Panpsychism

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Panpsychism

 

Illustration of the Neoplatonic concept of the World Soul emanating from The Absolute, in some ways a precursor to modern panpsychism

 

In philosophy of mind, panpsychism is the view that mind or a mind-like aspect is a fundamental and ubiquitous feature of reality. It has taken on a wide variety of forms. Contemporary academic proponents hold that sentience or subjective experience is ubiquitous, while distancing these qualities from complex human mental attributes; they ascribe a primitive form of mentality to entities at the fundamental level of physics but do not ascribe it to most aggregates, such as rocks or buildings.On the other hand, some historical theorists ascribed attributes such as life or spirits to all entities.

Panpsychism is one of the oldest philosophical theories, and has been ascribed to philosophers including Thales, Plato, Spinoza, Leibniz, William James, Alfred North Whitehead, and Galen Strawson. During the nineteenth century, panpsychism was the default theory in philosophy of mind, but it saw a decline during the middle years of the twentieth century with the rise of logical positivism. The recent interest in the hard problem of consciousness has revived interest in panpsychism.

Etymology

The term "panpsychism" has its origins with the Greek term pan (πᾶν : "all, everything, whole") and psyche (ψυχή: "soul, mind") as the unifying center of the mental life of us humans and other living creatures." Psyche comes from the Greek word ψύχω (psukhō, "I blow") and may mean life, soul, mind, spirit, heart, and 'life-breath'. The use of psyche is controversial due to it being synonymous with soul, a term usually taken to have some sort of supernatural quality; more common terms now found in the literature include mind, mental properties, mental aspect, and experience.

Terminology

The philosopher David Chalmers, who has explored panpsychism as a viable theory, distinguishes between microphenomenal experiences (the experiences of microphysical entities) and macrophenomenal experiences (the experiences of larger entities, such as humans).

History

Ancient

Two iwakura – a rock where a kami or spirit is said to reside in the religion of Shinto

 

Panpsychist views are a staple theme in pre-Socratic Greek philosophy. According to Aristotle, Thales (c. 624 – 545 BCE) the first Greek philosopher, posited a theory which held "that everything is full of gods." Thales believed that this was demonstrated by magnets. This has been interpreted as a panpsychist doctrine. Other Greek thinkers who have been associated with panpsychism include Anaxagoras (who saw the underlying principle or arche as nous or mind), Anaximenes (who saw the arche as pneuma or spirit) and Heraclitus (who said "The thinking faculty is common to all").

Plato argues for panpsychism in his Sophist, in which he writes that all things participate in the form of Being and that it must have a psychic aspect of mind and soul (psyche). In the Philebus and Timaeus, Plato argues for the idea of a world soul or anima mundi. According to Plato:

This world is indeed a living being endowed with a soul and intelligence ... a single visible living entity containing all other living entities, which by their nature are all related.

Stoicism developed a cosmology which held that the natural world was infused with a divine fiery essence called pneuma, which was directed by a universal intelligence called logos. The relationship of the individual logos of beings with the universal logos was a central concern of the Roman Stoic Marcus Aurelius. The metaphysics of Stoicism was based on Hellenistic philosophies such as Neoplatonism and Gnosticism also made use of the Platonic idea of the anima mundi.

Renaissance

Illustration of the Cosmic order by Robert Fludd, where the World Soul is depicted as a woman

 

After the closing of Plato's Academy by the Emperor Justinian in 529 CE, Neoplatonism declined. Though there were mediaeval Christian thinkers who ventured what might be called panpsychist ideas (such as John Scotus Eriugena), it was not a dominant strain in Christian thought. In the Italian Renaissance, however, panpsychism enjoyed something of an intellectual revival, in the thought of figures such as Gerolamo Cardano, Bernardino Telesio, Francesco Patrizi, Giordano Bruno, and Tommaso Campanella. Cardano argued for the view that soul or anima was a fundamental part of the world and Patrizi introduced the actual term panpsychism into the philosophical vocabulary. According to Giordano Bruno: "There is nothing that does not possess a soul and that has no vital principle." Platonist ideas resembling the anima mundi also resurfaced in the work of esoteric thinkers such as Paracelsus, Robert Fludd, and Cornelius Agrippa. 

Early modern period

In the seventeenth century, two rationalists can be said to be panpsychists, Baruch Spinoza and Gottfried Leibniz. In Spinoza's monism, the one single infinite and eternal substance is "God, or Nature" (Deus sive Natura) which has the aspects of mind (thought) and matter (extension). Leibniz' view is that there are an infinite number of absolutely simple mental substances called monads which make up the fundamental structure of the universe. While it has been said that the idealist philosophy of George Berkeley is also a form of pure panpsychism and that "idealists are panspychists by default", it has also been argued that such arguments conflate mentally-constructed phenomena with minds themselves. Berkeley rejected panpsychism and posited that the physical world exists only in the experiences minds have of it, while restricting minds to humans and certain other specific agents.

19th century

In the nineteenth century, panpsychism was at its zenith. Philosophers such as Arthur Schopenhauer, C.S Peirce, Josiah Royce, William James, Eduard von Hartmann, F.C.S. Schiller, Ernst Haeckel and William Kingdon Clifford as well as psychologists such as Gustav Fechner, Wilhelm Wundt and Rudolf Hermann Lotze all promoted panpsychist ideas.

Arthur Schopenhauer argued for a two-sided view of reality which was both Will and Representation (Vorstellung). According to Schopenhauer: "All ostensible mind can be attributed to matter, but all matter can likewise be attributed to mind".

