A Student's Guide Through the Great Physics Texts: Volume II: Space, Time and Motion

392 Pages·2015·4.692 MB·English

by  Kerry Kuehn (auth.)

Undergraduate Lecture Notes in Physics
Editors
NeilAshby
ProfessorEmeritus,UniversityofColorado,Boulder,CO,USA
WilliamBrantley
Professor,FurmanUniversity,Greenville,SC,USA
MichaelFowler
Professor,UniversityofVirginia,Charlottesville,VA,USA
MichaelInglis
Professor,SUNYSuffolkCountyCommunityCollege,Selden,NY,USA
HeinzKlose
ProfessorEmeritus,HumboldtUniversityBerlin,Germany
HelmySherif
Professor,UniversityofAlberta,Edmonton,AB,Canada
Undergraduate Lecture Notes in Physics (ULNP) publishes authoritative texts
covering topics throughout pure and applied physics. Each title in the series
is suitable as a basis for undergraduate instruction, typically containing practice
problems,workedexamples,chaptersummaries,andsuggestionsforfurtherreading.
ULNPtitlesmustprovideatleastoneofthefollowing:
• Anexceptionallyclearandconcisetreatmentofastandardundergraduatesubject.
(cid:129) Asolidundergraduate-levelintroductiontoagraduate,advanced,ornon-standard
subject.
(cid:129) Anovelperspectiveoranunusualapproachtoteachingasubject.
ULNPespeciallyencouragesnew,original,andidiosyncraticapproachestophysics
teachingattheundergraduatelevel.
ThepurposeofULNPistoprovideintriguing,absorbingbooksthatwillcontinueto
bethereader’spreferredreferencethroughouttheiracademiccareer.
Moreinformationaboutthisseriesathttp://www.springer.com/series/8917
Kerry Kuehn
A Student’s Guide Through
the Great Physics Texts
Volume II: Space, Time and Motion
2123
KerryKuehn
WisconsinLutheranCollege
Milwaukee
Wisconsin
USA
ISSN2192-4791 ISSN2192-4805(electronic)
ISBN978-1-4939-1365-7 ISBN978-1-4939-1366-4(eBook)
DOI10.1007/978-1-4939-1366-4
SpringerNewYorkHeidelbergDordrechtLondon
LibraryofCongressControlNumber:2014945636
© SpringerScience+BusinessMedia,LLC2015
Thisworkissubjecttocopyright.AllrightsarereservedbythePublisher,whetherthewholeorpartofthe
materialisconcerned,specificallytherightsoftranslation,reprinting,reuseofillustrations,recitation,
broadcasting,reproductiononmicrofilmsorinanyotherphysicalway,andtransmissionorinformation
storageandretrieval,electronicadaptation,computersoftware,orbysimilarordissimilarmethodology
nowknownorhereafterdeveloped.Exemptedfromthislegalreservationarebriefexcerptsinconnection
withreviewsorscholarlyanalysisormaterialsuppliedspecificallyforthepurposeofbeingenteredand
executed on a computer system, for exclusive use by the purchaser of the work. Duplication of this
publicationorpartsthereofispermittedonlyundertheprovisionsoftheCopyrightLawofthePublisher’s
location,initscurrentversion,andpermissionforusemustalwaysbeobtainedfromSpringer.Permissions
forusemaybeobtainedthroughRightsLinkattheCopyrightClearanceCenter.Violationsareliableto
prosecutionundertherespectiveCopyrightLaw.
Theuseofgeneraldescriptivenames,registerednames,trademarks,servicemarks,etc.inthispublication
doesnotimply,evenintheabsenceofaspecificstatement,thatsuchnamesareexemptfromtherelevant
protectivelawsandregulationsandthereforefreeforgeneraluse.
Whiletheadviceandinformationinthisbookarebelievedtobetrueandaccurateatthedateofpublication,
neithertheauthorsnortheeditorsnorthepublishercanacceptanylegalresponsibilityforanyerrorsor
omissionsthatmaybemade.Thepublishermakesnowarranty,expressorimplied,withrespecttothe
materialcontainedherein.
