboutafootinfront,rotated90degrees,andtheycan’tseethrough .Thentheassistantplacesathirdfilterbetweentheothertwo,rotatedat45degrees,andtheInstructor’sfacebe-comesvisibleagain .

• Instructorholdsaclearplasticfoodcontainerabovethestudents’headssotheycanlookupthroughitattheceilinglights .

• Thenheholdsafilterjustbeneaththecontainerandwalksaround,andstudentscanstillseethroughit .

• Thethirdtime,anassistantholdsasecondfilterbelowthecontainerwhiletheInstructorholdsoneaboveitandrotatesthefilterbackandforthwhilethestudentslookupthroughitatthelight .

• Askthestudentswhethertheyseeanything,butkeepitasecret .

Framed image without filter. Framed image with filter.

Rock-it Science Teacher’s Guide Polarized Light -- Page 4

Experiment Quick Recap:• Giveeachstudentastickofwoodandtwoplasticclips .Havethemglueonecliptoeachendofthestick .

• Thengivethemtwosmallsquaresofpolarizingfilter,oneforeachclip .

• Havethemmovethefiltersaroundtomakethemlookdarkandlight .

• Thenhavethemlookupattheceilinglightstoseewhatcolortheyappeartobe(purple) .

• Askiftheyseeanyrainbowsanywhere .Iftheylookatsomethingplastic,theymightseesome .

• Giveeachstudentaclearplasticspoonsotheycantrytoseetherainbowsinitwiththeirfilters .

• Havestudentswritetheirnameontheirstickwithper-manentmarker .Studentsgettokeepthedeviceandthesmallfilters .

Looking for rainbows in a plastic spoon.

Rock-it Science Teacher’s Guide Polarized Light -- Page 5

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

• Spring,LongandFlexible• Polarizedpictureinaframe• Polarizedplasticsheets,about8”x10”(3)• Laptopcomputer• Plasticclamshellcontainer(half)

Items needed for Students:

Consumables (per 4 students):

• PieceofWood,approx .1/4”x1/2”x6”• PlasticSwivelClip,2perstudent• Polarizingfilters,approx .2”x2”(2perstudent)• ClearPlasticSpoon• GlueStickOther:

• GlueGun• Markers,ColoredPermanent

Prep Work:

• Cutwoodpieces1/4”x1/2”x6”• Cutpolarizingfilters2”x2”

Long flexible spring.

Polarized Picture.

Gluing plastic clips onto wooden stick. Looking through two filters.

Story Recap: “Jack & Jill and the Minion Squids”

Rock-it Science Teacher’s Guide Polarized Light -- Page 6

Part 1:

• EvilMisterFredhastransformedhimselfintoaman-eatingsharkwithalaser-guidedbazookaonhisback .

• Hisminionsaresquidwithbaseballbats .• JackisagrapejellyfishandJillisanoctopus .• They’reherdingmackerel,whichtheycallmacaronifish,leadingthemtoFloridaforavacationatDisneyWorld .

• EvilMisterFredsneakeduponthemandateabunchofthemacaronifish .• JackandJillandthefishstartedswimmingasfastastheycouldtogetawayfromEvilMisterFredandfindsomeplacesafe .

• NearFlorida,there’saledgethatsticksoutintotheGulfofMexico .JackandJillwaitedthereanddecidedtocalltheAcmeStoreofEverythingandordersomethingtheycouldputintheway,sotheycouldgetthroughbutEvilMisterFredcouldn’tgetthrough .

Story Recap (cont.)

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

Ending:

• JackandJillbuilttwofences,onemadeofverticalslatsandtheothermadeofhorizontalslats .• WhenEvilMisterFredtriedtogetthrough,hegotcaughtinthefence .• TheminionstriedtobreakthefencewiththeirbaseballbatsandaccidentallyhitthefiringtriggeronEvilMisterFred’sbazooka .

• ThelaserbeamwaspointeddirectlyatJack’shead .Astheprojectilecametowardhim,heputhisheaddown,andthelaserwasreflectedoffthemirroredtopsurfaceofhisjellyjar .

