General Relativity and Solar System Stability
This is some neat research (and related to some of the work I did in my PhD).  For those who are just reading the comments, the authors are exploring the impact of general relativity on the stability of the Solar System.  It&#x27;s been known now for a few decades that the Solar System is only marginally stable [1].  The gravitational perturbations of all the planets on each other (though mostly coming from Jupiter) cause the orbits of the planets to change slowly over time.  It turns out, though, that Mercury is the closest to unstable, and has a ~1% chance of being ejected from the Solar System in the next billion years.<p>One of the interesting things about Mercury, is that general relativity has a non-negligible effect on its dynamics (the famous &quot;perihelion precession&quot; that Einstein explained).  What the authors did in this paper is run a number of long term simulations of the Solar System with general relativity --- but then they switched it off at a random time.  What they find is that after switching off general relativity the Solar System goes unstable shortly thereafter.  So the stability of the Solar System is highly dependent on general relativity.<p>As a side note, the second author on the paper is Hanno Rein, who wrote Rebound [2], which is a very cool state of the art gravitational simulator.  If you ever want to play around with gravitational dynamics, that&#x27;s what I&#x27;d recommend using.  (And that&#x27;s what they use in this paper.)<p>[1]: This is not terribly surprising because it turns out that nearly every dynamical system with more than three bodies is only marginally stable on a timescale of order its own lifetime.<p>[2]: <a href="https:&#x2F;&#x2F;github.com&#x2F;hannorein&#x2F;rebound">https:&#x2F;&#x2F;github.com&#x2F;hannorein&#x2F;rebound</a>