Coherent Quantum Physics

298 Pages·2019·4.851 MB·English

by  Arnold Neumaier

ArnoldNeumaier
CoherentQuantumPhysics
Texts and Monographs in
Theoretical Physics
|
Edited by
Michael Efroimsky, Bethesda, Maryland, USA
Leonard Gamberg, Reading, Pennsylvania, USA

Arnold Neumaier
Coherent Quantum
Physics
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A Reinterpretation of the Tradition
MathematicsSubjectClassification2010
Primary:81P15,81R30,46E22;Secondary:17B81,81T99
Author
Prof.Dr.ArnoldNeumaier
UniversitätWien
FakultåtfürMathematik
Oskar-Morgenstern-Platz1
1090Wien
Austria
[email protected]
ISBN978-3-11-066729-5
e-ISBN(PDF)978-3-11-066738-7
e-ISBN(EPUB)978-3-11-066736-3
ISSN2627-3934
LibraryofCongressControlNumber:2019947573
BibliographicinformationpublishedbytheDeutscheNationalbibliothek
TheDeutscheNationalbibliothekliststhispublicationintheDeutscheNationalbibliografie;
detailedbibliographicdataareavailableontheInternetathttp://dnb.dnb.de.
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ToMaria,
inhonoroftheCreatorofourmagnificentuniverse
Download Date | 10/31/19 1:08 PM
Preface
Inastatisticaldescriptionofnatureonlyexpectationvaluesorcorrelationsareobservable.
ChristofWetterich,1997[299,p.2678]
One is almost tempted to assert that the usual interpretation in terms of sharp eigenvalues is
‘wrong’,becauseitcannotbeconsistentlymaintained,whiletheinterpretationintermsofexpec-
tationvaluesis‘right’,becauseitcanbeconsistentlymaintained.
JohnKlauder,1997[160,p.6]
Whathasbecomeknownasthequantummeasurementproblem[…]encapsulatesmanyofthefun-
damentalconceptualdifficultiesthathavetothisdatepreventedusfromarrivingatacommonly
agreed-uponunderstandingofthephysicalmeaningoftheformalismofquantummechanicsand
ofhowthisformalismrelatestotheperceivedworldaroundus.
MaximilianSchlosshauer,2007[265,p.VIII]
Thisbookintroducesmathematicians,physicists,andphilosopherstoanew,coher-
ent approach to theory and interpretation of quantum physics (including quantum
mechanics,quantumstatisticalmechanics,quantumfieldtheory,andtheirapplica-
tions),inwhichclassicalandquantumthinkinglivepeacefullysidebysideandjointly
fertilizetheintuition.
An interpretation of quantum mechanics relates its formalism to the actual in-
formalpracticeofusingquantummechanicsinourscientificculture.Animpeccable
interpretationmustshowthatthereisafullyconsistentrelationbetweentheoryand
practice.Theinterpretationmayuseconceptsfamiliarfromourculturetoexplainthe
workingofquantumphysicsinpracticetoeveryone’ssatisfaction.
Whataretheshortcomingsofthecurrentapproaches?Theminimalstatistical
interpretationpredictsthestatisticsofoutcomesofexperiments.Itissilentaboutthe
interpretationofquantummechanicsintheabsenceofmeasurements,andtherefore
abouttheinterpretationofquantumphysicsappliedtothefarpastoftheuniverse,be-
foreexperimentswerepossible.Thisconstitutesaseriousgap—theinterpretationis
consistent,butincomplete(asitshouldbefora“minimal”interpretation).TheCopen-
hageninterpretation,whichclaimsthatnothingcanbeassertedintheabsenceofa
measurement,isalsoconsistent.Butthissoundsliketheconceptthatatreefallen
inthewoodhasfallenonlyaftersomeonehasseenit.Thisisoneofthereasonswhy
quantummechanicscomesacrossassomewhatstrange.Inamany-worldinterpreta-
tion,theworldsplitsandsplits,completelyunnoticedbyus,intoallpossiblefutures.
