Decades of observations of the gravitational deflection of electromagnetic waves at the solar limb show a very strong impact parameter dependency. Apparently, the gravitational deflection effect is an explainable phenomenon, which vary in relation to the solar limb due to an indirect interaction between the gravitational gradient of the sun and the deflected electromagnetic radiation itself. The famous equation of general relativity for the gravitational deflection of light was derived by an application of the conservation of energy.. It was assumed that the propagating wave in the solar plasma limb travel along a minimum-time or a minimum-energy path. Surprisingly, this result was found to be completely frequency independent. To date no clear distinctions can be made between a direct and an indirect interaction gravitation-electromagnetism interaction. The plasma limb of the sun is a representation of an indirect interaction between the gravitational field of the sun and the deflected electromagnetic waves. The minimum time calculation has been confirmed by a number of very-long-baseline interferometer (VLBI) measurements of the microwaves emitted by the extra galactic radio pulsar sources. Lebach et al. (1995). The impact parameter dependency of microwave signals at the solar limb has been experimentally verified showing that the microwave signals deflect precisely at the impact parameter R exactly at the plasma limb of the sun, where R is the solar radius and at an angle of exactly 1.75 arcsec. A gravitational deflection of microwave signals from extragalactic sources at higher impact parameters are yet to be observed or resolved.
