Pleasure

From Wikipedia, the free encyclopedia

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

Pleasure refers to experience that feels good, that involves the enjoyment of something. It contrasts with pain or suffering, which are forms of feeling bad. It is closely related to value, desire and action: humans and other conscious animals find pleasure enjoyable, positive or worthy of seeking. A great variety of activities may be experienced as pleasurable, like eating, having sex, listening to music or playing games. Pleasure is part of various other mental states such as ecstasy, euphoria and flow. Happiness and well-being are closely related to pleasure but not identical with it. There is no general agreement as to whether pleasure should be understood as a sensation, a quality of experiences, an attitude to experiences or otherwise. Pleasure plays a central role in the family of philosophical theories known as hedonism.

Overview

"Pleasure" refers to experience that feels good, that involves the enjoyment of something. The term is primarily used in association with sensory pleasures like the enjoyment of food or sex. But in its most general sense, it includes all types of positive or pleasant experiences including the enjoyment of sports, seeing a beautiful sunset or engaging in an intellectually satisfying activity. Pleasure contrasts with pain or suffering, which are forms of feeling bad. Both pleasure and pain come in degrees and have been thought of as a dimension going from positive degrees through a neutral point to negative degrees. This assumption is important for the possibility of comparing and aggregating the degrees of pleasure of different experiences, for example, in order to perform the Utilitarian calculus.

The concept of pleasure is similar but not identical to the concepts of well-being and of happiness. These terms are used in overlapping ways, but their meanings tend to come apart in technical contexts like philosophy or psychology. Pleasure refers to a certain type of experience while well-being is about what is good for a person. Many philosophers agree that pleasure is good for a person and therefore is a form of well-being. But there may be other things besides or instead of pleasure that constitute well-being, like health, virtue, knowledge or the fulfillment of desires. On some conceptions, happiness is identified with "the individual’s balance of pleasant over unpleasant experience". Life satisfaction theories, on the other hand, hold that happiness involves having the right attitude towards one's life as a whole. Pleasure may have a role to play in this attitude, but it is not identical to happiness.

Pleasure is closely related to value, desire, motivation and right action. There is broad agreement that pleasure is valuable in some sense. Axiological hedonists hold that pleasure is the only thing that has intrinsic value. Many desires are concerned with pleasure. Psychological hedonism is the thesis that all our actions aim at increasing pleasure and avoiding pain. Freud's pleasure principle ties pleasure to motivation and action by holding that there is a strong psychological tendency to seek pleasure and to avoid pain. Classical utilitarianism connects pleasure to ethics in stating that whether an action is right depends on the pleasure it produces: it should maximize the sum-total of pleasure.

Sources and types of pleasure

Many pleasurable experiences are associated with satisfying basic biological drives, such as eating, exercise, hygiene, sleep, and sex. The appreciation of cultural artifacts and activities such as art, music, dancing, and literature is often pleasurable. Pleasure is sometimes subdivided into fundamental pleasures that are closely related to survival (food, sex, and social belonging) and higher-order pleasures (e.g., viewing art and altruism). Bentham listed 14 kinds of pleasure; sense, wealth, skill, amity, a good name, power, piety, benevolence, malevolence, memory, imagination, expectation, pleasures dependent on association, and the pleasures of relief. Some commentators see 'complex pleasures' including wit and sudden realisation, and some see a wide range of pleasurable feelings.

Theories of pleasure

Pleasure comes in various forms, for example, in the enjoyment of food, sex, sports, seeing a beautiful sunset or engaging in an intellectually satisfying activity. Theories of pleasure try to determine what all these pleasurable experiences have in common, what is essential to them. They are traditionally divided into quality theories and attitude theories. An alternative terminology refers to these theories as phenomenalism and intentionalism. Quality theories hold that pleasure is a quality of pleasurable experiences themselves while attitude theories state that pleasure is in some sense external to the experience since it depends on the subject's attitude to the experience. More recently, dispositional theories have been proposed that incorporate elements of both traditional approaches.

Quality theories

In everyday language, the term "pleasure" is primarily associated with sensory pleasures like the enjoyment of food or sex. One traditionally important quality-theory closely follows this association by holding that pleasure is a sensation. On the simplest version of the sensation theory, whenever we experience pleasure there is a distinctive pleasure-sensation present. So a pleasurable experience of eating chocolate involves a sensation of the taste of chocolate together with a pleasure-sensation. An obvious shortcoming of this theory is that many impressions may be present at the same time. For example, there may be an itching sensation as well while eating the chocolate. But this account cannot explain why the enjoyment is linked to the taste of the chocolate and not to the itch. Another problem is due to the fact that sensations are usually thought of as localized somewhere in the body. But considering the pleasure of seeing a beautiful sunset, there seems to be no specific region in the body at which we experience this pleasure.

These problems can be avoided by felt-quality-theories, which see pleasure not as a sensation but as an aspect qualifying sensations or other mental phenomena. As an aspect, pleasure is dependent on the mental phenomenon it qualifies, it cannot be present on its own. Since the link to the enjoyed phenomenon is already built into the pleasure, it solves the problem faced by sensation theories to explain how this link comes about. It also captures the intuition that pleasure is usually pleasure of something: enjoyment of drinking a milkshake or of playing chess but not just pure or object-less enjoyment. According to this approach, pleasurable experiences differ in content (drinking a milkshake, playing chess) but agree in feeling or hedonic tone. Pleasure can be localized, but only to the extent that the impression it qualifies is localized.

