Introduction to “Quantum mechanics and reality”

137 T H E O R I A eISSN 0495-4548 – eISSN 2171-679X Theo ia, 2024, 39(2), 137-142 h ps://doi.o g/10.1387/ heo ia.26755 In oduc ion o “Quan um mechanics and eali y” (In oducción a “Mecánica cuán ica y ealidad”) Raoni A oyo* Uni e si y o Campinas JonasRa aelBecke A enha Fede al Uni e si y o San a Ca a ina Ch is ian de Ronde Uni e sidad de Buenos Ai es Raimundo Fe nández Mouján Uni e sidad Diego Po ales ABSTRACT: This pape in oduces he Special Issue o Theo ia en i led “Quan um mechanics and e- ali y”. We i s commen on i s o igins ela ed o he VIII In e na ional Wo kshop on Quan um Mechanics and Quan um In o ma ion, p omo ed by he In e na ional Ne wo k on Founda ions o Quan um Me- chanics and Quan um In o ma ion. We hen b ie ly in oduce each con ibu ion indi idually, b inging he pape s oge he unde he Special Issue’s opic. KEYWORDS: non-locali y, non- e lexi e logics, philosophy o quan um mechanics, quan um on ology and me aon ology, ealism and an i ealism. RESUMEN: Es e a ículo in oduce el núme o especial de Theo ia i ulado “Mecánica cuán ica y eali- dad”. En p ime luga , se explican sus o ígenes en elación con el VIII Talle In e nacional sob e Mecánica Cuán ica e In o mación Cuán ica, p omo ido po la Red In e nacional sob e los Fundamen os de la Mecá- nica Cuán ica e In o mación Cuán ica. A con inuación, se p esen a b e emen e cada con ibución de mane a indi idual, ag upándolas en o no al ema del núme o especial. PALABRAS CLAVE: no localidad, lógicas no e lexi as, iloso ía de la mecánica cuán ica, on ología cuán- ica y me aon ología, ealismo y an i ealismo. * Co espondence o: Raoni A oyo. Cen e o Logic, Epis emology and he His o y o Science, Uni e si y o Campinas, Rua Sé gio Bua que de Holanda, 251, 13083-859, Campinas, B azil.– [email p o ec ed] – h ps://o cid.o g/0000-0002-3800-8505 How o ci e: A oyo, Raoni; A enha , Jonas Ra aelBecke ; De Ronde, Ch is ian; Fe nández-Mouján, Raimundo (2024). «In oduc ion o “Quan um mechanics and eali y”»; Theo ia. An In e na ional Jou nal o Theo y, His o y and Founda ions o Science,39(2), 137-142. (h ps://doi.o g/10.1387/ heo ia.26755). Recei ed: 1 July, 2024; Final e sion: 22 July, 2024. ISSN0495-4548 - eISSN2171-679X / © 2024 UPV/EHU P ess This wo k is licensed unde a C ea i e Commons A ibu ion-NonComme cial-NoDe i a i es 4.0 In e na ional License Raoni A oyo, JonasRa aelBecke A enha , Ch is ian de Ronde, Raimundo Fe nández Mouján 138 Theo ia, 2024, 39/2, 137-142 1. Quan um Mechanics and Reali y The p edic i e capaci y and he immense ins umen al consequences o quan um mechanics seem o ell us wi h some con idence ha his physical heo y indeed cap u es a knowledge o , a leas , ce ain aspec s o eali y, o a ce ain necessi y wi hin i . Now, wha exac ly does i ell us abou eali y? Wha ision, wha ep esen a ion o eali y does i o e ? This is whe e con- sensus is lacking, hings ge complica ed, and some di icul p oblems begin. We see in he cu en deba e no only a huge numbe o dispa a e in e p e a ions mul iplying (wi h none ising abo e he o he s), bu e en a mo e gene al deba e eappea ing ega ding he ela ion- ship be ween physical heo ies and eali y. In his con ex , posi ions eme ge ha e en deny —mo e o less explici ly— ha he e is such a link wi h eali y, o , a leas , i s impo ance. A his poin , he ques ion o me aphysics, and i s ela ionship wi h physics, en e s he de- ba e. Quan um mechanics is he pe ec case o discussions abou he connec ion be ween me aphysics and science: i is ex emely well-con i med, on he one hand, bu i is elusi e, o say he leas , when i comes o elling us wha i is abou . Is i necessa y hen o add a me a- physics o he o mal and