Step 1: Sentence S1 introduces the topic — the existence of a force between everybody in the universe.
Step 2: Sentence Q logically follows as it mentions that this force has been investigated by scientists like Galileo and Newton.
Step 3: Sentence S explains the nature of this force, stating that it depends on the mass of the bodies involved.
Step 4: Sentence R provides a specific example related to the earth, making the concept clearer.
Step 5: Sentence P concludes by emphasizing that the force becomes considerable when one of the bodies is large, like the earth.