Thisissciencefictionbyconception.Theotherknowninterpretationsareeithervari-
ationsoftheaboveorrequireadditional,inprinciple,unobservable,andhencefic-
tionalstuff.Asaresult,muchofquantumphysicsappearstothegeneralpublicasa
kindofquantummagic.
Why do physicists live with this? A noteworthy aspect of the standard inter-
pretationsisthatthestatevectorcannotrepresentthewholeuniverse,sinceitmust
https://doi.org/10.1515/9783110667387-201
VIII | Preface
excludeanobserverormeasuringdevicethatdetermineswhenameasurementhas
occurred.Thisistheso-calledHeisenbergcutbetweenthequantumandtheclassical
world.Todate,thishasnotbeenaprobleminmakingsuccessfulexperimentalpredic-
tions,sopractitionersareoftensatisfiedwiththequantumformalisminastandardin-
terpretation.Traditionbuildsthequantumedificeonatime-honoredfoundationthat
accountsforessentiallyallexperimentalfacts.Butittakesa“shut-up-and-calculate”
attitudetowardstheinterpretationofthefoundations.Thetraditionalpresentationof
quantumphysicsisclearlyadequateforprediction,butseemsnottobesuitablefor
anadequateunderstanding.
Asecondreasonisthatanumberofpopular“quantummagicians”,veryexperi-
encedquantumphysicspractitionersspecializinginquantumoptics,liketogivetheir
audiencetheimpressionthatimportantpartsofquantummechanicsareweird.And
thegeneralpubliclovesit!Partofthemagicians’artconsistsofremainingsilentabout
thetruereasonswhythingsworkrationally,sincethentheweirdnessisgone,andwith
ittheentertainmentvalue.
Doesquantummechanicshavetobeweird?Itsellsmuchbettertothegeneral
publicifitispresentedthatway,andthereisalonghistoryofproceedinglikethis.But
itisanobstacleforeveryonewhowantstotrulyunderstandquantummechanics,and
tophysicsstudents,whohavetounlearnwhattheyweretoldaslaypersons.When
presentedintherightway,quantummechanicsisnotatallweird,butverycloseto
classicalmechanics.Muchoftheweirdnesscomesfromforcingquantummechanics
into the straightjacket of a particle picture. The particle picture breaks down com-
pletelyinthesubatomicdomain,aswitnessedbythemanyweirdthingsthatresult
fromsuchaview.
Coherentquantumphysicsremovestheradicalsplitbetweenclassicalmechanics
andquantummechanics.Thisbookdemonstratesthatatanylevelofdetail,Nature
canberationallyandobjectivelyunderstoodjustbyinterpretingthetraditional,well-
establishedmathematicsofquantumphysicsinanappropriateway.Thisrequiresa
reinterpretation of the tradition. The interpretation featured in this book succeeds
withoutanychangeinthetheory,andwithoutintroducingnewcounterintuitivefea-
turesornewtheoreticalconcepts.Theresultingquantumfeaturesthenareonlythose
familiarfromeverydaylife.
Nature,asweperceiveitwithoureyes,consistsofimages—inmathematicalterms
2-dimensionalfields,withproperties(colors)ateachpoint.Ourbrainsinterpretim-
agesasscenesina,strictlyspeaking,notdirectlyperceived3-dimensionalworldof
objects.Thesameobjectseemslargerorsmallerdependingonitsdistancefromus,
withashapethatisdeducedfromimagesshowingtheobjectfromdifferentperspec-
tives.Allourobservationsareindirect:Weperceiveimagesandothersensoryinforma-
tionandinferthetrue(theoretical,reproducible,invariant)propertiesoftheobjects
aroundus.
Fromtheexperienceofthemultitudeofsuchsensoryperceptionsofmanypeople,
ourculturecreatedanetworkofconceptsandrelationsnowcalledscience,andin