Engineering Quarterly Summer 2022

WELCOME!

TheEngineeringQuarterlyispublishedfour timeseachyearbythe HammSchoolofEngineeringattheUniversity ofMary.Ineachissue, wetrytoincludearticles fromeachofthefivemajorsweoffer:ElectricalEngineering,MechanicalEngineering, CivilEngineering,ComputerScience,and ConstructionManagement.TheintendedaudienceoftheEngineeringQuarterlyincludes engineers,engineeringstudents,engineering alumni,futureengineeringstudents,andpeopleworkinginfieldsrelatedtoengineering suchasscience,computing,andmathematics.

Inthisissuewedescribeourstudent designprojects,newfaculty,newbuilding, scholarships,andserviceactivities.Asusual, wealsoincludesomeproblemsfromour coursesthatyoumightliketotry.Enjoy!

Dr.TerryPilling Dean

ORDINATIONOF FATHER ATHANASIUS

OnJune12,2022,atSt.George AntiochianOrthodoxChristianCathedral, ourelectricalengineeringprofessorDeacon DamianOweiswasordainedtotheHoly Priesthood.HisnameisnowFatherAthanasiusOweis.

NEW FACULTY

ItisverygratifyingfortheHammSchoolof Engineeringtohaveaprofessorwhohasalso beenordained.WeareveryproudofFather Oweisandhopethathispresenceasapriest willfurtherintegratethereligiousandcultural educationofourstudentsaswellasprovidean inspirationtohisfellowfacultymembers.

Assal

AssalHaddad joinsourfaculty thisfallasProfessorofCiviland EnvironmentalEngineering.Assal receivedhisPh.D. inEnvironmentalEngineeringattheUniversityofCentral Floridain2011withthesis Assessmentofthe UseofVegetativeMulchasDailyandIntermediateAlternativeLandfillCover;hisM.S. inCivilEngineeringattheJordanUniversity ofScienceandTechnologyin2004;andhis B.S.inCivilEngineeringattheJordanUniversityofScienceandTechnologyin2001. HiscurrentresearchinvolvesSolidWaste Managementandlocalenvironmentalissues suchaswasteopenburning,evaluatinglocal landfillsthatarenotproperlyengineered,and socialenvironmentalawarenessandbehavior. BeforejoiningtheHammSchoolofEngineering,AssalwasaprofessorintheApplied ScienceUniversityintheCivilEngineering Department.Hishobbiesincludeplayingthe guitar,thepiano,andlearningtoplaythe drums,and“denyingthatnowthatIamover 44Iwillneverbearockstar.”AssalisinterestedintheprogressachievedinArtificial Intelligence.“Iamalwaysamazedabouthow closetheygottoimitatingandpredictinghumanbehavior.Iamobsessedwithhowthe Facebookalgorithmworks,thatIcannever reallyenjoythenewsfeedonFBbecauseIam toobusyanalyzingwhythealgorithmchose toshowmethisspecificadornewsbitatthis specifictime.”

neuronfiring.“Arthasalwaysbeenahobby ofmine.Ipaint,sketch,andcreatedigital artonatablet,usuallymakingportraitsor abstracts.Youmayseemedoodlingwhile thinkingabouttechnicalideasasithelpsme focus.IhavealsobeendoingCrossFitfortwo yearsnowandwillmorethanlikelyworkit intosomewordproblemsformyclasses.I deadlift205lbandoverheadsquat110lb,so askmeaboutmygains–theyarenotjustfor amplifiers!”

DayakarLavadiya joinsourfaculty thisfallasProfessorofCiviland MechanicalEngineering.Dayakar receivedhisPhD inCivilEngineering(structural mechanics)from NorthDakotaState Universityin2021withresearchonartificialintelligencefordamagedetectionininfrastructure.Histhesiswasentitled Neural NetworksandSensitivityAnalysisforDetectionandInterpretationofStructuralDamage.PriortothisaccomplishmentDayakar receivedhisfirstdoctorateinMechanicalEngineeringfromUtahStateUniversitywith emphasisoncompositematerialswiththesis EffectivePropertiesofRandomlyOriented KenafShortFiberReinforcedEpoxyComposite.Hiscurrentresearchinterestincludes sustainablematerialsforinfrastructure,solid mechanics,andapplicationofartificialintelligenceinengineering.Priortothisappointment,Dayakarwasapost-doctoralresearchfellowintheSustainableInfrastructure ResearchInitiative(SIRI)groupattheUniversityofNorthDakota.Dayakar’shobbies includeplayingsports(volleyball,cricket), watchingmovies,cooking,hiking,kayaking andcampingwithhiswifeJamieandthree stepchildren(Joshua,AdeleandJames).