Josiah Royce, the leading American absolute idealist held that reality was a "world self", a conscious being that comprised everything, though he didn't necessarily attribute mental properties to the smallest constituents of mentalistic "systems". The American pragmatist philosopher Charles Sanders Peirce espoused a sort of Psycho-physical Monism in which the universe was suffused with mind which he associated with spontaneity and freedom. Following Pierce, William James also espoused a form of panpsychism. In his lecture notes, James wrote:

Our only intelligible notion of an object in itself is that it should be an object for itself, and this lands us in panpsychism and a belief that our physical perceptions are effects on us of 'psychical' realities

In 1893, Paul Carus proposed his own philosophy similar to panpsychism known as 'panbiotism', which he defined as "everything is fraught with life; it contains life; it has the ability to live."

20th century

In the twentieth century, the most significant proponent of the panpsychist view is arguably Alfred North Whitehead (1861–1947). Whitehead's ontology saw the basic nature of the world as made up of events and the process of their creation and extinction. These elementary events (which he called occasions) are in part mental. According to Whitehead: "we should conceive mental operations as among the factors which make up the constitution of nature."

Bertrand Russell's neutral monist views tended toward panpsychism. The physicist Arthur Eddington also defended a form of panpsychism.

The psychologist Carl Jung, who is known for his idea of the collective unconscious, wrote that "psyche and matter are contained in one and the same world, and moreover are in continuous contact with one another", and that it was probable that "psyche and matter are two different aspects of one and the same thing". The psychologists James Ward and Charles Augustus Strong also endorsed variants of panpsychism.

The geneticist Sewall Wright endorsed a version of panpsychism. He believed that the birth of consciousness was not due to a mysterious property of increasing complexity, but rather an inherent property, therefore implying these properties were in the most elementary particles.

Contemporary

The panpsychist doctrine has recently seen a resurgence in the philosophy of mind, set into motion by Thomas Nagel's 1979 article "Panpsychism" and further spurred by Galen Strawson's 2006 article "Realistic Monism: Why Physicalism Entails Panpsychism." Its prominent proponents in the United States include Christian de Quincey, Leopold Stubenberg, David Ray Griffin, and David Skrbina. In the United Kingdom the case for panpsychism has been made in recent decades by Galen Strawson, Gregg Rosenberg, Timothy Sprigge, and Philip Goff. The British philosopher David Papineau, while distancing himself from orthodox panpsychists, has written that his view is "not unlike panpsychism" in that he rejects a line in nature between "events lit up by phenomenology [and] those that are mere darkness." The Canadian philosopher William Seager has also defended panpsychism.

In 1990, the physicist David Bohm published "A New theory of the relationship of mind and matter", a paper propounding a panpsychist theory of consciousness based on Bohm's interpretation of quantum mechanics. Bohm has a number of followers among philosophers of mind both in the United States (e.g. Quentin Smith) and internationally (e.g. Paavo Pylkkänen). The doctrine has also been applied in environmental philosophy by Australian philosopher Freya Mathews. Science editor Annaka Harris explores panpsychism as a viable theory in her book Conscious, though she stops short of fully endorsing the view.

The integrated information theory of consciousness (IIT), proposed by the neuroscientist and psychiatrist Giulio Tononi in 2004 and since adopted by other neuroscientists such as Christof Koch, postulates that consciousness is widespread and can be found even in some simple systems. However, it does not hold that all systems are conscious, leading Tononi and Koch to state that IIT incorporates some elements of panpsychism but not others. Koch has referred to IIT as a "scientifically refined version" of panpsychism.

Arguments in favor

Hard problem of consciousness

In the philosophy of mind, panpsychism is one possible solution to the so-called hard problem of consciousness. David Chalmers, who formulated the hard problem of consciousness, has argued panpsychism is one of multiple viable theories of consciousness in The Conscious Mind (1996) and subsequent work. Chalmers argues against any reductive solution to the hard problem of consciousness by presenting three related arguments: the explanatory argument, the conceivability argument, and the knowledge argument. He then discusses three possible non-reductive explanations of consciousness but leaves open the correct solution.

Hegelian argument

In a subsequent paper, Chalmers has built on his previous exploration of panpsychism and said that a "Hegelian" argument is the most convincing argument for panpsychism, although he admits that it is not definitive. The argument is Hegelian because it is based on Hegelian dialectic and the concepts of thesis, antithesis and synthesis.

Chalmers uses the materialist argument from causal closure as his thesis and the conceivability argument for mind–body dualism as his antithesis. Chalmers argues that each argument is persuasive, and that the most persuasive way to resolve both simultaneously is to adopt a form of panpsychism, which is the synthesis of the two arguments.

Chalmers, however, takes his argument further, and argues that for the thesis of panpsychism there is a separate antithesis of panprotopsychism- the proposition that everything in existence is proto-conscious as opposed to conscious. Chalmers tentatively proposes Russellian monism as a synthesis but he does not fully embrace this option and instead sees panpsychism and panprotopsychism as more plausible options.

Non-emergentism

Alleged problems with emergentism are often cited by panpsychists as grounds to reject reductive theories of consciousness. This argument can be traced back to the psychologist Wilhelm Wundt, who applied the phrase ex nihilo nihil fit ("nothing comes from nothing") in this context – saying thus the mental cannot arise from the non-mental.

Thomas Nagel

In the article "Panpsychism" in his 1979 book Mortal Questions, Thomas Nagel defines panpsychism as "the view that the basic physical constituents of the universe have mental properties", which he claims are non-physical properties. Nagel argues that panpsychism follows from four premises:

1. "Material composition", or commitment to materialism.
2. "Non-reductionism", or the view that mental properties cannot be reduced to physical properties.
3. "Realism" about mental properties.
4. "Non-emergence", or the view that "there are no truly emergent properties of complex systems".

