pected,thecharacterofthevariationofparyorbitalelentsdoesnotdiffersignificantlybeeentheitialandfalpartofeachtegration,atleastforven,earthandarstheelentsofrcury,especiallyitseentricity,seetochangetoasignificantextentthisispartlybecaetheorbitalti-scaleofthepistheshortestofalltheps,&nbshichleadstoaorerapidorbitalevolutionthanotherpsthenerostpaybenearesttostabilitythisresultappearstobesoagreent&nbsithskar's(1994,1996)expectationsthatrgeandirregurvariationsappeartheeentricitiesandclationsofrcuryonati-scaleofseveral109yrhowever,theeffectofthepossiblestabilityoftheorbitofrcuryaynotfatallyaffecttheglobalstabilityofthe&nbsholeparysysteogtothesallassofrcury&nbse&nbsillntionbrieflythelong-terorbitalevolutionofrcurytersection4glow-passfilteredorbitalelents
theorbitalotionoftheouterfivepsseesrigorolystableandquitereguroverthisti-span(seealsosection5)
32ti–frequencyaps
althoughtheparyotionexhibitsverylong-terstabilitydefedasthenon-existenceofcloseenunterevents,thechaoticnatureofparydynaicscanchangetheosciltoryperiodandaplitudeofparyorbitalotiongraduallyoversuchlongti-spansevensuchslightfluctuationsoforbitalvariationthefrequencydoa,particurlythecaseofearth,canpotentiallyhaveasignificanteffectonitssurfacecliatesystethroughsorsotionvariation(cfberger1988)
togiveanoverviewofthelong-terchangeperiodicityparyorbitalotion,&nbseperfordanyfastfouriertransforations(ffts)alongthetiaxis,andsuperposedtheresultgperiodgrastodrawo-dinsionalti–frequencyapsthespecificapproachtodragtheseti–frequencyapsthispaperisverysiple–uchsiplerthanthe&nbsaveletanalysisorskar's(1990,1993)frequencyanalysis
dividethelow-passfilteredorbitaldatatoanyfragntsofthesalengththelengthofeachdatasegntshouldbeaultipleof2ordertoapplythefft
eachfragntofthedatahasargeoverppgpart:forexaple,&nbshentheithdatabegsfrot=tiandendsatt=ti+t,thenextdatasegntrangesfroti+δt≤ti+δt+t,&nbshereδt?t&nbsentuethisdivisionuntil&nbsereachacertanubernby&nbshichtn+treachesthetotaltegrationlength
&nbseapplyanffttoeachofthedatafragnts,andobtanfrequencydiagras
eachfrequencydiagraobtaedabove,thestrengthofperiodicitycanberepcedbyagrey-scale(orlour)chart
&nbseperfortherepcent,andnnectallthegrey-scale(orlour)chartstoonegraphforeachtegrationthehorizontalaxisofthesenewgraphsshouldbetheti,iethestartgtisofeachfragntofdata(ti,&nbsherei=1,…,n)theverticalaxisrepresentstheperiod(orfrequency)oftheosciltionoforbitalelents
&nbsehaveadoptedanfftbecaeofitsoverwhelgspeed,scetheaountofnuricaldatatobedeposedtofrequencyponentsisterriblyhuge(severaltensofgbytes)
atypicalexapleoftheti–frequencyapcreatedbytheaboveproceduresisshownagrey-scalediagraasfig5,&nbshichshowsthevariationofperiodicitytheeentricityandclationofearthn+2tegrationfig5,thedarkareashowsthatatthetidicatedbythevalueontheabscissa,theperiodicitydicatedbytheordateisstrongerthanthelighterareaaroundit&nbsecanregnizefrothisapthattheperiodicityoftheeentricityandclationofearthonlychangesslightlyovertheentireperiodveredbythen+2tegrationthisnearlyregurtrendisqualitativelythesaothertegrationsandforotherps,althoughtypicalfrequenciesdifferpbypandelentbyelent
42long-terexchangeoforbitalenergyandangurontu
&nbsecalcuteverylong-periodicvariationandexchangeofparyorbitalenergyandangurontugfiltereddeunayelentsl,g,hgandhareequivalenttotheparyorbitalangurontuanditsverticalponentperunitasslisretedtotheparyorbitalenergyeperunitassase=?μ2/2l2ifthesysteispletelylear,theorbitalenergyandtheangurontueachfrequencybtbenstantnon-learitytheparysystecancaeanexchangeofenergyandangurontuthefrequencydoatheaplitudeofthelowest-frequencyosciltionshouldcreaseifthesysteisunstableandbreaksdowngraduallyhowever,suchasyptoofstabilityisnotproentourlong-tertegrations