Jerika

JerikaClevelandjoins ourfacultythisfallas ProfessorofElectrical EngineeringandComputerScience.Jerika receivedherMaster’s degree(2017)andher Ph.D.(2022)atNorth DakotaStateUniversity.ShewasaHap ArnoldScholarduring asummerinternshipin2017fortheAirForce ResearchLabsdowninEglin,FL.Herresearchhasbeeninappliedelectromagnetics withbiomedicalapplications.Hermaster’s work,entitled TheDesignandAnalysisof aMicrostripLineWhichUtilizesCapacitive GapsandMagneticResponsiveParticlesto VarytheReactanceoftheSurfaceImpedance. wasonthetheoryofusingmagnetitecore, silver-coatedparticlestochangethesignal directionofanantenna;andherPh.D.work isdesigningandcreatingthisantenna.She hascontinuedtodoadditionalworkwithundergraduateresearchersinelectromagnetics andprogrammingasimulationofahuman

SurendraBatukdeo joinsourfaculty thisfallasProfessorofElectrical Engineeringand ComputerScience. Surendraearned hisM.S.inElectricalEngineeringfromtheCaliforniaStateUniversityin Northridgein1999andhisB.S.inElectrical EngineeringfromWichitaStateUniversityin 1997.SincethenSurendrahasover20years ofindustryexperienceinsoftwareengineeringandartificialintelligenceasaneducator andmentorinemerginganddisruptivetechnologies.Heistheproudfatherofone14year oldson,heispassionateaboutflyingCessna, swimmingandrowing,andenjoyingbaroque music,andoneofhissevenhabitsisservice tomankind.

Dayakar

Surendra

2022SENIOR DESIGN PROJECTS

OnFriday,April22,theSeniorspresentedtheirdesignprojectsfromProfessor TomVolkman’sSeniorDesigncourse.We haveourseniordesignpresentationsatthe sametimeeachyearasthemeetingofourIndustryAdvisoryBoardsotherewereanumberofindustryengineerswhoattendedand helpedthefacultyjudgethepresentations.At theHammSchoolofEngineering,oursenior designprojectsaremultidisciplinaryprojects thatinvolveengineeringstudentsfromdifferentdepartments.Manyprojectsthataredesignedinindustryaremulti-disciplinaryones anditisthereforeimportantforourstudents toexperiencethisaspectoftheprocess.Itinvolveslearninghowtodelegatethebestengineerforagivenpartofthedesignandalso howtocommunicateeffectivelyacrossdisciplines.Italsoallowsourstudentstochoose moreinterestingprojectsfortheircapstoneseniordesigncourse.

ParkingGarage

WilliamBlewett,DavidsAtelbauers, BlakeRubio,DanielTurner,andIzaiahBitz designedaparkinggaragefortheUniversityofMarycampusfortheirseniordesign project.

WilliamTurner(ME)designedanelectronic sensorsystemtonotifyhowmanyspotsare openoneachlevelofthestructure.Aunique detectionsystemprovidesarooflevelindicatortonotifydriverswheretheopenspotsare locatedsodriverdoesn’thavetosearchfora parkingspace.

RoboticChessBoard

EthanMelder,RamiDouri,Michael Storick,andLucasMeyerdesignedandbuilt aroboticchessboardfortheirseniordesign project.Thegoalofthisprojectwastodeveloparoboticchessgameinwhichyouplay againstartificialintelligence(AI)controlled byacomputer.Aroboticarmcontrolsthe piecemovementascommandedbytheAI.

RamiDouri(EE)developedthesoftware forthechessengineandtocontroltherobotic arm.Thearmiscontrolledbyservomotors. Ramialsoassistedinbuildingthechessboard.

IzaiahBitz(CE)wasresponsiblefordefining theoverallscopeandpurposeoftheparking structure,aswellasdoingmathematicalcalculationsforboththestructuraldesignofthe reinforcedconcreteonthemainparkinglevelsandontheramps/entrances/exits.Davids Atelbauers(CE)performedananalysisonthe existingparkinglotstructuresaswellasdesignthefoundationforthenewstructure.He alsodesignedthedrainagesystemandperformedaneconomicanalysisofthedesign.

ElectricHydrofoil

KarsenMeyer,ChandlerOlson,Mark Sammons,andJamesJurekdesignedanElectricHydrofoilfortheirseniordesignproject. Thegoalofthisprojectwastoprototypean electrichydrofoilthatissignificantlycheaper thanonescurrentlyonthemarket,whileoperatingwiththesameorverysimilarperformancespecifications.

KarsenMeyer(ME)performedtheoveralldesignoftheboard,thehydrofoilandthe mast.Healsodesignedthewaterproofhousingforthebattery.

LucasMayer(ME)wasresponsiblefordesigningtheclawforpickingupthechess piecesandfordesigningthebaseandrail whichisconnectedtotheroboticarm.Ethan Melder(ME)designedthemechanicsforthe roboticarmandperformedanalysisonmaterialstrengthtoensurethatitwasstrong enoughtopickupandmovethechesspieces. MichaelStorick(EE)designedacircuitboard whichattachestothebottomofthechess boardanddetectsthemovementofchess pieces.Healsoassistedinthebuildingthe boardanddevelopingthegraphicalinterface fortheAI.0

BiomemticArm

DanielMinor,PeterSmith,andMatthew Bitner,designedabiomimeticarmfortheir seniordesignproject.Thegoalofthisproject wastocreateasemi-biomimeticroboticprosthetichand,fortransradialamputees,thatbalancesfunctionality,modularityandcosteffectiveness.