Nagel notes that new physical properties are discovered through explanatory inference from known physical properties; following a similar process, mental properties would seem to derive from properties of matter not included under the label of "physical properties", and so they must be additional properties of matter. He also argues that "the demand for an account of how mental states necessarily appear in physical organisms cannot be satisfied by the discovery of uniform correlations between mental states and physical brain states." Furthermore, Nagel argues mental states are real by appealing to the inexplicability of subjective experience, or qualia, by physical means. Nagel ties panpsychism to the failure of emergentism to deal with metaphysical relation: "There are no truly emergent properties of complex systems. All properties of complex systems that are not relations between it and something else derive from the properties of its constituents and their effects on each other when so combined." Thus he denies that mental properties can arise out of complex relationships between physical matter. 

Critics of panpsychism could deny proposition (2) of Nagel's argument. If mental properties are reduced to physical properties of a physical system, then it does not follow that all matter has mental properties: it is in virtue of the structural or functional organization of the physical system that the system can be said to have a mind, not simply that it is made of matter. This is the common functionalist position. This view allows for certain man-made systems that are properly organized, such as some computers, to have minds. This may cause problems when (4) is taken into account. Also, qualia seem to undermine the reduction of mental properties to brain properties.

Evolutionary

The most popular empirically based argument for panpsychism stems from evolution and is a form of the non-emergence argument. This argument begins with the assumption that evolution is a process that creates complex systems out of pre-existing properties but yet cannot make "entirely novel" properties. William Kingdon Clifford argued that:

... we cannot suppose that so enormous a jump from one creature to another should have occurred at any point in the process of evolution as the introduction of a fact entirely different and absolutely separate from the physical fact. It is impossible for anybody to point out the particular place in the line of descent where that event can be supposed to have taken place. The only thing that we can come to, if we accept the doctrine of evolution at all, is that even in the very lowest organism, even in the Amoeba which swims about in our own blood, there is something or other, inconceivably simple to us, which is of the same nature with our own consciousness ...

Quantum physics

Philosophers such as Alfred North Whitehead have drawn on the indeterminacy observed by quantum physics to defend panpsychism. A similar line of argument has been repeated subsequently by a number of thinkers including the physicist David Bohm, anesthesiologist Stuart Hameroff and philosophers such as Quentin Smith, Paavo Pylkkänen, and Shan Gao. The advocates of panpsychist quantum consciousness theories see quantum indeterminacy and informational but non-causal relations between quantum elements as the key to explaining consciousness. This approach has also been taken by Michael Lockwood (1991).

Intrinsic nature

These arguments are based on the idea that everything must have an intrinsic nature. They argue that while the objects studied by physics are described in a dispositional way, these dispositions must be based on some non-dispositional intrinsic attributes, which Whitehead called the "mysterious reality in the background, intrinsically unknowable". While we have no way of knowing what these intrinsic attributes are like, we can know the intrinsic nature of conscious experience which possesses irreducible and intrinsic characteristics. Arthur Schopenhauer argued that while the world appears to us as representation, there must be 'an object that grounds' representation, which he called the 'inner essence' (das innere Wesen) and 'natural force' (Naturkraft), which lies outside of what our understanding perceives as natural law.

Galen Strawson has called his form of panpsychism "realistic physicalism", arguing that "the experiential considered specifically as such – the portion of reality we have to do with when we consider experiences specifically and solely in respect of the experiential character they have for those who have them as they have them – that 'just is' physical".

Arguments against

One criticism of panpsychism is that it cannot be empirically tested. David Chalmers responds that while no direct evidence exists for the theory, neither is there direct evidence against it, and that he believes "there are indirect reasons, of a broadly theoretical character, for taking the view seriously" (see above).

A related criticism is what seems to many to be the theory's bizarre nature. John Searle states that panpsychism is an "absurd view" and that thermostats lack "enough structure even to be a remote candidate for consciousness." Philip Goff, on the other hand, writes that many theories now known to be true have faced resistance due to their intuitive strangeness, and that such intuitions should therefore not be used to assess theories.

The combination problem is frequently discussed as an objection to panpsychism. It can be traced to the writing of William James, but was given its present name by William Seager in 1995. While numerous solutions have been proposed, they have yet to gain widespread acceptance. Keith Frankish explains the combination problem as follows:

Panpsychists hold that consciousness emerges from the combination of billions of subatomic consciousnesses, just as the brain emerges from the organization of billions of subatomic particles. But how do these tiny consciousnesses combine? We understand how particles combine to make atoms, molecules and larger structures, but what parallel story can we tell on the phenomenal side? How do the micro-experiences of billions of subatomic particles in my brain combine to form the twinge of pain I’m feeling in my knee? If billions of humans organized themselves to form a giant brain, each person simulating a single neuron and sending signals to the others using mobile phones, it seems unlikely that their consciousnesses would merge to form a single giant consciousness. Why should something similar happen with subatomic particles?

Some have argued that the only properties shared by all qualia are that they are not precisely describable, and thus are of indeterminate meaning within any philosophy which relies upon precise definition according to these critics (that is, it tends to presuppose a definition for mentality without describing it in any real detail). The need to define better the terms used within the thesis of panpsychism is recognized by panpsychist David Skrbina, and he resorts to asserting some sort of hierarchy of mental terms to be used. Thus only one fundamental aspect of mind is said to be present in all matter, namely, subjective experience. Another panpsychist response has been that we already know what qualia are through direct, introspective apprehension; and we likewise know what conscious mentality is by virtue of being conscious. For Alfred North Whitehead, third-person description takes second place to the intimate connection between every entity and every other which is, he says, the very fabric of reality. To take a mere description as having primary reality is to commit the "fallacy of misplaced concreteness".

By placing subjective experience as the intrinsic nature of the physical world, panpsychists hope to avoid the problem of mental causation. However, Robert Howell has argued that all the causal functions are still accounted for dispositionally (i.e., in terms of the behaviors described by science), leaving phenomenality causally inert. He concludes: "This leaves us once again with epiphenomenal qualia, only in a very surprising place."