One objection to both the sensation theory and the felt-quality theory is that there is no one quality shared by all pleasure-experiences. The force of this objection comes from the intuition that the variety of pleasure-experiences is just too wide to point out one quality shared by all, for example, the quality shared by enjoying a milkshake and enjoying a chess game. One way for quality theorists to respond to this objection is by pointing out that the hedonic tone of pleasure-experiences is not a regular quality but a higher-order quality. As an analogy, a vividly green thing and a vividly red thing do not share a regular color property but they share "vividness" as a higher-order property.

Attitude theories

Attitude theories propose to analyze pleasure in terms of attitudes to experiences. So to enjoy the taste of chocolate it is not sufficient to have the corresponding experience of the taste. Instead, the subject has to have the right attitude to this taste for pleasure to arise. This approach captures the intuition that a second person may have exactly the same taste-experience but not enjoy it since the relevant attitude is lacking. Various attitudes have been proposed for the type of attitude responsible for pleasure, but historically the most influential version assigns this role to desires. On this account, pleasure is linked to experiences that fulfill a desire had by the experiencer. So the difference between the first and the second person in the example above is that only the first person has a corresponding desire directed at the taste of chocolate.

One important argument against this version is that while it is often the case that we desire something first and then enjoy it, this cannot always be the case. In fact, often the opposite seems to be true: we have to learn first that something is enjoyable before we start to desire it. This objection can be partially avoided by holding that it does not matter whether the desire was there before the experience but that it only matters what we desire while the experience is happening. This variant, originally held by Henry Sidgwick, has recently been defended by Chris Heathwood, who holds that an experience is pleasurable if the subject of the experience wants the experience to occur for its own sake while it is occurring. But this version faces a related problem akin to the Euthyphro dilemma: it seems that we usually desire things because they are enjoyable, not the other way round. So desire theories would be mistaken about the direction of explanation. Another argument against desire theories is that desire and pleasure can come apart: we can have a desire for things that are not enjoyable and we can enjoy things without desiring to do so.

Dispositional theories

Dispositional theories try to account for pleasure in terms of dispositions, often by including insights from both the quality theories and the attitude theories. One way to combine these elements is to hold that pleasure consists in being disposed to desire an experience in virtue of the qualities of this experience. Some of the problems of the regular desire theory can be avoided this way since the disposition does not need to be realized for there to be pleasure, thereby taking into account that desire and pleasure can come apart.

Philosophy

Main article: Hedonism

Pleasure plays a central role in theories from various areas of philosophy. Such theories are usually grouped together under the label "hedonism".

Ethics

Pleasure is related not just to how we actually act, but also to how we ought to act, which belongs to the field of ethics. Ethical hedonism takes the strongest position on this relation in stating that considerations of increasing pleasure and decreasing pain fully determine what we should do or which action is right. Ethical hedonist theories can be classified in relation to whose pleasure should be increased. According to the egoist version, each agent should only aim at maximizing her own pleasure. This position is usually not held in very high esteem. Utilitarianism, on the other hand, is a family of altruist theories that are more respectable in the philosophical community. Within this family, classical utilitarianism draws the closest connection between pleasure and right action by holding that the agent should maximize the sum-total of everyone's happiness. This sum-total includes the agent's pleasure as well, but only as one factor among many.

Value

Pleasure is intimately connected to value as something that is desirable and worth seeking. According to axiological hedonism, it is the only thing that has intrinsic value or is good in itself. This position entails that things other than pleasure, like knowledge, virtue or money, only have instrumental value: they are valuable because or to the extent that they produce pleasure but lack value otherwise. Within the scope of axiological hedonism, there are two competing theories about the exact relation between pleasure and value: quantitative hedonism and qualitative hedonism. Quantitative hedonists, following Jeremy Bentham, hold that the specific content or quality of a pleasure-experience is not relevant to its value, which only depends on its quantitative features: intensity and duration. On this account, an experience of intense pleasure of indulging in food and sex is worth more than an experience of subtle pleasure of looking at fine art or of engaging in a stimulating intellectual conversation. Qualitative hedonists, following John Stuart Mill, object to this version on the grounds that it threatens to turn axiological hedonism into a "philosophy of swine". Instead, they argue that the quality is another factor relevant to the value of a pleasure-experience, for example, that the lower pleasures of the body are less valuable than the higher pleasures of the mind.

Beauty

A very common element in many conceptions of beauty is its relation to pleasure. Aesthetic hedonism makes this relation part of the definition of beauty by holding that there is a necessary connection between pleasure and beauty, e.g. that for an object to be beautiful is for it to cause pleasure or that the experience of beauty is always accompanied by pleasure. The pleasure due to beauty does not need to be pure, i.e. exclude all unpleasant elements. Instead, beauty can involve mixed pleasure, for example, in the case of a beautifully tragic story. We take pleasure from many things that are not beautiful, which is why beauty is usually defined in terms of a special type of pleasure: aesthetic or disinterested pleasure. A pleasure is disinterested if it is indifferent to the existence of the beautiful object. For example, the joy of looking at a beautiful landscape would still be valuable if it turned out that this experience was an illusion, which would not be true if this joy was due to seeing the landscape as a valuable real estate opportunity. Opponents of aesthetic hedonism have pointed out that despite commonly occurring together, there are cases of beauty without pleasure. For example, a cold jaded critic may still be a good judge of beauty due to her years of experience but lack the joy that initially accompanied her work. A further question for hedonists is how to explain the relation between beauty and pleasure. This problem is akin to the Euthyphro dilemma: is something beautiful because we enjoy it or do we enjoy it because it is beautiful? Identity theorists solve this problem by denying that there is a difference between beauty and pleasure: they identify beauty, or the appearance of it, with the experience of aesthetic pleasure.

