对火星轨道变化问题的最后解释
作者君在作品相关中其实已经解释过这个问题。
不过仍然有人质疑——“你说得太含糊了”,“火星轨道的变化比你想象要大得多!”
那好吧,既然作者君的简单解释不够有力,那咱们就看看严肃的东西,反正这本书写到现在,嚷嚷着本书bug一大堆,用初高中物理在书中挑刺的人也不少。
以下是文章内容:
long-teraryorbitsinoursolarsystem
abstract
,atleastinoursis,±5x–plutosystemhavebeenmaintainedoverthe1011-yrtime-span.
1introduction
thequestionofthestabilityofoursolarsystersystem.
admp;amp;boss1996;itoamp;amp;tanikawa1999).,about±,(yoshinaga,kokuboamp;amp;makino1999).ofcoursethisstatementcannotbesimplyappliedtosystemswithstableorbitalresonancessuchastheneptune–plutosystem.
inadditiontothevaguenessoftheconceptofstability,theplanetsinoursolarsystearysystesforaperiodcoveringseveral10gyrtothoroughlyunderstandthelong-teraryorbits,sincechaoticdynamicalsystemsarecharacterizedbytheirstrongdependenceoninitialconditions.
fros(sussaryorbits,theyperforaryorbits,whichcanbeatypicalindicatoroftheinstabilitytisres(venustoneptune),whichcoveraspanof~,butitseesalsoreroscillations.
ontheotherhand,inhisaccurateses,especiallyofskar1996).theresultsoflaskarssecularperturbationtheoryshouldbeconfirmedandinvestigatedbyfullynumericalintegrations.
inthispaperwepresentpreliaryorbits,coveringaspanofseveral109yr,andoftwootherintegrationscoveringaspanof±5x,,atleastoveratiaryorbitaleleunayelermomentumdeficit,andresultsofoursimpletime–frequencyanalysisonallofourintegrations.
insection2webrieflyexplainourdynasthatspans±5x.
2descriptionofthenumericalintegrations
(本部分涉及比较复杂的积分计算,作者君就不贴上来了,贴上来了起点也不一定能成功显示。)
weutilizeasecond-orderwisdom–holmansymplecticmapasourmainintegrationmethod(wisdomamp;amp;holman1991;kinoshita,yoshidaamp;amp;nakai1991)withaspecialstart-upproceduretoreducethetruncationerrorofanglevariables,‘warmstart’(sahaamp;amp;tremaine1992,1994).
thestepsizeforthenuparetheseintegrationssimplyintermsofstepsizes.
intheintegrationoftheouterfiveplanets(f±),wefixedthestepsizeat400d.
weadoptgaussfandgfunctionsinthesymplecticmaptogetherwiththethird-orderhalleymethod(danby1992)smethodis15,buttheyneverreachedthemaximuminanyofourintegrations.
theintervalofthedataoutputisd(~547yr)forthecalculationsofallnineplanets(n±1,2,3),andaboutd(~yr)fortheintegrationoftheouterfiveplanets(f±).
althoughnooutputfilteringwasdonewhenthenumericalintegrationswereinprocess,.
accordingtooneofthebasicpropertiesofsyrngulartiveerrorintotalenergybyaboutoneorderofmagnitudeormore.
relativenungularngularmomentum,respectively,.
notethatdifferentoperatingsysternungularmomentum,whichshouldberigorouslypreserveduptomachine-eprecision.
sincethesyparethetestintegrationwiththetedtothevalue~8700°,about25rotationsofearthafter5gyr,,thelongitudeerrorofplutocanbeestimatedas~12°.thisvalueforplutoismuchbetterthantheresultinkinoshitaamp;amp;nakai(1996)wherethedifferenceisestimatedas~60°.
3numericalresults–
:noorbitalcrossingsnorcloseencountersbetweenanypairofplanetstookplace.
first,,orbitalpositionsoftheterrestrialplanetsdifferlittlebetweentheinitialandfinalpartofeachnuaryorbitalmotionremainnearlythesameastheyareatpresent.
verticalviewofthefourinnerplanetaryorbits(frondfinalpartsoftheintegrationsn±.(a)theinitialpartofn+1(t=x109yr).(b)thefinalpartofn+1(t=xx109yr).(c)theinitialpartofn?1(t=0to?x109yr).(d)thefinalpartofn?1(t=?x109to?x109yr).ineachpanel,x(takenfromde245).
thevariationofeccentricitiesandorbitalinclinationsfortheinnerfourplanetsintheinitialandfinalpartoftheintegrationn+,thecharacterofthevariationofplanetaryorbitaleles;s(1994,1996),.
theorbitalsseeroverthistime-span(seealsosection5).
