La flèche du temps, la cosmologie et la finalité
HERVÉ BARREAU CNRS-Strasbourg-Nancy
Dans Le Second Principe de la Science du Temps, dont le sous-titre s'énonce entropie, information, irréversibilité, Olivier Costa de Beauregard s'est donné comme but, semble-t-il, de montrer que, bien que les lois fonda- mentales de la physique soient invariantes par renversement du temps, c'est un fait que l'entropie croît dans l'univers, et que cette anisotropie du temps physique doit relever d'une raison qui n'est pas, en définitive, physique mais psychique et métaphysique. Il convient d'examiner les aspects essentiels de cette thèse, à la fois épistémologique et métaphysique, avant d'essayer de la prolonger avec des présupposés un peu différents. Tel est le dessein de cette contribution, qui veut être un hommage à l'un des maîtres les plus prestigieux de l'épistémologie française depuis la deuxième guerre mondiale, un maître auquel l'auteur de ces lignes doit de s'être avancé sur un sujet qui avait été balisé avant lui par l'expert et le géomètre incomparable qu'est Costa de Beauregard.
1 Les deux apports essentiels de la thèse du Second Principe
Il est difficile de partager certaines analyses de l'auteur, souvent reprises ou mentionnées, qui constituent des étapes importantes de cette thèse sur l'irréversibilité physique, laquelle est assez complexe, puisqu'elle privilégie l'aspect objectif par rapport à l'aspect subjectif du calcul des probabilités, bien qu'elle assigne finalement une raison subjective et psychique au dérou- lement de l'univers. En particulier l'analyse initiale que fait l'auteur du théorème de Bayes ne semble pas interdire, malgré le témoignage concordant d'autres auteurs, une "rétrodiction aveugle", pas davantage qu'elle n'autorise une "prédiction aveugle", puisque, dans les deux cas, il faut tenir compte de la "probabilité a priori des causes", et que, dans le premier cas, où l'on s'interroge sur l'éventualité d'une des causes possibles d'un événement donné,
LO IDXW WHQLU FRPSWH GX GpQRPLQDWHXU GX VHFRQG WHUPH GH OpTXDWLRQ XQ Gp QRPLQDWHXU TXL pQRQFH OD SUREDELOLWp WRWDOH GH OHIIHW TXHOOH TXHQ VRLW OD FDXVHSRXUTXHOHV\VWqPHGHVSUREDELOLWpVDSRVWHULRULGHVFDXVHVVRLWXQ YpULWDEOH V\VWqPH GH SUREDELOLWpV 5LHQ GDQV OpTXDWLRQ QH SHUPHW GRQF GH PHWWUH HQ pYLGHQFH OD FDUDFWqUH VSpFLDO GX UHWRXU YHUV OH SDVVp TXL HVW DX FRQWUDLUH WRXMRXUV FRQVLGpUp QRWDPPHQW GDQV OpTXDWLRQ LQLWLDOH GR HVW GpULYpH OHVWLPDWLRQ GH OD SUREDELOLWp FRQGLWLRQQHOOHD SRVWHULRULGHV FDXVHV FRPPH H[DFWHPHQW V\PpWULTXH GH OD SUpYLVLRQ GX IXWXU &HWWH VLWXDWLRQ QD ULHQGpWRQQDQWSXLVTXHOHWKpRUqPHGH%D\HVUHSRVHVHXOHPHQWVXUOLQGpSHQ GDQFH GH OD SUREDELOLWpD SULRUL GHV FDXVHV SDU UDSSRUW j OD SUREDELOLWp GHV HIIHWV UHODWLYHPHQW j OXQH GH OHXUV FDXVHV SRVVLEOHV 4XH GDQV OLJQRUDQFH KDELWXHOOH R ORQ HVW GHV SUREDELOLWpVD SULRUL GHV FDXVHV RQ OHV SUHQQH WRXWHV pJDOHV FH TXL VHPEOH UDLVRQQDEOH TXDQG RQ YHXW IDLUH VHUYLU OH WKpRUqPHjXQWHVWGK\SRWKqVHUHODWLYHPHQWjOXQHGHVFDXVHVSRVVLEOHVGXQ pYpQHPHQWFRQVLGpUpQHFKDQJHILQDOHPHQWULHQjODQDWXUHLQWHPSRUHOOHGX SUREOqPH,OHQVHUDLWDXWUHPHQWVLFRQQDLVVDQWSDUIDLWHPHQWODSUREDELOLWpD SULRULGHVFDXVHVRQVDYDLWFDOFXOHUGDQVFKDTXHFDV ODSUREDELOLWpGHOXQGH OHXUVHIIHWVSRVVLEOHV FDURQXWLOLVHUDLWDORUVXQHLQIRUPDWLRQVXSSOpPHQWDLUH DFTXLVH pYHQWXHOOHPHQW SDU GHV H[SpULHQFHV DQWpFpGHQWHV PDLV MXVWHPHQW OH WKpRUqPHGH%D\HVQHIDLWQXOOHPHQWDSSHOjFHVXSSOpPHQWGLQIRUPDWLRQSDU UDSSRUW DX FDV JpQpUDO GRQW LO WUDLWH &HWWH UpVHUYH VXU OD VLJQLILFDWLRQ GX WKpRUqPHTXLQRXVVHPEOHLPSRUWDQWHFRPSWHWHQXGHOXVDJHUpSpWpTXHIDLW ODXWHXU GXQ VRLGLVDQW SULQFLSHV GH %D\HV LQWHUGLVDQW OD UpWURGLFWLRQ DYHXJOH QHQOqYH DEVROXPHQW ULHQ j OD UHPDUTXDEOH GpPRQVWUDWLRQ TXRQ WURXYH SHX DSUqV GDQV ORXYUDJH GH OpTXLYDOHQFH GX SULQFLSH GH OHQWURSLH FURLVVDQWHHWGXSULQFLSHGHVDFWLRQVUHWDUGpHVRSFLWSS&HVWSDUFH GHUQLHUPR\HQPRQWUHODXWHXUTXRQSHXWUHOLHUOHVHQVGXWHPSVDXSULQFLSH SK\VLTXH GH FDXVDOLWp EHDXFRXS PLHX[ TXj ODLGH GH[SpULHQFHV GH SHQVpH TXLSUpVXSSRVHQWWRXMRXUVOHVHQVGXWHPSVFILELGSHWORQQHSHXWTXH VXLYUH VHPEOHWLO ODXWHXU VXU FH SRLQW TXL QHVW SDV PLV HQ pYLGHQFH DYHF DXWDQWGHFODUWpSDUOHQVHPEOHGHVH[SHUWVLELGS
