In science, life is a defunct scientific term used to classify motile or animate atomic structures, generally of larger size, found active or activated past approximately 4.1-billion-years ago mark (bacteria formation range) on the evolution timeline. [17] Synonyms include: living organism, living system, living being, living matter, living structure, etc., which are all said to be, in some way, in contrast to non-life. An older classification scheme was the organic (life) verses inorganic (non-life) distinction. American physicist Ronald Fox characterizes the question of how life arose from non-life as the uroboros puzzle. [18]

Criterion definitions
In the very popular 2008 book 13 Things That Don’t Make Sense, by American physicist Michael Brooks, number five is life. In this chapter, Brooks explains how traditionally there have been three ways to unravel the essential nature of life. [12] One is to find out how it started: trace the life back to the point where all that existed was chemistry. A pictorial view of the evolution timeline, however, shows this to be a futile effort, in that the only demarcation one can find is the sub-atomic to atomic transition point of the universe, approximately 13.5-billion years ago. The second method, according to Brooks, is to build something that is “alive” from scratch: take chemicals and put them together in ways that make them come alive. The 1952 Urey-Miller experiment, of course, is the poster child of this endeavor. [13] More recent attempt in this direction, include: cloning, making test tube babies, bring back to life extinct species using preserved DNA samples, etc. In nanotechnology, building things atom-by-atom, such as walking molecules, driving molecules, etc., is another type of proto-like life. Lastly, according to Brooks:

“[the third option to unraveling the essence of life is] to sit down and think about what exactly is it that marks the difference between living [matter] and nonliving matter and come up with the definition of life. It is this latter path that is perhaps the most well trodden. It is also the one widely admitted to be a dead end.”

In other words, it has become a guarantee that once a new criterion-based definition of life is put forth, it will only be a matter of time before a disproof becomes apparent. The following is a listing of various criterion definitions of life (and disproofs) ordered by date:

Date	Criterion	Person	Disproof
1944	(a) Something that moves, exchanging material with its environment, for a much longer period of time than we would expect (compared to inanimate things).	Erwin Schrödinger [14]	The solar system has been moving, exchanging asteroids and solar energy with its environment, for over 5 millions years now; but is not alive.
	(b) Something not at thermodynamic equilibrium.		A body of steam transforming during an engine cycle; but this is not alive.
	(c) Anything that feeds on negative entropy.	(Note: this is an incorrect description metabolism; which Schrodinger admits in a footnote should have been explained via free energy).	Many reactions release free energy (have a negative free energy change).
	(d) Anything that continually draws negative entropy from its environment.		A block of ice melting does so by absorbing entropy (heat) from its surroundings; but is not alive.
	(e) A system that moves disorder to order.		(a) A candle flame creates order from disorder in its environment and is patently not alive. [12] (b) Benard cells are an order-from-disorder phenomenon, but are not defined as alive.
1970	(a) Power of reproducing itself (e.g. a virus).	Linus Pauling [8]	(a) Plenty of computer programs could then be called alive, while plenty of people, sterile men and women, e.g. nuns, could not. [12] (b) The reactants of many simple chemical reactions are "reproduced" in the products; but we do define chemical reactions as being alive.
	(b) Possession of a metabolism; able to ingest food.		Other things that consume fuel and excrete waste products, such as automobiles, are not considered to be alive. [12]
1995	Contained within a boundary (e.g. bacteria).	Lynn Margulis [16]	The body of steam in a steam engine is contained within a boundary.
1999	(a) Anything that metabolizes, processing chemicals to gain energy.	Paul Davies [15]	Jupiter's Great Red Spot is said to metabolize or process chemicals to gain energy. [12]
	(b) Reproduce itself.		Mules don't and bush fires and crystals do. [12]
	(c) Has organized complexity; composed of interdependent systems, e.g. arteries and legs.		Modern cars are similar. [12]
	(d) Grows and develops.		As does rust.
	(e) Shows a combination of permanence and change; evolution through mutation and selection.
	(f) Anything autonomous; able to choose its own actions.		There is no such thing (see: free will, induced movement, etc.).
2007	(a) Able to replicate itself.	Martin Rees [11]	The early universe hydrogen-to-helium reaction is form of self-replication; but an atom is not considered to be alive.
	(b) Evolves over time.		The universe has evolved over time; but is not alive, nor has "life" ever been found anywhere in the universe.