History

Hellenistic philosophy

The ancient Cyrenaics posited pleasure as the universal aim for all people. Later, Epicurus defined the highest pleasure as aponia (the absence of pain), and pleasure as "freedom from pain in the body and freedom from turmoil in the soul". According to Cicero (or rather his character Torquatus) Epicurus also believed that pleasure was the chief good and pain the chief evil. The Pyrrhonist philosopher Aenesidemus claimed that following Pyrrhonism's prescriptions for philosophical skepticism produced pleasure.

Medieval philosophy

In the 12th century, Razi's "Treatise of the Self and the Spirit" (Kitab al Nafs Wa’l Ruh) analyzed different types of pleasure- sensuous and intellectual, and explained their relations with one another. He concludes that human needs and desires are endless, and "their satisfaction is by definition impossible."

Schopenhauer

The 19th-century German philosopher Arthur Schopenhauer understood pleasure as a negative sensation, one that negates the usual existential condition of suffering.

Psychology

Pleasure is often regarded as a bipolar construct, meaning that the two ends of the spectrum from pleasure to suffering are mutually exclusive. That is part of the circumplex model of affect.t, some lines of research suggest that people do experience pleasure and suffering at the same time, giving rise to so-called mixed feelings. Pleasure is considered one of the core dimensions of emotion. It can be described as the positive evaluation that forms the basis for several more elaborate evaluations such as "agreeable" or "nice". As such, pleasure is an affect and not an emotion, as it forms one component of several different emotions. The clinical condition of being unable to experience pleasure from usually enjoyable activities is called anhedonia. An active aversion to obtaining pleasure is called hedonophobia.

Pleasure and belief

The degree to which something or someone is experienced as pleasurable not only depends on its objective attributes (appearance, sound, taste, texture, etc.), but on beliefs about its history, about the circumstances of its creation, about its rarity, fame, or price, and on other non-intrinsic attributes, such as the social status or identity it conveys. For example, a sweater that has been worn by a celebrity is more desired than an otherwise identical sweater that has not, though considerably less so if it has been washed.

Motivation and behavior

Pleasure-seeking behavior is a common phenomenon and may indeed dominate our conduct at times. The thesis of psychological hedonism generalizes this insight by holding that all our actions aim at increasing pleasure and avoiding pain. This is usually understood in combination with egoism, i.e. that each person only aims at her own happiness. Our actions rely on beliefs about what causes pleasure. False beliefs may mislead us and thus our actions may fail to result in pleasure, but even failed actions are motivated by considerations of pleasure, according to psychological hedonism. The paradox of hedonism states that pleasure-seeking behavior commonly fails also in another way. It asserts that being motivated by pleasure is self-defeating in the sense that it leads to less actual pleasure than following other motives.

Sigmund Freud formulated his pleasure principle in order to account for the effect pleasure has on our behavior. It states that there is a strong, inborn tendency of our mental life to seek immediate gratification whenever an opportunity presents itself. This tendency is opposed by the reality principle, which constitutes a learned capacity to delay immediate gratification in order to take the real consequences of our actions into account. Freud also described the pleasure principle as a positive feedback mechanism that motivates the organism to recreate the situation it has just found pleasurable, and to avoid past situations that caused pain.

Cognitive biases

A cognitive bias is a systematic tendency of thinking and judging in a way that deviates from a normative criterion, especially from the demands of rationality. Cognitive biases in regard to pleasure include the peak–end rule, the focusing illusion, the nearness bias and the future bias.

The peak–end rule affects how we remember the pleasantness or unpleasantness of experiences. It states that our overall impression of past events is determined for the most part not by the total pleasure and suffering it contained but by how it felt at its peaks and at its end. For example, the memory of a painful colonoscopy is improved if the examination is extended by three minutes in which the scope is still inside but not moved anymore, resulting in a moderately uncomfortable sensation. This extended colonoscopy, despite involving more pain overall, is remembered less negatively due to the reduced pain at the end. This even increases the likelihood for the patient to return for subsequent procedures. Daniel Kahneman explains this distortion in terms of the difference between two selves: the experiencing self, which is aware of pleasure and pain as they are happening, and the remembering self, which shows the aggregate pleasure and pain over an extended period of time. The distortions due to the peak–end rule happen on the level of the remembering self. Our tendency to rely on the remembering self can often lead us to pursue courses of action that are not in our best self-interest.

A closely related bias is the focusing illusion. The "illusion" occurs when people consider the impact of one specific factor on their overall happiness. They tend to greatly exaggerate the importance of that factor, while overlooking the numerous other factors that would in most cases have a greater impact.

The nearness bias and the future bias are two different forms of violating the principle of temporal neutrality. This principle states that the temporal location of a benefit or a harm is not important for its normative significance: a rational agent should care to the same extent about all parts of their life. The nearness bias, also discussed under the labels "present bias" or "temporal discounting", refers to our tendency to violate temporal neutrality in regards to temporal distance from the present. On the positive side, we prefer pleasurable experiences to be near rather than distant. On the negative side, we prefer painful experiences to be distant rather than near. The future bias refers to our tendency to violate temporal neutrality in regards to the direction of time. On the positive side, we prefer pleasurable experiences to be in the future rather than in the past. On the negative side, we prefer painful experiences to be in the past rather than in the future.

