Earth spin, Earth spin axis, Spins of Sun and Planets, Mars, Jupiter, Saturn, Uranus, Neptune
Planetary spins including the spin of the sun can be calculated accurately from a slight extension of classical Newtonian physics into the planetary rotations especially between a planet and its satellites. As the earth acts a torque to rotate the moon synchronously with the orbital motion, there should be a reaction torque on the earth. It is demonstrated that the earth spin is driven by the force of the reaction torque, which leads the earth spin to be calculated from the fundamental quantities of the earth-moon system by almost an exact number 24h3m5s with taking into account the density distribution. It is also demonstrated that the earth spin axis which is tilted by 23.5 degree with respect to the earth orbit can be derived from the gravitation of the sun acting on the earth. The calculated number, 23.487 degree, is astonishingly close to the observation. The spin of the sun is also obtained by the same way as the earth by reducing the many body system into a two body system. The spins of the planets, Mars, Jupiter, Saturn, Uranus, and Neptune, are also calculated by the same theory and equations as those of the sun in a very consistent way. Astonishing accuracy of calculation results validates our theory and analysis. A possible experiment to measure the reaction torque in the earth is discussed.
* The manuscript and the text file of Mathcad program to calculate equations are attached.