PeterSmith(ME)performedanalysisof forwarddisplacementandinversekinematics, aswellas3Dmodelingofthephalangesand qualitycontrolofalljoints.

WilliamBlewett(CE)concentratedonthedesignofthesteelstructure,includingthesizing ofthecolumnsandbeams.Williamwasalso responsibleforsustainabilityissuesincorporatingsolarpanelsforenergyandgreenwalls tooffsetCO2emissions.BlakeRubio(CE) wasresponsibleforperformingsitesurveys, soilanalysisandgeotechnicalreportsassociatedwiththestructure.Healsoworkonthe foundationandsteeldesigns.

JamesJurek(ME)wasresponsiblefordevelopingacommunicationsystembetweena handtransmitterandareceiverintheboard tocontrolthespeed.MarkSammons(ME) designedacoolingsystemforthecoolingsystemtoensurethattheelectronics,batterypack andbatterymanagementsystemdon’toverheat.ChandlerOlson(EE)designedacontrol systemwhichdeterminesthespeedofthehydrofoil.

DanielMinor(ME)did3Dmodelingofthe palmandthumb,aswellasdid3Dprintingofthefingers,thumb,palmandforearm. Danielalsocreatedassemblydrawingsforall 3Dparts.

MatthewBittner(ME)didmodelingof theforearmandthewristuniversaljoint. Matthewconcentratedontheslavecontroller; determiningthepowerrequirementsandwritingArduinocodetorunalloftheservos.

NEW CIVIL ENGINEERING AND CONSTRUCTION MANAGEMENT LABORATORY

Constructionofthenewadditionforour ConstructionManagementandCivilEngineeringprogramsbeganinsummer,2021 andwascompletedthisfall.TheConstructionMaterialsLaboratorywassponsoredby MillerInsulationandcontainsourwetlabsfor concreteandasphaltworkaswellasacrane andtestingequipment.

Havingourownfacilitiesattachedtotheengineeringschoolwillmakethelogisticsmuch easierforthestudents.Itwillalsoallowusto usethefacilitiesandequipmentatourdiscretionwhichisnecessaryforstudentstowork onprojectsaroundtheclockaswedowithour otherlaboratoriesintheEngineeringSchool.

12+ 60× 2

Wehavebeenfortunateuntilnowthatlocal companieshaveallowedustousetheirlaboratoryandtestingfacilitiestoteachourstudentswhileweweredesigningandconstructingourownfacilities.

KenKenandKenDokuareastyleof arithmeticlogicpuzzleinventedin2004by JapanesemathteacherTetsuyaMiyamoto. KenKenderivesfromtheJapanesewordfor cleverness.AsinSudoku,thegoalofeach puzzleistofillagridwithdigits––1through

KENKEN PUZZLE ByNANCYKELLY

7+

10× 10+

÷

24

×

ThisSpringengineeringstudentsparticipatedintheannualUniversityofMaryservicetriptoAyaviri,Peru.Ayaviriisaremote townhighinamountainousdistrictofsouthernPeru.Thelocalpopulationisroughly 20,000andthoughpublicservicesdoexist theyarelimited.StudentsintheSt.GiannaSchoolofHealthScienceshaveregularly goneonthistriptoserveinaclinicandschool runbySalesianSistersinthearea.Students andfacultyintheHammSchoolofEngineeringarenowparticipatinginthistriptohelp intheclinicandextendthescopeofservices offeredbytheschool.Onthisfirstyearof engineeringinvolvement,thetwoengineering studentsandfacultymemberswereaskedto buildashelterforthesisters’chickenstoprovideprotectionduringtherainyseason.The constructionofthechickenshelterisoutlined below.Inaddition,wealsoparticipatedin otherrepairsaroundthesisters’facilitywith theotherstudentparticipants;includingrepairingaroad,facilitatingrepairstoagreenhouse,andpainting.Oneoftheengineering studentalsohelpedoutattheclinicbyrepairingexerciseequipmentandbyfabricatingassistivedevicessuchacrutches.

Hereweseeourtwoengineeringstudents settingoutontheirfirstdayreadytoworkin thelowoxygenlevelsandhighUVexposure at12,000ft.Atthiselevationhydrationisessential,sunscreenisamustandoverexertion couldleadtoseriousillness.

Oneofthefirsttaskswastodigpostholes fortheframeoftheshelter.Thechickenssaw anopportunityinthediggingtofindnewareas tonestandlookforfood.

HAAS SCHOLARSHIP

Nextweassembledandputuptheframes.We usedthecinderblocksasmakeshiftformsso thatwecouldassemblefouridenticalsides withouthavingtomakerepeatedmeasurements.

Thenweattachedthemetalsidingtofunction asboththeroofandflooringoftheshelter.

