you are switching from one environment (astrology?) to another (physics). one is not science. the other is.
the word radius has no relationship i know of to ra etymologically. and if you look up the modern meaning of radius in relationship to the width of a circle, it is a modern (ie non-classical) mathematical form. the ancients had the word but not the meaning of the word radius which we apply.
same with words to do with electricity, which derive from the Latin and Greek for amber, but were given their current sense by scientists in the seventeenth century who observed amber's attractive qualities.
just because you see that a word has a long usage doesn't mean that it has always held its definition. or that the associations you speculate upon actually have any history to them.
splitting ra and dius doesn't mean you have found something historically significant connecting the egyptian god ra with the latin "deus" meaning god.
sometimes a radius is just a radius.