The Heat Death of the Universe Briana Wilsey

The End of the Universe There are two main theories regarding the end of the universe The Big Crunch Occurs for a closed, spherical universe Universe returns to a very dense state similar to the beginning of the universe The Heat Death

Origins The heat death was first proposed in 1854 by Hermann von Helmholtz Clausius formulated the Second Law of Thermodynamics in terms of entropy in 1865

The Heat Death Flat, open and accelerating universe Heat Death occurs as the universe moves toward maximum entropy and minimum temperature

Entropy Entropy-a measure of the disorder of a system The Second Law of Thermodynamics The total entropy of a system must always increase Entropy increases as the universe evolves

Process As time increases toward infinity so does the size of the universe Average matter and energy densities approach zero

Indicators Stars burn out White dwarfs cool Black holes merge, drawn together by gravitational radiation They will eventually decay into photons and particles as a result of Hawking radiation In some theories, protons will decay and all baryonic matter will break down into more fundamental forms

Result Once all possible reactions have taken place, only fundamental particles and electromagnetic radiation, or heat, will remain The universe will have reached maximum entropy and no further reactions can take place There is not enough energy left to do work The universe fades away

Cold Death The universe cools as a result of expansion Eventually it becomes too cold to support life and the universe dies out Cold death and heat death are not the same, although they both result in low temperatures

Works Cited Hawley, John F., Holcomb, Katherine A. (2005). Foundations of Modern Cosmology. New York: Oxford University Press. Heat Death of the Universe. Retrieved March 26, 2006, from Birkedal-Hansen, Andreas, Al-Assam, Sarah. Retrieved March 26, 2006, from