It is shown that the quasi 27 day periodicity of the height of the 500 mbar level detected by King and related by him to the rotating sun consists of real persistent planetary waves within the spectral band with periods between 25 and 30 days. These waves have lifetimes of several months to one year and seem to be randomly generated by internal turbulent processes within the troposphere without any trigger mechanism from outside the atmosphere. On the other hand, the sector structure of the interplanetary magnetic field as well as the grouping of sunspots on preferred active longitudes rotate nearly rigidly with the sun with periods between about 26 and 28 days. The lifetimes of these structures range also between months and years. It is concluded that this accidential coincidence of two indpendent persistent turbulent processes possessing similar periods and similar lifetimes gives the illusion of a physical connection ('sun- weather- effect') which in fact does not exist.