Weweregivenahandwithsomeofthefinishingtouchesbysomehelpfuloccupational therapystudentsandwehandedtheshelter overtothesistersandthechickensonthe fourthandfinaldayofourserviceprojects.

Serviceprojectsliketheonedescribed hereareacorepartoftheidentityoftheUniversityofMaryandoftheeducationweintendtoimpart.Inthefuturewehopetoincreasethelevelofengineeringparticipationin theannualPerutripandexpandthescopeof theprojectswetakeon.

BenPihlistherecipientofthe2022HAAS scholarship.Benis seenherenexttothe injectionmolderthathe andhisclassmatesdesignedandfabricated thisyear,inEME323 -DesignofMachine Components.Bendid muchofthemachiningandalloftheweldingforthefabricationoftheinjectionmolder. TheHAASscholarshipisintendedtosupport studentsinlearningfabricationskillssuch asweldingandmachining.Themechanical engineeringfacultyawardtheHAASscholarshipannuallytoastudentwhoincorporates machinedandweldedcomponentsintotheir designprojects.

a. CivilEngineers:InfrastructureProject–comparetheuseofsteelvs.concrete forabuilding,theuseofasphaltvs. Portlandcementforaroad,Installing Ozone/Blacklight/Chemicaltreatment forawatertreatmentplant,etc.

BenPihl

b. ConstructionManagers:10-housesubdivisionbuildusingwoodsidingvs.aluminumsiding,constructionofaninfrastructureprojectwithinyourinterestarea(road,structure,pipeline,etc.), startingyourownconstructioncontractorcompany,etc.

c. ElectricalEngineeringandComputerScience:startasoftwarecompany,a factorybuildingelectricalcomponents, powerstations,useofautomateproductionvs.hand-made,comparisonof differentoperatingsystemsforacompany(i.e.Linux,Windows,Apple, Google,etc.allaspectsofthecompany runonthatsystem–employeeshave phones/laptops/otherdevicesexclusive tothatcompany),etc.

ENR460:SPRING PROJECT ByANTHONYWALDENMAIER

ENR460:EngineeringEconomy Spring2022 CourseProject 100pointspossible.

Thisassignmentissubjecttochange,pendingmajorityagreementamongthestudents ofENR460.Duetothediversenatureof thiscourse,thisprojectwillbegradedholistically,onthepremiseofcompleteness,thoroughness,anddepthofcompletedwork.Subjectiveopinionswillapply,butmustbereasonablyjustifiedwithvalidandrelevantarguments.

DueDates:

a. InitialProposal:3/25/2022bringtoclass asahardcopy.Thisisanopportunity toformgroupsforbackgroundresearch basedonsimilarprojects,timeforquestions,andclass-widediscussion(brain storming)

b. ProgressCheck:4/13/2022Submit,at minimum,the6(ormore)researched costs

c. FinalReport:4/27/2022Submitallproject documentsby3:00pm,theendofthe scheduledFinalExamPeriod.Early submissionswillreceive“EarlySubmissionCredit”equivalentto1point (1%)perday(maximumof10% bonus).Thiswillincludeasubmitted packetofthe“Deliverables”addressed laterinthisdocument.

Responsibilities:

Youareinchargeofgeneratingalifecyclecostanalysis(LCCA)relevanttoyour fieldofstudy.Youwillneedtogenerateat least2alternativeswhereyouwillcompare pricing,performance,socialimpacts,environmentalimpacts,economicalimpacts,andethicaldilemmasbetweenthetwooptions.Suggestedareasofstudyinclude:

d. MechanicalEngineers:Selectionofequipmentforamanufacturingprocess, openinganewautomotiveplant,automatedvs.humanlaborinaproductionplant,differentmaterialstobuild thesamething(i.e.carbonfibervs.aluminumvs.steel),etc.

e. SeniorDesignStudents:EconomicalAnalysisofyourproject.DoaLCCAof youprojectinanappropriatecontext (suchasmass-scaleproductionorconstruction).Yoursecondalternativemay considerachangeinmaterials,ways tobuild/manufacture,aestheticchanges withpotentialbenefits,useofbettervs. worsecomponents,etc.

f. MoreAbstract(suggestedforstudentswith unsureareaofinterest):Startacompany,upgradeafacility,rolloutanew product(i.e.thePlayStation6,thenext iPhone/Galaxy,etc.),etc.

Youwillneedtoresearchcostsandtime framesassociatedwithyourproject,looking atrelevantreal-worldknowledge.Youwill needtoresearchandgenerateatleastsix typesofcosts,whichmayinclude,butare notlimitedtothelistbelow,andidentifytime framesassociated(projectlifespan?Monthly vs.yearlycosts?One-timecosts?Etc.)

a. InitialCosts:constructioncosts,materials, start-upcosts,buyingvs.renting,etc.

b. Annual(orperiodic)costs:operationand maintenance,overhead,labor,etc.

c. Lifespanorprojectlife(thisshouldcover atleast10periodsorsubperiods(such asa10-monthconstructionproject,a 50-yeardesignlife,5yearsservicelife withreplacement,etc.)

d. LaborCostsassociated

e. SalvageValue(directre-salevalues,trade invalues,in-directsocialcosts/benefits, etc.)