3DUDLOOHXUVODSSHOTXHIDLWODXWHXUjODF\EHUQpWLTXHHWjODWKpRULHGHOLQ IRUPDWLRQ SRXU REWHQLU OH SULQFLSH GH &DUQRW JpQpUDOLVp R OLQIRUPDWLRQ REWHQXH j ODLGH GXQH H[SpULPHQWDWLRQ SK\VLTXH HVW GpGXLWH GH OD SHUWH JOR EDOH GH QpJXHQWURSLH HVW LQWpUHVVDQW SRXU PRQWUHU TXH FHWWH DFTXLVLWLRQ GH FRQQDLVVDQFH HVW GpULYpH GH OH[SpULHQFH TXL VHXOH SHXW LQIRUPHU DYHF FHUWL WXGH0DLVFHWDSSHOQHVHPEOHJXqUHSHUWLQHQWSRXUSRVHUOHSUREOqPHGHOD FRQYHUVLRQ GH OLQIRUPDWLRQ HQ QpJXHQWURSLH TXL LQWpUHVVH ODXWHXU GDQV OD SHUVSHFWLYHTXLODGHUHOLHUOpYROXWLRQELRORJLTXHjOpYROXWLRQSK\VLTXHGRQW ODOOXUHJpQpUDOHHVWFRQVLGpUpHFRPPHDFTXLVH/HSUREOqPHHQHIIHWHVWTXH
OpYROXWLRQ ELRORJLTXH DXWDQW TXH QRXV SRXYRQV OD UHFRQVWLWXHU SRXU FH TXL FRQFHUQH OKLVWRLUH GHV HVSqFHV YD YHUV OD FRPSOH[LWp HW ORUJDQLVDWLRQ QRQ YHUVOKRPRJpQpLWpHWOHGpVRUGUHFRPPHOHODLVVHUDLWSUpYRLUODORLSK\VLTXH GH OHQWURSLH FURLVVDQWH 0DLV QRWUH SULVH GH FRQQDLVVDQFH GH FHWWH GLVFRU GDQFH QD DXFXQ HIIHW VXU OLQYHUVLRQ FRQVWDWpH GH OD PDUFKH HW ODXWHXU QH VRXWLHQW pYLGHPPHQW ULHQ GH WHO /DXWHXU VDFFRUGH PrPH DYHF 5D\PRQG 5X\HU SRXU HVWLPHU TXLO IDXW UHIXVHU GLJQRUHU ODVSHFW VLJQLILFDWLI HW UHSUp VHQWDWLI GH OLQIRUPDWLRQDFTXLVLWLRQ GH FRQQDLVVDQFH HW WUDLWHU VHPEODEOH PHQW OLQIRUPDWLRQSRXYRLU GRUJDQLVDWLRQ DYHF ODTXHOOH HOOH VpFKDQJH GDQV VD WKpRULH PDLV DORUV QH IDXWLO SDV FRQJpGLHU OD WKpRULH PDWKpPDWLTXH GH OLQIRUPDWLRQ TXL UHSRVH VXU FHWWH LJQRUDQFH HW WHQLU FRPSWH VHXOHPHQW FRPPHODIDLW55X\HUGDQV/DF\EHUQpWLTXHHWORULJLQHGHOLQIRUPDWLRQ GH OLQIRUPDWLRQ VLJQLILDQWH TXL FDUDFWpULVH WRXW RUJDQLVPH YLYDQW" /H SUREOqPH HVW WRXMRXUV GDFWXDOLWp &HUWDLQV DXWHXUVVH FRQWHQWHQW GH FDUDF WpULVHU OHV V\VWqPHV pPHUJHQWV SDU OH[FHSWLRQ TXLOV SUpVHQWHQW SDU UDSSRUW DXSULQFLSHGHVRXVDGGLWLYLWpGHOHQWURSLHFKDQJpH GHVLJQH+GXWRXWSDU UDSSRUW DX[ HQWURSLHV GHV SDUWLHV FRQVWLWXDQWHV 6DQV DXFXQ GRXWH FHV V\VWqPHV pPHUJHQWV QREpLVVHQW SDV j OXQ GHV SULQFLSHV GH OD WKpRULH GH OLQIRUPDWLRQGH6KDQQRQHWFHWWHVLPSOHUHPDUTXHVXIILWjPRQWUHUFRPELHQ OHV V\VWqPHV QDWXUHOV TXL MRXLVVHQW GLQWHUDFWLRQ HQWUH OHXUV pOpPHQWV HWRX DYHF OHXU PLOLHX H[WpULHXU GLIIqUHQW GHV V\VWqPHV DUWLILFLHOV GH FRPPXQLFD WLRQ SRXU OHVTXHOV D pWp pODERUpH OD WKpRULH PDWKpPDWLTXH GH OLQIRUPDWLRQ
&H UpVXOWDW HVW LQWpUHVVDQW HQ OXLPrPH PDLV QH UHQVHLJQH QXOOHPHQW VXU OD SURGLJLHXVHIDFXOWpGLQYHQWLRQTXHODYLHVHPEOHDYRLUGpSOR\pHDXFRXUVGH OpYROXWLRQFUpDWLRQGHVHVSqFHVYLYDQWHV&RVWDGH%HDXUHJDUGVHJDUGHELHQ GHVRQF{WpGHQLHUFHWWHSURGLJLHXVHIDFXOWpTXH%HUJVRQDPLVHHQUHOLHIHW TXLOUHSUHQGjVRQFRPSWH,OFURLWUHQGUHVHQVLEOHODGLIILFXOWpGHODFUpDWLRQ GRUGUH RX GRUJDQLVDWLRQ SDU OD PLVH HQ YDOHXU GX FRHIILFLHQW GpTXLYDOHQFH .OQGpIDYRUDEOH j OD WUDQVLWLRQ LQIRUPDWLRQ YHUV QpJXHQWURSLH TXH GHV DXWHXUVFRPPH%ULOORXLQRQWLQWURGXLWSRXUH[RUFLVHUOHGpPRQGH0D[ZHOO HW LO LQWURGXLW OXLPrPH GDQV FHWWH SHUVSHFWLYH OH FRQFHSW GH QpJXHQWURSLH SRWHQWLHOOH &HVW FHW DWWDFKHPHQW DX[ LGpHV GLUHFWULFHV GH OD F\EHUQpWLTXH PrPHVLOFRQGXLWjOHVpODUJLUHWjOHVUpIRUPHUTXLQRXVVHPEOHSHXFUpGLEOH
R.Ruyer, la cybernétique et l'origine de l'information,Paris, Flammarion, 1954
cf.J.Ricard, "Reduction, Integration, Emergence and Complexity in Bio- logical Networks" in Complexity and Emergence, E.Agazzi & L.Montecucco ed., World Scientific, 2002,101-112
