Multiverse

From Wikipedia, the free encyclopedia

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

The multiverse is the hypothetical set of all universes. Together, these universes are presumed to comprise everything that exists: the entirety of space, time, matter, energy, information, and the physical laws and constants that describe them. The different universes within the multiverse are referred to variously as: "parallel universes", "flat universes", "other universes", "alternate universes", "multiple universes", "plane universes", "parent and child universes", "many universes", or "many worlds". One common assumption is that the multiverse is a "patchwork quilt of separate universes all bound by the same laws of physics."

The concept of multiple universes, or a multiverse, has been discussed throughout history. It has evolved and has been debated in various fields, including cosmology, physics, and philosophy. Some physicists have argued that the multiverse is a philosophical notion rather than a scientific hypothesis, as it cannot be empirically falsified. In recent years, there have been proponents and skeptics of multiverse theories within the physics community. Although some scientists have analyzed data in search of evidence for other universes, no statistically significant evidence has been found. Critics argue that the multiverse concept lacks testability and falsifiability, which are essential for scientific inquiry, and that it raises unresolved metaphysical issues.

Max Tegmark and Brian Greene have proposed different classification schemes for multiverses and universes. Tegmark's four-level classification consists of Level I: an extension of our universe, Level II: universes with different physical constants, Level III: many-worlds interpretation of quantum mechanics, and Level IV: ultimate ensemble. Brian Greene's nine types of multiverses include quilted, inflationary, brane, cyclic, landscape, quantum, holographic, simulated, and ultimate. The ideas explore various dimensions of space, physical laws, and mathematical structures to explain the existence and interactions of multiple universes. Some other multiverse concepts include twin-world models, cyclic theories, M-theory, and black-hole cosmology.

The anthropic principle suggests that the existence of a multitude of universes, each with different physical laws, could explain the asserted appearance of fine-tuning of our own universe for conscious life. The weak anthropic principle posits that we exist in one of the few universes that support life. Debates around Occam's razor and the simplicity of the multiverse versus a single universe arise, with proponents like Max Tegmark arguing that the multiverse is simpler and more elegant. The many-worlds interpretation of quantum mechanics and modal realism, the belief that all possible worlds exist and are as real as our world, are also subjects of debate in the context of the anthropic principle.

History of the concept

Antecedents

According to some, the idea of infinite worlds was first suggested by the pre-Socratic Greek philosopher Anaximander in the sixth century BCE. However, there is debate as to whether he believed in multiple worlds, and if he did, whether those worlds were co-existent or successive.

Ancient Indian thinkers, both Hindu and Buddhist, postulated multiple worlds/realms/universes.

The first figures to whom historians can definitively attribute the concept of innumerable worlds are the Ancient Greek Atomists, beginning with Leucippus and Democritus in the 5th century BCE, followed by Epicurus (341–270 BCE) and the Roman Epicurean Lucretius (1st century BCE). In the third century BCE, the philosopher Chrysippus suggested that the world eternally expired and regenerated, effectively suggesting the existence of multiple universes across time. The concept of multiple universes became more defined in the Middle Ages. In the Renaissance, Giordano Bruno (1548–1600) expressed the concept of infinite worlds.

Modern science

The American philosopher and psychologist William James used the term "multiverse" in 1895, but in a different context.

The concept first appeared in the modern scientific context in the course of the debate between Boltzmann and Zermelo in 1895.

In Dublin in 1952, Erwin Schrödinger gave a lecture in which he jocularly warned his audience that what he was about to say might "seem lunatic". He said that when his equations seemed to describe several different histories, these were "not alternatives, but all really happen simultaneously". This sort of duality is called "superposition".

Search for evidence

In the 1990s, after recent works of fiction about the concept gained popularity, scientific discussions about the multiverse and journal articles about it gained prominence.

Around 2010, scientists such as Stephen M. Feeney analyzed Wilkinson Microwave Anisotropy Probe (WMAP) data and claimed to find evidence suggesting that this universe collided with other (parallel) universes in the distant past. However, a more thorough analysis of data from the WMAP and from the Planck satellite, which has a resolution three times higher than WMAP, did not reveal any statistically significant evidence of such a bubble universe collision. In addition, there was no evidence of any gravitational pull of other universes on ours.

