Galilean moons century when other inner moons were discovered, and Marius' names became widely used. Galileo was able to develop a method of determining longitude based on the timing of the orbits of the Galilean moons. The times of the eclipses of the moons could be precisely calculated in advance, and compared with local observations on land or on ship to determine the local time and hence longitude. The main problem with the technique was that it was difficult to observe the Galilean moons through a telescope on a moving ship; a problem that Galileo tried to solve with the invention of
Galilean electromagnetism Galilean electromagnetism Galilean electromagnetism is a formal electromagnetic field theory that is consistent with Galilean invariance. Galilean electromagnetism is useful for describing the electric and magnetic fields in the vicinity of charged bodies moving at non-relativistic speeds relative to the frame of reference. The resulting mathematical equations are simpler than the fully relativistic forms because certain coupling terms are neglected. In electrical networks, Galilean electromagnetism provides possible tools to derive the equations used in low-frequency approximations in order to quantify the current crossing a capacitor or the voltage induced in a coil. As such, Galilean electromagnetism can be used to