Astrology, that unlikely and vague pseudoscience, makes much of the position of the planets at the moment of birth. The only known force a planet exerts on Earth is gravitational.

a) Calculate the gravitational force exerted on a 4.00kg baby by a 90kg father, 0.250m away at birth (assisting he is so close).

b) Calculate the force on the baby, due to Jupiter, if it is at its closest to the Earth, some 6.29x10
11
m away, showing it to be comparable to that of the father. The mass of Jupiter is about 1.90x10
27
kg. Other objects in the room, and the hospital building, also exert similar gravitational forces. (Of course, there could be an unknown force acting, but scientists first need to be convinced that there is even an effect, much less that an unknown force causes it.)