• SincethelaserwasreflectedbacktowardEvilMisterFred,theprojectileturnedaroundandhitEvilMisterFredbetweentheeyes .

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

Transcript: Introduction

Doyouknowwhatapoleis?[Student: It’s a long rod.]Yeah,youputaflagonapole .Youcouldputabirdhouseonapole .Whatelsecanyoudowithapole?AreallpolesfromPoland?No?Ifsomebodyhitsyouwithapole,doyoubecomepolarized?Well,itturnsout,youcanpolarizelight .Polarizemeans--IguessIcouldshowyoumoreeasilythanIcouldtellyou .SoIneedaspring .Icanshowyoupolar-izedlightonaspring .[Takes out a long flexible spring. A student stands on the table, and the Instructor stands at the opposite end, each holding one end of the spring.]Youholdwithbothhandsanddon’tletgo .You’rejustgoingtoholdwithbothhandsanddon’twiggleyourhands .

Regularlighthasdifferentappearances .Redlightisabiglazywave,likethat .[Rotates the spring like a jumprope, spinning it faster and faster to represent each color.]

Orangelighthastwohumps,likethat .Yellowlightwouldlooklikethreehumps .Abrightlightwouldbebighumps,anddimlightwouldbesmall .Greenlightwouldhavefourhumps .Lightisamixtureoftwokindsofenergy .Onekindofenergyismagneticenergy,andtheotherkindiselectricalenergy .Theelec-tricalenergygoesupanddownlikethis .Themagneticenergygoessidewayslikethat .Whenyouputthemtogether,itgoesroundandroundandroundtomakewhatwecalllight .Bluelighthasfivehumps .[Student: How many humps does black have?]Oh,Icanshowyoublack .Sothat’smostofthecolors .Youcanjustseeasyougodowntherainbow,yougetmoreandmorehumps .You’vegottowatchverycarefullytoseeblack .[Gradually stops rotating the spring until it’s almost still.]Areyouready?It’sgo-ingtohappenquickly .Ready,getset,go!Didyouseeit?[Student: It doesn’t move at all.]You’reright!Blackhasnoenergy,soitdoesn’tmove .[Student: What about white?]Wewanttodowhitelight .Whitelightisamixtureofred,orange,yellow,green,blue,andviolet--everything .[Speaking to student hold-ing the spring]Youshakeyourend,I’llshakemyend,andthat’sgoingtobewhitelight .[Student and teacher shake the spring in different directions, creating a chaotic pattern of humps.]Thisiswhitelight .Okay,youcanstop .

Student stands on table and holds one end of spring while Instructor twirls the other end.

Rock-it Science Teacher’s Guide Polarized Light -- Page 9

Sopolarizedlightisjustawaythatlightvibrates .Polarizedlightcanbepolarizeddifferentways .Itcanbepolarizedsideways [swings spring from side to side];itcanbepolarizedtallways[swings spring up and down];itcanbepolarizedatanangle[swings spring diagonally]betweentallwaysandsideways .Andwhenwepolarizelight,itchangesthewayitacts .Todaywe’regoingtodosomeexperimentswithpolarizedlight .[Stops moving spring and instructs student to let go and sit down.]

Onceuponatime,therewasanocean .Andtherewasavi-ciousman-eatingshark .Theyusuallyhaveaneye,likethat .Andthey’vegotsomegills .Andtheyhaveafinthatsticksuplikethat .Andtheyhaveatail,andprobablyvariousotherfins .Andthey’vegotlotsofteeth .Andthissharkcarriesabazookaonhisback .Andalaser-guidedsystem,likethat .Andhegoesoutthroughtheocean,searchingforthingstokill .It’shisjob .Andhe’sgotamustacheandahat .He’sanEvilMisterFredshark .EvilMisterFredfoundacardboardboxthatsaid“transmogrifier”onit .Andhejumpedintotheboxandsaid,“Iwonderwhatthisboxdoes .”Hejumpedinandpoof!--turnedhimselfintoashark .AndthenhecalledtheAcmeStoreofEverythingtogettheunderwaterbazookawiththelaserguid-ancesystem .

