作者君在作品相關中其實已經解釋過這個問題。
不過仍然有人質疑——“你說得太含糊了”，“火星軌道的變化比你想象要大得多！”
那好吧，既然作者君的簡單解釋不夠有力，那咱們就看看嚴肅的東西，反正這本書寫到現在，嚷嚷著本書bug一大堆，用初高中物理在書中挑刺的人也不少。
以下是文章內容：
Long-term iions and stability of plaary orbits in our solar system
abstract
we present the results of very long-term numerical iions of plaary orbital motions over 109 -yr time-spans including all nine plas. a quispe of our numerical data shows that the plaary motion， at least in our simple dynamical model， seems to be quite stable evehis very long time-span. a closer look at the lowest-frequency oscillations using a low-pass filter shows us the potentially diffusive character of terrestrial plaary motion， especially that of mercury. the behaviour of the etricity of mercury in our iions is qualitatively similar to the results from Jacques Laskar“s secular perturbation theory {e.g. emax～ 0.35 over ～± 4 gyr}. however， there are no apparent secular increases of etricity or ination in any orbital elements of the plas， which may be revealed by still loerm numerical iions. we have also performed a couple of trial iions including motions of the outer five plas over the duration of ± 5 × 1010 yr. the result indicates that the three major resonances in the une–Pluto system have been maintained over the 1011-yr time-span.
1 introdu
1.1Definition of the problem
the question of the stability of our solar system has beeed over several hundred years， sihe era of on. the problem has attracted many famous mathematis over the years and has played a tral role in the development of non-linear dynamid chaos theory. however， we do not yet have a definite ao the question of whether our solar system is stable or not. this is partly a result of the fact that the definition of the term ‘stability’ is vague when it is used iion to the problem of plaary motion in the solar syste actually it is not easy to give a clear， rigorous and physically meaningful definition of the stability of our solar syste
among many definitions of stability， here t the hill definition {gladman 1993}: actually this is not a definition of stability， but of instability. we define a system as being unstable when a close enter occurs somewhere in the system， starting from a certain initial figuration {chambers， wetherill boss 1996; ito tanikawa 1999}. a system is defined as experieng a close enter when two bodies approae another within an area of the larger hill radius. otherwise the system is defined as being stable. henceforward we state that our plaary system is dynamically stable if no close enter happens during the age of our solar system， about ±5 gyr. ially， this definition may be replaced by one in whi occurrence of any orbital crossiweeher of a pair of plaakes place. this is because we know from experiehat an orbital crossing is very likely to lead to a close enter in plaary and protoplaary systems {Yoshinaga， Kokubo makino 1999}. of course this statement ot be simply applied to systems with stable orbital resonances such as the une–Pluto syste
1.2Previous studies and aims of this research
in addition to the vagueness of the cept of stability， the plas in our solar system show a character typical of dynamical chaos {sussman wisdom 1988， 1992}. the cause of this chaotic behaviour is now partly uood as being a result of resonance overlapping {murray holman 1999; Lecar， Franklin holman 2001}. however， it would require iing over an ensemble of plaary systems including all nine plas for a period c several 10 gyr to thhly uand the long-term evolution of plaary orbits， since chaotiamical systems are characterized by their strong dependen initial ditions.
From that point of view， many of the previous long-term numerical iions included only the outer five plas {sussman wisdom 1988; Kinoshita nakai 1996}. this is because the orbital periods of the outer plas are so much lohan those of the inner four plahat it is much easier to follow the system fiven iion period. at present， the lo numerical iions published in journals are those of Dun Lissauer {1998}. although their main target was the effect of post-main-sequence solar mass loss oability of plaary orbits， they performed many iions c up to ～1011 yr of the orbital motions of the four jovian plas. the initial orbital elements and masses of plas are the same as those of our solar system in Dun Lissauer“s paper， but they decrease the mass of the sun gradually in their numerical experiments. this is because they sider the effect of post-main-sequence solar mass loss in the paper. sequently， they found that the crossing time-scale of plaary orbits， which be a typical indicator of the instability time-scale， is quite sensitive to the rate of mass decrease of the sun. when the mass of the sun is close to its p
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