FRPSWHWHQXGXSUREOqPHTXLHVWHQFDXVH&HWWHUpVHUYHjQRXYHDXQHQWDPH HQ ULHQ OD WUqV LPSRUWDQWH FRQWULEXWLRQ TXH IDLW &RVWD GH %HDXUHJDUG HQ DW WULEXDQWjOXQLYHUVOXLPrPHODUHVSRQVDELOLWpGHODGLUHFWLRQGXWHPSVSRXU OHV SKpQRPqQHV YLWDX[ FRPPH SRXU OHV SKpQRPqQHV SK\VLTXHV PrPH VLO UHVWHjH[SOLTXHUFRPPHQWFHWWHGLUHFWLRQXQLTXHVDFFRPPRGHGHODGpFURLV VDQFHORFDOHpYHQWXHOOHGHOHQWURSLHGDQVOHFDVGHFUpDWLRQGRUGUHDXVVLELHQ TXH GH OD FURLVVDQFH JpQpUDOH GH OHQWURSLH SK\VLTXH &HWWH FRQWULEXWLRQ VH WURXYH DX FKDSLWUH ,9 GX6HFRQG 3ULQFLSH /D ORL TXL LPSRVH j WRXWHV OHV pYROXWLRQV SDUWLHOOHV GDYRLU OD PrPH IOqFKH TXL HVW OD IOqFKH GH OpYROXWLRQ JOREDOHQDSDVGDXWUHRULJLQHTXHFHOOHFL DXFXQV\VWqPHSDUWLHOWDQWVRLW SHX FRPSOH[H QHVW VXIILVDPPHQW LVROp SRXU TXH VRQ pYROXWLRQ GH GURLW V\PpWULTXHHQWUHDYHQLUHWSDVVpQHVRLWHQIDLWFRQWDPLQpHSDUFHOOHGXWRXW GHOXQLYHUV&HVWODORLGXQHDFWLRQFRQWUDLJQDQWHH[HUFpHSDUOHWRXWVXUOD SDUWLH&KDTXH pYROXWLRQ SDUWLHOOH UHSURGXLW SDU IRUFH OHPSUHLQWH LQGpOpELOH GH OpYROXWLRQ WRWDOH LELGS &HWWH DIILUPDWLRQ FDSLWDOH QDXUDLW SDV JUDQG VHQV VL HOOH QH SRXYDLW VDFFRUGHU DYHF OD GLIIpUHQFH GHV pYROXWLRQV HQWURSLTXHV VLJQDOpHV SOXV KDXW HWTXLGRQFSRXUQRXVUHVWHHQFRUHLQH[SOL TXpH0DLVOLQWpUrWGHODIILUPDWLRQGH&RVWDGH%HDXUHJDUGHVW TXHOOHSHUPHW GHPDQLIHVWHUFHWDFFRUG$ODTXHVWLRQ3RXUTXRLOHWHPSVGHVrWUHVYLYDQWV RX FRQVFLHQWV H[SORUHWLO OD GLPHQVLRQ WHPSRUHOOH GH OXQLYHUV GDQV OH VHQV TXL IDLW DSSDUDvWUH OHV HQWURSLHV FRPPH FURLVVDQWHV HW OHV DFWLRQV FRPPH UHWDUGpHV HW QRQ SDV GDQV OH VHQV FRQWUDLUH" &RVWD GH %HDXUHJDUG SHXW UpSRQGUH &HVW SHXWrWUH SDUFH TXH OD YLHHWODFRQVFLHQFH VRQW REOLJpHV SDUQDWXUHGHUHJDUGHUGDQVOHVHQVRHVWODFHUWLWXGHHWGHWRXUQHUOHGRVj FHOXL R HVW OLQFHUWLWXGH $XWUHPHQWGLW/H IOX[ LQWpULHXUGH OD YLH SV\
FKLTXH HVW OLp GH PDQLqUH HVVHQWLHOOH j XQ IOX[ GLQIRUPDWLRQ HQWUDQWH LELGS &HWWH DGDSWDWLRQ QpFHVVDLUH GH OD YLH HW GH OD FRQVFLHQFH j OD PDUFKH SK\VLTXH GH OXQLYHUV GDQV OH VHQV GH OHQWURSLH FURLVVDQWH DYDLW pWp ELHQDSHUoXHQRWH&RVWDGH%HDXUHJDUGSDU%ROW]PDQQGRQWLOVHSODLWjFLWHU XQH UHPDUTXH SHUWLQHQWH'HPrPHTXHQXQHUpJLRQGpWHUPLQpH GHODVXU IDFHGHQRWUHSODQqWHQRXVFRQVLGpURQVFRPPHOHGHVVRXVODGLUHFWLRQTXLYD YHUVOHFHQWUHGHODWHUUHGHPrPHXQrWUHYLYDQWGDQVXQHSKDVHGpWHUPLQpH GX WHPSV GpVLJQHUD OD GLUHFWLRQ GH OD GXUpH TXL YD YHUV OHV pWDWV OHV PRLQV SUREDEOHV DXWUHPHQW TXH OD GLUHFWLRQ FRQWUDLUH OD SUHPLqUH VHUD SRXU OXL OH SDVVp RX OH FRPPHQFHPHQW HW OD VHFRQGH ODYHQLU RX OD ILQ HW GDSUqV FHWWH GpVLJQDWLRQ RQ DXUD WRXMRXUVDX GpEXW GX WHPSVXQ pWDW LPSUREDEOH &HWWH PpWKRGHPHVHPEOHODVHXOHTXLSHUPHWWHGHFRQFHYRLUOHGHX[LqPHSULQFLSH GH ODWKHUPRG\QDPLTXHVDQVHQWUDvQHUXQHPRGLILFDWLRQLUUpYHUVLEOHGH OXQL YHUV WRXW HQWLHU /HoRQV VXU OD WKpRULH GHV JD]WUDGIU 3DULV S
$LQVL SRXU %ROW]PDQQ XQH PRGLILFDWLRQ LUUpYHUVLEOH GH OXQLYHUV WRXW HQ
WLHUpWDLWIRUWGLIILFLOHjFRQFHYRLUHWGRQFjUHMHWHUHWLOLPDJLQDLWSOXW{WGHV UpJLRQVGH OXQLYHUVROpFDUWSDUUDSSRUWjOpTXLOLEUHWKHUPLTXHSRXYDLWDOOHU SRXUXQHGXUpHGpWHUPLQpHVRLWGDQVOHVHQVGHOHQWURSLHFURLVVDQWHVRLWGDQV OH VHQV GH OHQWURSLH GpFURLVVDQWH PDLV LQFRQWHVWDEOHPHQW SRXUOXLOHVrWUHV YLYDQWVYRLHQWOpYROXWLRQGDQVOHVHQVTXLYDYHUVOHSOXVSUREDEOHFDUOpYR OXWLRQFRQWUDLUHOHXUVHUDLWLQVXSSRUWDEOH3RLQFDUpDYDLWIDLWGHVUHPDUTXHVGH FH JHQUH LO Q\ D GH YLH SRVVLEOH TXH Oj R OHQWURSLH GpFURvW 0DLV DORUV QDYRQV QRXV SDV DIIDLUH LFL j XQH LQGLFDWLRQ LPSRUWDQWH QRWUH XQLYHUV QH VHUDLWLO SDV IDLW SRXU DEULWHU GHV rWUHV YLYDQWV HW FRQVFLHQWV TXHOOH TXH VRLW GDLOOHXUVORULJLQHGHFHX[FL",OIDXGUDUHYHQLUVXUFHSRLQW
(QUHWHQDQWOHVGHX[pFODLUDJHVPDMHXUVTXH&RVWDGH%HDXUHJDUGDDSSRU WpV DXSUREOqPHGHODGLUHFWLRQGXWHPSVODFURLVVDQFHXQLYHUVHOOHGHOHQWUR SLHGXQHSDUWODFRQYHQDQFHGHFHWWHFURLVVDQFHjOH[HUFLFHGHVIRQFWLRQVTXL FDUDFWpULVHQW OrWUH YLYDQW GDXWUH SDUW QH SHXWRQ SDV SURORQJHU FHV GHX[
OLJQHV GH SHQVpH HQ VH SRVDQW OHV TXHVWLRQV VXLYDQWHV HQ TXRL OD IOqFKH GX WHPSV HVWHOOH OLpH j OD FRVPRORJLH" HQ TXRL OD FRVPRORJLH SHXWHOOH rWUH OH WpPRLQGXQHILQDOLWpTXLVHPDQLIHVWHjOpYLGHQFHGDQVODFRQVFLHQFHHWGDQV OD YLH" &HVW j FHV GHX[ TXHVWLRQV TXH ORQ YRXGUDLW SOXV ORLQ DSSRUWHU TXHOTXHVpOpPHQWVGHUpSRQVH
/DIOqFKHGXWHPSVHWODFRVPRORJLH
&RVWDGH%HDXUHJDUGTXLOLHODIOqFKHGXWHPSVjODFRVPRORJLHQHSHXWOH IDLUH TXHQ LQWURGXLVDQW XQH SURSHQVLRQ FDUDFWpULVWLTXH GHV rWUHV YLYDQWV j RULHQWHUOHWHPSVGDQVOHVHQVGHOLQIRUPDWLRQHWGRQFGHOHQWURSLHFURLVVDQ WHV SULQFLSH GH &DUQRW JpQpUDOLVp SDU OD F\EHUQpWLTXH FDU LO VH WURXYH FRQWUDLQWSHQVHWLOSDUXQHLQWHUSUpWDWLRQRQWRORJLTXHWUqVVWULFWHGHODWKpR ULHGHOD5HODWLYLWp
