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-terabilityofplanetaryorbit
ab
ericalintegrationione-allnineplaneturnuleaalableevenoverte-illationeriallydiffurialplanetaryofricityofionrtotiontax～0.35over～±4gyr).rincrealinationinanyorbitaleleilllonger-terionedacoupleoftrialintegrationionof±5x1010yr.teoainedoverte-tion
1.1definitionoftabilityofouredoveeveralanyfaianyedacentralroleintofnon-lineardynayetableornot.tionoftueiontototionintuallyitilear，rigoroufuldefinitionoftranydefinitiony，an1adefinitionofability.ingunounteroccur，aininitialconfiguration(canikaiacloeriable.iableifnocloeruryr.incidentally，tcedbyoneineofanyorbitalcroakeauetiloaryandprotoplanetarya，kokubobealreune–pluto.
1.2previoueptofalofdynaanaubelyunderofreurrayar，frankliningoveraneneneteraryorbitalerizedbyteoninitialconditionpointofvieericalintegrationerfiveplanet1988;kinoalperiodnetlloegrationperiod.atprealintegratiopublianliain-ayofplanetaryorbitegrationo～1011yrofturjovianplanetaleleuranlientonain-aonaleofplanetaryorbitalindicatoroftale，ireaaainableover1010yr，orperanliurionofoneptune)，overayetconetableduringtaintainingalionerperturbationteandirregularvariationricitieerreiallyofe-urbationtedandinvealintegrationpreli-terionaryorbitaspanofoveringaalelapioniononcluegrationnetaryableinterentionedabove，atleayr.actually，inournuableterion:notonlydidnocloerrationperiod，butalaleleonfinedinanarroeandfrequencydootionandovervieerionplefigureabilityofotion.forreaderanddeeperinterealres，e(accesaleleeredreunayeleuuryanalyionion2inourdynaetionionoadekreegrationabilityofotioniarypoentionofnuiven.uvariationofplanetaryorbiterandincludeoion5，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–apaan1a，yoeduretoreducetlevariableaine1epegrationegrationalperiodoftury).aionoflloalintegrationofallnineplanet(1988，7.2d)andaine(1aketipleof2inordertoreducetionofround-offerrorintean(1alintegrationaryorbitapeper.turateenougifieiningteper(～0.05)iofury(～0.2)，oionepegrationoftep400d.
tionethod(danby1rkeplerequationerationaxiionervaloftiion8000000d(～21903yr)forterfiveplanetalintegrationess，ertoteralculationoredetail.
2.4erroreion
2.4.1relativeerrorrordingtooneoftplecticintegratorivequantitiealenergyandangularnuionediveerrory(～10?9)andoftotalangular(～10?11)onegrationperiod(fig.1).tedure，，iveerrorintotalenergybyaboutoneorderofore.
relativenungularalenergyδe/e0inournuion±1，2，3，otalenergyandtotalangularively，ande0anda0aretyr.
notetallibrarieureericalerrorioinround-offerrorlgorit.1，uationintalerrorint，orouision.
2.4.2errorinplanetarylongitudeplecticyandtotalangularicallybeagoodyofnuioneaionalerrorofplanetarylongitudealerrorintudelloparedt-tereerperioduracytionedarationepionartingonditionion.integrationproviderue’aryorbitalevolution.next，rationion，n?1.fortheperiodof3x105yr，eananoionrapolatedtot25rotationetrearly，tocanbeeinkinoedaalreion-teraryorbitalealdata.tnetabilityinallofournuionookplace.
3.1generaldeyofplanetaryorbit，eneralcaryorbiturialplanete-erfiveplanetlearlyfroonfigurationionnetofeacion，netioneireintegrationperiodtionionre.
verticalviearyorbition)attionneineofrialpartofn+1(t=0to0.0547x109yr).(b)t=4.9339x108to4.9886x109yr).(c)t=0to?0.0547x109yr).(d)t=?3.9180x109to?3.9727x109yr).ineacalof23684pointervalofabout2190yrover5.47x107yr.orbitrialplanetde245).
titieionndfinalpartoftionn+1ied，tionofplanetaryorbitalelenificantlybetndfinalpartofeacrvenuentiallyitent.tofalltoaiontaybeneareobeintationrvariationitieuryonatialeofyoftfatallyaffecttoercury.alevolutionofion4ueredorbitalelealnetableandquiteregularoverte-ion5).
3.2tiapnetary-ter