Deliverables:

1. InitialProposal(3/25/22)–providea copyofyourprojectideaandsomeinitialthoughtsonwhatcostsandconsiderationstoresearch.

2. ProgressCheck(4/13/22)–Submit,at minimum,the6(ormore)researched costs

3. ResearchSummary(4/27/22)–Provide alistortable(situational)withitemizedcostsandlifespansyouhaveresearched.Providethesourceofyour costsforeach(thiswilllikelybefrom awebsite;providetheoverallorganization,ahyperlink,andanyextradetail thatmaybesituational).

Example: RoadMaintenanceandMaterialsCosts(thisexampleisforthe sand/gravelmaterialusedasabase layerforroads)

i. Organization:NorthDakotaDepartmentofTransportation(NDDOT)

ii. www.dot.nd.gov/pacer/AABP2022E.pdf

iii. ExtraDetail:2022NDDOTBid Pricing,Spec302,Code120,AggregateBaseCourseClass5

iv. Price:$27.22perton

4. ApproachSummary(4/27/22)–in thissummary,explainhowyouidentifiedtheproblem(situational)andapproachedyoursolution.Explainorjustifywhyyouselectedyourproblem, whyyouchosespecificpricing,etc. Thissummaryshouldwalkthereader throughyourthoughprocess.

5. CostAnalysis(4/27/22)–Showthecost analysisofyourmultiplealternatives. Thismaybepresentedintheformof atable,bargraph,cumulativecostplot (costsvs.time),oranyothersituational andappropriatesummary.Calculations maybedoneonspreadsheetsoftware orbyhand(penmanshipandneatness count,beprofessional).

6. SummaryofResults(4/27/22)(HLC GS1.3,1.4,1.5,1.6)–clearlyand conciselypresentyouralternatives,finalcosts(intermsofPresentworth,Futureworth,EquivalentAnnualworth,or whatevercostmodelismostappropriate).Thissectionshouldsimplypresent thenameofthealternative,thecost,and thefinaldecision.Here,youcanalso identifyintangiblefactorsthatleadyou toselectingthelesseconomicoption. Example: SamsungTVvs.VizioTV (samesizeandsimilarspecs)

i. Samsung:PresentCost$1699

ii. Vizio:PresentCost$1599

iii. Economically,theViziowillcost lessandwouldbethebettereconomicchoice.However,theremoteoftheSamsungismorefamiliartotheuser,andtheuser’s historywithSamsunghasledto thechoiceofselectingtheSamsung.Theuseriswillingtopay the$100differencebasedonthe personaltrackrecordwithSamsung,thefeeloftheremotecontrol,andbrandname.Itwas

determined,subjectively,thatthe VizioTVhastoomanyunknowns, andthe$100differencewasnot enoughtoselecttheViziooverthe Samsung.

7. Reflection(4/27/22)–Afterallresearch,calculations,andworkisdone, reflectonyourwork.Youshouldaddresseachofthefollowingpointswith abriefparagraph(aboutfivesentences, butfeelfreetoelaborateandreflectfurther).Someofthesewillbemoreabstract,buttheyareintendedtohelpyou seetheprojectonaholisticorglobal level.Youareaskedtotakeastepback, takeadeepbreath,andthinkaboutthe bigpicture.Howdoesyourfinaldecisionimpactotherthings?

a. (ABET:4C,4D;HLC:GS1.1,1.3, 1.7,1.8)Identifyandassessany environmentalimpactsofyourselectedproject(i.e.whataffects, positiveornegative,wouldthis projecthaveontheenvironment?)

b. (ABET:4C,4D;HLC:GS1.2,1.3, 1.7,1.8,2.2,2.3,2.4)Identify andassesanysocialimpactsof yourproject(i.e.howwouldthis projectaffectsociety?Thisportionmayalsoaddressanyperformancemodelsyouused).

c. (ABET:4C,4D;HLC:GS1.3,1.7, 1.8)Identifyandassesseconomic issuesbeyondtheprojectitself (i.e.wouldyouselectionhavean impactonthegreateconomy;locally,regionally,nationally,etc.)

d. (HLC:SE1,SE3;GS2.1)Identify potentialsourcesofethicalconflictwithinyourproject(youmay directlyreflectusingthedataand researchyouhavecollected,or youmayreflectonanindirect/hypotheticalsituation). example: Yousoughtoperating costsfromasimilarmanufacturingprocess,knowingthatthe othercompanywillbeacompetitorinthemarket.Thoughthis maybethebestdatayoucanfind, thereisagrayareaintermsof conflictofinterestincomparing yoursetuptoacompetitor.You mayelaborateonwhatfutureethicalconflictscouldarise,andhow thesemayconflictwiththeBenedictineValuesyouhavelearnedin yourUMaryeducation.

e. (HLC:SE2.1,2.2)Identifyandassessanypotentialconflictsthat mayhavedevelopedthatconflict faithversusreason(wastherean instancewherefaithwascompromisedforthesakeofreason? Wasreasoncomprisedbasedon faith?Inthiscontext,“faith”may beinterpretedasreligiousfaith, faithinyourknowledgeorskill set,faithintheindustryorservice yourprojectaddresses,orother interpretations.

