http://physics.ucr.edu/~wudka/Physics7/Notes_www/node98.html In the link given below, it is explained how general relativity predicts the correct results. However I am curious about the answer of the following hypothetical scenario. Let us assume that we replaced gravity with the electromagnetic force. Then the force of attraction would be the same, and mercury would be negatively charged and the sun positively charged. The question is, would the same discrepancy occur?