Thermodynamics
In the 1916 work The Origin and Evolution of Life, American zoologist and paleontologist Henry Osborn was one of the first to dig into the question of what is living matter, using bits of thermodynamics logic, thus concluding that: [10]

“Living matter … represents a new assemblage of energies and new types of action, reaction, and interaction—to use the terms of thermodynamics—between those chemical elements which may be as old as the cosmos itself.”

In the study of thermodynamics of life, according to the 1947 views of Belgian-born English thermodynamicist Alfred Ubbelohde, life is viewed as animated matter. [7] Life, according to the 2008 views of Russian physical chemist Georgi Gladyshev, is a phenomenon of the existence of the energy-dependent dynamic hierarchic structures, driven by thermodynamics. [9]

Human chemistry
In human chemistry, life is a sub-atomic or chemical species in a state of evolution reactivity. [1] Life, in detail, is the animated interaction of matter with energy. Any variety of animate structure on the surface of the earth has a molecular formula and subsequently can be defined as a molecule. A bee, for example, is approximately a 20-element molecule. [2] Thus, for instance, human life being the activity of temporal interactions between systems of human molecules, is an advanced variety of atomic or molecular life.

In a general sense, the anthropomorphic version of life, e.g. human life, biological life, bacterial life, etc., began at the Planck-level. Variations of sub-atomic life, e.g. "quark life", is a newer area of investigation.

Clausius vs. Darwin

See main: Evolution thermodynamics

In 1850, German physicist Rudolf Clausius began to publish his memoirs, beginning with "On the Motive Power of Heat", on the newly forming science of thermo-dynamics, which showed that in the universe there is a tendency towards the increase of a system function called entropy; a function later shown to be equivalent to a measure of order or disorder is ideal gas phase systems. In 1859, English naturalist Charles Darwin published his Origin of Species, which showed that in nature there exists an ordering process, called evolution, progressing in time from lower forms of life to higher to more ordered forms.

Into the 1910s, the seeming contradiction between thermodynamics, loosely viewed colloquially as a disorganizing tendency, and the evolution of life, loosely viewed as an organizing tendency, was coming to the fore. In the 1914 book Problems in Science, for instance, Italian mathematician Federigo Enriques professed his conclusion on the matter to the effect that: “the mechanical hypothesis (first and second law) does not appear to be incompatible with the phenomenon of life, but it is unimportant for the study of these phenomena.” [5] The debate on the issue, however, remained unresolved. In 1976, the unanswered paradox of views had emerged to the effect that:

"Clausius and Darwin cannot both be right.”

— Roger Caillois, Coherences Aventureuses (1976), [6]

Recent difficulties on conception

See also: What is life? (theories of existence)

In current literature, stemming from a combination of Charles Darwin's 1871 supposition that the original spark of life may have begun in a "warm little pond, with all sorts of ammonia and phosphoric salts, lights, heat, electricity, etc. present, so that a protein compound was chemically formed ready to undergo still more complex changes" and fossil records indicating that bacteria existed on the surface of the earth about 3.85 billion years ago, there exists the commonly-held belief that biological life supposedly "sprang forth" on one particular day from inorganic non-life about 3.5 to 4 billion years ago. According to standard molecular evolution tables, which show the growth or forced buildup of atomic structure of animate molecules from the hydrogen atom to the human molecule, however, this logic is a false view. Correctly, biological life and chemical life are one and the same. [2]

Reaction mechanism view

See also: Induced movement

Life, in general is classified by evolution. Evolution, in component essence, is characterized by coupled chemical reactions in which smaller animate molecular structures react or reproduced to form larger molecular structures. To cite one example of this type of logic, in the 2005 book Genesis – the Scientific Quest for Life’s Origin, geologist and earth scientist Robert Hazen tells us correctly that life results whenever energy flows through a molecular system and that this energy can drive such molecular systems toward ever more levels of complexity.