fig7,thetotalorbitalenergyandangurontuofthefournerpsandallnepsareshownfortegrationn+2theupperthreepanelsshowthelong-periodicvariationoftotalenergy(denotedase-e0),totalangurontu(g-g0),andtheverticalponent(h-h0)ofthenerfourpscalcutedfrothelow-passfiltereddeunayelentse0,g0,h0denotetheitialvaluesofeachquantitytheabsolutedifferencefrotheitialvaluesisplottedthepanelsthelowerthreepanelseachfigureshowe-e0,g-g0andh-h0ofthetotalofnepsthefluctuationshownthelowerpanelsisvirtuallyentirelyaresultoftheassivejovianps
pargthevariationsofenergyandangurontuofthenerfourpsandallneps,itisapparentthattheaplitudesofthoseofthenerpsareuchsallerthanthoseofallneps:theaplitudesoftheouterfivepsareuchrgerthanthoseofthenerpsthisdoesnotanthatthenerterrestrialparysubsysteisorestablethantheouterone:thisissiplyaresultoftheretivesallnessoftheassesofthefourterrestrialpspared&nbsiththoseoftheouterjovianpsanotherthg&nbsenoticeisthatthenerparysubsysteaybeeunstableorerapidlythantheouteronebecaeofitsshorterorbitalti-scalesthiscanbeseenthepanelsdenotedasner4fig7&nbsherethelonger-periodicandirregurosciltionsareoreapparentthanthepanelsdenotedastotal9actually,thefluctuationsthener4panelsaretoargeextentasaresultoftheorbitalvariationofthercuryhowever,&nbsecannotneglectthentributionfrootherterrestrialps,as&nbse&nbsillseesubsequentsections
44long-teruplgofseveralneighbourgppairs
letseesodividualvariationsofparyorbitalenergyandangurontuexpressedbythelow-passfiltereddeunayelentsfigs10and11showlong-terevolutionoftheorbitalenergyofeachpandtheangurontun+1andn?2tegrations&nbsenoticethatsopsforapparentpairstersoforbitalenergyandangurontuexchangeparticur,venandearthakeatypicalpairthefigures,theyshownegativerretionsexchangeofenergyandpositiverretionsexchangeofangurontuthenegativerretionexchangeoforbitalenergyansthattheopsforacloseddynaicalsystetersoftheorbitalenergythepositiverretionexchangeofangurontuansthattheopsaresiultaneolyundercertalong-terperturbationscandidatesforperturbersarejupiterandsaturnalsofig11,&nbsecanseethatarsshowsapositiverretiontheangurontuvariationtotheven–earthsystercuryexhibitscertanegativerretionstheangurontuverstheven–earthsyste,&nbshichseestobeareactioncaedbythenservationofangurontutheterrestrialparysubsyste
itisnotclearattheont&nbshytheven–earthpairexhibitsanegativerretionenergyexchangeandapositiverretionangurontuexchange&nbseaypossiblyexpthisthroughobservgthegeneralfactthattherearenosecurtersparyseiajoraxesuptosend-orderperturbationtheories(cfbrouwer&apapclence1961boaletti&apappucao1998)thisansthattheparyorbitalenergy(whichisdirectlyretedtotheseiajoraxisa)ightbeuchlessaffectedbyperturbgpsthanistheangurontuexchange(whichretestoe)hence,theeentricitiesofvenandearthcanbedisturbedeasilybyjupiterandsaturn,&nbshichresultsapositiverretiontheangurontuexchangeontheotherhand,theseiajoraxesofvenandeartharelesslikelytobedisturbedbythejovianpsththeenergyexchangeaybeliitedonly&nbsiththeven–earthpair,&nbshichresultsanegativerretiontheexchangeoforbitalenergythepair
asfortheouterjovianparysubsyste,jupiter–saturnanduran–neptuneseetoakedynaicalpairshowever,thestrengthoftheiruplgisnotasstrongpared&nbsiththatoftheven–earthpair
5±5x1010-yrtegrationsofouterparyorbits
scethejovianparyassesareuchrgerthantheterrestrialparyasses,&nbsetreatthejovianparysysteasandependentparysystetersofthestudyofitsdynaicalstabilityhence,&nbseaddedaupleoftrialtegrationsthatspan±5x1010yr,cludgonlytheouterfiveps(thefourjovianpsplpluto)theresultsexhibittherigorostabilityoftheouterparysysteoverthislongti-spanorbitalnfigurations(fig12),andvariationofeentricitiesandclations(fig13)showthisverylong-terstabilityoftheouterfivepsboththetiandthefrequencydoasalthough&nbsedonotshowapshere,thetypicalfrequencyoftheorbitalosciltionofplutoandtheotherouterpsisalostnstantdurgtheseverylong-tertegrationperiods,&nbshichisdeonstratedtheti–frequencyapsonour&nbsebpage
theseotegrations,theretivenuricalerrorthetotalenergy&nbsas~10?6andthatofthetotalangurontu&nbsas~10?10
51resonancestheneptune–plutosyste
