second law of thermodynamics states that the entropy of the universe is always increasing.
second law of thermodynamics states that the entropy of the universe is always increasing.
which law states that the entropy of the universe is always increasing?
second law of thermodynamics
the second law of thermodynamics is concerned primarily with whether or not a given process is possible. the second law states that no natural process can occur unless it is accompanied by an increase in the entropy of the universe. stated differently, an isolated system will always tend to disorder. living organisms are often mistakenly believed to defy the second law because they are able to increase their level of organization. to correct this misinterpretation, one must refer simply to the definition of systems and boundaries. a living organism is an open system, able to exchange both matter and energy with its environment. for example, a human being takes in food, breaks it down into its components, and then uses those to build up cells, tissues, ligaments, etc. this process increases order in the body, and thus decreases entropy. however, humans also 1) conduct heat to clothing and other objects they are in contact with, 2) generate convection due to differences in body temperature and the environment, 3) radiate heat into space, 4) consume energy-containing substances (i.e., food), and 5) eliminate waste (e.g., carbon dioxide, water, and other components of breath, urine, feces, sweat, etc.). when taking all these processes into account, the total entropy of the greater system (i.e., the human and her/his environment) increases. when the human ceases to live, none of these processes (1-5) take place, and any interruption in the processes (esp. 4 or 5) will quickly lead to morbidity and/or mortality.
biological thermodynamics
the link with the laws of thermodynamics was further strengthened by hawking's discovery that quantum field theory predicts that a black hole radiates blackbody radiation at a constant temperature. this seemingly causes a violation of the second law of black hole mechanics, since the radiation will carry away energy from the black hole causing it to shrink. the radiation, however also carries away entropy, and it can be proven under general assumptions that the sum of the entropy of the matter surrounding a black hole and one quarter of the area of the horizon as measured in planck units is in fact always increasing. this allows the formulation of the first law of black hole mechanics as an analogue of the first law of thermodynamics, with the mass acting as energy, the surface gravity as temperature and the area as entropy.
black hole