'DQVXQFDGUH GHSHQVpHH[SOLFLWHPHQWFRYDULDQWDXVHQVPLQNRYVNLHQLO HVW QRQ VHXOHPHQW UHFRPPDQGp PDLV QpFHVVDLUH GH FRQFHYRLU OXQLYHUV FRPPH UpHOOHPHQW GpSOR\p GXQ VHXO FRXS GDQV VRQ pSDLVVHXU WHPSRUHOOH DXVVL ELHQ TXH GDQV VHV WURLV GLPHQVLRQV VSDWLDOHV &RPPH OpFULW IRUWHPHQW +:H\OOHPRQGHREMHFWLIVLPSOHPHQWHVWLOQDGYLHQWSDVRSFLWS
,OQHVDJLWSDVLFLGHPHWWUHHQGRXWHOpTXLYDOHQFHPpWULTXHGXWHPSVHWGH OHVSDFH LPSRVp SDU OD FRQVWDQWH XQLYHUVHOOHF PDLV GH UHPDUTXHU TXH VL OHVSDFHWHPSV PLQNRYVNLHQ GpIRUPp pYHQWXHOOHPHQW SDU XQH FRXUEXUH ULH PDQQLHQQHUHPSODFHGHIDLWSRXUQRWUHSK\VLTXHOHVSDFHHWOHWHPSVDEVR OXV GH 1HZWRQ FHOD QH YHXW SDV GLUH TXH FH FDGUH VSDWLRWHPSRUHO H[LVWHQH YDULHWXUHWSUpH[LVWHDX[pYpQHPHQWVTXL VHORJHQWHQOXL%LHQSOXW{WFHVRQW OHV IDLWV SK\VLTXHV SRXU QRXV TXL VH SURGXLVHQW GDERUG HQ REpLVVDQW DX SULQFLSHGH&DUQRWJpQpUDOLVpRXQRQHWVXUOHVTXHOVQRXVSURMHWRQVODJULOOH
VSDWLRWHPSRUHOOH TXL SHUPHW GH OHV PHVXUHU HQ XWLOLVDQW OD FRQVWDQWH XQL YHUVHOOHF &HWWH JULOOH VSDWLRWHPSRUHOOH QRXV HVW LQGLVSHQVDEOH SRXU IDLUH XQHSK\VLTXHFRKpUHQWHHWIpFRQGHHWRQGRLWGLUHTXHOOHQRXVHVWSURSRVpH SDU OD 1DWXUH HOOHPrPH 0DLV OD FRKpUHQFH GH QRWUH SK\VLTXH QLPSRVH DX FXQH QpFHVVLWp j OD 1DWXUH PrPH VL OD FRQVWDQWH XQLYHUVHOOHF REOLJH QRWUH UHSUpVHQWDWLRQ VSDWLRWHPSRUHOOH j HQ WHQLU FRPSWH GDQV QRV PHVXUHV SK\
VLTXHV'pMjODWKpRULHGHOD5HODWLYLWpJpQpUDOLVpHjODJUDYLWDWLRQQRXVREOLJH jSHQVHUTXHOHWUDMHWGHODOXPLqUHQHVWSDVUHFWLOLJQHFRPPHRQOHVXSSRVH UDLVRQQDEOHPHQW j QRWUH pFKHOOH PDLV FXUYLOLJQH TXDQG OHVSDFHWHPSV HVW GpIRUPp SDU OD SUpVHQFH GHV PDVVHVpQHUJLHV &HVW GpMj VXIILVDQW SRXU QRXV QRWLILHU TXH OHVSDFHWHPSV ULJLGH GH 0LQNRYVNL QHVW TXXQH DSSUR[LPDWLRQ YDODEOHjQRWUHpFKHOOH0DLVQRXVGHYRQVrWUHSUrWVjIDLUHXQSDVVXSSOpPHQ WDLUH&HQRXYHDXSDVTXLHVWGpFLVLIHVWHIIHFWXpSDUOHSURORQJHPHQWGHOD WKpRULH UHODWLYLVWH GH OD JUDYLWDWLRQ GDQV VRQ DSSOLFDWLRQ j O8QLYHUV HQWLHU
$ORUVQRXVGHYRQVFRQFHYRLUXQ8QLYHUVG\QDPLTXHGRQWOHVOLPLWHVVSDWLD OHVYDULHQWDYHFOHWHPSVSRXUYXTXHQRXVFRQVHQWLRQVjGRWHUO8QLYHUVGHV SURSULpWpV JOREDOHV GKRPRJpQpLWp HW GLVRWURSLH VSDWLDOHV TXL VDFFRUGHQW VL ELHQDYHFOHVH[LJHQFHVUHODWLYLVWHV$ORUVQRXVSpQpWURQVGDYDQWDJHGDQVOHV VHFUHWVGHOD1DWXUHHWQRXVSRXYRQVFRQFHYRLUVRQ+LVWRLUHTXLFRPPHQFH DYHF OH %LJ %DQJ FRPPH XQH SHUSpWXHOOH H[SDQVLRQ GRQW OH WHUPH UHVWH LQFHUWDLQ HW VHORQ OpWDW GH QRV FRQQDLVVDQFHV UHODWLYHV j OD PDWLqUHQRLUH SHXWrWUHLQH[LVWDQW
/D FRVPRORJLH UHODWLYLVWH LVVXH GHV WUDYDX[ G(LQVWHLQ HW LQLWLpH SDU VD SURSUH FRQWULEXWLRQ QHVW VDQV GRXWH TXXQH FRQVWUXFWLRQ WKpRULTXH SHUPLVH SDU OREVHUYDWLRQ DVWURQRPLTXH PDLV TXL SRXUUDLW rWUH UpIXWpH &HSHQGDQW GHSXLVVRL[DQWHTXLQ]HDQVTXHOOHHVWQpHODQFpHSDU/HPDvWUHHWFRUURERUpH SDUOHVREVHUYDWLRQVGH+XEEOHTXLHXWGDERUGGHODUpWLFHQFHj\FURLUHHOOH D SX VXUPRQWHU OHV GLIIpUHQWHV REMHFWLRQV TXL OXL RQW pWp IDLWHV UHFHYRLU GH OXQLYHUVHO UD\RQQHPHQW FRVPLTXH j . XQH FRQILUPDWLRQ DWWHQGXH HW UDQJHUGDQVOHFDGUHGHOH[SDQVLRQFRVPLTXHODQDLVVDQFHGHVpOpPHQWVSK\V LFRFKLPLTXHV TXH QRXV FRQQDLVVRQV FRPPH GH OD IRUPDWLRQ GHV pWRLOHV HW JDOD[LHV &HOD VXIILW SRXU OXL GRQQHU j GpIDXW GXQH FHUWLWXGH LPSRVVLEOH j DWWHLQGUH GDQV FH GRPDLQH XQH YUDLVHPEODQFH TXDXFXQH WKpRULH ULYDOH HQOD PDWLqUHQDSXDWWHLQGUH
2U LO HVW FODLU TXXQH FRVPRORJLH UHODWLYLVWH QHVW SRVVLEOH TXH VL ORQ Gp FRXSOHOHWHPSVGHVWURLVGLPHQVLRQVVSDWLDOHVHQLQWURGXLVDQWOHWHPSVFRV PLTXHW FHOXL TXRQ REWLHQGUDLW HQ V\QFKURQLVDQW OHV WHPSV SURSUHV GHV JDOD[LHV FRPPH OD GpILQL -+HLGPDQ &HVW +HUPDQQ :H\O OXLPrPH TXL DYDLW GRQQp j FH WHPSV OH TXDOLILFDWLI GH FRVPLTXH HW ORQ SHXW FURLUHTXLOOHFRQVLGpUDLWFRPPHUpHOPrPHVLFRPPHLOODGLWDXVVLOHV
SDFHWHPSV PLQNRYVNLHQ RX ULHPDQQLHQ pWDLW REMHFWLI SXLVTXH FH GHUQLHU HVW FRQIRUPH DX[ H[LJHQFHV IRXUQLHV SDU OD 1DWXUH HOOHPrPH GH QRWUH UH SUpVHQWDWLRQGHVORLVGHVSKpQRPqQHV
