I'm reading through Sparknotes' explanation of the equation: U = -Gm1m2/r "Off the surface of the Earth, there’s no obvious reference point from which to measure gravitational potential energy. Conventionally, we say that an object that is an infinite distance away from the Earth has zero gravitational potential energy with respect to the Earth. Because a negative amount of work is done to bring an object closer to the Earth, gravitational potential energy is always a negative number when using this reference point." I really don't understand why bringing an object closer to Earth would do negative work. I've been trying to wrap my head around this statement for a bit and I'd appreciate a good explanation or some guidance. From what I understand work = F*d*cos(theta) so negative work would mean pushing the object away, wouldn't it? Why would that be required to bring an object closer to Earth?