As the cloud shrinks in size, its central temperature increases, as a result of its gravitational potential energy being converted to thermal energy.
We are assuming that the mentioned cloud, is a cloud of interstellar dust (nebula), in which this definition is applicable. Since energy cannot disappear, the lost gravitational potential energy would have to transform into something else, in this case, thermal energy, or simply heat, which will increase the overall temperature of the cloud.
Because Earth's gravitational pull is so strong, we do not notice the pull from other objects. Earth's gravity pulls everything to the center of Earth and prevents us from flying off into space
