A critical thinking exercise on what, thermodynamically, if any thing, constitutes "life", from Robert Balmer’s Modern Engineering Thermodynamics (2010), wherein students are queried to use the black box approach, to see of science recognizes the existence of any sort of “life state”. (Ѻ) |
“Our reconstruction of the history of the early solar system and the events that led to the origin of the earth informs us that around 3.5 billion years ago or earlier a complicated chain of chemical events occurred to evolve animated molecular structures from inanimate atoms.”
Life-centric term Counter term User Life Non-life Living Non-living Alive Dead Animal life (vegetable life) Mineral life Biotic Abiotic Living organism Organism Living system System Living being Being Living matter Non-living matter Living state Nonliving state Paul Davies (1999) (Alive matter) Dead matter Christian de Quincy (2002) Living molecule Molecule Living energy Energy Sentient Insentient Christian de Quincy (2002) Conscious matter Nonconscious matter Christian de Quincy (2002) (Living chemicals) Non-living chemicals Paul Davies (2003)
See: Life terminology upgradesSome of the terms that hold up in the modern sense include:
Physical science term Counter term User Reactive Non-reactive (inert) Libb Thims (2007) Organic (carbon-based) Inorganic (non carbon-based) Animate engine Inanimate engine James Johnstone (1921) Animate energy Inanimate energy Bernard Beaudreau (2005) Organic engine Inorganic engine James Johnstone (1921) Animate Inanimate William Sidis (1920) (Reactive matter) Inert matter Christian de Quincy (2002)
AgNCO + NH4Cl → (NH2)2CO + AgCl
See main: Life attribute and failing; See also: Definitions of lifeIn the very popular 2008 book 13 Things That Don’t Make Sense, by American physicist Michael Brooks, the fifth thing that doesn't make sense in modern science is life. 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.”
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 (see: note to chapter 6) 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. | ||
1953 | DNA = "secret of life" | Francis Crick [21] | |
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. | Michael Brooks [12] | Other things that consume fuel and excrete waste products, such as automobiles, are not considered to be alive. | |
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
“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.”
See main: Evolution thermodynamicsIn 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.
“Clausius and Darwin cannot both be right.”— Roger Caillois, Coherences Aventureuses (1976) [6]
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]
See also: Induced movementLife, 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.