The Earth is round, and so are the Sun and the moon. Even the planets, their satellites and the stars are also spherical. Do you know, why all these heavenly bodies are spherical in shape? According to a law of science, every physical system in the Universe tries to attain a state of minimum energy for maximum stability. It is an established fact that if a sphere is made from a given volume of any material it will have the least surface area compared to any other form. Consequently, the spherical bodies have the minimum surface energy. Substances try to acquire a round form like a football in order to achieve the state of minimum energy, that is, the state of maximum stability. This is why the Sun, the moon, the stars, the Earth and all other heavenly bodies have a spherical shape. The raindrops are also spherical. It is so because the surface of the spherical drops has the minimum energy and maximum stability. Whatever be the process of producing the water drops, they immediately try to acquire a spherical shape. All substances try to acquire a round form in order, to achieve the state of minimum energy that is state of maximum stability. This is why all heavenly bodies have spherical shape. Atoms and molecules are also spherical in shape. Even the electrons, protons and neutrons present in the atoms are also spherical. You might have observed that every man tries to earn the most with the least effort. Every student tries to secure maximum marks after putting in the minimum labour. Thus, we see that the tendency to come to the minimum energy state is found in all the living and non-living bodies. As soon as a substance acquires the minimum energy state, its shape becomes spherical.