Galileo was the first person to show that at any given place, all bodies big or small fall freely when dropped, with the same (uniform) acceleration, if the resistance due to air is negligible. The gravitational attraction ofa body towards the center of the earth results in the same acceleration for all bodies at a particular location, irrespective of their mass, shape or material, and this acceleration is called the acceleration due to gravity, g. The value of gvaries from place to place, being greatest at the poles and the least at the equator. Because this value is large, bodies fall quickly to the surface of the earth when dropped, and so it is very difficult to measure their acceleration directly with considerable accuracy.