Stability of the Solar System is unlikely any of the planets will collide with each other or be ejected from the system in the next few billion years, and the Earth's orbit will be relatively stable. Since Newton's law of gravitation (1687), mathematicians and astronomers (such as Laplace, Lagrange, Gauss, Poincaré, Kolmogorov, Vladimir Arnold and Jürgen Moser) have searched for evidence for the stability of the planetary motions, and this quest led to many mathematical developments, and several successive 'proofs' of stability of the Solar System. The orbits of the planets are open to long-term variations. Modeling the Solar System is a case of the
Gustav Holst likens to "unresolved timelessness ... never ending, since space does not end, but drifting away into eternal silence". Apart from his concession with "I Vow to Thee..."', Holst insisted on the unity of the whole work, and opposed the performance of individual movements. Nevertheless, Imogen wrote that the piece had "suffered from being quoted in snippets as background music". During and after the composition of "The Planets", Holst wrote or arranged numerous vocal and choral works, many of them for the wartime Thaxted Whitsun Festivals, 1916–18. They include the "Six Choral Folksongs" of 1916, based on West Country tunes, of