Another criticism of panpsychism has been that it is not useful for explaining the functions of the brain. Giulio Tononi and Christof Koch write that while panpsychism integrates consciousness into the physical world in a way that is "elegantly unitary," its "beauty has been singularly barren. Besides claiming that matter and mind are one thing, it has little constructive to say and offers no positive laws explaining how the mind is organized and works."

In relation to other theories

A diagram summarizing Cartesian dualism, physicalism, idealism, and neutral monism, four positions to which panpsychism has been compared in various ways

 

Idealism

Writing in 1950, Charles Hartshorne said that panpsychism, in contrast to many forms of idealism, holds that for all minds there is a single, external, spatio-temporal world, which is not just ideas in a divine mind. He said panpsychism was thus a form of realism. David Chalmers also contrasts panpsychism to idealism (as well as to materialism and dualism). On the other hand, Uwe Meixner argues that panpsychism can come in both dualistic and idealist forms. He further divides the latter into "atomistic idealistic panpsychism," which he ascribes to David Hume, and "holistic idealistic panpsychism," which he favors.

Dualism

David Chalmers describes panpsychism as an alternative to both materialism and dualism. Philip Goff similarly describes panpsychism as an alternative to both physicalism and substance dualism. Chalmers describes panpsychism as respecting the conclusions of both the causal argument against dualism and the conceivability argument for dualism. Goff has argued that panpsychism avoids the disunity of dualism, under which mind and matter are ontologically separate, as well as dualism's problems explaining how mind and matter interact.

Neutral monism

The relationship between neutral monism and panpsychism is complex, and further complicated by the variety of formulations of neutral monism. In versions of neutral monism in which the fundamental constituents of the world are neither mental nor physical, it is quite distinct from panpsychism. On the other hand, in versions where the fundamental constituents are both mental and physical, neutral monism is closer to panpsychism or at least dual aspect theory. Neutral monism and panpsychism (as well as sometimes dual aspect theory) are sometimes grouped together as similar theories.

Physicalism and materialism

Panpsychism encompasses many theories, united by the notion that consciousness is ubiquitous; these can in principle be reductive materialist, dualist, or something else. Galen Strawson maintains that panpsychism is a form of physicalism, on his view the only viable form. On the other hand, David Chalmers describes panpsychism as an alternative to both materialism and dualism. Philip Goff similarly describes panpsychism as an alternative to both physicalism and substance dualism.

Emergentism

Panpsychism is incompatible with emergentism. In general, theories of consciousness fall under one or the other umbrella; they either hold that consciousness is present at a fundamental level of reality (panpsychism) or that it emerges higher up (emergentism).

Animism and hylozoism

Panpsychism is distinct from animism or hylozoism, which hold that all things have a soul or are alive, respectively. Neither animism nor hylozoism has attracted contemporary academic interest.

Variants

Panexperientialism

The form of panpsychism under discussion in the contemporary literature is more specifically known as panexperientialism, the view that conscious experience is present everywhere at a fundamental level. Panexperientialism can be contrasted with pancognitivism, the view that thought is present everywhere at a fundamental level, a view which had some historical advocates, but has not garnered present-day academic adherents; as such contemporary panpsychists do not believe microphysical entities have complex mental states such as beliefs, desires, fears, and so forth.

Panexperientialism is associated with the philosophies of, among others, Charles Hartshorne and Alfred North Whitehead, although the term itself was invented by David Ray Griffin in order to distinguish the process philosophical view from other varieties of panpsychism. The ecological phenomenology developed in the writings of the American cultural ecologist and philosopher, David Abram, is often described as a form of panexperientialism, as is the "poetic biology" developed by Abram's close associate, the German biologist Andreas Weber.

Whitehead's metaphysics incorporated a scientific worldview similar to Einstein's theory of relativity into the development of his philosophical system. His process philosophy argues that the fundamental elements of the universe are "occasions of experience," which can together create something as complex as a human being. This experience is not consciousness; there is no mind-body duality under this system, since mind is seen as a particularly developed kind of experience. Whitehead was not a subjective idealist, and while his occasions of experience (or "actual occasions") resemble Leibniz's monads, they are described as constitutively interrelated. He embraced panentheism, with God encompassing all occasions of experience and yet still transcending them. Whitehead believed that these occasions of experience are the smallest element in the universe—even smaller than subatomic particles. Building off Whitehead's work, process philosopher Michel Weber argues for a pancreativism.

Panprotopsychism

Panprotopsychism is a theory related to panpsychism. It is discussed as a viable theory of consciousness in the works of David Chalmers.

Cosmopsychism

Cosmopsychism is the theory that the cosmos is a proper whole, a unified object that is ontologically prior to its parts. Proponents of cosmopsychism claim that the cosmos as a whole is the fundamental level of reality and that it instantiates consciousness, which is how the view differs from panpsychism, where the claim is usually that the smallest level of reality is fundamental and instantiates consciousness. Accordingly, human consciousness, for example, is merely derivative from the cosmic consciousness. 

In eastern philosophy

In the art of the Japanese rock garden, the artist must be aware of the "ishigokoro" ('heart', or 'mind') of the rocks ^[52]

 

According to Graham Parkes: "Most of traditional Chinese, Japanese and Korean philosophy would qualify as panpsychist in nature. For the philosophical schools best known in the west — Neo-confucianism and Japanese Buddhism – the world is a dynamic force field of energies known as qi or bussho (Buddha nature) and classifiable in western terms as psychophysical." According to Advaita Vedanta, the non-dualistic school of Hinduism, Brahman is the underlying consciousness that is the foundation of all reality.

