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 compositions. In the "Two Songs without Words" of 1906, Holst showed that he could create his own original music using the folk idiom. An orchestral folksong fantasy "Songs of the West", also written in 1906, was withdrawn by the composer and never published, although it emerged in the 1980s in the form of an arrangement for wind band by James Curnow. In the years before the First World War, Holst composed in a variety of genres. Matthews considers the evocation of a North African town in the "Beni Mora" suite of 1908 the composer's most individual work to that date;