Andnowhe’szoomingallovertheplace,buthemisseshisminions .Andheneedssomesortofaminionthingthatcanswimasfastashimbutthat’skindofdumb .Sohegotsomesquid .Squidminions .There,squidminions,allovertheplace .Oh,yeah,theyneedbaseballbats,huh?[Student: No, get them spearguns.]No,they’dkilleachother .They’reonlygoodwithbaseballbats .There .Therearesquidsallovertheplace,followingEvilMisterFredaround,terrorizingtheocean .

AndJackandJillweredownthere .WhatshouldJackandJillbeturnedinto?Jellyfish?Okay,JackandJillarejellyfish .Jackisagrapejellyfish .He’sajarofgrapejelly .Andhemusthaveatailofsomesort,andheneedssomeclaw-likehandsfromacrab .AndJillcanbesomethingdifferentbecause,youknow,youcanbeanythingyouwant .Okay,Jillcanbeanoctopus .[Draws an octopus with long curly hair.]Oh,Jackneedstohavehair .[Adds short straight hair to the grape jelly jar.]There .

AndJackandJillareherdingmackerel .Buttheycallthemmacaronifish .Soyouhaveallthesemacaronifish,liketubes .

Story: “Jack & Jill and the Minion Squids”

Evil Mister Fred as a shark.

The minion squids.

Jack as a grape jelly fish, Jill as an octopus.

Rock-it Science Teacher’s Guide Polarized Light -- Page 10

They’retakingthemacaronifishforavacationinFlorida .They’vebeenupbyAlaskawhereit’sreallycoldandtherearelotsofwhales .They’regoingtogotoFloridaandgotoDisneyWorld .EvilMisterFredischasingafterthembecausehelikesmacaroni .Andhewantstozoomthroughthereandjustswallowthemallup--arrrrrgh!AndEvilMisterFredcamezoomingby,andoutfrombehindsomealgaeandsomerocksandsomeseaweed,andka-chonk!--ateawholebunchofmacaronifish .AndJackandJillsaid,“Ohh!EvilMisterFred,how’dyougetdownhere?Whatareyoudoing?”EvilMisterFredsaid,“Justcametomakeyourdayalittlebitmoreenjoyable .”AndJackandJillsaid,“That’snotenjoyable .Youjustatesomeofourfriends .”AndEvilMisterFredsaid,“Buurrp!Yep,they’regood,too .”

AndJackandJillstartedtorunasfastastheycould,totrytoswimawayfromEvilMisterFred .Andtheywentoverhillsanddownintodales,throughportholesinsunkenshipsandeverywheretheycouldgo,tryingtogetridofEvilMisterFred .AndEvilMisterFredfollowedthemwherevertheywent .AndJackandJillsaid,“We’vegottogosomeplacethat’ssafer,someplacethatEvilMisterFredcan’tgo .”OnthewaytoFlorida,FloridamakeskindofaledgethatsticksdownintotheGulfofMexico .Andtheysaid,“We’llcalltheAcmeStoreofEverything,andwe’llputsomethinginthewaysowecangetthroughandEvilMisterFredcan’tgetthrough .”IfyouwereJackandJill,whatwouldyouputinthewatertostopthatEvilMisterFred?

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

Andwe’regoingtoleavethis“Tobecontinued . . .”

Macaroni Fish.

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

Demo:Herewehaveathing[holds up a frame with a gray screen mounted on it diagonally, so part of the background is transparent.] [To camera operator]Whatdoyouseethroughyourlens,bytheway?[Camera operator: I can see my reflection in the dark part, and I can see through the light part.]Okay,good .Now,I’mgoingtoshowyouthis,andyoutellmewhatyousee[walks around the table so each student can get a close look. Some students think there’s a picture but can’t describe it ac-curately.]Nowontheotherside,whatdoyousee?[Flips over the frame, showing the back of the grey frame. Students don’t see anything.]

