Time

In General > s.a. arrow of time; causality; Evolution.
* Concept: The oldest known concepts of time are cyclic; Only with the Zoroastrian Persians, and Abraham's idea of a universal God (between 2100 and 1500 BC?) and later Judaism, was there a deity intimately related to the fate of one's children, and the idea of a future; This introduced in the Judaeo-Christian tradition and Western thought the philosophical view of a linear, irreversible time; Aymara of the Andean highlands view the past as in front of us (see can see it), and the future as behind us.
* Re absolute time: In classical physics, with special relativity time and time translation invariance have lost their independent identity from the rest of spacetime coordinate transformations (Einstein: time is an illusion), but not so in common sense and in quantum mechanics; It has been claimed that the contradiction can be solved by the path-integral approach.
@ Being vs becoming: Savitt in(01) [being and becoming]; Markosian in(02); Davies SA(02)sep [flow]; Greene NYT(03); Le Poidevin in(04) [perception]; Hartle AJP(05)feb-gq/04 [emergence of past, present and future]; Ellis GRG(06)gq, a0812-essay [block universe vs evolution]; Miller qp/06-in [quantum mechanics as a consistency condition]; Christian in(07)gq/06 [new generalized theory]; Sorkin gq/07-in [causal set sequential growth models as examples].
@ Relationalist view: Barbour 99; Barbour a0903-FQXi; Rovelli a0903-FQXi; Girelli et al a0903-FQXi [emergence model]; > s.a. parametrized theories.

Related Concepts > s.a. clocks; Simultaneity.
* Advanced time: The advanced time at a point x' with respect to (x, t) is the time at which a signal leaving (x, t) and traveling at the speed of light, arrives at x', or t_adv:= t + r/c, where r:= x–x'.

References
@ Interdisciplinary Perspectives on Time Ann NYAS 138(67)367-915 [*]; Baert ed-00; Buccheri et al ed-03.
@ General: Flood & Lockwood ed-86; Griffin ed-86; Costa de Beauregard 87; Levich ed-95, ed-96; Rovelli NCB(95); Svozil in(96)-a0904 [and intrinsic observers]; Parr 97; Butterfield ed-99; Foschini qp/99; Tokuo IJTP(09) [time intervals as basic objects, and orthologic]; Boyarsky & Góra IJTP(09) [based on a particle's interaction with the Higgs field]; Tuisku et al PRS(09) [and thermodynamics, flow of energy].
@ Books, I: Landsberg 82; Fraser 87; Gold ed-87; Coveney & Highfield 90; Fraser ed-90; Friedman 90; Lockwood 05 [and time travel].
@ History: Whitrow 89; Szamosi HS(90) [Newtonian]; Borst 93 [Middle Ages]; Novikov 98; Narayan a0708 [Indian cosmology, cycles].
@ Philosophical / conceptual: Whitrow 81; Horwich 87; Smith 93 [and language]; Caticha mp/00-in; Weiskopf BJPS(04) [and cognitiion]; Oaklander 04 [ontology]; Harrington SHPMP(08) [point-present theories and the future]; Lobo a0710-in.

In Classical Mechanics
* Idea: In its usual presentation, classical mechanics appears to give time a very special role, but it is well known that it can be formulated so as to treat time on the same footing as the other variables in the extended configuration space.
@ As dynamical variable: Grigorescu CJP(00)mp [canonical]; Bhamathi & Sudarshan PLA(03).
@ In thermodynamics: da Costa & Sant'Anna FPL(01)gq, mp/01, FP(02) [thermodynamics without t].
@ Related topics: Jaroszkiewicz & Norton JPA(97) [discrete time].

In Special Relativity [> s.a. special relativity.]
* Idea: Loses the uniqueness it had in classical mechanics; Time is no longer a specific function, but just a measure of timelike distance along some worldline; The direction of time is now defined up to a Lorentz transformation.
@ General references: Rodrigues & Rosa FP(89); Kobe AJP(93)nov [parametrizations]; Selleri FP(97); Lindesay & Gill FP(04) [proper ]; Ya'acov JPA(06) [internal time]; Boyarsky & Gora a0705 [time measurement definition using fundamental scale].
@ Effects: Goy & Selleri FPL(97)gq [rotation]; Bahder gq/98 [rotating clock]; Leffert ap/02/MNRAS [running backwards??].

In Other Theories > s.a. time in quantum mechanics.
* Two-time physics: The theory proposed by Itzhak Bars and collaborators has one extra timelike and one extra spacelike dimension (4+2); Claimed to be free of problems with unitarity and causality, and to explain CP conservation in QCD without the need for the axion, among other things.
@ Parametrized theories: Hartle & Kuchar in(84); Magnin NCB(96), NCB(98) [relational]; Albrecht & Iglesias PRD(08)-a0708 [emergent]; Rañada & Tiemblo FP(08); > s.a. time in gravity; time in quantum gravity.
@ Two-time physics: Bars PRD(00)ht, PRD(00)ht [in field theory], CQG(01)ht/00 [survey]; Bars & Deliduman PRD(01)ht [particle + gauge field]; Bars PRD(06)ht, ht/06-in [and standard model]; Chagas ht/06 [with minimum length]; news pn(07)jun; Bars & Kuo PRL(07) [with N = 1 Supersymmetry]; Chagas a0802 [in quantum mechanics]; Craig & Weinstein PRS(09) [initial-value problem]; > s.a. black holes in modified theories; brane world; higher-dimensional gravity; kaluza-klein theory; time in gravity and quantum gravity.
@ Complex time: Mejías et al CSF(04); Fujii qp/07-in [comment on a paper by Rajeev].
@ Different views: Oleinik et al qp/00-in [dynamical inhomogeneity]; Lynds FPL(03).

Online Resources > see International Society for the Study of Time; FQXi essay contest.

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send feedback and suggestions to bombelli at olemiss.edu – modified 17 oct 2009