East Asian Buddhism

According to D. S. Clarke, panpsychist and panexperientialist aspects can be found in the Huayan and Tiantai (Jpn. Tendai) Buddhist doctrines of Buddha nature, which was often attributed to inanimate objects such as lotus flowers and mountains. Tiantai patriarch Zhanran argued that "even non-sentient beings have Buddha nature."

Who, then, is "animate" and who "inanimate"? Within the assembly of the Lotus, all are present without division. In the case of grass, trees and the soil...whether they merely lift their feet or energetically traverse the long path, they will all reach Nirvana.

The Tiantai school was transmitted to Japan by Saicho, who spoke of the "buddha-nature of trees and rocks".

According to the 9th-century Shingon Buddhist thinker Kukai, the Dharmakaya is nothing other than the physical universe and natural objects such as rocks and stones are included as part of the supreme embodiment of the Buddha. The Soto Zen master Dogen also argued for the universality of Buddha nature. According to Dogen, "fences, walls, tiles, and pebbles" are also "mind" (心,shin). Dogen also argued that "insentient beings expound the teachings" and that the words of the eternal Buddha "are engraved on trees and on rocks . . . in fields and in villages". This is the message of his "Mountains and Waters Sutra" (Sansui kyô).

Ideal gas

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Ideal_gas

An ideal gas is a theoretical gas composed of many randomly moving point particles whose only interactions are perfectly elastic collisions. The ideal gas concept is useful because it obeys the ideal gas law, a simplified equation of state, and is amenable to analysis under statistical mechanics.

In most usual conditions (for instance at standard temperature and pressure), most real gases behave qualitatively like an ideal gas. Many gases such as nitrogen, oxygen, hydrogen, noble gases, and some heavier gases like carbon dioxide can be treated like ideal gases within reasonable tolerances. Generally, a gas behaves more like an ideal gas at higher temperature and lower pressure, as the potential energy due to intermolecular forces becomes less significant compared with the particles' kinetic energy, and the size of the molecules becomes less significant compared to the empty space between them. One mole of an ideal gas has a capacity of 22.710947(13) litres at standard temperature and pressure (a temperature of 273.15 K and an absolute pressure of exactly 10⁵ Pa) as defined by IUPAC since 1982.

The ideal gas model tends to fail at lower temperatures or higher pressures, when intermolecular forces and molecular size becomes important. It also fails for most heavy gases, such as many refrigerants, and for gases with strong intermolecular forces, notably water vapor. At high pressures, the volume of a real gas is often considerably larger than that of an ideal gas. At low temperatures, the pressure of a real gas is often considerably less than that of an ideal gas. At some point of low temperature and high pressure, real gases undergo a phase transition, such as to a liquid or a solid. The model of an ideal gas, however, does not describe or allow phase transitions. These must be modeled by more complex equations of state. The deviation from the ideal gas behaviour can be described by a dimensionless quantity, the compressibility factor, Z.

The ideal gas model has been explored in both the Newtonian dynamics (as in "kinetic theory") and in quantum mechanics (as a "gas in a box"). The ideal gas model has also been used to model the behavior of electrons in a metal (in the Drude model and the free electron model), and it is one of the most important models in statistical mechanics.

 

 

Types of ideal gas

There are three basic classes of ideal gas:

• the classical or Maxwell–Boltzmann ideal gas,
• the ideal quantum Bose gas, composed of bosons, and
• the ideal quantum Fermi gas, composed of fermions.

The classical ideal gas can be separated into two types: The classical thermodynamic ideal gas and the ideal quantum Boltzmann gas. Both are essentially the same, except that the classical thermodynamic ideal gas is based on classical statistical mechanics, and certain thermodynamic parameters such as the entropy are only specified to within an undetermined additive constant. The ideal quantum Boltzmann gas overcomes this limitation by taking the limit of the quantum Bose gas and quantum Fermi gas in the limit of high temperature to specify these additive constants. The behavior of a quantum Boltzmann gas is the same as that of a classical ideal gas except for the specification of these constants. The results of the quantum Boltzmann gas are used in a number of cases including the Sackur–Tetrode equation for the entropy of an ideal gas and the Saha ionization equation for a weakly ionized plasma.

Classical thermodynamic ideal gas

The classical thermodynamic properties of an ideal gas can be described by two equations of state:

Ideal gas law

Relationships between Boyle's, Charles's, Gay-Lussac's, Avogadro's, combined and ideal gas laws, with the Boltzmann constant k_B = RN_A = n RN  (in each law, properties circled are constant and properties not circled are variable)

The ideal gas law is the equation of state for an ideal gas, given by:

${\displaystyle PV=nRT\,}$

where

• P is the pressure
• V is the volume
• n is the amount of substance of the gas (in moles)
• R is the gas constant (0.08206 L·atm·K⁻¹·mol⁻¹)
• T is the absolute temperature.

The ideal gas law is an extension of experimentally discovered gas laws. It can also be derived from microscopic considerations.

Real fluids at low density and high temperature approximate the behavior of a classical ideal gas. However, at lower temperatures or a higher density, a real fluid deviates strongly from the behavior of an ideal gas, particularly as it condenses from a gas into a liquid or as it deposits from a gas into a solid. This deviation is expressed as a compressibility factor. 

This equation is derived from

• Boyle's law: ${\displaystyle V\propto {\frac {1}{P}}}$;
• Charles's law: ${\displaystyle V\propto T}$;
• Avogadro's law: ${\displaystyle V\propto n}$.

After combining three laws we get

${\displaystyle V\propto {\frac {nT}{P}}}$

That is:

${\displaystyle V=R\left({\frac {nT}{P}}\right)}$

${\displaystyle PV=nRT}$.