6LO8QLYHUVHVWHQH[SDQVLRQVRQHQWURSLHHVWFURLVVDQWHHWVDWHPSpUDWXUH GpFURvW HW ORQ D SX PRQWUHU TXH VD WHPSpUDWXUH pWDLW GDQV XQ kJH PRLQV DYDQFpGHVRQH[SDQVLRQVXSpULHXUHj.2QWURXYHOjODORLGXQHDFWLRQ FRQWUDLJDQWHH[HUFpH SDUOH WRXWVXUODSDUWLHFRPPHOHUpFODPDLWSOXVKDXW
&RVWD GH %HDXUHJDUG DILQ GREWHQLU OD IOqFKH GH OpYROXWLRQ JOREDOH 4XHO PHLOOHXU PR\HQ GREWHQLU FHWWH IOqFKH TXH GH OD WURXYHU GpMj SURSRVpH SDU OpYROXWLRQ PrPHGHO8QLYHUV"%HDXFRXSGHWUDYDX[UpFHQWVVRQWIDYRUDEOHV jFHWWHPDQLqUHGHYRLU
'DQV FHW DSSHO DX WHPSV FRVPLTXH RQ WURXYH DXVVL OD UpDOLVDWLRQ GXQH FRQGLWLRQTXH5HLFKHQEDFKHW*UQEDXPDYDLHQWH[LJpHSRXUUHQGUHFRPSWH GXQ SRLQW GH YXH SXUHPHQW SK\VLTXH GH OD GLUHFWLRQ GX WHPSV2Q VDLW TXH FHVDXWHXUVFRQVWDWDQWTXHOLQWHUSUpWDWLRQVWDWLVWLTXHGHOHQWURSLHQHSHUPHW WDLW SDV GDVVXUHU FHWWH GLUHFWLRQ FRQVWDQWH FRPPH %ROW]PDQQ HQ DYDLW OLQ WLPH FRQYLFWLRQ DYDLHQW LPDJLQp OD WKpRULH GHVEUDQFK V\VWHPV VHORQ ODTXHOOH GHV V\VWqPHV TXL RQWpWpHQLQWHUDFWLRQVpFDUWHQWOHVXQVGHVDXWUHV GDQVXQpWDWGHUHODWLYHPHQWEDVVHHQWURSLHHWpYROXHQWHQVXLWHSRXUODSOX SDUWGDQVOHVHQVGXQHHQWURSLHFURLVVDQWH&RVWDGH%HDXUHJDUGTXLVLJQDOH FHWWH WKpRULH RSFLWS VH UDOOLH j OLQWHUSUpWDWLRQ GH *UQEDXP SOXW{W TXj FHOOH GH 5HLFKHQEDFK GDQV OD PHVXUH R FH GHUQLHU RSSRVDLW OD WKpRULH GHVEUDQFKV\VWHPVjFHOOHGXQHLQWHUDFWLRQIDLEOHDYHFOXQLYHUV&RVWDGH
%HDXUHJDUG FRQVLGqUH DX FRQWUDLUH DYHF *UQEDXP HW :KLWURZ TXH OD WKpRULH GHV V\VWqPHV LVROpV HW FHOOH GHVEUDQFK V\VWHPV QH VRQW TXH GHX[
DVSHFWVGLIIpUHQWVGXQHVHXOHHWPrPHWKpRULHVWDWLVWLTXHLELGHWFHWWHYXH GpULYHGHOpTXLYDOHQFHHQWUHOHSULQFLSHGHVDFWLRQVUHWDUGpHVHWFHOXLGHOHQ WURSLHFURLVVDQWHpWDEOLHSOXVKDXW0DLVDORUVTXHFKH]&RVWDGH%HDXUHJDUG HW*UQEDXPFHWWHLQWHUSUpWDWLRQVHWURXYHOLpHjODSRVLWLRQGXQEORFVSDWLR WHPSRUHO LPPRELOH FH TXL UHTXLHUW OLQWHUYHQWLRQ GrWUHV YLYDQWV SRXU LQWUR GXLUHTXHOTXHGHYHQLUGDQVFHEORFLOHVWSOXVFRKpUHQWQRXVVHPEOHWLOGH OLHUODFURLVVDQFHGHOHQWURSLHDYHFOpYROXWLRQJOREDOHGHO8QLYHUVPDUTXpH SDUODYDQFHGXWHPSVFRVPLTXH
cf. H.D.Zeh, The Physical Basis of the Direction of Time, Spinger-Verlag, 1989, 104-133
/DFRVPRORJLHHWODILQDOLWp
&RVWD GH %HDXUHJDUG FRQVLGqUH OD ILQDOLWp FRPPH OLQYHUVH GH OD FDXVDOLWp SK\VLTXH7HOOHpWDLWGDLOOHXUVODSRVLWLRQGH%HUJVRQTXH&RVWDGH%HDXUH JDUGUHSUHQGDXPRLQVVXUFHSRLQW&HTXLVHIDLWjWUDYHUVHWDX[GpSHQVGH OD QpJXHQWURSLH GX FRVPRV TXL VH GpIDLW FHVWOLQIRUPDWLRQ GHV SV\FKLVPHV LQFDUQpVGDQVODPDWLqUH&HTXLGpFURvWPRLQVYLWHTXHODVHXOHQpJXHQWURSLH PDWpULHOOH GX SULQFLSH GH &DUQRW FHWWH SOXV PpWDSK\VLTXH GHV ORLV SK\
VLTXHV FI %HUJVRQ(YROXWLRQ FUpDWULFHFKDS,,,S FHVW OD VRPPH QpJXHQWURSLHLQIRUPDWLRQGXSULQFLSHGH&DUQRWJpQpUDOLVpGH%ULOORXLQ HWGH5RWKVWHLQ(WODIRUFHLQFDSDEOHGDUUrWHUPDLVDSWHjUHWDUGHUODSHUWH GHODQpJXHQWURSLHLQLYHUVHOOHFHVWHQFRUHOLQIRUPDWLRQPDLVFHWWHIRLVVRXV VRQDVSHFWDULVWRWpOLFLHQUHJpQpUDWHXUGHQpJXHQWURSLHRSFLWS2QQH GLVFXWHUD SDV LFL ODVSHFW DULVWRWpOLFLHQ GH OLQIRUPDWLRQ SULVH FRPPH SRX YRLU GRUJDQLVDWLRQFDULOFRUUHVSRQGGHIDLWDXU{OHFRQVWLWXWLIGHVIRUPHV VXEVWDQWLHOOHV GDQV OD SKLORVRSKLH DULVWRWpOLFLHQQH GH OD 1DWXUH 6LJQDORQV FHSHQGDQW TXH FKH] $ULVWRWH FHV IRUPHV pWDLHQW pWHUQHOOHV UHIOHWV GDQV OH PRQGHSK\VLTXHGHO$FWHSXUpWHUQHODXTXHOHOOHVpWDLHQWVXVSHQGXHV,OQH SHXW pYLGHPPHQW HQ rWUH DLQVL GDQV XQH SHUVSHFWLYH pYROXWLYH TXH &RVWD GH
%HDXUHJDUG DGRSWH QRQ VHXOHPHQW j OD VXLWH GH %HUJVRQ PDLV GH WRXV OHV PRGHUQHV 3RXU QRWLILHU TXLO VDJLW ELHQ GXQ DJHQW SK\VLTXH &RVWD GH
%HDXUHJDUG HQ YLHQW j IDLUH DSSHO j XQ SULQFLSH GH FRQVHUYDWLRQ TXL SHUPHW GH UpJpQpUHU OD QpJXHQWURSLH SHUGXH VRXV OD IRUPH GLQIRUPDWLRQSRXYRLU GRUJDQLVDWLRQ7RXWVHSDVVHGDQVODGLUHFWLRQROHVSV\FKLVPHVH[SORUHQW OD H GLPHQVLRQ GH OHVSDFHWHPSV FRPPH VL OD QpJXHQWURSLH GH OXQLYHUV VH SHUGDLW LQH[RUDEOHPHQW GDQV FKDTXH PDLOOH GH OD WUDPH GHV SKpQRPqQHV FRPPH OHDX GXQ IOHXYH GX GpVHUW VRXV OHV VDEOHV 0DLV TXL VDLW SHXWrWUH VL FHTXHSHUGO8QLYHUVQHVHUHWURXYHSDVDLOOHXUVVRXVXQHDXWUHIRUPH"6LO QHIDXWSDVLFLXQHIRLVGHSOXVUHVWLWXHUOpQRQFpGXQSULQFLSHGHFRQVHUYD WLRQ HQ SRVDQW XQH GpILQLWLRQ DGpTXDWHHW ODLVVHU DX[ UHFKHUFKHV IXWXUHV OH VRLQ GH[SORUHU RSpUDWLYHPHQW OHV LPSOLFDWLRQV GX SRVWXODW FRUUHVSRQGDQW"
