Complex sentence: Albert Einstein predicted that a repulsive form of gravity emanates from empty space, he first conceived of the notion of a repulsive force in space in his attempt to explain the balance of the universe against the inward pull of its own gravity.
Split into simpler sentences: Albert Einstein predicted that a repulsive form of gravity emanates from empty space. He first conceived of the notion of a repulsive force in space in his attempt to explain the balance of the universe against the inward pull of its own gravity.