Brain and reward system

See also: Affective neuroscience

Pleasure centers

This section is an excerpt from Reward system § Pleasure centers.[edit]

Pleasure is a component of reward, but not all rewards are pleasurable (e.g., money does not elicit pleasure unless this response is conditioned). Stimuli that are naturally pleasurable, and therefore attractive, are known as intrinsic rewards, whereas stimuli that are attractive and motivate approach behavior, but are not inherently pleasurable, are termed extrinsic rewards. Extrinsic rewards (e.g., money) are rewarding as a result of a learned association with an intrinsic reward. In other words, extrinsic rewards function as motivational magnets that elicit "wanting", but not "liking" reactions once they have been acquired.

The reward system contains pleasure centers or hedonic hotspots – i.e., brain structures that mediate pleasure or "liking" reactions from intrinsic rewards. As of October 2017, hedonic hotspots have been identified in subcompartments within the nucleus accumbens shell, ventral pallidum, parabrachial nucleus, orbitofrontal cortex (OFC), and insular cortex. The hotspot within the nucleus accumbens shell is located in the rostrodorsal quadrant of the medial shell, while the hedonic coldspot is located in a more posterior region. The posterior ventral pallidum also contains a hedonic hotspot, while the anterior ventral pallidum contains a hedonic coldspot. In rats, microinjections of opioids, endocannabinoids, and orexin are capable of enhancing liking reactions in these hotspots. The hedonic hotspots located in the anterior OFC and posterior insula have been demonstrated to respond to orexin and opioids in rats, as has the overlapping hedonic coldspot in the anterior insula and posterior OFC. On the other hand, the parabrachial nucleus hotspot has only been demonstrated to respond to benzodiazepine receptor agonists.

Hedonic hotspots are functionally linked, in that activation of one hotspot results in the recruitment of the others, as indexed by the induced expression of c-Fos, an immediate early gene. Furthermore, inhibition of one hotspot results in the blunting of the effects of activating another hotspot. Therefore, the simultaneous activation of every hedonic hotspot within the reward system is believed to be necessary for generating the sensation of an intense euphoria.

Reward system and motivation

While all pleasurable stimuli can be seen as rewards, some rewards do not evoke pleasure. Based upon the incentive salience model of reward – the attractive and motivational property of a stimulus that induces approach behavior and consummatory behavior – an intrinsic reward has two components: a "wanting" or desire component that is reflected in approach behavior, and a "liking" or pleasure component that is reflected in consummatory behavior. Some research indicates that similar mesocorticolimbic circuitry is activated by quite diverse pleasures, suggesting a common neural currency. Some commentators opine that our current understanding of how pleasure happens within us remains poor, but that scientific advance gives optimism for future progress.

Animal pleasure

See also: Reward system § Animals vs humans, and Animal sexual behaviour § Sex for pleasure

In the past, there has been debate as to whether pleasure is experienced by other animals rather than being an exclusive property of humankind; however, it is now known that animals do experience pleasure, as measured by objective behavioral and neural hedonic responses to pleasurable stimuli.

Language politics

From Wikipedia, the free encyclopedia

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

 

The politics of language are evident in French-speaking Brussels, which is located in the Flanders region of Belgium, where people typically speak Flemish. Divisive preference of either language is avoided by using both French and Flemish on nearly all signs in Brussels.

Language politics is the way language and linguistic differences between peoples are dealt with in the political arena. This could manifest as government recognition, as well as how language is treated in official capacities.

The topic is a multi-faceted one. As such, this page serves as a nexus for some of the overall topics with easy access to relevant pages. Below are some categories in languages and the politics surrounding them, along with examples and links to other relevant pages.

Language planning and policy

Main article: Language planning

Language planning refers to concerted efforts to influence how and why languages are used in a community. It is usually associated with governmental policies which largely involve status planning, corpus planning and acquisition planning. There are often much interaction between the three areas. Status planning involves giving a language or languages a certain standing against other languages and is often associated with language prestige and language function. Corpus planning often involves linguistic prescription as decisions are made in graphization, standardization and modernization of a language. Acquisition planning fundamentally involves language policies to promote language learning.

Status planning

• Legal status of a language as an official language in a country, state, or other jurisdiction. This generally means that all official documents affecting a country or region are published in the official language(s), but not in those that are not. Evidence in a court of law may also be expected to be presented in an official language.
• In countries where there are more than one main language, there are often political implications in decisions that are seen to promote one group of speakers over another, and this is often referred to as language politics. An example of a country with this type of language politics is Belgium.
• In countries where there is one main language, immigrants seeking full citizenship may be expected to have a degree of fluency in that language ('language politics' then being a reference to the debate over the appropriateness of this). This has been a feature of Australian politics.
• At various times minority languages have either been promoted or banned in schools, as politicians have either sought to promote a minority language with an aim of strengthening the cultural identity of its speakers, or ban its use (either in teaching, or on occasion an entire ban on its use), with an aim of promoting a national identity based on the majority language. An example of recent promotion of a minority language is the promotion of Welsh or Leonese by the Leonese City Council and an example of official discouragement of a minority language is of Breton.
• Language politics also sometimes relate to dialect, where speakers of a particular dialect are perceived to speak a more culturally 'advanced' or 'correct' form of the language. Politicians may therefore try to use that dialect rather than their own when in the public eye. Alternatively, at times those speaking the dialect perceived as more 'correct' may try to use another dialect when in the public eye to be seen as a 'man/woman of the people'.