RSFLWSS (Q IDLW OH SRVWXODW PpWDSK\VLTXH GRQW OH FRQWHQX UHVWH FHSHQGDQW SK\VLTXH HVW ELHQ SRVp SXLVTXH &RVWD GH %HDXUHJDUG SRXUVXLW 1RXVDYRQVSURSRVpVRXVODSUpFpGHQWHUXEULTXHODWKqVHTXHODFWLRQHIIL FDFH GH OKRPPH RX GH ODQLPDO LPSOLTXH OH[LVWHQFH DYHF XQ WDX[ FHUWDLQH PHQW WUqV IDLEOH GH VRXUFHV GH QpJXHQWURSLH 1RXV VRPPHV LFL REOLJp SDU OHQVHPEOHGHODSKLORVRSKLHEHUJVRQLHQQHGpWHQGUHFHWWHK\SRWKqVHjWRXWOH GRPDLQH GH ORUJDQRJHQqVH RQWRJHQqVHHWSK\ORJHQqVH 0DLV DORUV FHV VRXUFHV K\SRWKpWLTXHV HW WUqV IDLEOHV GH QpJXHQWURSLHTXHVRQWHOOHVGRQF"
0DQLIHVWHPHQWULHQ GDXWUH TXH GHV UpVXUJHQFHV GH OD SHUWH GH OD QpJXHQ WURSLHXQLYHUVHOOHLELGS
'H OD IDoRQ TXL YLHQW GrWUH H[SOLTXpH LO DSSDUDvW GRQF TXH OD FDXVDOLWp SK\VLTXH HQ SHUGDQW GH OD QpJXHQWURSLH OD FqGH j XQ SRXYRLU SV\FKLTXH GH ILQDOLWpPpWDSK\VLTXHTXLUHVWLWXHOLQIRUPDWLRQSHUGXHVRXVODIRUPHGXFRP SRUWHPHQW YLWDO HW GHV HVSqFHV YLYDQWHV 4XDQG %HUJVRQ YRXODLW TXH OpODQ YLWDOGXIDLWGHVRQDUUrWODLVVDLWWRPEHUGDQVOHQWURSLHFURLVVDQWHWRXWHOD PDWLqUHTXLODYDLWHPSRUWpHGDQVVDFRXUVHDVFHQGDQWH&RVWDGH%HDXUHJDUG TXL YHXW TXH OXQLYHUV PDWpULHO VRLW LPPRELOH LPDJLQH TXH OD QpJXHQWURSLH LQIRUPDWLRQTXLVWUXFWXUHOXQLYHUVHQWLHUVRLWWHOOHTXHQVHSHUGDQWOHORQJGHV OLJQHVGXQLYHUVTXHSDUFRXUHQWOHVrWUHVYLYDQWVHOOHHQWUHGDQVXQVRXVVRO GR HOOH UHVXUJLW SRXU GRQQHU YLH j FHV PrPHV rWUHV YLYDQWV HW j OKLVWRLUH IXOJXUDQWHGHVHVSqFHV7HOOHHVWODYLVRQJUDQGLRVHTXLFO{W/H6HFRQG3ULQ FLSHGHOD6FLHQFHGX7HPSV
/H FRVPRV HVW DLQVL DJHQFp TXH GHV TXDWUH GLPHQVLRQV GH VRQ HVSDFH WHPSVFHVWOHORQJGHODTXDWULqPHTXHVpWHQGHQWOHVOLJQHVGHIRUFHOHUDWWD FKDQWjVRQSULQFLSHHWjVDILQ&HSULQFLSHHWFHWWHILQODPDWLqUHOHVVXELW V\PpWULTXHPHQW HW VWDWLTXHPHQW pWHQGXH TXHOOH HVW OH ORQJ GH VD GLPHQVLRQ WHPSRUHOOHFRPPHHOOHHVWpWDOpHGDQVVHV WURLVGLPHQVLRQVVSDWLDOHV
/HV SV\FKLVPHV LQFDUQpV GDQV OD PDWLqUH DX FRQWUDLUH VRQW j FKDTXH LQV WDQW GH OHXU YLH j OD SHLQH HW j OD MRLH ,PSRVVLEOH SRXU HX[ GH UHWRXUQHU HQ DUULqUHHWPrPHGHVDUUrWHUODORLGHQRQGpFURLVVDQFHGHOHXUSURSUHLQIRU PDWLRQOHOHXUGpIHQG3RXUHX[XQVHXOSUREOqPHWRXWDXWUHpWDQWVXSHUIpWD WRLUHFHOXLGXERQXVDJHGHOLQIRUPDWLRQFHVWjGLUHHQILQGXFRPSWHGX WHPSV
9RLOjSRXUTXRLFHVWVHXOHPHQWGHVSV\FKLVPHVLQFDUQpVGDQVODPDWLqUHHW WRXW j IDLW VSpFLDOHPHQW GHV SV\FKLVPHV FRQVFLHQWV TXRQ SHXW GLUH TXHQ FKHPLQDQWOHORQJGXQHGLPHQVLRQWHPSRUHOOHDJHQFpHDGKRFLOVpPDQHQWGH ODXWHXUGHOD1DWXUHFRPPHGHOHXUVRXUFHHWUHWRXUQHQWj/XLFRPPHjOHXU ILQRSFLWSS
/D GLIILFXOWp GXQH WHOOH YLVLRQ FHVW TXH OH WHPSV QD GH VHQV GDQV OHV GHX[ DFFHSWLRQV GX WHUPH VLJQLILFDWLRQ HW GLUHFWLRQ TXH SRXU OHV rWUHV YL YDQWV VSpFLDOHPHQW SRXU OHV rWUHV FRQVFLHQWV WDQGLV TXH OD GLPHQVLRQ WHP SRUHOOH GH OXQLYHUV HVW DJHQFpHDG KRF FHVWjGLUH SRXU TXH FHV PrPHV rWUHVVRLHQWjFKDTXHLQVWDQWGHOHXUYLHjODSHLQHHWjODMRLH&HWWHYLVLRQ VDXYHJDUGHDVVXUpPHQWODYDOHXUVXUpPLQHQWHGHODYLHHWGHODFRQVFLHQFHSDU UDSSRUW DX[ SKpQRPqQHV SK\VLTXHV HW ORQ GRLW rWUH UHFRQQDLVVDQW j XQ WKpRULFLHQ GH OD SK\VLTXH GH PDQLIHVWHU FHWWH YDOHXU DYHF WDQW GpFODW 0DLV FHWWHYLVLRQFRPPHFHOOHGH%HUJVRQGRQWHOOHVLQVSLUHDFFHQWXHOHGXDOLVPH GH OHVSULW HW GH OD YLH TXL pPDQH GH OHVSULW HQ WDQW TXH FUpDWHXU GLQIRUPD WLRQ HW GH ODPDWLqUH&HGXDOLVPHVHPDQLIHVWHHQSDUWLFXOLHUSDUOHGHVWLQ
DVVH] EUXWDO TXL HVW DVVLJQp j O8QLYHUV GDQV OH SDUDJUDSKH TXL VXLW LPPpGL DWHPHQWOHVWURLVSDUDJUDSKHVGHODFLWDWLRQSUpFpGHQWH
4XDQWjO8QLYHUVTXLVHPEOHjSOXVLHXUVWKpRULFLHQVpPDQHUGXQHIDQWDV WLTXH H[SORVLRQ GH FDXVDOLWp SRXUTXRL SHXWrWUH QH ILQLUDLWLO SDV GDQV XQH JLJDQWHVTXHLPSORVLRQGHILQDOLWp"6LMDPDLVODQpJXHQWURSLHSHUGXHDXFRXUV GHVPLOOpQDLUHVGHYDLWrWUHUpLQIXVpHDX&RVPRVSHQGDQWXQHGXUpHpTXLYDODQW j TXHOTXHV MRXUV OH SDVVDJH XQLYHUVHO GH OD ORL GHV DFWLRQV UHWDUGpHV j FHOOH GHV DFWLRQV DYDQFpHV VHUDLW XQH FDWDVWURSKH VDQV QRP SRXU WRXV FHX[ TXL PRXUUDLHQWGHODYLYUH&HVWjODSOHLQHIRUFHGHVWHUPHVTXHOHVYHUWXVGHV
