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Thursday, February 12, 2015

Love


From Wikipedia, the free encyclopedia


Archetypal lovers Romeo and Juliet portrayed by Frank Dicksee

Love is a variety of different feelings, states, and attitudes that ranges from interpersonal affection ("I love my mother") to pleasure ("I loved that meal"). It can refer to an emotion of a strong attraction and personal attachment.[1] It can also be a virtue representing human kindness, compassion, and affection—"the unselfish loyal and benevolent concern for the good of another".[2] It may also describe compassionate and affectionate actions towards other humans, one's self or animals.[3]
Ancient Greeks identified four forms of love: kinship or familiarity (in Greek, storge), friendship (philia), sexual and/or romantic desire (eros), and self-emptying or divine love (agape).[4][5] Modern authors have distinguished further varieties of romantic love.[6] Non-Western traditions have also distinguished variants or symbioses of these states.[7] This diversity of uses and meanings combined with the complexity of the feelings involved makes love unusually difficult to consistently define, compared to other emotional states.

Love in its various forms acts as a major facilitator of interpersonal relationships and, owing to its central psychological importance, is one of the most common themes in the creative arts.[8]

Love may be understood as a function to keep human beings together against menaces and to facilitate the continuation of the species.[9]

Definitions

The word "love" can have a variety of related but distinct meanings in different contexts. Many other languages use multiple words to express some of the different concepts that in English are denoted as "love"; one example is the plurality of Greek words for "love". Cultural differences in conceptualizing love thus doubly impede the establishment of a universal definition.[10]

Although the nature or essence of love is a subject of frequent debate, different aspects of the word can be clarified by determining what isn't love (antonyms of "love"). Love as a general expression of positive sentiment (a stronger form of like) is commonly contrasted with hate (or neutral apathy); as a less sexual and more emotionally intimate form of romantic attachment, love is commonly contrasted with lust; and as an interpersonal relationship with romantic overtones, love is sometimes contrasted with friendship, although the word love is often applied to close friendships. (Further possible ambiguities come with usages "girlfriend", "boyfriend", "just good friends").

Fraternal love (Prehispanic sculpture from 250–900 AD, of Huastec origin). Museum of Anthropology in Xalapa, Veracruz, Mexico

Abstractly discussed love usually refers to an experience one person feels for another. Love often involves caring for or identifying with a person or thing (cf. vulnerability and care theory of love), including oneself (cf. narcissism). In addition to cross-cultural differences in understanding love, ideas about love have also changed greatly over time. Some historians date modern conceptions of romantic love to courtly Europe during or after the Middle Ages, although the prior existence of romantic attachments is attested by ancient love poetry.[11]

The complex and abstract nature of love often reduces discourse of love to a thought-terminating cliché. Several common proverbs regard love, from Virgil's "Love conquers all" to The Beatles' "All You Need Is Love". St. Thomas Aquinas, following Aristotle, defines love as "to will the good of another."[12] Bertrand Russell describes love as a condition of "absolute value," as opposed to relative value.[citation needed] Philosopher Gottfried Leibniz said that love is "to be delighted by the happiness of another."[13] Biologist Jeremy Griffith defines love as "unconditional selflessness".[14]

Love is sometimes referred to as an "international language" that overrides cultural and linguistic divisions.[clarification needed]

Impersonal love

A person can be said to love an object, principle, or goal to which they are deeply committed and greatly value. For example, compassionate outreach and volunteer workers' "love" of their cause may sometimes be born not of interpersonal love but impersonal love, altruism, and strong spiritual or political convictions.[15] People can also "love" material objects, animals, or activities if they invest themselves in bonding or otherwise identifying with those things. If sexual passion is also involved, then this feeling is called paraphilia.[16]

Interpersonal love

Interpersonal love refers to love between human beings. It is a much more potent sentiment than a simple liking for another. Unrequited love refers to those feelings of love that are not reciprocated. Interpersonal love is most closely associated with interpersonal relationships.[15] Such love might exist between family members, friends, and couples. There are also a number of psychological disorders related to love, such as erotomania.