Corpus planning

Corpus planning consists of three traditionally recognised forms: graphization, standardization and modernization. Graphization involves the development of written scripts and orthography of languages. Standardization involves giving a selected variety of a language precedence over the other varieties as the "standard" form for others to emulate. Modernization often involves expanding the lexicon of a language as a result of language shift over time.

• To promote national identity, what are strictly dialects of the same language may be promoted as separate languages to promote a sense of national identity (examples include Danish and Norwegian, and Serbian and Croatian – the latter two also use different scripts for what is linguistically the same language – Cyrillic for Serbian and roman script for Croatian). Whether or not something is a language can also involve language politics, for instance, Macedonian.
• On the contrary, to unify the country, China worked towards a common national language with a standard written script (see: Standard Chinese). The efforts started as early as 1912 after the establishment of the Republic of China. Initial efforts tried to create a language that was phonologically hybridised from the existing languages but they later on settled on pronunciations based on the Beijing variety of Mandarin. Nonetheless, there were still influence from the other Chinese varieties in this standard language. All other language varieties are officially known as 方言 fāngyán which directly translates to regional speech or more well known as Chinese dialects despite being mutually unintelligible. However, the different speakers communicate via a common written script known as a unified Chinese script. After the Chinese Civil War, the People's Republic of China continued the efforts of a common national language, renaming the standard language from 国语 guóyǔ ("national language") to 普通话 pǔtōnghuà ("common speech") in 1955.
• 'Political correctness' describes the situation where language forms must be used (or not used) to comply with national (or group) ideology
• Co-existence of competing spelling systems for the same language, associated with different political camps. Examples:
  • Debate on traditional and simplified Chinese characters
  • Simplification of Russian orthography; proposals for such a reform were viewed as subversive in the late years of the Russian Empire and were implemented by the Bolsheviks in 1918, after which the "old orthography" became associated with the White movement.
  • The two spelling systems for the Belarusian language, one of which is associated with the country's political opposition.

Language is also utilised in political matters to unify, organise and criticise in order to unify a political group.

• The Moldovan Cyrillic alphabet preserved in Transnistria.

Acquisition planning (language in education)

Acquisition planning often manifests in education policies after the status and corpus planning policies have been introduced. These policies can take in the form of compulsory language education programmes, enforcing a specific language of instruction in schools or development of educational materials. In some countries, mainstream education is offered in one language: English in the United States, Italian in Italy, Russian in Russia, just to name a few. In some countries, mainstream education provide education in several languages. This is especially common in countries with more than one official languages. Some countries promote multilingualism in their policies: bilingual policy in Singapore, three-language formula in India, just to name a few.

Linguistic discrimination

Main article: Linguistic discrimination

 

Martin Luther King Jr. Elementary, Vancouver, Washington, building entrance, November, 2019

Linguistic discrimination, or linguicism, refers to unequal treatment of speakers of different languages or language varieties. It can be observed with regard to spoken language, where speakers may be discriminated against based on their regional dialect, their sociolect, their accent, or their vocabulary. In terms of language planning, linguistic discrimination can occur at different stages, such as the choice of one or more official languages, choosing the language of instruction, the availability of essential services such as health care in minority languages, and the protection or lack thereof of minority languages and dialects.

In the United States, speakers of African-American Vernacular English (AAVE) often experience linguistic discrimination. A study, published in 1982, of attitudes towards AAVE at Martin Luther King Junior Elementary school in Ann Arbor, Michigan, revealed that black students who primarily spoke AAVE received less help from their teachers in comparison to their white peers. One social worker observed that these AAVE-speaking students faced a significant linguistic barrier to academic achievement and success in the predominantly White American society at that time. This is one example of a larger controversy surrounding African-American Vernacular English in education.

Colonialism

Main article: Colonialism

 

Guerillas rugendas

Colonialism is a significant context in which linguistic discrimination takes place. When territories were colonized for the purpose of settlement buildling, indigenous languages became gravely endangered because the native speaker groups were either destroyed by war and disease, or had undergone a partial language shift to speak their master's language. In exploitation colonies however, colonizers would usually only teach their language to a select group of locals. In postcolonial states like India, it was observed that the difference in language education had widened the socioeconomic class divide. Thus, access to education, social mobility, and economic opportunities were deprived of the locals who had not learnt the colonial language of before.

Approximately 1.35 billion people in the world now speak English, with about 360 million native English speakers. As of 2015, more than 75% of all scientific papers were published in English. English is also the most commonly studied foreign language in the world. This global prevalence of English can be attributed to many developments that have occurred in recent history, namely, the expansion of the British Empire, which has resulted in the establishment of English as an official language in at least 75 countries. David Crystal gives a detailed explanation about the spread of English worldwide in Chapter 9 of A History of the English Language (ed. Richard M. Hogg). Robert Phillipson has posited this is an example of linguistic imperialism. However, this notion is contested in the field of applied linguistics.

