Legend has it that Isaac Newton had the moment of inspiration that would lead to his theory of gravity when, on a warm afternoon, he saw an apple fall from a tree and wondered why it should fall down ...

Scientists think a new framework for quantum gravity could offer clues about a mysterious 5th fundamental force of nature.

What is the difference between mass and matter? Gravity is the force of action between two objects. It’s called a natural force because it acts at a distance rather than needing to be in contact.

Is gravity just an emergent effect of entropy? Gravity might not be a more fundamental than the force of a stretched elastic band. Maybe gravity is just an entropic byproduct—an emergent effect of the ...