In 2015, an astrophysicist may have found evidence of alternate or parallel universes by looking back in time to a time immediately after the Big Bang, although it is still a matter of debate among physicists. Dr. Ranga-Ram Chary, after analyzing the cosmic radiation spectrum, found a signal 4,500 times brighter than it should have been, based on the number of protons and electrons scientists believe existed in the very early universe. This signal—an emission line that arose from the formation of atoms during the era of recombination—is more consistent with a universe whose ratio of matter particles to photons is about 65 times greater than our own. There is a 30% chance that this signal is noise, and not really a signal at all; however, it is also possible that it exists because a parallel universe dumped some of its matter particles into our universe. If additional protons and electrons had been added to our universe during recombination, more atoms would have formed, more photons would have been emitted during their formation, and the signature line that arose from all of these emissions would be greatly enhanced. Chary said:

Many other regions beyond our observable universe would exist with each such region governed by a different set of physical parameters than the ones we have measured for our universe.

— Ranga-Ram Chary, USA Today

Chary also noted:

Unusual claims like evidence for alternate universes require a very high burden of proof.

— Ranga-Ram Chary, "Universe Today"

The signature that Chary has isolated may be a consequence of incoming light from distant galaxies, or even from clouds of dust surrounding our own galaxy.

Proponents and skeptics

Modern proponents of one or more of the multiverse hypotheses include Lee Smolin, Don Page, Brian Greene, Max Tegmark, Alan Guth, Andrei Linde, Michio Kaku, David Deutsch, Leonard Susskind, Alexander Vilenkin, Yasunori Nomura, Raj Pathria, Laura Mersini-Houghton, Neil deGrasse Tyson, Sean Carroll and Stephen Hawking.

Scientists who are generally skeptical of the concept of a multiverse or popular multiverse hypotheses include Sabine Hossenfelder, David Gross, Paul Steinhardt, Anna Ijjas, Abraham Loeb, David Spergel, Neil Turok, Viatcheslav Mukhanov, Michael S. Turner, Roger Penrose, George Ellis, Joe Silk, Carlo Rovelli, Adam Frank, Marcelo Gleiser, Jim Baggott and Paul Davies.

Arguments against multiverse hypotheses

In his 2003 New York Times opinion piece, "A Brief History of the Multiverse", author and cosmologist Paul Davies says multiverse hypotheses are non-scientific, but based on faith.

George Ellis says that scientists have proposed the idea of the multiverse as a way of explaining the nature of existence. He points out that it ultimately leaves those questions unresolved because it is a metaphysical issue that cannot be resolved by empirical science. He argues that observational testing is at the core of science and should not be abandoned:

Nothing is wrong with scientifically based philosophical speculation, which is what multiverse proposals are. But we should name it for what it is.

Philosopher Philip Goff argues that the inference of a multiverse to explain the apparent fine-tuning of the universe is an example of Inverse Gambler's Fallacy.

Stoeger, Ellis, and Kircher note that in a true multiverse theory, "the universes are then completely disjoint and nothing that happens in any one of them is causally linked to what happens in any other one. This lack of any causal connection in such multiverses really places them beyond any scientific support".

In May 2020, in a Forbes blog post, astrophysicist Ethan Siegel expressed criticism of the claim of results from the Antarctic Impulsive Transient Antenna providing evidence for the multiverse, commenting that parallel universes would have to remain a science fiction dream for the time being.

Scientific American contributor John Horgan also argues against the idea of a multiverse, claiming that they are "bad for science."

Types

Max Tegmark and Brian Greene have devised classification schemes for the various theoretical types of multiverses and universes that they might comprise.

Max Tegmark's four levels

Cosmologist Max Tegmark has provided a taxonomy of universes beyond the familiar observable universe. The four levels of Tegmark's classification are arranged such that subsequent levels can be understood to encompass and expand upon previous levels. They are briefly described below.

Level I: An extension of our universe

A prediction of cosmic inflation is the existence of an infinite ergodic universe, which, being infinite, must contain Hubble volumes realizing all initial conditions.

Accordingly, an infinite universe will contain an infinite number of Hubble volumes, all having the same physical laws and physical constants. In regard to configurations such as the distribution of matter, almost all will differ from our Hubble volume. However, because there are infinitely many, far beyond the cosmological horizon, there will eventually be Hubble volumes with similar, and even identical, configurations. Tegmark estimates that an identical volume to ours should be about 10¹⁰¹¹⁵ meters away from us.

Given infinite space, there would be an infinite number of Hubble volumes identical to ours in the universe. This follows directly from the cosmological principle, wherein it is assumed that our Hubble volume is not special or unique.

Level II: Universes with different physical constants

In the eternal inflation theory, which is a variant of the cosmic inflation theory, the multiverse or space as a whole is stretching and will continue doing so forever, but some regions of space stop stretching and form distinct bubbles (like gas pockets in a loaf of rising bread). Such bubbles are embryonic level I multiverses.