Internal energy

The other equation of state of an ideal gas must express Joule's law, that the internal energy of a fixed mass of ideal gas is a function only of its temperature. For the present purposes it is convenient to postulate an exemplary version of this law by writing:

${\displaystyle U={\hat {c}}_{V}nRT}$

where

• U is the internal energy
• ĉ_V is the dimensionless specific heat capacity at constant volume, approximately 32 for a monatomic gas, 52 for diatomic gas, and 3 for non-linear molecules if we ignore quantum vibrational contribution. These formulas arise from application of the classical Equipartition Theorem.

That U for an ideal gas depends only on temperature is a consequence of the ideal gas law, although in the general case ĉ_V depends on temperature and an integral is needed to compute U. 

Microscopic model

In order to switch from macroscopic quantities (left hand side of the following equation) to microscopic ones (right hand side), we use

${\displaystyle nR=Nk_{\mathrm {B} }\ }$

where

• N is the number of gas particles
• k_B is the Boltzmann constant (1.381×10⁻²³ J·K⁻¹).

The probability distribution of particles by velocity or energy is given by the Maxwell speed distribution.

The ideal gas model depends on the following assumptions:

• The molecules of the gas are indistinguishable, small, hard spheres
• All collisions are elastic and all motion is frictionless (no energy loss in motion or collision)
• Newton's laws apply
• The average distance between molecules is much larger than the size of the molecules
• The molecules are constantly moving in random directions with a distribution of speeds
• There are no attractive or repulsive forces between the molecules apart from those that determine their point-like collisions
• The only forces between the gas molecules and the surroundings are those that determine the point-like collisions of the molecules with the walls
• In the simplest case, there are no long-range forces between the molecules of the gas and the surroundings.

The assumption of spherical particles is necessary so that there are no rotational modes allowed, unlike in a diatomic gas. The following three assumptions are very related: molecules are hard, collisions are elastic, and there are no inter-molecular forces. The assumption that the space between particles is much larger than the particles themselves is of paramount importance, and explains why the ideal gas approximation fails at high pressures. 

Heat capacity

The dimensionless heat capacity at constant volume is generally defined by

${\displaystyle {\hat {c}}_{V}={\frac {1}{nR}}T\left({\frac {\partial S}{\partial T}}\right)_{V}={\frac {1}{nR}}\left({\frac {\partial U}{\partial T}}\right)_{V}}$

where S is the entropy. This quantity is generally a function of temperature due to intermolecular and intramolecular forces, but for moderate temperatures it is approximately constant. Specifically, the Equipartition Theorem predicts that the constant for a monatomic gas is ĉ_V = 32 while for a diatomic gas it is ĉ_V = 52 if vibrations are neglected (which is often an excellent approximation). Since the heat capacity depends on the atomic or molecular nature of the gas, macroscopic measurements on heat capacity provide useful information on the microscopic structure of the molecules. 

The dimensionless heat capacity at constant pressure of an ideal gas is:

${\displaystyle {\hat {c}}_{P}={\frac {1}{nR}}T\left({\frac {\partial S}{\partial T}}\right)_{P}={\frac {1}{nR}}\left({\frac {\partial H}{\partial T}}\right)_{P}={\hat {c}}_{V}+1}$

where H = U + PV is the enthalpy of the gas. 

Sometimes, a distinction is made between an ideal gas, where ĉ_V and ĉ_P could vary with temperature, and a perfect gas, for which this is not the case.

The ratio of the constant volume and constant pressure heat capacity is the adiabatic index

${\displaystyle \gamma ={\frac {c_{P}}{c_{V}}}}$

For air, which is a mixture of gases, this ratio is 1.4.

Entropy

Using the results of thermodynamics only, we can go a long way in determining the expression for the entropy of an ideal gas. This is an important step since, according to the theory of thermodynamic potentials, if we can express the entropy as a function of U (U is a thermodynamic potential), volume V and the number of particles N, then we will have a complete statement of the thermodynamic behavior of the ideal gas. We will be able to derive both the ideal gas law and the expression for internal energy from it. 

Since the entropy is an exact differential, using the chain rule, the change in entropy when going from a reference state 0 to some other state with entropy S may be written as ΔS where:

${\displaystyle \Delta S=\int _{S_{0}}^{S}dS=\int _{T_{0}}^{T}\left({\frac {\partial S}{\partial T}}\right)_{V}\!dT+\int _{V_{0}}^{V}\left({\frac {\partial S}{\partial V}}\right)_{T}\!dV}$

where the reference variables may be functions of the number of particles N. Using the definition of the heat capacity at constant volume for the first differential and the appropriate Maxwell relation for the second we have:

${\displaystyle \Delta S=\int _{T_{0}}^{T}{\frac {C_{V}}{T}}\,dT+\int _{V_{0}}^{V}\left({\frac {\partial P}{\partial T}}\right)_{V}dV.}$

Expressing C_V in terms of ĉ_V as developed in the above section, differentiating the ideal gas equation of state, and integrating yields:

${\displaystyle \Delta S={\hat {c}}_{V}Nk\ln \left({\frac {T}{T_{0}}}\right)+Nk\ln \left({\frac {V}{V_{0}}}\right)}$

which implies that the entropy may be expressed as:

${\displaystyle S=Nk\ln \left({\frac {VT^{{\hat {c}}_{V}}}{f(N)}}\right)}$

where all constants have been incorporated into the logarithm as f(N) which is some function of the particle number N having the same dimensions as VT^ĉ_V in order that the argument of the logarithm be dimensionless. We now impose the constraint that the entropy be extensive. This will mean that when the extensive parameters (V and N) are multiplied by a constant, the entropy will be multiplied by the same constant. Mathematically:

${\displaystyle S(T,aV,aN)=aS(T,V,N).\,}$

From this we find an equation for the function f(N)

${\displaystyle af(N)=f(aN).\,}$

Differentiating this with respect to a, setting a equal to 1, and then solving the differential equation yields f(N):

