Entropy and life



Much writing and research has been devoted to the relationship between the thermodynamic quantity entropy and the evolution of life. In 1910, American historian Henry Adams printed and distributed to university libraries and history professors the small volume A Letter to American Teachers of History proposing a theory of history based on the Gibbs free energy to elaborate on this issue.

Origin

 This section does not cite any references or sources.
Please improve this section by adding citations to reliable sources. Unverifiable material may be challenged and removed. (November 2007)

In 1863, Ludwig Boltzmann. In 1875, building on the works of Clausius and Kelvin, Boltzmann reasoned[3]:

“ The general struggle for existence of animate beings is not a struggle for raw materials – these, for organisms, are air, water and soil, all abundantly available – nor for energy which exists in plenty in any body in the form of heat, but a struggle for [negative] entropy, which becomes available through the transition of energy from the hot sun to the cold earth. ”
 

Early views

In 1876, American civil engineer Carnot; which constitute the fundamental laws of our subject." McCulloch then goes on to show that these two laws may be combined in a single expression as follows:

S = \int {dQ\over \tau }

where

S = entropy
dQ = equals a differential amount of thermodynamic system
τ = absolute temperature

McCullen then declares that the applications of these two laws, i.e. what are presently known as the second law of thermodynamics, are innumerable. He then states:

“ When we reflect how generally physical phenomena are connected with thermal changes and relations, it at once becomes obvious that there are few, if any, branches of natural science which are not more or less dependent upon the great truths under consideration. Nor should it, therefore, be a matter of surprise that already, in the short space of time, not yet one generation, elapsed since the mechanical theory of heat has been freely adopted, whole branches of physical science have been revolutionized by it. ”

McCulloch then gives a few examples of what he calls the “more interesting examples” of the application of these laws in extent and utility. The first example he gives, is physiology wherein he states that “the body of an animal, not less than a steamer, or a locomotive, is truly a theory of heat, which, according to McCullen, states that the “heat of the body generally and uniformly is diffused instead of being concentrated in the chest”. McCullen then gives an example of the second law, where he states that friction, especially in the smaller blooded-vessels, must develop heat. Without doubt, animal heat is thus in part produced.” He then asks: “but whence the expenditure of energy causing that friction, and which must be itself accounted for?

To answer this question he turns to the mechanical theory of heat and goes on to loosely outline how the heart is what he calls a “force-pump”, which receives blood and sends it to every part of the body, as discovered by William Harvey, that “acts like the piston of an engine and is dependent upon and consequently due to the cycle of nutrition and excretion which sustains physical or organic life.” It is likely, here, that McCulloch was modeling parts of this argument on that of the famous Carnot cycle. In conclusion, he summarizes his first and second law argument as such:

“ Everything physical being subject to the heat equivalent of that of work. ”

What is life?

Later, building on this premise, in the famous 1944 book What is Life?, Nobel-laureate physicist negative entropy.[4] In a note to What is Life?, however, Schrödinger explains his usage of this term:

“ Let me say first, that if I had been catering for them [physicists] alone I should have let the discussion turn on free energy instead. It is the more familiar notion in this context. But this highly technical term seemed linguistically too near to energy for making the average reader alive to the contrast between the two things. ”

This is what is argued to differentiate life from other forms of matter organization. In this direction, although life's dynamics may be argued to go against the tendency of second law, which states that the entropy of an isolated system tends to increase, it does not in any way conflict or invalidate this law, because the principle that entropy can only increase or remain constant applies only to a heat can enter or leave. Whenever a system can exchange either heat or matter with its environment, an entropy decrease of that system is entirely compatible with the second law.[5]

In 1964, James Lovelock was among a group of scientists who were requested by NASA to make a theoretical life detection system to look for life on Mars during the upcoming space mission. When thinking about this problem, Lovelock wondered “how can we be sure that Martian life, if any, will reveal itself to tests based on Earth’s lifestyle?” [6] To Lovelock, the basic question was “What is life, and how should it be recognized?” When speaking about this puzzling issue with some of his colleagues at the Jet Propulsion Laboratory, he was asked, well what would you do to look for life on Mars? To this Lovelock replied:

“ I’d look for an entropy reduction, since this must be a general characteristic of life. ”

Thus, according to Lovelock, to find signs of life, one must look for a “reduction or a reversal of entropy.”

Gibbs free energy

In recent years, the thermodynamic interpretation of evolution in relation to entropy has begun to utilize the concept of the second law of thermodynamics. The Gibbs free energy is given by:

\Delta G \equiv \Delta H-T \Delta S \,

The minimization of the Gibbs free energy is a form of the free energy, in the form of nutrients or sunlight, and returning to their surroundings an equal amount of energy as heat and entropy."[7]

Similarly, according to the chemist Gibbs free energy that enters the biosphere from outside sources."[8]

References

  1. ^ Adams, Henry. (1986). History of the United States of America During the Administration of Thomas Jefferson (pg. 1299). Library of America.
  2. ^ Adams, Henry. (1910). A Letter to American Teachers of History. Google Books, Scanned PDF. Washington.
  3. ^ Boltzmann, Ludwig (1974). The second law of thermodynamics (Theoretical physics and philosophical problems). Springer-Verlag New York, LLC. ISBN-13: 9789027702500. 
  4. ^ Schrödinger, Erwin (1944). What is Life - the Physical Aspect of the Living Cell. Cambridge University Press. ISBN 0-521-42708-8. 
  5. ^ The common justification for this argument, for example, according to renowned chemical engineer Kenneth Denbigh, from his 1955 book The Principles of Chemical Equilibrium, is that "living organisms are open to their environment and can build up at the expense of foodstuffs which they take in and degrade."
  6. ^ Lovelock, James (1979). GAIA - A New Look at Life on Earth. Oxford University Press. ISBN 0-19-286218-9. 
  7. ^ Lehninger, Albert (1993). Principles of Biochemistry, 2nd Ed.. Worth Publishers. ISBN 0-87901-711-2. 
  8. ^ Avery, John (2003). Information Theory and Evolution. World Scientific. ISBN 981-238-399-9. 

Further reading

  • La Cerra, P. (2003). The First Law of Psychology is the Second Law of Thermodynamics: The Energetic Evolutionary Model of the Mind and the Generation of Human Psychological Phenomena. Human Nature Review, Volume 3: 440-447. Full text

See also
 
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Entropy_and_life". A list of authors is available in Wikipedia.