Examples:

i. Yourprojectmayhavesomereligiousimplicationsthatdirectly(orindirectly)conflictwithyourspiritualbackground,suchasbuyingless expensivepartsfromacompanythatdoesnothavethe samevaluesasyouhave. Theconflictmayarisethat youarecompromisingyour faithtosavemoneyonthe parts.Inarealworldcontext,Chick-Fil-AandHobby Lobbyhavebothcomeunder fireinrecentyearsforstaying truetotheirethical/moral/religiousbeliefs–whichhas compromisedprofitabilityof thecompany.

ii. RefertotheSamsungvs.Vizio exampleintheSummaryof Resultsdescription.The user’sfaithintheSamsung bradleadthemtoundermine theeconomicdecision.This wouldbeaconflictbetween faithandreasonthatcanbe addressed.

Themotionsoftheplanets,moons,asteroids,andotherobjectsinthesolarsystem aregovernedbythegravity.Thegravitational forceisdescribedbyEinstein’sGeneralTheoryofRelativity.Inthecaseofweakgravitationalfields(asisthecaseinmostregionsof thegalaxyexceptnearexoticobjectssuchas blackholes)wecanuseeitherNewton’slaw, orthefirstordercorrectiontoNewton’slaw calledthe Post-NewtonianApproximation to calculatethemotionstoaverygooddegreeof accuracy.Engineersandscientistshaveused thelawsofgravitytosendrocketsandspace probesacrossthesolarsystem,landedthem onotherplanets,andexploredmoons,asteroids,andmanyotherthings.Wecaneven useNewton’slawstosimulatetheevolution ofthesolarsystemovertimeandpredictwhat wouldhappeninvariousinterestingcircumstancessuchasifanotherstarorablackhole passednearbyorifanasteroidorcometgot knockedoutoftheKeiperbeltandenteredthe innersolarsystem.

Inthisarticlewewillcreateacomputer modelofthesolarsystembyimplementing thegravitybetweenbetweeneachpairofparticles,placingthesysteminaninitialconfiguration,andthenlettingitevolveovertimeto seewhathappens.Agoodreferenceforinformationonthesolarsystemisthewebsite www.nineplanets.org andfurtherlinks tositesyouwillfindthere.

Sincewewillbetrackingtheorbitsofvariousobjectsinathree-dimensionaluniverse weneedtodescribethemintermsof vectors Soletusfirstwriteaprogramtodefineand manipulatevectors.Examinethefollowing headerfilecalled vector.h

EXPLORINGTHE SOLAR SYSTEM ByTERRYPILLING

velocities,\n", "masses,andradiiofanyparticles youwanttouse.\n", "<parameterfile>containsoneline foreachparticle\n", "andtheformatofeachlineis:\n", "\nxyzv_xv_yv_zmass radius\n", "\nTheoutputisthetimeinthefirst column\n", "followedbycolumnscontainingthex, y,andz\n", "coordinatesofeachoftheparticles .\n\n",

};

yourecognizethatweareusinghugeunits!)

Wehavealsopositionedtheearthandthe moonandgiventhemasmallinitialvelocityinthey-directionsothattheywillorbit ratherthanmerelyfallintothesun.Wehave designedtheunitssothatoneunitoftimeis equaltoadayandsowhenyouruntheprogrambytyping

./a.outinitfile3651>datafile

int main( int argc, char ** argv){

if (argc!=4){ for ( int i=0; * help[i];i++)fputs( help[i],stderr); return 1;

}

youwillgetafilecontainingtheoutputof365 daysoforbitaldata.

int TIME=atoi(argv[2]),time=0,dt =atoi(argv[3]),i,j; int NUM_PARTICLES=0;

FILE * infile; char line[255];

if ((infile=fopen(argv[1],"r"))!= 0){

while (fgets(line, sizeof (line), infile)!=0)NUM_PARTICLES++;

} fclose(infile);

double x,y,z,v_x,v_y,v_z,mass,radius,R

;

particleplanet[NUM_PARTICLES];

vectorzero,r;

if ((infile=fopen(argv[1],"r"))!= 0){ for (i=0;i<NUM_PARTICLES;i++){ fgets(line, sizeof (line),infile); sscanf(line,"%lf%lf%lf%lf%lf%lf%lf% lf",&x,&y,&z,&v_x,&v_y,&v_z,& mass,&radius); planet[i].set_pos(x,y,z); planet[i].set_vel(v_x,v_y,v_z); planet[i].set_statics(mass,radius);

} fclose(infile);

}

Nowletusshowhowtousethegravity ofJupitertoslingshotaspaceprobetoPluto. StartwiththefollowinginitializationfilecontainingthedatafortheSun,theEarth,Jupiter, Pluto,andanartificialsatellite(whichweapproximateasmassless)

slingshot-pluto.init

00000019889000.6961

149.59787070002.57350105.974000

150002.9241.604000

778.3300001.12838401900.00

4504.3300000.4700160102.00

Wenextrunoursimulationfor600days whichgivesthefollowingtrajectory.ItisinterestingsinceitshowsthespaceprobescatteringgravitationallyoffofJupiterresulting inaslingshotboostwhichsendsitinanew directionatagreaterspeed.Nextwerunthe simulationfor33,000days.Theresultingtrajectoryshowstheprobereachingfartherout inthesolarsystemthanPlutobutthenvisitingPlutoonthewayback.