–frequencymaps
althoughtheplanetaryrlyinthecaseofearth,canpotentiallyhaveasignificanteffectonitssurfaceclirinsolationvariation().
togiveanoverviewofthelong-teraryorbitalskars(1990,1993)frequencyanalysis.
.
eachfragrgeoverlappingpart:forexample,whentheithdatabeginsfromt=tiandendsatt=ti+t,thenextdatasegmentrangesfromti+δt≤ti+δt+t,whereδt?+treachesthetotalintegrationlenh.
weapplyanffttoeachofthedatafragments,andobtainnfrequencydiagrams.
ineachfrequencydiagracedbyagrey-scale(orcolour)chart.
weperforcexisrepresentstheperiod(orfrequency)oftheoscillationoforbitalelements.
wehaveadoptedanfftbecauseofitsoverwhelposedintofrequencyponentsisterriblyhuge(severaltensofgbytes).
atypicalexabyplanetandelementbyelement.
wecalculateverylong-periodicvariationandexchangeofplanetaryorbitalenergyandangularunayelementsl,g,=?,,suchasymptomofinstabilityisnotprominentinourlong-termintegrations.
,thetotalorbitalenergyandangularponent(h-h0),g0,,.
cosandallnineplanets,itisapparentthattheasares::,,wecannotneglectthecontributionfros,aswewillseeinsubsequentsections.
+1andn?,,,wecanseethatarysubsystem.
itisnotclearatthearyorbitalenergy(whichisdirectlyrelatedtothesesthanistheangulartestoe).hence,theeccentricitiesofvenusandearthcanbedisturbedeasilybyjupiterandsaturn,,–earthpair,whichresultsinanegativecorrelationintheexchangeoforbitalenergyinthepair.
asfortheouterjovianplanetarysubsysteparedwiththatofthevenus–earthpair.
5±5x1010-yrintegrationsofouterplanetaryorbits
sincethejovianplanetaryarys(thefourjovianplanetspluspluto).(),andvariationofeccentricitiesandinclinations(),thetypicalfrequencyoftheorbitaloscillationofplutoandtheotherouterplanetsisalmostconstantduringtheseverylong-termintegrationperiods,whichisdemonstratedinthetime–frequencymapsonourwebpage.
inthesetwointegrations,therelativenungularmomentumwas~10?10.
–plutosystem
kinoshitaaaryorbitsover±x,,λdenotesthemeanlongitude,Ωisthelongitudeoftheascendingnodeand?.
rgumentθ1=3λp?2λn??plibratesaround180°withanamplitudeofabout80°andalibrationperiodofabout2x104yr.
theargumentofperihelionofplutowp=θ2=?p?Ωplibratesaround90°x(1962).
thelongitudeofthenodeofplutoreferredtothelongitudeofthenodeofneptune,θ3=Ωp?Ωn,,,theinclinationofplutobecoeses90°.whenθ3becoeseses90°;aterconfirni,nobiliamp;amp;carpino(1989).
anargumentθ4=?p??n+3(Ωp?Ωn)libratesaround180°withalongperiod,~x108yr.
inournurgurduringthewholeintegrationperiod(figs14–16).however,thefourthresonance(iv)appearstobedifferent:thecriticalargutionovera1010-yrtime-scale().thisisaninterestingfactthatkinoshitaamp;amp;nakais(1995,1996)shorterintegrationswerenotabletodisclose.
6discussion
whatkindofdynaarysystearysystearysubsystearyseparationsbythesaregreaterthan26rh,,,.
,thewideseparationandsrendersthedisturbanceineffective;thedegreeofdisturbancebyjovianplanetsiso(ej)(orderofsisaforcedoscillationhavinganamplitudeofo(ej).heighteningofeccentricity,forexampleo(ej)~,(amp;;26rh).
althoughournursystem,.
——以上文段引自ito,;tanikawa,,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。