Different bubbles may experience different spontaneous symmetry breaking, which results in different properties, such as different physical constants.

Level II also includes John Archibald Wheeler's oscillatory universe theory and Lee Smolin's fecund universes theory.

Level III: Many-worlds interpretation of quantum mechanics

Schrödinger's cat in the many-worlds interpretation, where a branching of the universe occurs through a superposition of two quantum mechanical states

Hugh Everett III's many-worlds interpretation (MWI) is one of several mainstream interpretations of quantum mechanics.

In brief, one aspect of quantum mechanics is that certain observations cannot be predicted absolutely. Instead, there is a range of possible observations, each with a different probability. According to the MWI, each of these possible observations corresponds to a different "world" within the universal wave function, with each world as real as ours. Suppose a six-sided die is thrown and that the result of the throw corresponds to observable quantum mechanics. All six possible ways the die can fall correspond to six different worlds. In the case of the Schrödinger's cat thought experiment, both outcomes would be "real" in at least one "world".

Tegmark argues that a Level III multiverse does not contain more possibilities in the Hubble volume than a Level I or Level II multiverse. In effect, all the different worlds created by "splits" in a Level III multiverse with the same physical constants can be found in some Hubble volume in a Level I multiverse. Tegmark writes that, "The only difference between Level I and Level III is where your doppelgängers reside. In Level I they live elsewhere in good old three-dimensional space. In Level III they live on another quantum branch in infinite-dimensional Hilbert space."

Similarly, all Level II bubble universes with different physical constants can, in effect, be found as "worlds" created by "splits" at the moment of spontaneous symmetry breaking in a Level III multiverse. According to Yasunori Nomura, Raphael Bousso, and Leonard Susskind, this is because global spacetime appearing in the (eternally) inflating multiverse is a redundant concept. This implies that the multiverses of Levels I, II, and III are, in fact, the same thing. This hypothesis is referred to as "Multiverse = Quantum Many Worlds". According to Yasunori Nomura, this quantum multiverse is static, and time is a simple illusion.

Another version of the many-worlds idea is H. Dieter Zeh's many-minds interpretation.

Level IV: Ultimate ensemble

The ultimate mathematical universe hypothesis is Tegmark's own hypothesis.

This level considers all universes to be equally real which can be described by different mathematical structures.

Tegmark writes:

Abstract mathematics is so general that any Theory of Everything (TOE) which is definable in purely formal terms (independent of vague human terminology) is also a mathematical structure. For instance, a TOE involving a set of different types of entities (denoted by words, say) and relations between them (denoted by additional words) is nothing but what mathematicians call a set-theoretical model, and one can generally find a formal system that it is a model of.

He argues that this "implies that any conceivable parallel universe theory can be described at Level IV" and "subsumes all other ensembles, therefore brings closure to the hierarchy of multiverses, and there cannot be, say, a Level V."

Jürgen Schmidhuber, however, says that the set of mathematical structures is not even well-defined and that it admits only universe representations describable by constructive mathematics—that is, computer programs.

Schmidhuber explicitly includes universe representations describable by non-halting programs whose output bits converge after a finite time, although the convergence time itself may not be predictable by a halting program, due to the undecidability of the halting problem. He also explicitly discusses the more restricted ensemble of quickly computable universes.

Brian Greene's nine types

The American theoretical physicist and string theorist Brian Greene discussed nine types of multiverses:

Quilted

The quilted multiverse works only in an infinite universe. With an infinite amount of space, every possible event will occur an infinite number of times. However, the speed of light prevents us from being aware of these other identical areas.

Inflationary

The inflationary multiverse is composed of various pockets in which inflation fields collapse and form new universes.

Brane

The brane multiverse version postulates that our entire universe exists on a membrane (brane) which floats in a higher dimension or "bulk". In this bulk, there are other membranes with their own universes. These universes can interact with one another, and when they collide, the violence and energy produced is more than enough to give rise to a Big Bang. The branes float or drift near each other in the bulk, and every few trillion years, attracted by gravity or some other force we do not understand, collide and bang into each other. This repeated contact gives rise to multiple or "cyclic" Big Bangs. This particular hypothesis falls under the string theory umbrella as it requires extra spatial dimensions.

Cosmos animation of a cyclic universe

Cyclic

The cyclic multiverse has multiple branes that have collided, causing Big Bangs. The universes bounce back and pass through time until they are pulled back together and again collide, destroying the old contents and creating them anew.

