Assertion: gravity | /r/HasProperty | the reason
Facets:
Source sentences:
text: 2011 Gravity is the reason for the existence of an atmosphere on Earth.
text: Gravity is ubiquitous, omnipresent and causes objects to accelerate towards the centers of other objects exerting gravitational attraction (like the center of the Earth).
text: weak force (which relates to radioactivity), strong force (the force that binds up protons and neutrons within the atom) and gravitational force (the reason why apples fall to the ground and the moon revolves around the Earth).
text: Or that gravity is the reason a ball comes back down when you throw it into the air, instead of just traveling higher and higher?