為什麼太陽系中的行星最終都將傾斜遠離太陽？

01-06

天文學

第一感覺是翻譯問題。

然後我就開始百度了（題主不給消息來源差評~）

首先是福布斯中文網：30 under 30：年輕科學家改變世界，當中有一位叫Konstantin Batygin的加州理工學院助理教授，文章中描述他解決了一個世紀難題：太陽系中的行星最終都將傾斜遠離太陽，也就是題主的問題。

於是我順藤摸瓜找英文原版：http://www.forbes.com/30under30/#/science，發現原來不是翻譯問題，英文原文的意思就是這樣......

於是我又上Caltech的網站找Konstantin Batygin，找到一篇關於他的採訪：The Birth and Death of Our Solar System: An Interview with Konstantin Batygin

時間有限沒有細讀，暫時沒在這篇採訪中發現關於「太陽系中的行星最終都將傾斜遠離太陽」（如有相關信息還請指出謝謝），但在採訪中Konstantin Batygin提到：

For example, the simulations reveal that if you wait long enough, Mercury will leave the solar system. It will become unstable, its orbit will become unbound, and it will take off.

Konstantin Batygin舉了個栗子說如果時間足夠長，水星有可能會離開太陽系。

僅僅是水星。

水星距離太陽最近，可能會離開太陽而不是掉入太陽，但是不能由此推斷其他行星也會離開太陽，採訪者的下一個問題讓Konstantin Batygin道出了水星如此怪異的原因：

Really? Even though it"s the closest planet to the sun, it just flies off rather than falling into the sun?
Yes. It"s called chaotic diffusion. This happens over a multibillion-year timescale. Planetary orbits are a little bit like weather. We can"t predict the weather for longer than three days. But we can generally expect that the weather is not going to change by thousands of degrees; it"s going to be in some bounded range. Planetary orbits are like that. They vary, but they mostly hang out in a well-defined region of phase space. Occasionally, though, they leave that phase space and transition into a different shape. This is why Mercury takes off at some point in the future. It"s a beautiful problem. You"ve got eight members of the system—planets—whose masses are low. But over long time spans, they exchange angular momentum in a deterministic yet unpredictable manner. If you wait long enough, at one point Mercury bites off more angular momentum deficit than it can chew and leaves the solar system.

簡單來說四個字：混沌效應。

結論：福布斯（英文）的某個記者對相關內容過度推斷。

PS：時間倉促，結論不保證百分百準確，哪位知友有空可深挖。

PPS：非本專業，不了解是否有其他學者的研究得出太陽系中的行星（部分或全部）會遠離太陽的推論，如有還請多多指教。