"When we say ‘science explains’ something we usually mean that there exists a scientific description of the phenomenon in question. Thus the force of gravity — rather important since it keeps us from bumping around on the ceiling like helium balloons — can be expressed by a simple mathematical formula. The formula equates the gravitational force between two objects to the product of their masses multiplied by a universal constant (the ‘gravitational constant’) and divided by the square of the distance between them. But does the equation ‘explain’ why you don’t bump your head on the ceiling? Not really. It tells us there is a force that keeps your feet on the ground, but you knew that already. It also quantifies that force, allowing us to calculate its strength in any particular case, which is extremely useful. But it doesn't tell us why there is such a force, why it follows an inverse square law, and why the ‘gravitational constant’ has the value that it does. The equation is a description of gravity rather than an explanation."
--Edgar Andrews, from Who Made God?