Linguistic Imperialism

Main article: Linguistic imperialism

Linguistic imperialism refers to the dominance of one language over another on a national (and sometimes international) scale as a result of language policy and planning. According to Robert Phillipson, it is a variant of linguicism and is enacted through systemic changes and language attitudes, resulting in unfair treatment of non-dominant language groups. This form of discrimination works in ways similar to racism, sexism, and classism, on a national administrative scale.

As an example, a case study on the usage of Irish Sign Language (ISL) in Ireland revealed unfair treatment of a deaf community in Ireland. The study observed the enforcement of English over ISL in the educational system, as well as the prohibition of ISL among deaf children who were deemed capable enough to learn oral language (oralism). The study also highlighted anti-ISL language attitudes among school officials, unequal pay of ISL teachers, unequal status given to ISL in the education system, and the systemic marginalisation of ISL users. Efforts to elevate the usage of English over ISL also entailed the teaching of Manually Coded English (MCE) to deaf students, a signed language based on the grammatical structure of English. Unfortunately, MCE and other manually coded languages are often difficult and slow to use for communication among signers. Despite this, such language policies have influenced members of the deaf community (especially older members) to internalise the belief that ISL is inferior to spoken language.

Names and politics

See also: Toponymy and Critical toponymy

Critical toponymies

Toponymy is the study of place names (from Ancient Greek: τόπος / tópos, 'place', and ὄνομα / onoma, 'name'). According to Lawrence D. Berg and Jani Vuolteenaho, traditional research into place names has focused more on describing their origins in an empirical way. However, they note that there are 'power relations inherent in geographical naming', because to have the power to name something is to have the 'power of "making places"'. Their book, Critical Toponymies, is, according to them, the 'first interdisciplinary collection published in English that tackles explicitly place naming as "a political practice par excellence of power over space"', and gathers research from various scholars about the politics inherent in the naming of places.

Choice of language

Road signs in Karasjok (Kárášjohka), northern Norway. The top and bottom names are Northern Sámi; the second-from-bottom is Finnish; the rest are Norwegian.

As an example, the powers-that-were in Norway began strictly regulating Sámi place names in the 1870s, replacing them with Norwegian names in official documents, even suggesting that if no Norwegian name had yet been made for a certain place, a Norwegian translation ought of the name ought to be used on maps. This 'toponymic silence' gave the impression that Norwegians had settled in places where the Sámi historically lived; and the silence lives on till the present -- Norwegians may believe that Sámi place names which have not been recorded on maps etc. are not in common use (even though they are); alternatively, since Sámi names for natural features have remained but not names for settlements, Norwegians may believe that Sámi people only reside in otherwise uninhabited areas. Now, even though Sámi place names can be restored to official status, they must still be proven to actually be in use among the community. This is not the case for Norwegian names, which will remain official even if few people in the locality use that name. With these observations, it can be concluded that the Sámi have not received full 'decolonisation' yet - the colonisation being in the Norwegian power to rename Sámi places.

Choice of pronunciation

In places where native names have been reclaimed in writing, there is a secondary issue of pronunciation. With reference to New Zealand, Robin Kearns and Lawrence Berg note that how a place name is pronounced also has a political meaning. Letters to the editors of New Zealand newspapers sometimes complain about newscasters' choice to pronounce place names in a more Māori-like way. Even if Lake Taupo maintains an ostensibly Māori-derived name, some argued against a Member of Parliament telling others to read it 'toe-po' ([ˈtoʊpɔː]; see Taupo). Kearns and Berg note that the written forms of Māori place names give no hints as to how they should be pronounced, and so even some Māori speakers might not know the 'true' pronunciation. These people might not be trying to make any political statement by reading the names their own way. Even so, their utterance of the name becomes situated in a wider political context of 'a resurgence of Maori cultural forms, and increasing calls for self-determination', which 'presents a threatening and uncertain environment for members of the status quo'. In this way, language in the form of place names becomes part of politics - part of the 'contest over the symbolic ownership of place' in New Zealand.

Cross-state conflicts

Even across states, agreement on a single name is difficult. This can apply to places which a state does not own: for example, see the Sea of Japan naming dispute or the Persian Gulf naming dispute. Mapmakers often acquiesce by creating two versions of the same map, but with the names of geographical features swapped out depending on which state the maps are sold in. Notably, Greece objected to the use of the name 'Macedonia' by the then newly-independent Republic of North Macedonia. According to Naftalie Kadmon, the Greek government was worried that '[c]laims of the South Yugoslavians to the name Macedonia might in time lead to political demands towards Greece, and finally to military aggression.' The case was escalated to the UN, and it was decided that the new state should be named the Former Yugoslav Republic of Macedonia (FYROM).

A view of Piran from Savudrija. The Bay of Piran/Savudrija separates these two settlements.

These conflicts between states regarding names still nevertheless indicate a conflict over ownership or belonging. For example, the Bay of Piran between Croatia and Slovenia began being referred to by Croatian official sources as the Bay of Savudrija (Savudrijska vala) around the early 2000s. In both cases, the names of the bay are taken from towns (Piran is in Slovenia, and Savudrija is in Croatia). This recent Croatian insistence on a new name linked to Croatia 'represents a transfer of the identity of the bay elsewhere - to another place far from Piran', and stakes 'Croatia's ownership of this part of the bay'.

