There is an enemy when you’re climbing mountains. The enemy is the cold. Cold is the biggest enemy and maybe the only enemy in the Everest. The enemy is not the strong wind, thin air or avalanches because they could be predicted or avoided. But the cold, people do not even recognise as one. Cold is constant, cold is everywhere you cannot avoid or run away from it. To fight this enemy we need to understand the enemy. We have the third law of thermodynamics which says the heat in a system will run out if not replaced. This is called entropy. Cold takes over when heat is not there. Cold wins over heat. Heat is expensive, it needs work. Cold is free it does not need to do anything. Earth is a system, Human being is a system, the universe is a system. You can have system in a system. Earth being inside the system of the Universe or human being inside the system of Earth. The heat in a system will eventually run out and replaced by cold. The Earth will be colder too if the Sun is not ...