The harmonic law would suggest that Neptune will take to orbit the Sun than Mercury.?

The harmonic law, often associated with Kepler's Third Law of Planetary Motion, states that the square of the orbital period of a planet is proportional to the cube of the semi-major axis of its orbit. This means that planets farther from the Sun, like Neptune, have longer orbital periods than those closer, like Mercury. Therefore, Neptune takes significantly longer to complete one orbit around the Sun compared to Mercury, which has a shorter orbital period due to its proximity to the Sun.