Recognition of importance of names

The United Nations Economic and Social Council (ECOSOC) set up the United Nations Group of Experts on Geographical Names (UNGEGN) and the United Nations Conferences on the Standardization of Geographical Names (UNCSGN). The UNCSGN has three main objectives:

• 'encourage national and international geographical names standardization;
• 'promote the international dissemination of nationally standardized geographical names information; and
• 'adopt single romanization systems for the conversion of each non-Roman writing system to the Roman alphabet.'

The UNCSGN occurs every five years, and the UNGEGN 'meets between the Conferences to follow up the implementation of resolutions adopted by the Conferences and to ensure continuity of activities between Conferences'.

Other names

The politics applied to naming places can also applies to naming ethnic groups. For example, it is generally offensive to use words which are considered by some to have negative implications (pejorative exonyms) to describe a group of people: e.g. 'Gypsies' (or even more negatively, 'Gypos') instead of 'Romani', or indeed using the term 'Gypsies' to cover Traveller peoples as well as Romani people.

As another example, the Haudenosaunee Confederacy writes that although they have been 'called the Iroquois Confederacy by the French, and the League of Five Nations by the English, the confederacy is properly called the Haudenosaunee Confederacy meaning People of the long house.' The rejection of the exonym 'Iroqouis' (which is still the name used in, for example, the Wikipedia page) is inherent in the statement that the confederacy (and the people) are properly called 'Haudenosaunee'.

Angular momentum of light

From Wikipedia, the free encyclopedia

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

The angular momentum of light is a vector quantity that expresses the amount of dynamical rotation present in the electromagnetic field of the light. While traveling approximately in a straight line, a beam of light can also be rotating (or "spinning", or "twisting") around its own axis. This rotation, while not visible to the naked eye, can be revealed by the interaction of the light beam with matter.

There are two distinct forms of rotation of a light beam, one involving its polarization and the other its wavefront shape. These two forms of rotation are therefore associated with two distinct forms of angular momentum, respectively named light spin angular momentum (SAM) and light orbital angular momentum (OAM).

The total angular momentum of light (or, more generally, of the electromagnetic field and the other force fields) and matter is conserved in time.

Introduction

Light, or more generally an electromagnetic wave, carries not only energy but also momentum, which is a characteristic property of all objects in translational motion. The existence of this momentum becomes apparent in the "radiation pressure" phenomenon, in which a light beam transfers its momentum to an absorbing or scattering object, generating a mechanical pressure on it in the process.

Light may also carry angular momentum, which is a property of all objects in rotational motion. For example, a light beam can be rotating around its own axis while it propagates forward. Again, the existence of this angular momentum can be made evident by transferring it to small absorbing or scattering particles, which are thus subject to an optical torque.

For a light beam, one can usually distinguish two "forms of rotation", the first associated with the dynamical rotation of the electric and magnetic fields around the propagation direction, and the second with the dynamical rotation of light rays around the main beam axis. These two rotations are associated with two forms of angular momentum, namely SAM and OAM. However this distinction becomes blurred for strongly focused or diverging beams, and in the general case only the total angular momentum of a light field can be defined. An important limiting case in which the distinction is instead clear and unambiguous is that of a "paraxial" light beam, that is a well collimated beam in which all light rays (or, more precisely, all Fourier components of the optical field) only form small angles with the beam axis.

For such a beam, SAM is strictly related with the optical polarization, and in particular with the so-called circular polarization. OAM is related with the spatial field distribution, and in particular with the wavefront helical shape.

In addition to these two terms, if the origin of coordinates is located outside the beam axis, there is a third angular momentum contribution obtained as the cross-product of the beam position and its total momentum. This third term is also called "orbital", because it depends on the spatial distribution of the field. However, since its value is dependent from the choice of the origin, it is termed "external" orbital angular momentum, as opposed to the "internal" OAM appearing for helical beams.

Mathematical expressions for the angular momentum of light

One commonly used expression for the total angular momentum of an electromagnetic field is the following one, in which there is no explicit distinction between the two forms of rotation:

$${\displaystyle \mathbf {J} =\varepsilon _{0}\int \mathbf {r} \times \left(\mathbf {E} \times \mathbf {B} \right)d^{3}\mathbf {r} ,}$$

where ${\displaystyle \mathbf {E} }$ and ${\displaystyle \mathbf {B} }$ are the electric and magnetic fields, respectively, ${\displaystyle \epsilon _{0}}$ is the vacuum permittivity and we are using SI units.

However, another expression of the angular momentum naturally arising from Noether’s theorem is the following one, in which there are two separate terms that may be associated with SAM (${\displaystyle \mathbf {S} }$) and OAM (${\displaystyle \mathbf {L} }$):

$${\displaystyle \mathbf {J} =\varepsilon _{0}\int \left(\mathbf {E} \times \mathbf {A} \right)d^{3}\mathbf {r} +\varepsilon _{0}\sum _{i=x,y,z}\int \left(E^{i}\left(\mathbf {r} \times {\boldsymbol {\nabla }}\right)A^{i}\right)d^{3}\mathbf {r} =\mathbf {S} +\mathbf {L} ,}$$

where ${\displaystyle \mathbf {A} }$ is the vector potential of the magnetic field, and the i-superscripted symbols denote the cartesian components of the corresponding vectors.