empi ical con en o he heo y? O pe haps a pa icula me aphys- ics al eady appea s o be p esupposed om he ou se in he s anda d model used by physicis s? And, in a b oade sense, his speci ic deba e ega ding quan um mechanics o ces upon us a mo e gene al ques ion: wha is gene ally he ole o me aphysics wi hin scien i ic heo ies? Concomi an wi h he ques ion o me aphysics, de elopmen s equen ly appea ha emphasize he need o an on ology. I quan um mechanics is going o ell us some hing abou eali y, hen one should pe haps begin wi h he subjec ma e o he heo y: is i a heo y ha deals wi h wa es, pa icles, o some hing else en i ely di e en , such as wa e unc ions? And how should we deduce he answe ? These a e opics ha in he cu en de- ba es a e aken o be a ques ion o on ology. Wi h he emphasis on on ology, ano he neces- sa y concep ual ques ion appea s: wha a e he di e ences and ela ions be ween me aphys- ics and on ology in he con ex o hese deba es? E en when emb acing his on ological deba e and ying o s a by iden i ying he en- i ies desc ibed by he heo y, we ind some a he s ange phenomena ha aise ano he mo e speci ic ques ion: a e he en i ies ha exis acco ding o quan um mechanics eally indi iduals? I so, wha accoun o indi iduals would wo k? O , pe haps, hey a e no eally indi iduals? Maybe he e y idea o objec s, o a oms, is no e y ui ul o an unde s and- ing o he heo y, and adically di e en ca ego ies a e equi ed by he heo y? Should we c ea e such new ca ego ies, o could hey pe haps be ead-o di ec ly om he heo y? Wi h hese impo an ques ions in mind, he VIII In e na ional Wo kshop on Quan- um Mechanics and Quan um In o ma ion was held, p omo ed by he In e na ional Ne - wo k on Founda ions o Quan um Mechanics and Quan um In o ma ion and he Re- sea ch G oup o Logic and Founda ions o Science (CNPq). I is om he e y in e es ing p esen a ions and deba es ha ook place in ha e en ha his special issue was bo n. 2. The con ibu ions Con ibu ions o his issue add ess di ec ly he ques ion conce ning he connec ion be- ween quan um mechanics and eali y, in di e en le els. He e, we b ie ly p esen he pa- pe s. h ps://doi.o g/10.1387/ heo ia.26755 139 In oduc ion o “Quan um mechanics and eali y” — Allo i (2024). As we men ioned in he p e ious sec ion, one o he p oblems wi h a quan um mechanical iew o eali y is ha i is no easy o see wha he heo y is ell- ing us. In cu en li e a u e, op ions mul iply hemsel es, popula ing he wo ld wi h e y di e en posi s. The choice o which iew o adop canno be made on pu ely empi ical g ounds. Which ea u es should we p i ilege? Hidden a iables a e an op- ion o ha e mo e classically ela ed op ions. Should we go ha way? Valia Allo i’s pape add esses his p oblem om a speci ic pe spec i e. A e Bell’s amous heo- em on non-locali y, a p ominen way o ha e local hidden a iables is in a supe de- e minis ic uni e se. Supe de e minism is a ancy name o good old ashioned de e - minism in gene al philosophy, he idea acco ding o which e e y ou come is al eady de e mined by p e ious causes. So i you heo y is supe de e minis ic, you hidden a iables could be local. Allo i shows he p oblems in such a hough , iz. ha supe - de e minis ic heo ies a e, in he own wo ds, “unin o ma i e, un alsi iable, and un- con i mable” (p.161). In pa icula , i is a gued ha con ex uali y is pu ely ad hoc in supe de e minis ic heo ies, hen hese aspec s mus be added o he balance when compa ing cos s be ween supe de e minism and non-locali y. — Ae s and Sassoli de Bianchi (2024). The pape discusses he cons uc ion o spa- ce ime as ela ed o Eins ein’s ela i i y e olu ion which, acco ding o he au ho s has no been ully accomplished. They a gue ha “ he ou -dimensional