THE+END+OF+THE+WORLD+(The+Heat+Death+of+the+Universe)

toc The heat death of the universe is the idea that eventually the universe will burn up and die. But really not. It's actually the concept that the universe will eventually reach its maximum entropy, having no remaining free thermal energy with which to make reactions react.

=Early Conception= The second law of thermodynamics states that entropy tends to increase in an isolated system. This idea is at the root of the concept of Heat Death; the universe being the largest and only isolated system in existence, it naturally has an entropy that increases over time. Because of this, as time goes on, the entropy in the universe will asymptotally approach its potential maximum, at which point reactions would no longer be able to occur. In other words, over time, the universe is experiencing a slow dissipation of all mechanical energy.

History
The theory of the heat death of the universe was brought to light by William Thomson, later Lord Kelvin, during the 1860s. The idea was formulated following the discovery of the [|laws of thermodynamics] ([|Funk]). Helmholtz said, "We must admire the sagacity of Thomson, who, in the letters of a long-known little mathematical formula which speaks only of the heat, volume, and pressure of bodies, was able to discern the consquences which threatened the universe, though certainly after an infinite period of time, with eternal death" (Lewis). William Hopkins, the Cambridge tutor of William Thomson (see below), was also instrumental in the development of the theory of the heat death of the universe. Hopkins concluded that, "'the heat of the sun must ultimately be diminished, and the physical condition of the earth therefore altered, in a degree inconsistent with the theory of non-progression.' With limited and constantly dissipated resources, the Earth similarly must have had hot and //finite// past - and a cold and uninhabitable future" (Lewis). ===William Thomson (Lord Kelvin) (1824-1907) === Born in 1824, William Thomson was a Scottish mathematical physicist. In 1848, he constructed the first absolute temperature scale, "a scale that was independent of the particular properties of any specific material substances such as mercury or air" (Lewis). Thomson also calculated in 1854 an estimation of the sun's lifespan, and also calculated figures similar to the aging of the sun for the cooling of the earth (Lewis). Despite his theories and calculations regarding the heat death of the universe, and the cold and dark future that, in his opinion, awaits the earth, Thomson also questioned whether or not the earth might possess within itself some kind of powers for re-concentrating its physical energies and creating life once more, following the heat death of the universe (Lewis). Despite his questions and further potential theories, Thomson's theory of the heat death of the universe was widely accepted, and has been built upon throughout the centuries.

=Is heat death really hot?= The short answer to this question is 'no'. Heat Death is not "Hot Death," more the opposite: it's literally the death of Heat. When the universe has reached total thermal equillibrium, everything will be at absolute zero. Absolute zero causes the death of stars, which turn into black holes and white dwarfs. Eventually, the night sky will be completely dark (epoch of degeneration). Particles and subatomic particles inside of the nuclei of stars will begin a slow decay; the decay of protons releases radiation, and therefore, carbon ceases to exist. As we all know, carbon-based life is not possible, so this will be the most significant change in the cesation of the universe. As radiation is continually released, black holes eventually disintigrate, and there is no longer physical matter in the universe. All that is left is mostly electrons and radiation. Hence, the dark era. :D Another theory leading to the dark age, as mentioned earlier, is the theory of increasing entropy. It is speculated that entropy is contained in all black holes. As these black holes disintigrate, they release contained entropy (which is consequently what causes objects to get sucked into them), therefore incresing universal entropy. The only way for the universe to exist, in order, as it does now, is for the entropy level to remain below the maximum value. It is said that we are currently at an entropy level of 10^104, while the maximum remains at 10^122. We are a long ways off from reaching this level, but our level today is significantly higher than that of the early universe (10^88). =Where are we now? Timeframe for the Apocalypse= Now, with all this talk of death and cold and hot and universes imploding, you might be wondering "When will we all die??" The answer to this question is comforting. Both because the universe is so enormous, and is constantly expanding, and because there is so much energy in the universe and so much variation in the levels of energy between different points (a multi-thousand kelvin star vs. empty space), Heat Death is not going to happen for another 100 trillion trillion trillion years. I'd say that's plenty of time to party, wouldn't you? =Bibliography= "CNN - Physicists Describe Grim End of the World - Jan. 15, 1997." //CNN.com - Breaking News, U.S., World, Weather, Entertainment & Video News//. Web. 01 June 2010. [].

Cowen, Ron. "New Calculations Suggest Universe May Be Closer to Heat Death - US News and World Report." //US News & World Report - Breaking News, World News, Business News, and America's Best Colleges - USNews.com//. Science News, 5 Oct. 2009. Web. 03 June 2010. .

Funk, Jacob. "Heat Death of the Universe." //Astrophysics//. 11 Apr. 2010. Web. 03 June 2010. .

Lewis, Christopher J. T. //Heat and Thermodynamics: A Historical Perspective//. Westport, Conn.: Greenwood, 2007. Print.