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-terabilityof
ab
ericalintegrationione-allnineionofournuleaalableevenoverte-illationeriallydiffurialiallytricityofionrtotiontax～0.35over～±4gyr).rincrealinationinanyorbitaleleilllonger-terionedacouionionof±5x1010yr.teoainedoverte-tion
1.1definitionoftabilityofouredoveeveralanyfaianyedacentralroleintofnon-lineardynayetableornot.tionoftueiontototionintuallyitilear，rigoroufuldefinitionoftranydefinitiony，an1adefinitionofability.ingunounteroccur，aininitialconfiguration(coaanikaiacloeriable.iableifnocloeruryr.incidentally，tcedbyoneineofanyorbitalcroakeauetiloaryandakino1entcannotbealreune–.
1.2enetalofdyna1988，1belyunderofreurrayaan1an2001).ingoveraneneneteraryorbitalerizedbyteoninitialconditionericalintegrationerfive1988;kinoauitirationegratiopubliain-ayofrationo～1011yrofturjovianialorbitaleleurentonain-aonaleofanbeatyale，ireaaainableover1010yr，oredfourionofoneoverayetconetableduringtaintainingalionerrvariationricitieerreiallyofe-urbationtedandinvealintegrationalintegrationaryorbitaspanofoveringaalelaioniononcluegrationnetaryableinterentionedabove，atleayr.actually，inournuableterion:notonlydidnocloerrationnetaryorbitaleleonfinedinanarroeandfrequencydootionandovervieerioneoftabilityofotion.forreaderanddeeericalres，e(accesaleleeredreunayeleuuryanalyionion2inourdynaetionionoadekreegrationabilityofotioniaryaleleionofnuiven.uvariationofaloludeoion5，alintegrationion6eraryauionoftio
（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。）
2.3nuilizea–aeta，yoialoreducetlevariableaine1ealintegrationegrationalnet(ereegrationofallnine(1988，7.2d)andaine(1aketiionofround-offerrorinteednuaryorbitaeer.turateenougifieiningteer(～0.05)iofury(～0.2)，oioneerfive400d.
tionethod(danby1rkeberofintaxiionervaloftiion8000000d(～21903yr)forterfivealintegrationess，ertoteralculationoredetail.
2.4erroreion
2.4.1relativeerrorrordingtooneoftorivequantitiealenergyandangularnuionediveerrory(～10?9)andoftotalangular(～10?11)onegrationialedtiveerrorintotalenergybyaboutoneorderofore.
relativenungularalenergyδe/e0inournuion±1，2，3，otalenergyandtotalangularively，ande0anda0aretyr.
notetallibrarieureericalerrorioinround-offerrorlgorit.1，uationintalerrorint，orouision.
2.4.2errorinudealenergyandtotalangularicallybeagoodyofnuioneaionalerrorofitudealerrorintudelloainlong-tereerainintegrationedarationeionartingonditionion.integrationionofion.next，rationion，n?1.fortheperiodof3x105yr，eananoionra25rotationetrearly，tocanbeeinkinoedaalreion-teraryorbitalealdata.tnetabilityinallofournuionookeneraldeyof，eneralcaryorbiturialalenetlearlyfroonfigurationionnetofeacion，netioneireintegrationrvariationionre.
verticalviearyorbition)attionneineofrialo0.0547x109yr).(b)t=4.9339x108to4.9886x109yr).(c)t=0to?0.0547x109yr).(d)t=?3.9180x109to?3.9727x109yr).ineacalof236842190yrover5.47x107yr.orbitrialde245).
titieionndfinalionn+1ied，tionofentantlybetndfinalion，atleaarury，eity，nificantextent.tofalltoaiontaybeneareobeintationrvariationitieuryonatialeofyoftfatallyaffecttoercury.alevolutionofion4ueredorbitalelealnetableandquiteregularoverte-ion5).
3.2tiaionexabilitydefinedaloarydynatorynetaryorbitale-fluctuationicularlyintentiallyonitionvariation(cf.berger1988).
togiveanovervieeinaryorbitalanyfaioneaxienae–frequencyucanalyskaryanalyeredorbitaldataintoelengtaieoverlaini+t，te，alintegrationlengttoeacydiagraainedabove，tycanbereale(orcolour)ctonnectalltolour)creactia(ti，icalaxiy)oftaleleedanfftbecauofnue(ealexayedurealediagraityintlinationofeartion.infig.5，tedbyterareaaroundit.ityoftlinationofeartlyovertoveredbytrendieinotrotyieandele.