Youmayliketospendsometimeplaying aroundwiththisprogrambythrowingafew cometsorJupitersizedplanetsintothemix andseewhathavoctheycanplayonthesolarsystem.Itisquitesurprisinghoweasily perturbationscanruineverythingandendup throwingtheearthandthemoonclearoutof thesolarsystem!Forexample,hereisaninitializationfilecontainingasmallcometanda Jupiterinadditiontothesun,earthandmoon.

0000001988900.696 149.59780002.573505.97400 149.21340002.674400.07350 10000000.20.040 20000000.1198800

while (time<=TIME){

//printoutthetime

printf("%d\t",time);

//calculatethenewpositionsand velocities

//usingtheaccelerations for (i=0;i<NUM_PARTICLES;i++){ planet[i].new_vel(planet[i].vel()+dt

* planet[i].accel()); planet[i].new_pos(planet[i].pos()+dt

* planet[i].vel()); planet[i].pos().print();

} printf("\n");

//calculatethenewaccelerations for (i=0;i<NUM_PARTICLES;i++){ planet[i].new_accel(zero); for (j=0;j<i;j++){ r=planet[i].pos() planet[j].pos ();

R=r.mag(); planet[j].new_accel(planet[j].accel ()+newton * planet[i].mass() * r /(R*R*R)); planet[i].new_accel(planet[i].accel () newton * planet[j].mass() * r /(R*R*R));

} } time+=dt;

} return 0;

}

Theprogramtakesafilenameandaninteger ascommandlinearguments.Thefilenameis onewhichcontainstheinitialdataregarding theparticles.Thefirstintegeristhenumber oftimestepsyouwouldliketohaveandthe secondintegeristhenumberofdaysbetween eachtimestep.Forexample,forthesun,the earthandthemoonyouwouldwantafilecontainingthefollowingthreelines.

00000019889.6961

149.59780002.573505.974.0000

149.21340002.673400.073.0000

Thefirstlinetellsusthatwehavechosen thisobjecttoresideattheoriginofour3dimensionalcoordinatesystem.Ithasahuge massandradius(asisevenmoreclearwhen

Thisis,infact,exactlywhatNASAscientistsandengineersdoinordertoreachfartherintothesolarsystemusinglessspacecraft fuel.Theygetagravityboostfromtheplanets alongtheway.

Thefollowingtablegivesthedataforthe majorplanetsinthesolarsystem.Thedistancesareinunitsofamillionmeters,thevelocitiesoftheplanetsaregiveninmillionskm perday,andthemassesareinkilograms.

NameDistVelocMass

Sun1.99e30

Mercury579104.3596803.30e23

Venus1082003.0257284.87e24

Earth1496002.7385605.97e24

Moon3840.0500007.35e22

Mars2279402.0848326.42e23

Jupiter7783301.1283841.90e27

Saturn14294000.8346245.68e26

Uranus28709900.5875208.68e25

Neptune45043000.4700161.02e26

Pluto59135200.4095361.27e22

WehavegiventhecometandJupitersomeinitialmotioninthez-direction.Youwillfindit veryinterestingtoincreasethetimescaleand seehowthesystemevolves.Itisremarkable howstablethissystemisasyoucanseeifyou runit20000daysorso.Youwillseethatthe earthandmoonmanagetostaytogethereven withtheextraperturbationsoftheirorbits. Now,tryincreasingthemassoftheJupitera littleifyouwanttoseesomerealhavoccreated!Ihaveevenfoundcertainconfigurations whichwillsendtheearthorthemoonoutto twiceitsusualdistancefromthesunforasinglecycleandthenitreturnsagain.Iwonderif thissortofthingcouldhavebeenthecauseof theice-ageswehavehadintheancientpast?