Landscape

The landscape multiverse relies on string theory's Calabi–Yau spaces. Quantum fluctuations drop the shapes to a lower energy level, creating a pocket with a set of laws different from that of the surrounding space.

Quantum

The quantum multiverse creates a new universe when a diversion in events occurs, as in the real-worlds variant of the many-worlds interpretation of quantum mechanics.

Holographic

The holographic multiverse is derived from the theory that the surface area of a space can encode the contents of the volume of the region.

Simulated

The simulated multiverse exists on complex computer systems that simulate entire universes. A related hypothesis, as put forward as a possibility by astronomer Avi Loeb, is that universes may be creatable in laboratories of advanced technological civilizations who have a theory of everything. Other related hypotheses include brain in a vat-type scenarios where the perceived universe is either simulated in a low-resource way or not perceived directly by the virtual/simulated inhabitant species.

Ultimate

The ultimate multiverse contains every mathematically possible universe under different laws of physics.

Twin-world models

Concept of a twin universe, with the beginning of time in the middle

There are models of two related universes that e.g. attempt to explain the baryon asymmetry – why there was more matter than antimatter at the beginning – with a mirror anti-universe. One two-universe cosmological model could explain the Hubble constant (H₀) tension via interactions between the two worlds. The "mirror world" would contain copies of all existing fundamental particles. Another twin/pair-world or "bi-world" cosmology is shown to theoretically be able to solve the cosmological constant (Λ) problem, closely related to dark energy: two interacting worlds with a large Λ each could result in a small shared effective Λ.

Cyclic theories

Main article: Cyclic model

In several theories, there is a series of, in some cases infinite, self-sustaining cycles – typically a series of Big Crunches (or Big Bounces). However, the respective universes do not exist at once but are forming or following in a logical order or sequence, with key natural constituents potentially varying between universes (see § Anthropic principle).

M-theory

See also: Introduction to M-theory, M-theory, Brane cosmology, and String theory landscape

A multiverse of a somewhat different kind has been envisaged within string theory and its higher-dimensional extension, M-theory.

These theories require the presence of 10 or 11 spacetime dimensions, respectively. The extra six or seven dimensions may either be compactified on a very small scale, or our universe may simply be localized on a dynamical (3+1)-dimensional object, a D3-brane. This opens up the possibility that there are other branes which could support other universes.

Black-hole cosmology

Main article: Black-hole cosmology

Black-hole cosmology is a cosmological model in which the observable universe is the interior of a black hole existing as one of possibly many universes inside a larger universe. This includes the theory of white holes, which are on the opposite side of space-time.

Anthropic principle

Main article: Anthropic principle

The concept of other universes has been proposed to explain how our own universe appears to be fine-tuned for conscious life as we experience it.

If there were a large (possibly infinite) number of universes, each with possibly different physical laws (or different fundamental physical constants), then some of these universes (even if very few) would have the combination of laws and fundamental parameters that are suitable for the development of matter, astronomical structures, elemental diversity, stars, and planets that can exist long enough for life to emerge and evolve.

The weak anthropic principle could then be applied to conclude that we (as conscious beings) would only exist in one of those few universes that happened to be finely tuned, permitting the existence of life with developed consciousness. Thus, while the probability might be extremely small that any particular universe would have the requisite conditions for life (as we understand life), those conditions do not require intelligent design as an explanation for the conditions in the Universe that promote our existence in it.

An early form of this reasoning is evident in Arthur Schopenhauer's 1844 work "Von der Nichtigkeit und dem Leiden des Lebens", where he argues that our world must be the worst of all possible worlds, because if it were significantly worse in any respect it could not continue to exist.

Occam's razor

Proponents and critics disagree about how to apply Occam's razor. Critics argue that to postulate an almost infinite number of unobservable universes, just to explain our own universe, is contrary to Occam's razor. However, proponents argue that in terms of Kolmogorov complexity the proposed multiverse is simpler than a single idiosyncratic universe.

For example, multiverse proponent Max Tegmark argues:

[A]n entire ensemble is often much simpler than one of its members. This principle can be stated more formally using the notion of algorithmic information content. The algorithmic information content in a number is, roughly speaking, the length of the shortest computer program that will produce that number as output. For example, consider the set of all integers. Which is simpler, the whole set or just one number? Naively, you might think that a single number is simpler, but the entire set can be generated by quite a trivial computer program, whereas a single number can be hugely long. Therefore, the whole set is actually simpler... (Similarly), the higher-level multiverses are simpler. Going from our universe to the Level I multiverse eliminates the need to specify initial conditions, upgrading to Level II eliminates the need to specify physical constants, and the Level IV multiverse eliminates the need to specify anything at all... A common feature of all four multiverse levels is that the simplest and arguably most elegant theory involves parallel universes by default. To deny the existence of those universes, one needs to complicate the theory by adding experimentally unsupported processes and ad hoc postulates: finite space, wave function collapse and ontological asymmetry. Our judgment therefore comes down to which we find more wasteful and inelegant: many worlds or many words. Perhaps we will gradually get used to the weird ways of our cosmos and find its strangeness to be part of its charm.

