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 to another house in Cheltenham, where Adolph recruited his sister Nina to help raise the boys. Gustav recognised her devotion to the family and dedicated several of his early compositions to her. In 1885 Adolph married Mary Thorley Stone, another of his pupils. They had two sons, Matthias (known as "Max") and Evelyn ("Thorley"). Mary von Holst was absorbed in theosophy and not greatly interested in domestic matters. All four of Adolph's sons were subject to what one biographer calls "benign neglect", and Gustav in particular was "not overburdened with attention or understanding, with a weak sight and a weak