${\displaystyle f(N)=\Phi N\,}$

where Φ may vary for different gases, but will be independent of the thermodynamic state of the gas. It will have the dimensions of VT^ĉ_V/N. Substituting into the equation for the entropy:

${\displaystyle {\frac {S}{Nk}}=\ln \left({\frac {VT^{{\hat {c}}_{V}}}{N\Phi }}\right).\,}$

and using the expression for the internal energy of an ideal gas, the entropy may be written:

${\displaystyle {\frac {S}{Nk}}=\ln \left[{\frac {V}{N}}\,\left({\frac {U}{{\hat {c}}_{V}kN}}\right)^{{\hat {c}}_{V}}\,{\frac {1}{\Phi }}\right]}$

Since this is an expression for entropy in terms of U, V, and N, it is a fundamental equation from which all other properties of the ideal gas may be derived. 

This is about as far as we can go using thermodynamics alone. Note that the above equation is flawed – as the temperature approaches zero, the entropy approaches negative infinity, in contradiction to the third law of thermodynamics. In the above "ideal" development, there is a critical point, not at absolute zero, at which the argument of the logarithm becomes unity, and the entropy becomes zero. This is unphysical. The above equation is a good approximation only when the argument of the logarithm is much larger than unity – the concept of an ideal gas breaks down at low values of VN. Nevertheless, there will be a "best" value of the constant in the sense that the predicted entropy is as close as possible to the actual entropy, given the flawed assumption of ideality. A quantum-mechanical derivation of this constant is developed in the derivation of the Sackur–Tetrode equation which expresses the entropy of a monatomic (ĉ_V = 32) ideal gas. In the Sackur–Tetrode theory the constant depends only upon the mass of the gas particle. The Sackur–Tetrode equation also suffers from a divergent entropy at absolute zero, but is a good approximation for the entropy of a monatomic ideal gas for high enough temperatures.

${\displaystyle {\frac {\Delta S}{Nk{\hat {c}}_{V}}}=\ln \left({\frac {P}{P_{0}}}\right)+\gamma \ln \left({\frac {V}{V_{0}}}\right)=\ln \left({\frac {PV^{\gamma }}{P_{0}V_{0}^{\gamma }}}\right)\implies PV^{\gamma }=const.\;{\text{for isentropic process}}}$

Social class in American history

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Social_class_in_American_history

Social class is an important theme for historians of the United States for over decades. The subject touches on many other elements of American history such as that of changing U.S. education, with Greater education attainment leading to expanding household incomes for many social groups. The overall level of prosperity grew greatly in the U.S. through the 20th century as well as the 21st century, anchored in changes such as growing American advances in science and technology with American inventions such as the phonograph, the portable electric vacuum cleaner, and so on. Yet much of the debate has focused lately on whether social mobility has fallen in recent decades as income inequality as risen, what scholars such as Katherine S. Newman have called the "American nightmare."

For most of American history, social class barriers were fundamentally rigid, with various private and public institutions enforcing rules based on racial segregation and other forms of classifying people based on prejudices such as antisemitism and Hispanophobia. All this changed greatly with the rise of broad-based prosperity in the aftermath of World War II and efforts to expand Constitutional civil rights under the law to groups such as African-Americans and Hispanic-Americans. Issues regarding social class have remained hot-button topics in U.S. politics, with the American Great Recession causing massive socio-economic harm across the country from southerners to northerners to working-class whites to middle-class blacks.

Colonial period

Historians in recent decades have explored in microscopic detail the process of settling the new country and creating the social structure.

Southern colonies

The main themes have been the class system of the plantation South. These include the plantation masters and their families, as typified by the Byrd family. The plantation elite in gen regions of the Chesapeake, with some attention to South Carolina as well. The region had very few urban places apart from Charleston, where a merchant elite maintained close connections with nearby plantation society. It was a goal of prosperous merchants, lawyers and doctors in Charleston to buy lands and retire as country gentlemen. Charleston supported diverse ethnic groups, including Germans and French, as well as a free black population. Beyond the plantations yeoman farmers operated small holdings, sometimes with a slave or two. Missionaries commented on their lack of religiosity. The plantation areas of Virginia were integrated into the vestry system of the established Anglican church. By the 1760s a strong tendency to emulate British society was apparent in the plantation regions. However the growing strength of republicanism created a political ethos that resisted imperial taxation without local consent. Led by Virginia, the Southern Colonies resisted the British policy of taxation without representation, and supported the American Revolution, sending wealthy planters George Washington to lead the armies and Thomas Jefferson to declare the principles of independence, as well as thousands of ordinary folk to man the armies.

19th century

Frontier

Historian Frederick Jackson Turner had a frontier based theory. The frontier itself was egalitarian as land ownership was available to all free men. Second deference faded away as frontiersmen treated each other as equals. Third the frontiersmen forced new levels of political equality through Jefferson Democracy and Jacksonian Democracy. Finally the frontier provided a safety valve whereby discontented easterners could find their own lands. Historians now agree that few Eastern city people went to the frontier, but many farmers did so; before 1850 the America had few cities, which were mostly small, and the vast majority of people were rural. According to the Turner model, the social structure of the East was similar to the familiar European class-based structure, while the West increasingly became more socially, politically, and economically equal.

The Plain Folk of the Old South

Frank Lawrence Owsley in Plain Folk of the Old South (1949) redefined the debate by starting with the writings of Daniel R. Hundley who in 1860 had defined the Southern middle class as "farmers, planters, traders, storekeepers, artisans, mechanics, a few manufacturers, a goodly number of country school teachers, and a host of half-fledged country lawyers, doctors, parsons, and the like." To find these people Owsley turned to the name-by-name files on the manuscript federal census. Owsley argued that Southern society was not dominated by planter aristocrats, but that yeoman farmers played a significant role in it. The religion, language, and culture of these common people created a democratic "plain folk" society.

