In the physical sciences, mass and weight are different. The mass of an object is a measure of the amount of matter in the object. Weight is a measure of the force on the object caused by a gravitational field. In other words, weight is how hard gravity pulls on an object. This means the mass of an object will remain at wherever it is on the earth's surface, but if it is moved from the equator to the North Pole, its weight will grow by 0.5% because of the increase in the earth's gravitational field.