Astrology has never so far as I know proposed a scientific mechanism by which the planets should affect the lives of us mortals. I suppose this is fair enough, you wouldn’t expect magic to work by normal laws. If the position of Jupiter says you should spend the rest of the week face down in the mud, well there’s no rule saying that Jupiter’s going to wreck its vengeance on you with any of the four known fundamental forces.
Of course there’s no indication that Jupiter or any other planet has anything to do with your personality at all by virtue of its position during your birth, or indeed that astrology is anything other than a way to turn confirmation bias into money. But let’s run some numbers, and let’s pretend that its hypothetical mystic force has something to do with good old fashioned gravity. We’ll do this because it sets up a classic intro problem where the student compares the gravitational influence of Jupiter compared to the gravitational influence of the doctor performing the delivery.
First we need the equation that gives the gravitational force between two objects:
G is the gravitational constant, M is the mass of the planet Jupiter (or the delivery doctor), m is the mass of the baby, r is the distance between them. But we’re not interested in the force, we’re interested in now the two forces compare to each other. Since G and m are the same in both cases, we can just compare the ratio of the masses of the affecting bodies to their distances.
The mass of Jupiter is about 1.9e27 kilograms, and the mass of a doctor might be around 80 kilograms. The distance to Jupiter typically is somewhere in the vicinity of 7.5e11 meters, and the distance from the emerging kid to the doctor might be taken to be… I dunno, half a meter.
Dropping the factor of Gm, I get the proportional influence of gravity from Jupiter to be 3,377 kg/m^2. Th influence from the doctor is 320 kg/m^2. Don’t worry, the units aren’t important. Neither are the numbers, only how the compare to each other. We see that Jupiter has about ten times the gravitational attraction. Which is pretty small nonetheless. The influence of a smaller and more distant planet like Saturn would be much less.
So Jupiter beats out your doc, but barely. At least in terms of gravitational pull… in terms of your future I suspect the good doctor is more important.