Nowwe’regoingtotakesomestuff,magicalstuff .[Instructor pulls out a polar-izing filter and holds it in front of his face.]Here’ssomesunglassmaterial .Whenyoulookthroughthis,whatdoyousee?[Students: You.]Okay .[Rotates filter 90

degrees.]Doyoustillseeme?[Stu-dents: Yes.] [Flips filter over.] Doyouseemenow?[Students: Yes.]Okay,I’mgoingtoholdthis[filter]infrontofthis[framed screen],andthenyoutellmeifyouseethepictureornot .[Instructor walks around with the filter in front of the screen so students can see it close up, and they all see the picture of a female crossing guard with some children. As he goes, he also moves filter up and down to show the framed screen with and without the filter on it.]

Now,whatcolorwasthedressthattheladywaswearing?[Students: Black.]Wouldyoubetyourpar-ents’caronthat?[Students: No.]You’resupposedtosayyes .Youguyswererightthere .Youwitnessedthispicturerightinfrontofyourveryface,you’reeyewitnessestothecrime .Aladyinthecrosswalkwasthrowingchildreninfrontofpassingbuses .Wasshewearingablackdress?[Student: She was not.]Howdoyouknow?[Student: She was holding a stop sign so the children could cross at the crosswalk.]I’mgoingtocomebyagainquickly .Whatcolorisherdress?Isitgreen?Isitpurple?Isitorange?Eye-witnesses,somepeoplesayit’swhite,somepeoplesayit’sblack .

Now,I’mthejudge,I’mthejury,andI’mtheexecutioner .Isayshewaswearingawhitedress,andyou’reallwrong .Ha,ha,ha!AndIcanproveittoyou--there![Puts the filter in front of the picture again, but turned sideways, and walks around with it.]See?It’sawhitedress .[Student: You switched it!]Itturnsoutyouwereright .AndsomebodyelseobservedthatIturnedthismaterial .Okay,sothisone[the picture in the frame] stayedthesame, [and other one changed.]

Grey screen in a frame.

Sunglass material.

Image in frame with Polarizing Filter in front.

Rotate the filter and the dress looks white.

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

[Instructor holds a polarizing filter in front of a laptop computer to show how the computer screen becomes invisible and then visible again as the filter is rotated.]

[Instructor takes out another filter and holds it in front of his face.]Okay,canyouseeme?[Students: Yes.]Canev-erybodyseemyface?[Takes out another filter.]IfIputthisoneupinfrontofmyface,willyoustillbeabletoseeme?[Students: Yes.]Okay .Putssecondfilterinfrontofthefirstone .Doyoustillseeme?[Students: Yes.]Okay,nowareyouready?[Rotates the second filter 90 degrees, which blocks out his face, then rotates it back again, making him vis-ible.]Okay,soIcanturnmyselfonandoff .

Now,I’mgoingtoturnmy-selfoff[holds first filter close to his face and the second one about a foot in front, rotated 90 degrees].YoucanseeI’moffhere .Nowmyassistantisgoingtoputanotheroneinbetweenmytwoandseeifhecanmakemereappearagain .[Assistant places a filter between the other two, at a 45-degree angle, and instructor’s face is visible again.]ThereIam,[assistant removes third filter]andthereIgoawayagain .

Soyoucanmakethingsappearanddisap-pearwithpiecesofplastic .Andyoucanmakethemchangefromblacktowhiteorwhitetoblack,ifyoudoitcarefully .Youcandoitoncomputerscreens .Italsodoessomethingelse .[Picks up a clear plastic food container and holds it above a student’s head so he can look through it to the lights in the ceiling.]Whatdoyousee?[Student: Lights.]Doyouseeanyheavy?

NowI’mgoingtoholdupthis--it’scalledapolarizingfilter .I’mgoingtoholdupapolarizingfilter[holds filter just beneath

Left: Filter in front of computer screen. Right: Filter rotated.

Using two filters to block out face.

With a third filter between, he reappears.

With one filter above the plastic container and one underneath, you begin to see rainbows in the plastic (see red circle).