mo ion in Minkowski space can be be e unde s ood i placed in he b oade pe spec i e o quan um mechanics, i non-locali y is in e p e ed as non-spa iali y, hus indica ing he exis ence o an unde lying non-spa ial eali y” (p.165). This discussion is hen also ela ed o he concep uali y in e p e a ion o quan um mechanics ha has been al eady de eloped by Ae s and Sassoli de Bianchi. The pape p o ides an in e es - ing and o iginal discussion which connec s wo o he mos impo an heo ies o he 20 hcen u y, namely, ela i i y and quan um mechanics. — A oyo and A enha (2024)1. This pape elabo a es on he ques ion o wha quan um mechanics could each us abou eali y, on a mo e gene al le el. G an ing ha di e en e sions o quan um heo y popula e he wo ld wi h di e en en i- ies, A oyo and A enha de elop upon hei p e ious wo k on he di e ence be- ween on ology and me aphysics, his ime dis inguishing be ween wo senses o ‘on ology’. The i s pa is he ca alog one migh ex ac om scien i ic heo ies (e.g. whe he he e a e mul i e ses o no acco ding o he Many Wo lds In e p e- a ion o E e e ian quan um mechanics). This pa is hence ‘na u alizable’. The non-na u alizable pa o on ology is whe he ‘wo lds’ as pe in he ca alog-aspec o on ology should be ca ego ized as ‘objec s’ o ‘s uc u es’ in he ype-aspec o on- ology. — da Cos a (2024). Going e en deepe on he le el o cha ac e iza ion o quan um en i ies, a ene able adi ion da ing back o some eadings o Sch ödinge sugges s ha quan um en i ies a e no indi iduals. This claim has ecei ed a o mal ende - ing h ough he de elopmen o non- e lexi e sys ems o logic. The pionee in such de elopmen s, P o esso New on da Cos a, sugges ed ha his ea u e could be cap- 1 This pape wen h ough he pee - e iewing p ocess as usual, and none o he gues edi o s ook pa in any s age o he edi o ial p ocess, so we’d like o hank Ja ie Gonzalez de P ado Salas o his. Raoni A oyo, JonasRa aelBecke A enha , Ch is ian de Ronde, Raimundo Fe nández Mouján 140 Theo ia, 2024, 39/2, 137-142 u ed by o mal languages whe e he ela ion o iden i y is es ic ed when i comes o w i ing o mulas ( hese sys ems we e la e de eloped and u he explo ed by P o . Décio K ause). Now, da Cos a hono s us wi h a pape wi h addi ional de el- opmen s on he opic. The new p oposal by da Cos a consis s in es ic ing iden i y no a he le el o o ma ion o o mulas, bu o ha ing asse able o mulas: we can only asse o mulas in ol ing iden i y p o ided ha he i ems whose iden i y a e being exp essed ac ually sa is y some e y speci ic condi ions. This ce ainly b ings a new pe spec i e on non- e lexi e logics. Also, da Cos a indica es how o de elop a e sion o quan um mechanics as based on his new sys em, an accoun di e - ing om s anda d non- e lexi e accoun s (e.g. K ause & A enha , 2016). This is he i s pos humous publica ion o P o esso New on da Cos a, who passed away sho ly a e ha ing his pape accep ed in his jou nal. — K ause (2024). K ause’s a icle discusses he me hodological aspec s o he discussion ela ed o he connec ion o heo y and eali y, wi h special emphasis on he quan um case. In pa icula , K ause is conce ned wi h he p oblem o how o connec he em- pi ical wo ld wi h he highly abs ac and ma hema ised models o ou heo ies. This ela ion is o en aken o g an ed, bu as he pape a gues, i is highly p oblema ic. K ause adds a new dimension o he deba e b inging o he o e he ole o he ma h- ema ical heo ies employed in he cons uc ions o he models; gi en he plu ali y o non-classical heo ies ha can do ha job, signi ican ly di e en accoun s may esul om using di e en such heo ies in he me alanguage (which K ause calls he me a- ma hema ics). So, in a sense, e en he chosen logic ma e s o he