Pair of Lovers. 1480–1485

Throughout history, philosophy and religion have done the most speculation on the phenomenon of love. In the 20th century, the science of psychology has written a great deal on the subject. In recent years, the sciences of psychology, anthropology, neuroscience, and biology have added to the understanding of the nature and function of love.

Biological basis

Biological models of sex tend to view love as a mammalian drive, much like hunger or thirst.[17] Helen Fisher, a leading expert in the topic of love, divides the experience of love into three partly overlapping stages: lust, attraction, and attachment. Lust is the feeling of sexual desire; romantic attraction determines what partners mates find attractive and pursue, conserving time and energy by choosing; and attachment involves sharing a home, parental duties, mutual defense, and in humans involves feelings of safety and security.[18] Three distinct neural circuitries, including neurotransmitters, and three behavioral patterns, are associated with these three romantic styles.[18]Lust is the initial passionate sexual desire that promotes mating, and involves the increased release of chemicals such as testosterone and estrogen. These effects rarely last more than a few weeks or months. Attraction is the more individualized and romantic desire for a specific candidate for mating, which develops out of lust as commitment to an individual mate forms. Recent studies in neuroscience have indicated that as people fall in love, the brain consistently releases a certain set of chemicals, including the neurotransmitter hormones, dopamine, norepinephrine, and serotonin, the same compounds released by amphetamine, stimulating the brain's pleasure center and leading to side effects such as increased heart rate, loss of appetite and sleep, and an intense feeling of excitement.
Research has indicated that this stage generally lasts from one and a half to three years.[19]

Since the lust and attraction stages are both considered temporary, a third stage is needed to account for long-term relationships. Attachment is the bonding that promotes relationships lasting for many years and even decades. Attachment is generally based on commitments such as marriage and children, or on mutual friendship based on things like shared interests. It has been linked to higher levels of the chemicals oxytocin and vasopressin to a greater degree than short-term relationships have.[19] Enzo Emanuele and coworkers reported the protein molecule known as the nerve growth factor (NGF) has high levels when people first fall in love, but these return to previous levels after one year.[20]

Psychological basis

Psychology depicts love as a cognitive and social phenomenon. Psychologist Robert Sternberg formulated a triangular theory of love and argued that love has three different components: intimacy, commitment, and passion. Intimacy is a form in which two people share confidences and various details of their personal lives, and is usually shown in friendships and romantic love affairs. 
 
Commitment, on the other hand, is the expectation that the relationship is permanent. The last and most common form of love is sexual attraction and passion. Passionate love is shown in infatuation as well as romantic love. All forms of love are viewed as varying combinations of these three components. Non-love does not include any of these components. Liking only includes intimacy. Infatuated love only includes passion. Empty love only includes commitment. Romantic love includes both intimacy and passion. Companionate love includes intimacy and commitment. Fatuous love includes passion and commitment. Lastly, consummate love includes all three.[21] American psychologist Zick Rubin sought to define love by psychometrics in the 1970s. His work states that three factors constitute love: attachment, caring, and intimacy.[22] [23]

Grandmother and grandchild, Sri Lanka

Following developments in electrical theories such as Coulomb's law, which showed that positive and negative charges attract, analogs in human life were developed, such as "opposites attract." Over the last century, research on the nature of human mating has generally found this not to be true when it comes to character and personality—people tend to like people similar to themselves. However, in a few unusual and specific domains, such as immune systems, it seems that humans prefer others who are unlike themselves (e.g., with an orthogonal immune system), since this will lead to a baby that has the best of both worlds.[24] In recent years, various human bonding theories have been developed, described in terms of attachments, ties, bonds, and affinities. Some Western authorities disaggregate into two main components, the altruistic and the narcissistic. This view is represented in the works of Scott Peck, whose work in the field of applied psychology explored the definitions of love and evil. Peck maintains that love is a combination of the "concern for the spiritual growth of another," and simple narcissism.[25] In combination, love is an activity, not simply a feeling.