Herearesomefurtherinterestingavenues youmightliketoexplore:

orbitalprecession: RuntheEarth-Moon-Sun simulationfor366days.Thenadjusttheview sothatyoucanseethespotwheretheearth meetsupwithitsoriginalpositionayearbefore.YoushouldnoticethattheEarthexactly linesupwithitspreviouspathsothattheorbitclosesintoacircle.However,whatdoyou noticeabouttheorbitofthemoon?Doesthe earth’sorbitlineupproperlywhenallofthe planetsareincludedinthesimulationrather thanonlytheearth,themoonandthesun?

blackholes: Whatwouldhappenifastaror ablackholeflewbyoursolarsystemjustoutsidetheorbitofPluto?Hint:Justaddanothersun,startingataboutthesameplaceas Plutoandwithsomefairlylargeinitialvelocitywhichwouldcarryitstraightpastwithout deflectingitnoticeably.Nowadjusttheseparametersandwatchwhathavociscreatedin thesolarsystem.Thissituationispossibly whatwillhappeniftheAndromedagalaxy collideswithourowngalaxy,TheMilkyWay. ItlooksasthoughAndromedaisonacollision courseand,dependingonoursidewaysmotion,itwillcollidewithusin7billionyears. GalileanSatellites: Usethedatafromthe internettomodeltheJoviansystem.Inother words,haveJupiterinplaceofthesun,and themoonsofJupiterorbitingit.Notethatin ordertogetbetteraccuracyyoumaywantto gototheinternetandfindtheexactpositions

andorbitalvelocitiesoftheGalileansatellitesatsomeparticulardateandthenseehow theyevolvefromthere.Canyoupredictwith anyaccuracywheretheywillbeseveraldays later?YoucouldevenlookatJupiterwitha telescopeandcheckyouranswersinceyou caneasilyseethefourGalileansatellitesorbitingJupiterwithamoderatesizedtelescope.

OortCloud: Foralongtimeitwasknown thatalthougheverythinginthesolarsystem includingshortperiodcometstravelinthe samedirectionaroundthesun,thelongperiodcomets(whichtakemillionsofyearsto return)haveorbitsthatarerandom.Theycan comeinfromaboveorbelowtheplaneofthe orbitsoftherestofthesolarsystemandthey canmoveinbothprogradeorretrogrademotion.Thiswasafactthatnobodycouldexplain.Thenin1950DutchAstronomerJan Oortwroteanarticleinwhichhearguedthat iftherewereahugenumberofcometsmovinginslowcircularorbitsintheprogradedirectionandintheplaneofthesolarsystem butataverylargedistancefromthesun(from 10,000to100,000AU),thenthepassingof severalstarsparallel(aboveandbelow)the planeofthesolarsystemwouldbeenoughto completelyrandomizetheorbitsofthecomets untiltheyformedacloudaroundthesolarsystem(nowcalledtheOortcloud)andthatthis cloudwouldexplainthestrangeorbitalcharacteristicsofthelongperiodcomets.Tryto modelthiswithacomputersimulation.Start

withanumberofcometsat,say,50,000AUin circularorbitsintheplaneofthesolarsystem. Thenhaveafewstarsflybyatsay75,000AU ormore,bothaboveandbelowtheplaneand atrandomtimes.Doesthiscausetheoriginalorbitstobecomearandomizedcloudas Oorthypothesized?Whatabouttheoriginof thelongperioddiskofcomets?Ifyoustart yoursimulationwithafewinnerplanetsas wellasamultitudeofkilometer-sizedcomets onshortperiodorbits,willtheplanetseventuallythrowthecometsouttolongperiodcircularorbitssothattheOortcloudcouldthen formviathepassingofstars?

MassExtinction: AnotherDutchastronomer,namedPietHut,observedthatextinctioneventsduetocometshappenroughly every26millionyears.Thisledhimtohypothesizethatthesunisactuallypartofabinarystarsystemwithanotherstarhedubbed ‘Nemesis’.Thehypothesisisthatevery26 millionyearstheotherstarcomesclosetothe suninitsellipticalorbitanddisturbscomets fromtheOortcloud,someofwhichthenattaincollisiontrajectorieswiththeearth.Other astronomershavesaidthatHut’sideawould notworkbecauseoverthecourseof26millionyears,otherstarswouldpassinbetween theotherstarandthesunduetothemotion ofthesunaroundthegalacticcenter.Hut thendidsimulationswhichseemtoshowthat thehypotheticalbinarysystemofthesunand Nemesisisextremelystableundersuchper-

turbationsandwouldcontinuetocausetheeffectontheOortcloudevenifotherstarspass inbetweenonceinawhile.Yourtaskistotry andrepeatHut’ssimulation.Setupabinary systembetweenthesunandanotherstarwith alargetimescalesuchthatittakes26million yearstoorbitthesun.Thenthrowsomestray starsthroughthemiddleandseeifthisdisruptsthesystemandruinsthe26millionyear period.Ifitdoesnot,thenyouhaveverified thepossibilitythatthesunispartofabinary systemandthatthismayindeedberesponsiblefortheperiodicmassextinctions.Canyou thinkofanyotherpossiblereasonsfortheperiodiccycleandtestthemaswell?

Chaos: Startingwithonlytwoplanets, JupiterandSaturnforexample,thesystemis stable.Showthisbyrunningasimulationfor severalbillionyears.ThenaddUranusinto themixandsothesamethingandyouwill seethatthesystemischaotic.I.e.Ineach case,runtwosimulationseachdifferingby someverysmallperturbation.Thetwo-body systemwillbestable,whereasthethree-body systemwillbechaotic.