Printedonacid-freepaper
SpringerispartofSpringerScience+BusinessMedia(www.springer.com)
ForCindy
Preface
WhatistheNatureofthisBook?
Thisfour-volumebookgrewfromafour-semestergeneralphysicscurriculumwhich
IdevelopedandtaughtforthepastdecadetoundergraduatestudentsatWisconsin
LutheranCollegeinMilwaukee.Thecurriculumisdesignedtoencourageacritical
andcircumspectapproachtonaturalsciencewhileatthesametimeprovidingasuit-
ablefoundationforadvancedcourseworkinphysics.Thisisaccomplishedbyholding
beforethestudentsomeofthebestthinkingaboutnaturethathasbeencommittedto
writing.Thescientifictextsfoundhereinareconsideredclassicspreciselybecause
theyaddresstimelessquestionsinaparticularlyhonestandconvincingmanner.This
doesnotmeanthateverythingtheysayistrue—infactmanyclassicscientifictexts
contradictoneanother—butitisbythecarefulreading, analysisanddiscussionof
the most reputable observations and opinions that one may begin to discern truth
fromerror.
WhoIsthisBookfor?
Likefinewine,theclassictextsinanydisciplinecanbeenjoyedbyboththenoviceand
theconnoisseur.Forexample,Sophocles’tragicplayAntigonecanbeappreciatedby
theyoungstudentwhoisdrawntothestoryoftheheroinewhobravestherighteous
wrath of King Creon by choosing to illegally bury the corpse of her slain brother,
andalsobytheseasonedscholarwhocarefullyevaluatestherelationshipbetween
justice, divine law and the state. Likewise, Galileo’s Dialogues Concerning Two
New Sciences can be enjoyed by the young student who seeks a clear geometrical
descriptionofthespeedoffallingbodies, andalsobytheseasonedscholarwhois
amusedbyGalileo’switandsarcasm,orwhofindsinhisDialoguestheprogressive
Aristotelianismofcertainlatemedievalscholastics.1
1SeeWallace,W.A.,TheProblemofCausalityinGalileo’sScience,TheReviewofMetaphysics,
36(3),607–632,1983.
vii
viii Preface
Havingsaidthis,Ibelievethatthisbookisparticularlysuitableforthefollowing
audiences.First,itcouldserveastheprimarytextbookinanintroductorydiscussion-
based physics course at the university level. It was designed to appeal to a broad
constituencyofstudentsatsmallliberalartscollegeswhichoftenlacktheresources
to offer the separate and specialized introductory physics courses found at many
state-fundeduniversities(e.g.Physicsforpoets,Physicsforengineers,Physicsfor
health-care-professionals, Physics of sports, etc.). Indeed, at my institution it is
commontohavehistoryandfineartsstudentssittinginthecoursealongsidebiology
andphysicsmajors.Advancedhigh-schoolorhome-schoolstudentswillfindinthis
bookaphysicscurriculumthatemphasizesreadingcomprehension,andwhichcan
serveasabridgeintocollege-levelwork.Itmightalsobeadoptedasasupplementary
text for an advanced placement course in physics, astronomy or the history and
philosophyofscience.Manypracticingphysicists,especiallythoseatthebeginning
oftheirscientificcareers,maynothavetakentheopportunitytocarefullystudysome
of the foundational texts of physics and astronomy. Perhaps this is because they
have(quiteunderstandably)focusedtheirattentiononacquiringastrongtechnical
proficiencyinanarrowsubfield.Suchindividualswillfindhereinastructuredreview
of such foundational texts. This book will also likely appeal to humanists, social
scientistsandmotivatedlay-readerswhoseekathematically-organizedanthologyof
textswhichofferinsightintothehistoricaldevelopmentandculturalsignificanceof
contemporaryscientifictheories.Finally,andmostimportantly,thisbookisdesigned
forthebenefitoftheteachingprofessor.Earlyinmycareerasafacultymember,I
wasaffordedconsiderablefreedomtodevelopaphysicscurriculumatmyinstitution
whichwouldsustainmyinterestfortheforeseeablefuture—perhapsuntilretirement.