— Max Tegmark

Possible worlds and real worlds

In any given set of possible universes – e.g. in terms of histories or variables of nature – not all may be ever realized, and some may be realized many times. For example, over infinite time there could, in some potential theories, be infinite universes, but only a small or relatively small real number of universes where humanity could exist and only one where it ever does exist (with a unique history). It has been suggested that a universe that "contains life, in the form it has on Earth, is in a certain sense radically non-ergodic, in that the vast majority of possible organisms will never be realized". On the other hand, some scientists, theories and popular works conceive of a multiverse in which the universes are so similar that humanity exists in many equally real separate universes but with varying histories.

There is a debate about whether the other worlds are real in the many-worlds interpretation (MWI) of quantum mechanics. In Quantum Darwinism one does not need to adopt a MWI in which all of the branches are equally real.

Modal realism

Possible worlds are a way of explaining probability and hypothetical statements. Some philosophers, such as David Lewis, posit that all possible worlds exist and that they are just as real as the world we live in. This position is known as modal realism.

Deep ecology

From Wikipedia, the free encyclopedia

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

Deep ecology is an environmental philosophy that promotes the inherent worth of all living beings regardless of their instrumental utility to human needs, and argues that modern human societies should be restructured in accordance with such ideas.

Deep ecologists argue that the natural world is a complex of relationships in which the existence of organisms is dependent on the existence of others within ecosystems. They argue that non-vital human interference with or destruction of the natural world poses a threat not only to humans, but to all organisms that make up the natural order.

Deep ecology's core principle is the belief that the living environment as a whole should be respected and regarded as having certain basic moral and legal rights to live and flourish, independent of its instrumental benefits for human use. Deep ecology is often framed in terms of the idea of a much broader sociality: it recognizes diverse communities of life on Earth that are composed not only through biotic factors but also, where applicable, through ethical relations, that is, the valuing of other beings as more than just resources. It is described as "deep" because it is regarded as looking more deeply into the reality of humanity's relationship with the natural world, arriving at philosophically more profound conclusions than those of mainstream environmentalism.

The movement does not subscribe to anthropocentric environmentalism (which is concerned with conservation of the environment only for exploitation by and for human purposes), since deep ecology is grounded in a different set of philosophical assumptions. Deep ecology takes a holistic view of the world humans live in and seeks to apply to life the understanding that the separate parts of the ecosystem (including humans) function as a whole. The philosophy addresses core principles of different environmental and green movements and advocates a system of environmental ethics advocating wilderness preservation, non-coercive policies encouraging human population decline, animism and simple living.

Origins and history

In his original 1973 deep ecology paper, Arne Næss stated that he was inspired by ecologists who were studying the ecosystems throughout the world. Næss also made clear that he felt the real motivation to "free nature" was spiritual and intuitive. "Your motivation comes from your total view or your philosophical, religious opinions," he said, "so that you feel, when you are working in favour of free nature, you are working for something within your self, that ... demands changes. So you are motivated from what I call 'deeper premises'."

In a 2014 essay, environmentalist George Sessions identified three people active in the 1960s whom he considered foundational to the movement: author and conservationist Rachel Carson, environmentalist David Brower, and biologist Paul R. Ehrlich. Sessions considers the publication of Carson's 1962 seminal book Silent Spring as the beginning of the contemporary deep ecology movement. Næss also considered Carson the originator of the movement, stating "Eureka, I have found it" upon encountering her writings.

Another event cited as foundational to the movement was the publication in the 1960s of photographs of Earth from space taken by the Apollo astronauts.

Principles

Deep ecology proposes an embracing of ecological ideas and environmental ethics (that is, proposals about how humans should relate to nature). It is also a social movement based on a holistic vision of the world. Deep ecologists hold that the survival of any part is dependent upon the well-being of the whole, and criticise the narrative of human supremacy, which they say has not been a feature of most cultures throughout human evolution.