koshita&apapnakai(1996)tegratedtheouterfiveparyorbitsover±55x109yrtheyfoundthatfourajorresonancesbeeenneptuneandplutoareataeddurgthe&nbsholetegrationperiod,andthattheresonancesaybetheacaesofthestabilityoftheorbitofplutotheajorfourresonancesfoundprevioresearchareasfollowsthefollogdescription,λdenotestheanlongitude,Ωisthelongitudeoftheascendgnodeand?isthelongitudeofperihelionsubscriptspandndenoteplutoandneptune
anotionresonancebeeenneptuneandpluto(3:2)thecriticalarguntθ1=3λp?2λn??plibratesaround180°&nbsithanaplitudeofabout80°andalibrationperiodofabout2x104yr
thearguntofperihelionofpluto=θ2=?p?Ωplibratesaround90°&nbsithaperiodofabout38x106yrthedoantperiodicvariationsoftheeentricityandclationofplutoaresynchronized&nbsiththelibrationofitsarguntofperihelionthisisanticipatedthesecurperturbationtheorynstructedbykozai(1962)
thelongitudeofthenodeofplutoreferredtothelongitudeofthenodeofneptune,θ3=Ωp?Ωn,circutesandtheperiodofthiscircutionisequaltotheperiodofθ2libration&nbshenθ3beeszero,iethelongitudesofascendgnodesofneptuneandplutooverp,theclationofplutobeesaxiu,theeentricitybeesiuandthearguntofperihelionbees90°&nbshenθ3bees180°,theclationofplutobeesiu,theeentricitybeesaxiuandthearguntofperihelionbees90°aga&nbsillias&apapbenson(1971)anticipatedthistypeofresonance,ternfirdbyini,nobili&apapcarpo(1989)
anarguntθ4=?p??n+3(Ωp?Ωn)libratesaround180°&nbsithalongperiod,~57x108yr
ournuricaltegrations,theresonances(i)–(iii)are&nbsellataed,andvariationofthecriticalarguntsθ1,θ2,θ3reasiirdurgthe&nbsholetegrationperiod(figs14–16)however,thefourthresonance(iv)appearstobedifferent:thecriticalarguntθ4alternateslibrationandcircutionovera1010-yrti-scale(fig17)thisisanterestgfactthatkoshita&apapnakai's(1995,1996)shortertegrations&nbserenotabletodisclose
6discsion
&nbshatkdofdynaicalchanisatasthislong-terstabilityoftheparysyste?&nbsecanidiatelythkofoajorfeaturesthatayberesponsibleforthelong-terstabilityfirst,thereseetobenosignificantlower-orderresonances(anotionandsecur)beeenanypairaongthenepsjupiterandsaturnareclosetoa5:2anotionresonance(thefao‘greatequality’),butnotjttheresonancezonehigher-orderresonancesaycaethechaoticnatureoftheparydynaicalotion,buttheyarenotsostrongastodestroythestableparyotion&nbsiththelifetioftherealsorsystethesendfeature,&nbshich&nbsethkisoreiportantforthelong-terstabilityofourparysyste,isthedifferencedynaicaldistancebeeenterrestrialandjovianparysubsystes(ito&apaptanikawa1999,2001)&nbshen&nbseasureparyseparationsbytheutualhillradii(r_),separationsaongterrestrialpsaregreaterthan26rh,&nbshereasthoseaongjovianpsarelessthan14rhthisdifferenceisdirectlyretedtothedifferencebeeendynaicalfeaturesofterrestrialandjovianpsterrestrialpshavesallerasses,shorterorbitalperiodsand&nbsiderdynaicalseparationtheyarestronglyperturbedbyjovianpsthathavergerasses,longerorbitalperiodsandnarrowerdynaicalseparationjovianpsarenotperturbedbyanyotherassivebodies
thepresentterrestrialparysysteisstillbegdisturbedbytheassivejovianpshowever,the&nbsideseparationandutualteractionaongtheterrestrialpsrendersthedisturbanceeffectivethedegreeofdisturbancebyjovianpsiso(ej)(orderofagnitudeoftheeentricityofjupiter),scethedisturbancecaedbyjovianpsisaforcedosciltionhavganaplitudeofo(ej)heightengofeentricity,forexapleo(ej)~005,isfarfrosufficienttoprovokestabilitytheterrestrialpshavgsucha&nbsideseparationas26rhth&nbseassuthatthepresent&nbsidedynaicalseparationaongterrestrialps(&apgt26rh)isprobablyoneoftheostsignificantnditionsforatagthestabilityoftheparysysteovera109-yrti-spanourdetailedanalysisoftheretionshipbeeendynaicaldistancebeeenpsandthestabilityti-scaleofsorsysteparyotionisnowon-gog
althoughournuricaltegrationsspanthelifetiofthesorsyste,thenuberoftegrationsisfarfrosufficienttofilltheitialphasespaceitisnecessarytoperfororeandorenuricaltegrationstonfirandexaedetailthelong-terstabilityofourparydynaics
——以上文段引自ito,t&aptanikawa,klong-tertegrationsandstabilityofparyorbitsoursorsysteonnotrastronsoc336,483–500(2002)
这只是作者君参考的一篇文章,关于太阳系的稳定性。
还有其他论文,不过也都是英文的,相关课题的中文文献很少,那些论文下载一篇要九美元(《nature》真是暴利),作者君写这篇文章的时候已经回家,不在检测中心,所以没有数据库的使用权,下不起,就不贴上来了。