&LHX[VHUDLHQWpEUDQOpHVTXHFKDFXQVHQWLUDLWVDYLHELRORJLTXHVHGLVVRXGUH HQ VRQ FRQWUDLUH DEVROX SHQGDQW TXH OHV &LHX[ VHUDLHQW UHSOLpV FRPPH XQH WRLOHGHWHQWHLELGS
&HWWHYLVLRQFDWDVWURSKLTXHGHODILQGHO8QLYHUVQHPDQTXHFHUWHVSDVGH FRKpUHQFHDYHFODPpWDSK\VLTXHGpYHORSSpHSRXUUHQGUHFRPSWHGHODGLUHF WLRQ GX WHPSV 0DLV RXWUH TXHOOH UHSRVH VXU OH SRVWXODW GH OLPPRELOLWp GX
&RVPRV GRQW RQ D YX SOXV KDXW TXLO QH VLPSRVH SDV j OD UpIOH[LRQ FULWLTXH VXU OHV IRQGHPHQWV GH OD SK\VLTXH HOOH SRVWXOH pJDOHPHQW XQ SULQFLSH GH FRQVHUYDWLRQ GH OD QpJXHQWURSLH GRQW RQ SHXW GLUH pJDOHPHQW TXLO QH VLP SRVHSDVjXQHUpIOH[LRQTXLVLQWHUURJHVXUOHVUDSSRUWVGHODFDXVDOLWpHWGHOD ILQDOLWpGRQWLOHVWGLIILFLOHGHGLUHTXHOOHVQHVRQWTXHOHQYHUVHWODYHUVGXQ PrPH SURFHVVXV /D FDXVDOLWp QHVW MDPDLV SULVH HQ GpIDXW WDQGLV TXH OD IL QDOLWp OHVW VRXYHQW FHUWDLQHPHQW DX QLYHDX KXPDLQ GH QRWUH H[SpULHQFH HW SUREDEOHPHQW OH ORQJ GH OpYROXWLRQ EXLVVRQQDQWH GHV HVSqFHV YLYDQWHV 8Q JUDQG QRPEUH GDFWLRQV KXPDLQHV VRQW PDXYDLVHV GX PRLQV GDQV OHXUV FRQ VpTXHQFHVHWXQJUDQGQRPEUHGHVSqFHVQHFRQFRXUHQWJXqUHjODEHDXWpGX VSHFWDFOH GH OD 1DWXUH )DXWLO UHJUHWWHU OHV GLQRVDXUHV GLVSDUXV j OD ILQ GX 6HFRQGDLUHIDXWLOUHJUHWWHUOHVHVSqFHVGLVSDUXHVGDQVOHXUJUDQGHPDMRULWp jODILQGX3ULPDLUH"6LO\DHXGHVFDWDVWURSKHVGHODYLHFHVWTXHVRQ+LV WRLUH ELHQ TXHOOH VRLW PHUYHLOOHXVH QH VHPEOH SDV UpSRQGUHjODFWXDOLVDWLRQ GXQHORLSK\VLTXHHWPpWDSK\VLTXHXQLTXHWHOOHTXHOHSDVVDJHGHODQpJXHQ WURSLHjOLQIRUPDWLRQHWVRQLQYHUVH
&HVWSRXUTXRLHQUHFRQQDLVVDQWTXRQVHSODFHWRXMRXUVLFLDXSODQPpWD SK\VLTXH R VH SRVHQW GH WHOOHV TXHVWLRQV RQ SURSRVHUD XQH YLVLRQ XQ SHX GLIIpUHQWHGHODYHQWXUHGHODILQDOLWpGDQVOD1DWXUH&HUWHVFHWWHYLVLRQSRV WXOHTXHO$XWHXUGHOD1DWXUHGRLWDYRLUXQSODQHWFHUDLVRQQHPHQWHVWFLUFX ODLUHSXLVTXHFHVWSUpFLVpPHQWODSSDUHQFHGXQSODQTXLQRXVIDLWSHQVHUjXQ
$XWHXUGHOD1DWXUH0DLVFHWWHFLUFXODULWpDWWHLQWWRXVOHVSULQFLSHVPpWDSK\
VLTXHVHWHOOHQHGRLWSDVQRXVWURXEOHUVHXOHPHQWQRXVDYHUWLUTXRQVHSODFH jXQQLYHDXGH[SOLFDWLRQTXLQDSDVOKRPRJpQpLWpVLIUDSSDQWHPDLVDXVVLVL OLPLWpH GH OH[SOLFDWLRQ VFLHQWLILTXH 4XDQG LO VDJLW GH PpWDSK\VLTXH RQ
HPEUDVVHWRXMRXUVGHVDSSDUHQFHVHWGHVUpDOLWpVKpWpURJqQHVTXRQHVVDLHGH PHWWWUHHQUDSSRUWGHODIDoRQODSOXVYUDLVHPEODEOHSRVVLEOH.DQWDGLWTXH ODUDLVRQHVWWRXWjIDLWLPSXLVVDQWHjFHWWHWkFKHPDLVFHVWTXLOSUHQDLWSRXU PRGqOHODUDLVRQVFLHQWLILTXHGHVRQWHPSVGRQWRQQHSHXWGLUHTXHOOHRIIUDLW XQYLVDJHGpILQLWLIGHODUDLVRQ$XMRXUGKXLQRXVQDYLJXRQVHQPpWDSK\VLTXH DYHF OD WULSOH UpIpUHQFH GH OD PpFDQLTXH FODVVLTXH GH OD 5HODWLYLWp HW GH OD PpFDQLTXH TXDQWLTXH FRPPH OD IDLW &RVWD GH %HDXUHJDUG HW QRXV QRXV LQ VSLURQVDXVVLFRPPHLOODIDLWGHPrPHGHVUpVXOWDWVGHODELRORJLHFRPPH GHVGRQQpHVGHOH[SpULHQFHKXPDLQH
'DQV ODYLVLRQpYROXWLYHGHO8QLYHUVTXLHVWODQ{WUHFHTXLQRXVIUDSSH FHVW TXH OD PDWLqUH HW OD YLH RQW pYROXp GXQH IDoRQ TXH OH KDVDUG GDQV VRQ DFFHSWLRQ FODVVLTXH UHQFRQWUH GH VpULHV FDXVDOHV LQGpSHQGDQWHV FRQWLQ JHQFHHVWWUqVLPSXLVVDQWjH[SOLTXHUHWTXLIDLWDSSDUDvWUHXQHILQDOLWpVRXV ODIRUPHGXQGHVVHLQGRQWOHVFRPSRUWHPHQWVDQLPDX[HWKXPDLQVDSSDUDLV VHQWFRPPHGHSkOHVUpSOLTXHVTXLOVHUDLWLPSUXGHQWGHSUHQGUHSRXUPRGq OHV ,O IDXW SHQVHU OD ILQDOLWp VDQV DQWKURSRPRUSKLVPH QL YLWDORPRUSKLVPH PDLV LO IDXW OD SHQVHU TXDQG PrPH FRPPH XQH XQLWp VXSpULHXUHTXLVLQVqUH GDQVGHVSURFHVVXVGLYHUVHQQHFHVVDQWGHYDULHUVHVPR\HQVGROHGDQJHU GHIDLUHGHODILQDOLWpOLQYHUVHGHODFDXVDOLWpSRXUUpDOLVHUXQHILQWUDQVFHQ GDQWH/H[SUHVVLRQGHFHWWHILQDOLWpGDQVOHODQJDJHTXLQRXVHVWGLVSRQLEOH DXUD WRXMRXUV TXHOTXH FKRVH GH GpILFLHQW HW GDSSURFKp 6L FHVW XQ VFLHQWL ILTXHTXLHQSDUOHDORUVLOUHGRXEOHGHSUpFDXWLRQVFDULOQHVWSDVKDELWXpj VHPRXYRLUGDQVFHWWHVSKqUHjODTXHOOHVDVFLHQFHOLQWURGXLWVDQVOXLGRQQHU OHVPR\HQVGHODSHQVHU2QSHUoRLWFHWHPEDUUDVTXLQH[FOXWSDVODFRQYLF WLRQGDQVFHWWH SKUDVHUHPDUTXDEOHPHQWEDODQFpHGH'\VRQ/RUVTXHQRXV UHJDUGRQVOXQLYHUVHWLGHQWLILRQVOHVPXOWLSOHVDFFLGHQWVGHODSK\VLTXHHWGH ODVWURQRPLH TXL RQW WUDYDLOOp GH FRQFHUW j QRWUH SURILW WRXW