  Commenting the 11-year sunspot cycle, Wolf (1859, MNRAS 19, 85-86)
conjectured that "the variations of spot frequency depend on the influences of
Venus, Earth, Jupiter, and Saturn". The high synchronization of our planetary
system is already nicely revealed by the fact that the ratios of the planetary
orbital radii are closely related to each other through a scaling-mirror
symmetry equation (Bank and Scafetta, Front. Astron. Space Sci. 8, 758184,
2022). Reviewing the many planetary harmonics and the orbital invariant
inequalities that characterize the planetary motions of the solar system from
the monthly to the millennial time scales, we show that they are not randomly
distributed but clearly tend to cluster around some specific values that also
match those of the main solar activity cycles. In some cases, planetary models
have even been able to predict the time-phase of the solar oscillations
including the Schwabe 11-year sunspot cycle. We also stress that solar models
based on the hypothesis that solar activity is regulated by its internal
dynamics alone have never been able to reproduce the variety of the observed
cycles. Although planetary tidal forces are weak, we review a number of
mechanisms that could explain how the solar structure and the solar dynamo
could get tuned to the planetary motions. In particular, we discuss how the
effects of the weak tidal forces could be significantly amplified in the solar
core by an induced increase in the H-burning. Mechanisms modulating the
electromagnetic and gravitational large-scale structure of the planetary system
are also discussed.