These two expressions can be proved to be equivalent to each other for any electromagnetic field that vanishes fast enough outside a finite region of space. The two terms in the second expression however are physically ambiguous, as they are not gauge-invariant. A gauge-invariant version can be obtained by replacing the vector potential A and the electric field E with their “transverse” or radiative component ${\displaystyle \mathbf {A} _{\perp }}$ and ${\displaystyle \mathbf {E} _{\perp }}$, thus obtaining the following expression:

$${\displaystyle \mathbf {J} _{\perp }=\varepsilon _{0}\int \left(\mathbf {E} _{\perp }\times \mathbf {A} _{\perp }\right)d^{3}\mathbf {r} +\varepsilon _{0}\sum _{i=x,y}\int \left({E^{i}}_{\perp }\left(\mathbf {r} \times {\boldsymbol {\nabla }}\right)A_{\perp }^{i}\right)d^{3}\mathbf {r} .}$$

A justification for taking this step is yet to be provided. The latter expression has further problems, as it can be shown that the two terms are not true angular momenta as they do not obey the correct quantum commutation rules. Their sum, that is the total angular momentum, instead does.^{[citation needed]}

An equivalent but simpler expression for a monochromatic wave of frequency ω, using the complex notation for the fields, is the following:

$${\displaystyle \mathbf {J} ={\frac {\varepsilon _{0}}{2i\omega }}\int \left(\mathbf {E} ^{\ast }\times \mathbf {E} \right)d^{3}\mathbf {r} +{\frac {\varepsilon _{0}}{2i\omega }}\sum _{i=x,y,z}\int \left({E^{i}}^{\ast }\left(\mathbf {r} \times {\boldsymbol {\nabla }}\right)E^{i}\right)d^{3}\mathbf {r} .}$$

Let us now consider the paraxial limit, with the beam axis assumed to coincide with the z axis of the coordinate system. In this limit the only significant component of the angular momentum is the z one, that is the angular momentum measuring the light beam rotation around its own axis, while the other two components are negligible.

$${\displaystyle \mathbf {J} \approx {\frac {{\hat {z}}\epsilon _{0}}{2\omega }}\int \left(\left|E_{\text{L}}\right|^{2}-\left|E_{\text{R}}\right|^{2}\right)d^{3}\mathbf {r} +{\frac {{\hat {z}}\varepsilon _{0}}{2i\omega }}\int \sum _{i=x,y,z}\left({E^{i}}^{\ast }{\frac {\partial }{\partial \phi }}E^{i}\right)d^{3}\mathbf {r} .}$$

where ${\displaystyle E_{\text{L}}}$ and ${\displaystyle E_{\text{R}}}$ denote the left and right circular polarization components, respectively.

Exchange of spin and orbital angular momentum with matter

Spin and orbital angular momentum interaction with matter

When a light beam carrying nonzero angular momentum impinges on an absorbing particle, its angular momentum can be transferred on the particle, thus setting it in rotational motion. This occurs both with SAM and OAM. However, if the particle is not at the beam center the two angular momenta will give rise to different kinds of rotation of the particle. SAM will give rise to a rotation of the particle around its own center, i.e., to a particle spinning. OAM, instead, will generate a revolution of the particle around the beam axis. These phenomena are schematically illustrated in the figure.

In the case of transparent media, in the paraxial limit, the optical SAM is mainly exchanged with anisotropic systems, for example birefringent crystals. Indeed, thin slabs of birefringent crystals are commonly used to manipulate the light polarization. Whenever the polarization ellipticity is changed, in the process, there is an exchange of SAM between light and the crystal. If the crystal is free to rotate, it will do so. Otherwise, the SAM is finally transferred to the holder and to the Earth.

Spiral Phase Plate (SPP)

Schematic of generating light orbital angular momentum with spiral phase plate.

In the paraxial limit, the OAM of a light beam can be exchanged with material media that have a transverse spatial inhomogeneity. For example, a light beam can acquire OAM by crossing a spiral phase plate, with an inhomogeneous thickness (see figure).

Pitch-Fork Hologram

Schematic showing generation of orbital angular momentum of light in a Gaussian beam.

A more convenient approach for generating OAM is based on using diffraction on a fork-like or pitchfork hologram (see figure). Holograms can be also generated dynamically under the control of a computer by using a spatial light modulator.

Q-Plate

The q-plate effect for left and right-hand circular polarizations.

Another method for generating OAM is based on the SAM-OAM coupling that may occur in a medium which is both anisotropic and inhomogeneous. In particular, the so-called q-plate is a device, currently realized using liquid crystals, polymers or sub-wavelength gratings, which can generate OAM by exploiting a SAM sign-change. In this case, the OAM sign is controlled by the input polarization.

Cylindrical Mode Converters

pi/2-cylindrical mode converter transforms HG mode into a proper LG mode.

OAM can also be generated by converting a Hermite-Gaussian beam into a Laguerre-Gaussian one by using an astigmatic system with two well-aligned cylindrical lenses placed at a specific distance (see figure) in order to introduce a well-defined relative phase between horizontal and vertical Hermite-Gaussian beams.

Possible applications of the orbital angular momentum of light

The applications of the spin angular momentum of light are undistinguishable from the innumerable applications of the light polarization and will not be discussed here. The possible applications of the orbital angular momentum of light are instead currently the subject of research. In particular, the following applications have been already demonstrated in research laboratories, although they have not yet reached the stage of commercialization:

1. Orientational manipulation of particles or particle aggregates in optical tweezers
2. High-bandwidth information encoding in free-space optical communication
3. Higher-dimensional quantum information encoding, for possible future quantum cryptography or quantum computation applications
4. Sensitive optical detection