In his study of Edgefield County, South Carolina, Orville Vernon Burton classified black society into the poor, the yeoman middle class, and the elite. A clear line demarcated the elite, but according to Burton, the line between poor and yeoman was never very distinct. Stephanie McCurry argues, yeomen were clearly distinguished from poor whites by their ownership of land (real property). Yeomen were "self-working farmers," distinct from the elite because they worked their land themselves alongside any slaves they owned. Ownership of large numbers of slaves made the work of planters completely managerial.

Minorities

African Americans

The study of slavery as a social and economic system dates from Ulrich B. Phillips in the early 20th century. He argued that plantation slavery was a school for civilizing the blacks, albeit one that produced no graduates. His favoritism toward the slave owners was finally challenged by neoabolitionist historians in the 1950s, most notably Kenneth Stampp. Since the 1960s a large literature has emerged on the social structure of the slave system, especially on such topics as family life, gender roles, resistance to slavery, and demographic trends. The study of free blacks has been slower to emerge because of the shortage of records, but historians have been filling in the picture North and South with studies of free black urban communities, and their religious and political leaders. 

The post-slavery era has been dominated by political studies, especially of Reconstruction and Jim Crow. The black churches were not only a political force, but became central to the black community in both urban and rural areas. The emergence of a black musical culture has been linked both to slavery (as in the Blues), and to church music.

Asian Americans

Asian Americans had small communities in New York City before 1860. Their greatest growth came on the Pacific Coast, during the Gold Rush and railroad booms of the 1860s. The Chinese who remained in America were violently driven out of the mining and railroad camps, and largely forced into Chinatowns in the larger cities, especially San Francisco. The Chinese exclusion laws of the 1880s created special legal problems, which numerous have explored. The Chinatowns were over 90% male, augmented by a trickle of immigration, and slowly shrank in size until 1940. Local and national attitudes became much more favorable to the Chinese after 1940, largely because of American support for China in World War II.

Japanese immigration was a major factor in the history of Hawaii, and after its annexation in 1898 large numbers moved to the West Coast. Anti-Japanese hostility was strong down to 1941, when it intensified and most Japanese on the West Coast were sent to relocation camps, 1942-44. After 1945 the trickle of immigration from the Philippines, India and Korea grew steadily, creating large communities on the West Coast.

Hispanics

In 1848 after the Mexican–American War, the annexation of Texas and the Southwest introduced a Hispanic population that had full citizenship status. About 10,000 Californios lived in the southern part of California, and were numerically overwhelmed by migrants form the East by 1900 that their identity was almost lost. In New Mexico, by contrast, the Mexican population maintained its highly traditionalistic and religious culture, and retained some political power, into the 21st century. The Tejano population of Texas supported the revolution against Mexico in 1836, and gained full citizenship. In practice, however, most were ranch hands with limited political rights under the control of local bosses. 

Industrial Northeast

The industrialization of the Northeast dramatically changed the social structure. New wealth abounded, with the growth of factories, railroads, and banks from the 1830 to the 1920s. Hundreds of small cities sprang up, together with 100 large cities (of 100,000 or more population by 1920). Most had a base in manufacturing. The urban areas came to have a complex class structure, compounded of wealth (the more the better), occupation (with the learned professions at the top), and family status (the older the better). Ethnic-religious groups had their separate social systems (such as German Lutherans and Irish Catholics). The New England Yankee was dominant in business, finance, education, and high society in most Northern cities, but gradually lost control of politics to a working class coalition led dominated by bosses and immigrants, including Irish Catholics. Hundreds of new colleges and academies were founded to support the system, usually with specific religious or ethnic identities. Heterogeneous state universities became important after 1920.

Ethnicity and social class

The most elaborate and in-depth studies of social class have focused on the working class, especially regarding occupation, immigration, ethnicity, family structure, education, occupational mobility, religious behavior, and neighborhood structure. Before 1970 historians emphasized the success, and the painful processes, of assimilation into American culture, as studied by Oscar Handlin. In recent decades the internal value systems have been explored, as well as the process of occupational mobility. Most of the studies have been localized (because of the need for the exhaustive use of censuses and local data) so that generalizations have been difficult to make. In recent years European scholars have become interested in the international flows so that there are now studies following people from Europe to America over their lifetimes. 

Labor historians have moved from a focus on national labor unions to microscopic studies of the workers in particular industries in particular cities. The consensus has been that the workers had their own political and cultural value system. The political values were based on a producer's ethic, that is the working class was the truly productive sector of society, and expressed a version of republicanism that was similar to the middle class version. This enabled the businessman's party, the Republican party, to enjoy a strong base among Protestant blue collar workers, and prevented the emergence of a strong Socialist movement.

20th century

The Progressive Era, with its emphasis on factualism and scientific inquiry produced hundreds of community studies, mostly using descriptive statistics to cover issues of poverty, crime, migration, religiosity, education, and public health. The emergence of systematic social science, especially sociology, shifted the center of class studies into sociology departments. The most representative example was the Middletown books by Robert Lynd and Helen Lynd, which gave a microscopic look at class structures in a typical small city (Muncie, Indiana). After 1960 localized studies gave way to national surveys, with special emphasis on the process of social mobility and stratification.

A classic theme was trying to see if the middle class was shrinking, or if the opportunities for upward mobility had worsened over time. After 1960 a growing concern with education led to many studies dealing with racial integration, and performance in schools by racial and gender groupings.

The disposable income of the American upper class was sharply reduced by high income tax rates during the 1930s, 40s, and 50s. During this period corporate executives had relatively modest incomes, lived modestly, and had few servants.