Deep ecology presents an eco-centric (Earth-centred) view, rather than the anthropocentric (human-centred) view, developed in its most recent form by philosophers of the Enlightenment, such as Newton, Bacon, and Descartes. Proponents of deep ecology oppose the narrative that man is separate from nature, is in charge of nature, or is the steward of nature, or that nature exists as a resource to be freely exploited. They cite the fact that indigenous peoples under-exploited their environment and retained a sustainable society for thousands of years, as evidence that human societies are not necessarily destructive by nature. They believe that the current materialist paradigm must be replaced – as Næss pointed out, this involves more than merely getting rid of capitalism and the concept of economic growth, or "progress", that is critically endangering the biosphere. "We need changes in society such that reason and emotion support each other," states Næss: "... not only a change in a technological and economic system, but a change that touches all the fundamental aspects of industrial societies. This is what I mean by a change of 'system'."

Deep ecologists believe that the damage to natural systems sustained since the industrial revolution now threatens social collapse and possible extinction of humans, and are striving to bring about the kind of ideological, economic and technological changes Næss mentioned. Deep ecology claims that ecosystems can absorb damage only within certain parameters, and contends that civilization endangers the biodiversity of the Earth. Deep ecologists have suggested that the human population must be substantially reduced, but advocate a gradual decrease in population rather than any apocalyptic solution

In a 1982 interview, Arne Næss commented that a global population of 100 million (0.1 billion) would be desirable. However, others have argued that a population of 1–2 billion would be compatible with the deep ecological worldview. Deep ecology eschews traditional left wing–right wing politics, but is viewed as radical ("Deep Green") in its opposition to capitalism, and its advocacy of an ecological paradigm.

Unlike conservation, deep ecology does not advocate the controlled preservation of the landbase, but rather "non-interference" with natural diversity except for vital needs. In citing humans as being responsible for excessive environmental destruction, deep ecologists actually refer to "humans within civilization, especially industrial civilization", accepting the fact that the vast majority of humans who have ever lived did not live in environmentally destructive societies – the excessive damage to the biosphere has been sustained mostly over the past hundred years.

In 1985, Bill Devall and George Sessions summed up their understanding of the concept of deep ecology with the following eight points:

• The well-being of human and nonhuman life on earth is of intrinsic value irrespective of its value to humans.
• The diversity of life-forms is part of this value.
• Humans have no right to reduce this diversity except to satisfy vital human needs
• The flourishing of human and nonhuman life is compatible with a substantial decrease in human population.
• Humans have interfered with nature to a critical level already, and interference is worsening.
• Policies must be changed, affecting current economic, technological and ideological structures.
• This ideological change should focus on an appreciation of the quality of life rather than adhering to an increasingly high standard of living.
• All those who agree with the above tenets have an obligation to implement them.

Development

YPJ members in a greenhouse farm, for ecological cooperative farming in Rojava (AANES)

The phrase "Deep Ecology" first appeared in a 1973 article by the Norwegian philosopher Arne Næss. Næss referred to "biospherical egalitarianism-in principle", which he explained was "an intuitively clear and obvious value axiom. Its restriction to humans is ... anthropocentrism with detrimental effects upon the life quality of humans themselves... The attempt to ignore our dependence and to establish a master-slave role has contributed to the alienation of man from himself." Næss added that from a deep ecology point of view "the right of all forms [of life] to live is a universal right which cannot be quantified. No single species of living being has more of this particular right to live and unfold than any other species".

Sources

Old-growth forest in Biogradska Gora National Park, Montenegro.

Deep ecology is an eco-philosophy derived from intuitive ethical principles. It does not claim to be a science, although it is based generally on the new physics, which, in the early 20th century, undermined the reductionist approach and the notion of objectivity, demonstrating that humans are an integral part of nature; this is a common concept always held by primal peoples.

Devall and Sessions, however, note that the work of many ecologists has encouraged the adoption of an "ecological consciousness", quoting environmentalist Aldo Leopold's view that such a consciousness "changes the role of Homo sapiens from conqueror of the land community to plain member and citizen of it."

Though some detractors assert that deep ecology is based on the discredited idea of the "balance of nature", deep ecologists have made no such claim. They do not dispute the theory that human cultures can have a benevolent effect on the landbase, only the idea of the control of nature, or human supremacy, which is the central pillar of the industrial paradigm. The tenets of deep ecology state that humans have no right to interfere with natural diversity except for vital needs: the distinction between "vital" and "other needs" cannot be drawn precisely. Deep ecologists reject any mechanical or computer model of nature, and see the Earth as a living organism, which should be treated and understood accordingly.