Indeed, readingandre-readingtheclassictextsassembledhereinhasprovidedme
countlesshoursofenjoyment,reflectionandinspiration.
HowisthisBookUnique?
Here I will offer a mild critique of textbooks typically employed in introductory
universityphysicscourses.Whilewhatfollowsisadmittedlyabitofacaricature,I
believeittobeaquiteplausibleone.Idothisinordertohighlighttheuniquefeatures
andemphasesofthepresentbook. Inmanyuniversity-levelphysicstextbooks, the
chapterformatfollowsastandardrecipe.First,acceptedscientificlawsarepresented
intheformofoneormoremathematicalequations.Thisisfollowedbyafewexample
problems so the student can learn how to plug numbers into the aforementioned
equationsandhowtoavoidcommonconceptualorcomputationalerrors.Finally,the
student is presented with contemporary applications which illustrate the relevance
oftheseequationsforvariousindustrialordiagnostictechnologies.
While this method often succeeds in preparing students to pass certain stan-
dardized tests or to solve fairly straightforward technical problems, it is lacking
in important respects. First, it is quite bland. Although memorizing formulas and
learninghowtoperformnumericalcalculationsiscertainlycrucialforacquiringa
Preface ix
workingknowledgeofphysicaltheories,itisoftenthemoregeneralquestionsabout
theassumptionsandthemethodsofsciencethatstudentsfindparticularlystimulating
andenticing.Forinstance,inhisfamousMathematicalPrinciplesofNaturalPhilos-
ophy,Newtonenumeratesfourgeneralrulesfordoingphilosophy.Nowthereader
maycertainlychoosetorejectNewton’srules,butNewtonhimselfsuggeststhatthey
arenecessaryforthesubsequentdevelopmentofhisuniversaltheoryofgravitation.
Is he correct? For instance, if one rejects Rules III and IV—which articulate the
principleofinduction—theninwhatsensecanhistheoryofgravitybeconsidered
universal?Questionslike“isNewton’stheoryofgravitycorrect?”and“howdoyou
know?” canappealtotheinnatesenseofinquisitivenessandwonderthatattracted
manystudentstothestudyofnaturalscienceinthefirstplace.Moreover,inseeking
asolutiontothesequestions,thestudentmusttypicallyacquireadeeperunderstand-
ingofthetechnicalaspectsofthetheory.Inthisway,broadlyposedquestionscan
serveasamotivationandaguidetoobtainingadetailedunderstandingofphysical
theories.
Second, andperhapsmoreimportantly, themethodemployedbymoststandard
textbooksdoesnotpreparethestudenttobecomeapracticingscientistpreciselybe-
causeittendstomaskthewayscienceisactuallydone.Thescienceispresentedas
anaccomplishedfact;theprescribedquestionsrevolvelargelyaroundtechnological
applications of accepted laws. On the contrary, by carefully studying the founda-
tionaltextsthemselvesthestudentisexposedtothepolemicaldebates,thetechnical
difficultiesandthecreativeinspirationswhichaccompaniedthedevelopmentofsci-
entifictheories.Forexample,whenstudyingthemotionoffallingbodiesinGalileo’s
Dialogues,thestudentmustconsideralternativeexplanationsoftheobservedphe-
nomena;mustunderstandthestrengthsandweaknessesofcompetingtheories;and
mustultimatelyaccept—orreject—Galileo’sproposalonthebasisofevidenceand
reason.ThroughthisprocessthestudentgainsadeeperunderstandingofGalileo’s
ideas,theirsignificance,andtheirlimitations.