VHPEOH VrWUH SDVVp FRPPH VL O8QLYHUV GHYDLW HQ TXHOTXHVRUWHVDYRLUTXHQRXVDYLRQVj DSSDUDvWUH ,O VHUDLW VDQV GRXWH SOXV VDWLVIDLVDQW GXQ SRLQW GH YXH ORJLTXH GDWWULEXHUFHVDYRLUGHODILQSRXUVXLYLHjO$XWHXUGHO8QLYHUVSOXW{WTXj O8QLYHUVOXLPrPHPDLVFRPPHRQODGLWSOXVKDXWODUDLVRQLFLWRXUQHHQ FHUFOH VL ELHQ TXH O8QLYHUV TXDQG RQ OHQYLVDJH GDQV VD WRWDOLWp SHXW rWUH SULVSRXUVRQ$XWHXUTXDQGOH[LVWHQFHGHFHGHUQLHUQHVWSDVMXVWLFLDEOHSDU OHV ORLV GH OD SK\VLTXH 8QH DXWUH IDoRQ GH FRQWRXUQHU FH GpOLFDW SUREOqPH PpWDSK\VLTXHHVWGLQWURGXLUHODORFXWLRQWRXWVHPEOHVrWUHSDVVpFRPPHVL FDULOHVWGLIILFLOHGDWWULEXHUjO8QLYHUVXQGHVVHLQTXLVHPEOHUHOHYHUSOXW{W GH VRQ $XWHXU (QFRUH XQH IRLV OD JUDPPDLUH GH OD PpWDSK\VLTXH QH[LVWH
F.J.Dyson, Scientific American, 225, september 1971, p.51
QXOOHSDUWHWFKDFXQOLPSURYLVHFRPPHLOSHXW&HODQHYHXWSDVGLUHTXHOHV DIILUPDWLRQV GH OD PpWDSK\VLTXH TXL VRQW WRXWHV UHODWLYHV DX SUREOqPH GH OD ILQDOLWpGHWRXWFHTXLH[LVWHOKRPPH\FRPSULVVRLHQWGpQXpHVGHVHQVRX SXUHPHQW VXEMHFWLYHV &KDFXQ FRPSUHQG GH TXRL LO HVW TXHVWLRQ TXDQG RQ LQYRTXH OHSULQFLSH DQWKURSLTXH&H QHVW SDV OH OLHX GpQXPpUHU OHV DUJX PHQWV SK\VLTXHV HW FRVPRORJLTXHV TXRQ D OpJLWLPHPHQW GpYHORSSpV GHSXLV XQTXDUWGHVLqFOHHQVDIDYHXU,OVXIILWGHVHUHQGUHFRPSWHTXHOKRPPH TXL SHQVH O8QLYHUV QH SHXW pYLWHU GH SHQVHU TXHGXQHFHUWDLQHIDoRQQRXV IPHVFRQoXVGqVOHFRPPHQFHPHQW
2Q YRLW TXH OHV FKHPLQV GH OD PpWDSK\VLTXH TXLQYLWH j SUHQGUH OH GpYH ORSSHPHQW GH OD SK\VLTXH FRQWHPSRUDLQH VRQW DXVVL GLYHUV TXH OH VRQW SDU DLOOHXUVOHVGRFWULQHVPpWDSK\VLTXHVKLVWRULTXHPHQWGLVSRQLEOHV&HQHVWSDV GHFHWWHGLYHUVLWpTXLOIDXGUDLWVHSODLQGUHELHQTXHOOHFRQWUDVWHDYHFOXQLWp TXH OD VFLHQFH SDUYLHQW SDUIRLV j UpDOLVHU GDQV XQ GRPDLQH SDUWLFXOLHU PDLV SOXW{W GX GLVFUpGLW GRQW HOOH SHXW VRXIIULU GDQV XQH DWPRVSKqUH LQWHOOHFWXHOOH GRPLQpHSDUOHPRGqOHVFLHQWLILTXHGXVDYRLU4XHOHWULRPSKHGHFHPRGqOH QH VRLW TXDSSDUHQW RX SURYLVRLUH RQ GRLW j &RVWD GH %HDXUHJDUG GH ODYRLU PRQWUp GXQH IDoRQ TXL D LQFLWp EHDXFRXS GpSLVWpPRORJXHV j UpIOpFKLU j VD VXLWHWDQWFHWWHIDoRQpWDLWHPSUHLQWHjODIRLVGHULJXHXUHWGDXGDFH
&RQFOXVLRQ
5LHQ QREOLJH VHPEOHWLO XQ pSLVWpPRORJXH j VRXWHQLU TXH OXQLYHUV HVW pWDOpVSDWLRWHPSRUHOOHPHQWGDQVVHVTXDWUHGLPHQVLRQV5LHQQHOREOLJHQRQ SOXV j UHQGUH FRPSWH GH OD IRUPLGDEOH SRXVVpH GH QpJXHQWURSLHLQIRUPDWLRQ TXHPDQLIHVWHOpYROXWLRQGHODYLHSDUOK\SRWKqVHGXQSULQFLSHGHFRQVHUYD WLRQ GH OLQIRUPDWLRQ TXL VH FDFKHUDLW GDQV OHV VRXVVROV GH OXQLYHUV SK\
VLTXH0DLVVLORQPHWjSDUWFHVGHX[SUpVXSSRVpVSODFpVDX[IRQGHPHQWVGH OD YLVLRQ GpYHORSSpH GDQV/H 6HFRQG 3ULQFLSH GH OD 6FLHQFH GX 7HPSVHW PrPHVLORQ\VXEVWLWXHUHVSHFWLYHPHQWOHSUpVXSSRVpGXWHPSVFRVPLTXHHW OHSULQFLSHDQWKURSLTXHDORUVODSOXSDUWGHVGpYHORSSHPHQWVGHFHOLYUHTXL HVW VL VWLPXODQW SRXU OD UHFKHUFKH pSLVWpPRORJLTXH HW PpWDSK\VLTXH JDUGHQW WRXWH OHXU SRUWpH ,O \ D SHX GH OLYUHV SKLORVRSKLTXHV GRQW RQ SXLVVH HQ GLUH DXWDQWTXDUDQWHDQVDSUqVOHXUSDUXWLRQ
cf.H.Barreau, "La physique et la nature", Annales de la Fondation Louis de Broglie, vol.26, 1/3, 2002, 43-53
Steven Weinberg, Les trois premières minutes de l'Univers, Paris, Seuil, 1978,p.179
%LEOLRJUDSKLH
>@ H.Barreau, "La physique et la nature", Annales de la Fondation Louis de
Broglie, Vol.26 -n°spécial 1/3, 2001, 43-53
>@ O.Costa de Beauregard, Le Second Principe de la Science du Temps, entropie,
information, irréversibilité, Paris, Editions du Seuil, 1963
>@ O.Costa de Beauregard, "Le Second Principe de la Science du Temps" in Le
Temps et la pensée physique contemporaine, s.l;d; de J.L.Rigal, Paris, Dunod, 1968, 115-128
>@ A.Grünbaum, Philosophical Problems of Space and Time, second, enlarged
edition, D.Reidel, 1973
>@ H.Reichenbach, The Direction of Time, edited by Maria Reichenbach,
University of California Press, 1971
>@ R.Ruyer, La cybernétique et l'origine de l'information, Paris, Flammarion, 1954
>@ H.D.Zeh, The phyysical Basis of the Direction of Time, Springer-Verlag,1989
0DQXVFULWUHoXOHQRYHPEUH