Life on earth, according to Hazen, is a result of energy interactions among versatile carbon-based molecules. From these carbon-based systems, according to Hazen, come the emergence of larger molecular structures, along with the selection, concentration, and assembly of life’s membranes, proteins, and genetic molecules. Eventually, according to this logic, these biomolecular structures would form self-replicating cycles, or chemical systems that could copy themselves and compete for finite and dwindling supplies of resources. Ultimately, in Hazen’s view, competition between different self-replicating cycles works to trigger evolution by natural selection, and subsequently the development of life. This is a very accurate depiction. To elaborate on this picture, Hazen cites space biologist Gerald Joyce’s working definition of life: "Life is a self-sustained chemical system capable of undergoing Darwinian evolution." [3]

Hazen reasons, accurately, that ‘any attempt to formulate an absolute definition that distinguishes life from non-life represents a false dichotomy.’ The first cell did not just appear, according to Hazen, but rather arose through a sequence of emergent events, similar to how fossil records show that new evolved species have continuously emerged throughout history. First there was organic synthesis, then molecular selection and diversification, followed by increases in atomic complexity and further molecular evolution.

Moreover, ‘what appears to us as a yawning divide between life and non-life,’ according to Hazen, ‘obscures the fact that the chemical evolution of life occurred in a stepwise sequence of successively more complex stages of emergence.’ Hazen tells us that the basics of these steps began with a pre-biotic earth enriched with organic molecules, which then evolved to form functional clusters of molecules, perhaps arranged on a mineral surface, which assembled into larger self-replicating molecular systems that were able to copy themselves, then on to encapsulation in membranes, and finally to cellular life. [4]

References
1. Thims, Libb. (2007). Human Chemistry (Volume One), (preview), (pg. 43). Morrisville, NC: LuLu.
2. (a) Thims, Libb. (2007). Human Chemistry (Volume One), (preview), (ch. 5 "Molecular Evolution"). Morrisville, NC: LuLu.
(b) Molecular Evolution Table - Institute of Human Thermodynamics
3. Gerald Joyce, NASA Exobiology Panel [1994]
4. Hazen, Robert M. (2005). Genesis – the Scientific Quest for Life’s Origin. Washington, DC: Joseph Henry Press.
5. Enriques, Federigo. (1914). Problems of Science (section: “The Mechanical Hypothesis and the Phenomena of Life”, (pgs. 367-87). Open Court Publishing.
6. (a) Caillois, Roger. (1976). Coherences Aventureuses. Paris: Gallimard.
(b) Thaxton, Charles B., Bradley, Walter L., Olsen, Roger L. (1992). The Mystery of Life’s Origin: Reassessing Current Theories, (ch. 7: “Thermodynamics of Living Systems”, ch. 8: “Thermodynamics and the Origin of Life”). Lewis and Stanley.
(c) Bushev, Michael. (1994). Synergetics: Chaos, Order, Self-organization, (pg. 130). World Scientific.
7. Ubbelohde, Alfred René. (1947). Time and Thermodynamics, (ch. IX: “Thermodynamics and Life”). Oxford University Press.
8. Pauling, Linus. (1970). General Chemistry, (section: "The Nature of Life", pgs. 767-69). New York: Dover.
9. Gladyshev, Georgi. (2008). "What is life? Bio-Physical Perspectives." Knol., Oct.
10. Osborn, Henry Fairfield. (1918). The Origin and Evolution of Life: On the Theory of Action, Reaction and Interaction of Energy (section: “Four Questions Regarding Life” , pgs 1-9; section: “The Energy Concept of Life”, pgs 10-17). Charles Scribner’s Sons.
11. Rees, Martin. (2005). Universe: the Definitive Visual Guide (pg. 52). Dorling Kindersley.
12. (a) Brooks, Michael. (2008). 13 Things That Don’t Make Sense: the Most Baffling Mysteries of Our Time (ch. 5: Life, pgs. 69-82). DoubleDay.
(b) The book is based on an article that originally appeared in the March 19, 2005 issue of New Scientist.
13. Miller-Urey experiment – Wikipedia.
14. Schrödinger, Erwin. (1944). What is Life? (ch. 6 “Order, Disorder, and Entropy", pgs. 67-75). Cambridge: Cambridge University Press.
15. Davies, Paul. (1999). The 5th Miracle: the Search for the Origin and Meaning of Life (pg. 7). Touchstone.
16. Margulis, Lynn and Sagan, Dorion. (1995). What is Life? (pg. 113). Simon and Schuster.
17. Thims, Libb. (2009). “Letter: Life a Defunct Scientific Theory”, Journal of Human Thermodynamics, Vol. 5, pgs. 20-21.
18. Fox, Ronald F. (1988). Energy and the Evolution of Life (The Uroboros Puzzle, pgs. 3-4). New York: W.H. Freeman and Company.

External link
● A Tree of Life – ScienceMag.org
● Life – Wikipedia.