Cristian Rosado: Heat Death of the Universe: Reasons why it may or may not happen

Heat death is a suggested final state of the Universe in which it would not have free thermodynamic energy. In other words, the Universe would reach thermodynamic equilibrium and in consequence, its maximum entropy. When we see the term “heat death”, the first thing that comes to our minds is high temperature, but this theory does not imply any particular temperature. The hypothesis is developed from the ideas of William Thomson, a British mathematical physicist and engineer, also the “creator” of the Kelvin temperature scale. He took the theory of heat as mechanical energy loss in nature, as stated in the first two laws of thermodynamics, and extended it to larger processes in the Universe. This would happen if all available energy, such as energy from heat, moves to places of less energy, such as colder places. If this happens, there would be no heat transfer through the Universe, in consequence, no more work can be done or “extracted” from it. Every process in the Universe that consumes energy, including our Earth, would cease. Although this process would probably take an infinite time so that all the energy or heat would be equally distributed through the whole Universe, this theory makes sense when taking to consideration the first two laws of thermodynamics. The first law of thermodynamics says that when energy passes as work, heat, etc., into or out of a system (when energy is transferred), its internal energy changes according to the law of conservation of energy, this statement suggests that energy is not totally transferred, some energy would remain with the initial system. Then we can say that after a lot of time, there would be less energy available to transfer until there would be none. The second law of thermodynamics states that in a natural thermodynamic process, the entropy or disorder of the system is always increasing, by knowing this, we can conclude that eventually it will reach a maximum entropy where no energy would be free to transfer. Even though this explanations make sense and have their scientific prove and laws, they are based on laws we apply to systems we have studied and we can control, the Universe is huge and we don’t know certainly if this laws would apply to it entirely, maybe there are unknown forces or sources of energy that human kind have not discovered yet. Other point that may make people think this can’t happen is the fact that universe is at constant expansion. If the Universe is always expanding, there would not be an equilibrium because there would always be more objects to transfer energy or more heat sources. Also it is proposed by Ludwig Boltzmann, an Austrian physicist and philosophe, in “The Second Law as a law of disorder” that in an expanding universe, the value of maximum entropy increases faster than the Universe gains entropy, causing the Universe to move further away from a heat death. It is hard to predict what would happen to the Universe, especially when we know so little about it, the heat death may be one option for the future of our Universe.