Aspects

Environmental education

In 2010, Richard Kahn promoted the movement of ecopedagogy, proposing using radical environmental activism as an educational principle to teach students to support "earth democracy" which promotes the rights of animals, plants, fungi, algae and bacteria. The biologist Dr. Stephan Harding has developed the concept of "holistic science", based on principles of ecology and deep ecology. In contrast with materialist, reductionist science, holistic science studies natural systems as a living whole. He writes:

We encourage ... students to use [their] sense of belonging to an intelligent universe (revealed by deep experience), for deeply questioning their fundamental beliefs, and for translating these beliefs into personal decisions, lifestyles and actions. The emphasis on action is important. This is what makes deep ecology a movement as much as a philosophy.

Spirituality

Further information: Ecospirituality

Deep ecologist and physicist Frijof Capra has said that "[Deep] ecology and spirituality are fundamentally connected because deep ecological awareness is, ultimately, spiritual awareness."

Arne Næss commented that he was inspired by the work of Spinoza and Gandhi, both of whom based their values on grounds of religious feeling and experience. Though he regarded deep ecology as a spiritual philosophy, he explained that he was not a "believer" in the sense of following any particular articles of religious dogma. "...it is quite correct to say that I have sometimes been called religious or spiritual", he said, "because I believe that living creatures have an intrinsic worth of their own, and also that there are fundamental intuitions about what is unjust."

Næss criticised the Judeo-Christian tradition, stating the Bible's "arrogance of stewardship consists in the idea of superiority which underlies the thought that we exist to watch over nature like a highly respected middleman between the Creator and Creation". Næss further criticizes the reformation's view of creation as property to be put into maximum productive use.

However, Næss added that while he felt the word "God" was "too loaded with preconceived ideas", he accepted Spinoza's idea of God as "immanent" – "a single creative force [...] constantly creating the world by being the creative force in Nature." He did not, he said, "exclude the possibility that Christian theological principles are true in a certain sense."

Joanna Macy in "the Work that Reconnects" integrates Buddhist philosophy with a deep ecological viewpoint.

Criticisms

Eurocentric bias

Guha and Martínez Alier critique the four defining characteristics of deep ecology. First, because deep ecologists believe that environmental movements must shift from an anthropocentric to an ecocentric approach, they fail to recognize the two most fundamental ecological crises facing the world: overconsumption in the global north and increasing militarization. Second, deep ecology's emphasis on wilderness provides impetus for the imperialist yearning of the West. Lastly, because deep ecology equates environmental protection with wilderness preservation its radical elements are confined within the American wilderness preservationist movement.

While deep ecologists accept that overconsumption and militarization are major issues, they point out that the impulse to save wilderness is intuitive and has no connection with imperialism. This claim by Guha and Martínez Alier, in particular, closely resembles statements made, for instance, by Brazilian president Jair Bolsonaro declaring Brazil's right to cut down the Amazon Rainforest. "The Amazon belongs to Brazil and European countries can mind their own business because they have already destroyed their own environment." The inference is clearly that, since European countries have already destroyed their environment, Brazil also has the right to do so: deep ecological values should not apply to them, as they have not yet had their 'turn' at maximum economic growth.

With regard to "appropriating spiritual beliefs", Arne Næss pointed out that the essence of deep ecology is the belief that "all living creatures have their own intrinsic value, a value irrespective of the use they might have for mankind." Næss stated that supporters of the deep ecology movement came from various different religious and spiritual traditions, and were united in this one belief, albeit basing it on various different values.

Deep versus Shallowness

When Arne Næss coined the term deep ecology, he compared it favourably with shallow ecology which he criticized for its utilitarian and anthropocentric attitude to nature and for its materialist and consumer-oriented outlook, describing its "central objective" as "the health and affluence of people in the developed countries." William D. Grey believes that developing a non-anthropocentric set of values is "a hopeless quest". He seeks an improved "shallow" view. Deep ecologists point out, however, that "shallow ecology" (resource management conservation) is counter-productive, since it serves mainly to support capitalism, the means through which industrial civilization destroys the biosphere. The eco-centric view thus only becomes "hopeless" within the structures and ideology of civilization. Outside it, however, a non-anthropocentric world view has characterised most "primal" cultures since time immemorial, and, in fact, obtained in many indigenous groups until the industrial revolution and after. Some cultures still hold this view today. As such, the eco-centric narrative is not alien to humans, and may be seen as the normative ethos in human evolution. Grey's view represents the reformist discourse that deep ecology has rejected from the beginning.