iew o eali y ha one hopes o de i e om quan um mechanics. A case s udy is p esen ed h ough he heo y o quasi-se s and quan um pa icles lacking indi iduali y. — Rue sche (2024). Rue sche’s piece is, up o his da e, he mos ho ough p esen a- ion and de ense o he Loca o e s ance on he philosophy o science. The loca o e posi ion was de eloped o deal wi h on ological plu ali y in science. While p e i- ous wo k in he ield deal wi h plu ali y be ween di e en domains o science (e.g., non- ela i is ic quan um mechanics and quan um ield heo y Rue sche, 2015), his a icle ackles how he loca o e deals wi h on ological plu ali y wi hin he same domain o inqui y. A case in poin is he on ological plu ali y in quan um in e p e- a ions, o example, he ques ion o whe he o no quan um mechanics implies we’ e li ing in a mul i e se. I we a e (hence he E e e ian in e p e a ion is co - ec ), hen we should add his en i y o he wo ld’s on ological ca alog. The p ob- lem wi h his ca alog is ha i is incompa ible wi h ano he on ological ca alog, iz., ha quan um mechanics implies ha we’ e li ing in a single wo ld (hence he E e - e ian in e p e a ion is inco ec ). Rue sche’s own answe o his is he loca o e one, acco ding o which we don’ need o choose and we don’ need o be an i ealis s as well. The choice o a single pic u e is, a e all, is equi ed only by he loca o e’s a ch-enemy, he Cyclops. The Cyclops’ iew is he backg ound agains which he s alema e be ween ealism and an i ealism has been es ablished in quan um ounda ions, and he loca o e’s way ou o i is o ecognize ha quan um mechanics is an in e es ing heo y, and o doub ha “in e es ing heo ies ha e winning in e p e a ions” (p.255). Compe - ing in e p e a ions shouldn’ be seen as compe ing in such a pic u e, whe e in e - p e a ion di e si y is welcomed as a sign o heal h o he in e es ing heo y. So e.g. h ps://doi.o g/10.1387/ heo ia.26755 141 In oduc ion o “Quan um mechanics and eali y” Bohmian mechanics should be used o one end (e.g., o p ese e he pa icle-pic- u e) whe eas s anda d quan um mechanics should be used o o he ends (e.g. eaching physics cou ses). Tha ’s, as he au ho he sel ecognizes, a sugges ion ha is “[...] bold, and liable o be me wi h esis ance” (p.259). Acknowledgmen s This Special Issue is dedica ed o he memo y o P o esso New on da Cos a (1929-2024). We would like o hank he Edi o s o Theo ia, especially Ja ie and Ma c, wi h whom we wo ked oge he o ind he bes e e ees, and o discuss he bes ou come o he pape s unde pee e iew, always aiming o p o ide a sensible and cons uc i e e iew o he au- ho s (e en in he un o una e ejec ion cases). We hank he au ho s o p omp ly ag eeing o collabo a e wi h he p ojec , and he pa icipan s o he VIII In e na ional Wo kshop on Quan um Mechanics and Quan um In o ma ion. REFERENCES Ae s, D., & Sassoli de Bianchi, M. (2024). The na u e o ime and mo ion in ela i is ic ope a ional eal- i y. Theo ia. An In e na ional Jou nal o Theo y, His o y and Founda ions o Science, 39(2), 165-191. (h ps://doi.o g/10.1387/ heo ia.24930) Allo i, V. (2024). Hidden a iables and Bell’s heo em: Local o no ? Theo ia. An In e na ional Jou nal o Theo y, His o y and Founda ions o Science, 39(2), 143-163. (h ps://doi.o g/10.1387/ heo ia.24617) A oyo, R., & A enha , J. R. B. (2024). Quan um on ology de-na u alized: Wha we can’ lea n om quan- um mechanics. Theo ia. An In e na ional Jou nal o Theo y, His o y and Founda ions o Science, 39(2), 193-218. (h ps://doi.o g/10.1387/ heo ia.24955) da Cos a, N. C. A. (†) (2024). Rema ks on quan um mechanics and non- e lexi e logic. Theo ia. An In e na- ional Jou nal o Theo y, His o y and Founda ions o Science, 39(2), 219-228. (h ps://doi.o g/10.1387/ heo ia.24771) K ause, D. (2024). A way o see he in e play be ween heo y and eali y wi h a look a he quan um case. Theo ia. An In e na ional Jou nal o Theo y, His o y and Founda ions o Science, 39(2), 229-244. (h ps://doi.o g/10.1387/ heo ia.24759) K ause, D., & A enha , J. R. B. (2016). P esen ing non e lexi e quan um mechanics: Fo malism and me a- physics. Cade nos de His ó ia e Filoso ia da Ciência, 2(1), 59-91. Rue sche, L. (2015). The Shaky Game+ 25, o : On loca o aci y. Syn hese, 192(11), 3425-3442. Rue sche, L. (2024). The mi acles a gumen mee s quan um mechanics: Towa d a loca o e philosophy o physics. Theo ia. An In e na ional Jou nal o Theo y, His o y and Founda ions o Science, 39(2), 245-261. (h ps://doi.o g/10.1387/ heo ia.24976) aoni a oyo is a pos doc esea che a he Cen e o Logic, Epis emology and he His o y o Sci- ence, based a he Uni e si y o Campinas, B azil, and a esea ch ellow unde g an #2021/11381-1, São Paulo Resea ch Founda ion (FAPESP); membe o Resea ch G oup in Logic and Founda ions o Sci- ence (CNPq). His main philosophical in e es s a e he me hodological and epis emological aspec s o he me aphysics o science, and i s ela ion wi h scien i ic ealism. add ess: Cen e o Logic, Epis emology and he His o y o Science, Uni e si y o Campinas, Rua Sé gio Bua que de Holanda, 251, 13083-859, Campinas, B azil. E-mail: [email p o ec ed] – ORCID: 0000-0002-3800-8505. Raoni A oyo, JonasRa aelBecke A enha , Ch is ian de Ronde, Raimundo Fe nández Mouján 142 Theo ia, 2024, 39/2, 137-142 Jonas a ael Becke a enha is an associa e p o esso o he Depa men o Philosophy o he Fede al Uni- e si y o San a Ca a ina (Flo ianópolis, B azil). Membe o he edi o ial boa d o P incipia —An In e - na ional Jou nal o Epis emology. He is he coo dina o o he Resea ch G oup in Logic and Founda ions o Science (CNPq). His main a eas o in e es a e Logic, philosophy o logic and pa aconsis ency, and he sea ch o a p oduc i e in e ac ion be ween science and me aphysics, wi h a ocus on quan um me- chanics. add ess: Depa men o Philosophy, Fede al Uni e si y o San a Ca a ina, Campus Uni e si á io Rei o João Da id Fe ei a Lima, s/n T indade – Flo ianópolis – SC, CEP: 88035-972. Caixa Pos al: 5064, Flo i- anópolis, B azil. E-mail: [email p o ec ed] – ORCID: 0000-0001-8570-7336. ch is ian de onde is an Independen Resea che o he Consejo Nacional de In es igaciones Cien í icas y Técnicas (CONICET) de A gen ina. Associa e P o esso o he Na ional Uni e si y A u o Jau e che and coo dina o o he g oup o Philosophy o Physics o he Uni e si y o Buenos Ai es. He is also membe o he Cen e Leo Apos el o In e disciplina y S udies (V ije Uni e si ei B ussel) and o he In e na- ional Ne wo k o Founda ions o Quan um Mechanics and Quan um In o ma ion. His main a eas o in- e es a e he philosophy and ounda ions o quan um mechanics. add ess: Ins i u o de Filoso ía D . Alejand o Ko n, Facul ad de Filoso ía, Uni e sidad de Buenos Ai es, Puán 480, 4 o. piso, o . 431, C1406CQJ, Buenos Ai es, A gen ina. E-mail: [email p o ec ed]. aiMundo e nández MouJán is a pos doc o al esea che a he Philosophy Ins i u e o he Diego Po ales Uni e si y, San iago de Chile (suppo ed by ANID-FONDECYT, p ojec numbe : 3240436). He is also a membe o he Cen e Leo Apos el o In e disciplina y S udies (V ije Uni e si ei B ussel) and he In- e na ional Ne wo k on Founda ions o Quan um Mechanics and Quan um In o ma ion. His main in e - es s a e ancien and con empo a y heo y o knowledge and he philosophy o quan um mechanics. add ess: Ins i u o de Filoso ía, Uni e sidad Diego Po ales, A enida Ejé ci o Libe ado , 260 (8370056 San iago de Chile-Chile). E-mail: [email p o ec ed] – ORCID: 0000-0002-7074-8036.