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

[Note: Part of the video is missing here, where the Instructor describes how to build a device that will allow students to manipulate polarizing filters. The video picks up with the students gluing two plastic clips to either end of a stick of wood.]

Whenyourglueishardandwhenyou’resittingtheremoreorlessquietly,we’llgiveyoutwoofthesepolarizingfilters .[Each students receives two 2”x2” filters and puts one in each clip.]Afteryougetyourpiecesandfiguredouthowtomakeitlookdark,thenlookatthelightsupaboveandseewhatcolorthoseare .[Students: Purple.]Aretheymaple-surple-purpleorplainpurple?Doyouseeanyrainbowsanywhere?[Most students say: No. One student says: On that plastic ball.]Ah!That’swhatIwashop-ingsomebodywouldsay .Somebodyelsenoticedtherewererainbowsintheplasticball .

Haveyounoticedthatwhenyouleastexpectit,itstartstorainspoons?[Tosses a bunch of clear plastic spoons onto the ta-ble.]Grabaspoonandfindtherainbow .Canyouseerainbowsinyourspoon?[Students: Yes.]Rainbowsallovertheplace .[Student: If you look up at the light, you see more rainbows.]

[Instructor passes out permanent markers so students can write their name on their stick of wood. They get to take home the device, including the two filters.]

Experiment: “Polarized Light”

the plastic container and passes them above the students’ heads].There--whatdoyousee?[Students: Light.]

Okay,nowwe’regoingtousetwoofthese .We’regoingtobringthesamethingby .Myassistant’sgoingtoholdhisperpendiculartomine,andwe’regoingtowalkaroundandseewhatweseewhenwecomeoveryourhead .[Assistant holds one filter below the container; Instructor holds another one above it and rotates the filter back and forth while holding it over each student’s head.]Doyouseeanythingwhenwedothis?[Student: Yes.]Don’ttell,it’sasecret .Noonemustknow .

Gluing the plastic clips onto the stick of wood.

Manipulating the filters.

Rainbows in the plastic spoon.

Rock-it Science Teacher’s Guide Polarized Light -- Page 14

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

[Note: Part of the video is missing here. In the story, Jack and Jill have built an underwater fence made of vertical slats, and another one in front of it made of horizontal slats. The Evil Mister Fred shark and his minion squids can’t get through it. When Evil Mister Fred tried to get through, he got stuck between the two fences.]

Theminionsquidsstartedgoingbang,bang,bang,bang,tryingtobreakthefence .Buttheycouldn’tbreakthefence .Andminions,they’renotreallyskillfulwiththeirbaseballbats .Asthey’rebangingaround,tryingtofreeEvilMisterFred,oneofthemaccidentallyhitthefiringtriggeronhisbazooka .Andthebazookawentbooozzzzhhh!Anditshootsoutunderwaterrockets .Andtherocketsfollowthelaserbeam .ThelaserbeamwaspointedstraightatJack’sgrapejellyhead .AnditlookedlikethiswasgoingtobetheendofJack .Andthethingwentshootingforwardathighspeed,andJacksaid,“Uh-oh!”Hesawabazookathinghithimrightbetweenhiseyes .Hesays,“No!”andheputhisheaddownlikethis .Thetopofhisjarhadamirrorfinishonit,andthelaserbeambouncedoff--ba-jinggg!--andpointedrightbetweenEvilMisterFred’seyes .Andthebazookathingsaid,“Where’ditgo?Where’ditgo?”Itturnedaroundandsaid,“Oh!Thereitis!”Ba-zhooom!Crash!AndthatwastheendofEvilMis-terFred .Everybodylivedhappilyeverafter,exceptEvilMisterFred .

[Student asks a question off-camera about the fence and the filters.]Oneofthemwasupanddown .Oneofthemwassideways .Whenyouhavethemlikethis,youwatchthelightanditlooksblack .Onlythetiny,tinywavesofultravioletcangetthrough .Whenyouputsomethinginthemiddle,ithelpsthembendsothenyoucanseetherainbowcolor .

End of Story * DO NOT * present this part of the lesson until after the experiments!