Misanthropy

Social ecologist Murray Bookchin interpreted deep ecology as being misanthropic, due in part to the characterization of humanity by David Foreman, of the environmental advocacy group Earth First!, as a "pathological infestation on the Earth". Bookchin mentions that some, like Foreman, defend misanthropic measures such as organising the rapid genocide of most of humanity.^[28] In response, deep ecologists have argued that Foreman's statement clashes with the core narrative of deep ecology, the first tenet of which stresses the intrinsic value of both nonhuman and human life. Arne Næss suggested both a slow decrease in human population over an extended period and immigration restrictionism, not genocide.^[29]

Bookchin's second major criticism is that deep ecology fails to link environmental crises with authoritarianism and hierarchy. He suggests that deep ecologists fail to recognise the potential for humans to solve environmental issues. In response, deep ecologists have argued that industrial civilization, with its class hierarchy, is the sole source of the ecological crisis. The eco-centric worldview precludes any acceptance of social class or authority based on social status. Deep ecologists believe that since ecological problems are created by industrial civilization, the only solution is the deconstruction of the culture itself.

Sciencism

Daniel Botkin concludes that although deep ecology challenges the assumptions of western philosophy, and should be taken seriously, it derives from a misunderstanding of scientific information and conclusions based on this misunderstanding, which are in turn used as justification for its ideology. It begins with an ideology and is political and social in focus. Botkin has also criticized Næss's assertion that all species are morally equal and his disparaging description of pioneering species. Deep ecologists counter this criticism by asserting that a concern with political and social values is primary, since the destruction of natural diversity stems directly from the social structure of civilization, and cannot be halted by reforms within the system. They also cite the work of environmentalists and activists such as Rachel Carson, Aldo Leopold, John Livingston, and others as being influential, and are occasionally critical of the way the science of ecology has been misused.

Utopianism

Eco-critic Jonathan Bate has called deep ecologists utopians, pointing out that "utopia" actually means "nowhere" and quoting Rousseau's claim that "the state of nature no longer exists and perhaps never did and probably never will." Bate asks how a planet crowded with cities

could possibly be returned to the state of nature? And ...who would want to return it there? ... Life in the state of nature, Thomas Hobbes reminded readers of Leviathan in 1650, is solitary, poor, ignorant, brutish and short. It may be necessary to critique the values of the Enlightenment, but to reject enlightenment altogether would be to reject justice, political liberty and altruism.

Bates's criticism rests partly on the idea that industrial civilization and the technics it depends on are themselves "natural" because they are made by humans. Deep ecologists have indicated that the concept of technics being "natural" and therefore "morally neutral" is a delusion of industrial civilization: there can be nothing "neutral" about nuclear weapons, for instance, whose sole purpose is large-scale destruction. Historian Lewis Mumford divides technology into "democratic" and "authoritarian" technics ("technics" includes both technical and cultural aspects of technology). While democratic technics, available to small communities, may be neutral, authoritarian technics, available only to large-scale, hierarchical, authoritarian societies, are not. Such technics are unsustainable, and need to be abandoned, as supported by point #6 of the deep ecology platform.

With reference to the degree to which landscapes are natural, Peter Wohlleben draws a temporal line (roughly equivalent to the development of Mumford's "authoritarian" technics) at the agricultural revolution, about 8000 BC, when "selective farming practices began to change species." This is also the time when the landscape began to be intentionally transformed into an ecosystem completely devoted to meeting human needs.

Links with other philosophies

Peter Singer critiques anthropocentrism and advocates for animals to be given rights. However, Singer has disagreed with deep ecology's belief in the intrinsic value of nature separate from questions of suffering. Michael E. Zimmerman groups deep ecology with feminism and civil rights movements. Nelson contrasts it with ecofeminism. The links with animal rights are perhaps the strongest, as "proponents of such ideas argue that 'all life has intrinsic value'".

David Foreman, the co-founder of the radical direct-action movement Earth First!, has said he is an advocate for deep ecology. At one point, Arne Næss also engaged in direct action when he chained himself to rocks in front of Mardalsfossen, a waterfall in a Norwegian fjord, in a successful protest against the building of a dam.

Some have linked the movement to green anarchism.

Further, the movement is related to cosmopolitan localism that has been proposed as a structural framework to organize production by prioritising socio-ecological well-being over corporate profits, over-production and excess consumption.

The object-oriented ontologist Timothy Morton has explored similar ideas in the books Ecology without Nature: Rethinking Environmental Aesthetics (2009) and Dark Ecology: For a Logic of Future Coexistence (2016).