Moreover,whenstudyingthefoundationaltexts,thestudentisobligedtothought-
fullyaddressissuesoflanguageandterminology—issueswhichsimplydonotarise
when learning from standard textbooks. In fact, when scientific theories are being
developed the scientists themselves are usually struggling to define terms which
capture the essential features of their discoveries. For example, Oersted coined a
termwhichistranslatedas“electricconflict”todescribetheeffectthatanelectrical
currenthasonanearbymagneticcompassneedle.Hewasattemptingtodistinguish
betweenthepropertiesofstationaryandmovingcharges,buthelackedthemodern
conceptofthemagneticfieldwhichwaslaterintroducedbyFaraday.Whenstudents
encounterafamiliartermsuchas“magneticfield,”theytypicallyacceptitassettled
terminology,andtherebypresumethattheyunderstandthephenomenonbyvirtueof
recognizingandmemorizingthecanonicalterm.Butwhentheyencounteranunfa-
miliartermsuchas“electricconflict,”aspartofthescientificargumentfromwhich
itderivesandwhereinitissituated,theyaretutoredintotheoriginalargumentand
arethusobligedtothinkscientifically,alongwiththegreatscientist.Inotherwords,
when reading the foundational texts, the student is led into doing science and not
merelyintomemorizingandapplyingnomenclature.
x Preface
Generallyspeaking, thisbookdrawsupontwothingsthatwehaveincommon:
(i) a shared conversation recorded in the foundational scientific texts, and (ii) an
innatefacultyofreason.Thecarefulreadingandanalysisofthefoundationaltexts
isextremelyvaluableinlearninghowtothinkclearlyandaccuratelyaboutnatural
science.Itencouragesthestudenttocarefullydistinguishbetweenobservationand
speculation,andfinally,betweentruthandfalsehood.Theabilitytodothisisessen-
tial when considering the practical and even philosophical implications of various
scientifictheories.Indeed,oneofthecentralaimsofthisbookistohelpthestudent
grownotonlyasapotentialscientist,butasaneducatedperson.Morespecifically,it
willhelpthestudentdevelopimportantintellectualvirtues(i.e.goodhabits),which
willservehimorherinanyvocation,whetherinthemarketplace,inthefamily,or
insociety.
HowisthisBookOrganized?
This book is divided into four separate volumes; the plan is to publish volumes I
and II concurrently in the autumn of 2014, and volumes III and IV approximately
a year later. Within each volume, the readings are centered on a particular theme
and proceed chronologically. For example, Volume I is entitled The Heavens and
theEarth.Itprovidesanintroductiontoastronomyandcosmologybeginningwith
thegeocentrismofAristotle’sOntheHeavensandPtolemy’sAlmagest,proceeding
throughheliocentrismadvancedinCopernicus’RevolutionsoftheHeavenlySpheres
and Kepler’s Epitome of Copernican Astronomy, and arriving finally at big bang
cosmologywithLemaître’sThePrimevalAtom.VolumeII,Space,TimeandMotion,
providesacarefullookatthescienceofmotionandrest. Here, studentsengagein
a detailed analysis of significant portions of Galileo’s Dialogues Concerning Two
NewSciences,Pascal’sTreatiseontheEquilibriumofFluidsandtheWeightofthe
MassofAir,Newton’sMathematicalPrinciplesofNaturalPhilosophyandEinstein’s
Relativity.
TheforthcomingVolumeIIIisentitledElectricity,MagnetismandLight.Itwill
provideastudyofthetheoreticalandexperimentaldevelopmentoftheelectromag-
netic theory of light using texts by William Gilbert, Benjamin Franklin, Charles
Coulomb,AndréMarieAmpère,ChristiaanHuygens,JamesClerkMaxwell,Hein-
richHertz,AlbertMichelson,andothers.VolumeIVwillprovideanexplorationof
modernphysics,focusingonradiation,atomismandthequantumtheoryofmatter.
SelectionswillbetakenfromworksbyJosephFourier,WilliamThomson, Joseph
Thomson,JamesClerkMaxwell,ErnestRutherford,MaxPlanck,JamesChadwick,
NielsBohr,ErwinSchrödingerandWernerHeisenberg.
While the four volumes of the book are arranged around distinct themes, the
readings themselves are not strictly constrained in this way. For example, in his
TreatiseonLight,Huygensisprimarilyinterestedindemonstratingthatlightcanbe
bestunderstoodasawavepropagatingthroughanaetherealmediumcomprisedof
tiny, hard elastic particles. In so doing, he spends some time discussing the speed