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
Newtonian potential harmonic function in the special case of three variables, where it served as the fundamental gravitational potential in Newton's law of universal gravitation. In modern potential theory, the Newtonian potential is instead thought of as an electrostatic potential. The Newtonian potential of a compactly supported integrable function "ƒ" is defined as the convolution where the Newtonian kernel Γ in dimension "d" is defined by Here ω is the volume of the unit "d"-ball, and sometimes sign conventions may vary; compare and . In the high-dimensional case formula_3, the Newtonian potential is the opposite of the Riesz potential formula_4. The Newtonian