Psychologist Erich Fromm maintained in his book The Art of Loving that love is not merely a feeling but is also actions, and that in fact, the "feeling" of love is superficial in comparison to one's commitment to love via a series of loving actions over time.[15] In this sense, Fromm held that love is ultimately not a feeling at all, but rather is a commitment to, and adherence to, loving actions towards another, oneself, or many others, over a sustained duration.[15] Fromm also described love as a conscious choice that in its early stages might originate as an involuntary feeling, but which then later no longer depends on those feelings, but rather depends only on conscious commitment.[15]

Evolutionary basis

Evolutionary psychology has attempted to provide various reasons for love as a survival tool. Humans are dependent on parental help for a large portion of their lifespans compared to other mammals. Love has therefore been seen as a mechanism to promote parental support of children for this extended time period. Another factor may be that sexually transmitted diseases can cause, among other effects, permanently reduced fertility, injury to the fetus, and increase complications during childbirth. This would favor monogamous relationships over polygamy.[26]

Comparison of scientific models

Biological models of love tend to see it as a mammalian drive, similar to hunger or thirst.[17] Psychology sees love as more of a social and cultural phenomenon. Certainly love is influenced by hormones (such as oxytocin), neurotrophins (such as NGF), and pheromones, and how people think and behave in love is influenced by their conceptions of love. The conventional view in biology is that there are two major drives in love: sexual attraction and attachment. Attachment between adults is presumed to work on the same principles that lead an infant to become attached to its mother. The traditional psychological view sees love as being a combination of companionate love and passionate love. Passionate love is intense longing, and is often accompanied by physiological arousal (shortness of breath, rapid heart rate); companionate love is affection and a feeling of intimacy not accompanied by physiological arousal.

Cultural views

Ancient Greek

Greek distinguishes several different senses in which the word "love" is used. For example, Ancient Greek has the words philia, eros, agape, storge, and xenia. However, with Greek (as with many other languages), it has been historically difficult to separate the meanings of these words totally. At the same time, the Ancient Greek text of the Bible has examples of the verb agapo having the same meaning as phileo.
Agape (ἀγάπη agápē) means love in modern-day Greek. The term s'agapo means I love you in Greek. The word agapo is the verb I love. It generally refers to a "pure," ideal type of love, rather than the physical attraction suggested by eros. However, there are some examples of agape used to mean the same as eros. It has also been translated as "love of the soul."

Eros (ἔρως érōs) (from the Greek deity Eros) is passionate love, with sensual desire and longing. The Greek word erota means in love. Plato refined his own definition. Although eros is initially felt for a person, with contemplation it becomes an appreciation of the beauty within that person, or even becomes appreciation of beauty itself. Eros helps the soul recall knowledge of beauty and contributes to an understanding of spiritual truth. Lovers and philosophers are all inspired to seek truth by eros. Some translations list it as "love of the body."

Philia (φιλία philía), a dispassionate virtuous love, was a concept addressed and developed by Aristotle.[citation needed] It includes loyalty to friends, family, and community, and requires virtue, equality, and familiarity. Philia is motivated by practical reasons; one or both of the parties benefit from the relationship. It can also mean "love of the mind."

Storge (στοργή storgē) is natural affection, like that felt by parents for offspring.

Xenia (ξενία xenía), hospitality, was an extremely important practice in Ancient Greece. It was an almost ritualized friendship formed between a host and his guest, who could previously have been strangers. The host fed and provided quarters for the guest, who was expected to repay only with gratitude. The importance of this can be seen throughout Greek mythology—in particular, Homer's Iliad and Odyssey.

Ancient Roman

The Latin language has several different verbs corresponding to the English word "love." amō is the basic verb meaning I love, with the infinitive amare (“to love”) as it still is in Italian today. The Romans used it both in an affectionate sense as well as in a romantic or sexual sense. From this verb come amans—a lover, amator, "professional lover," often with the accessory notion of lechery—and amica, "girlfriend" in the English sense, often being applied euphemistically to a prostitute. The corresponding noun is amor (the significance of this term for the Romans is well illustrated in the fact, that the name of the City, Rome—in Latin: Roma—can be viewed as an anagram for amor, which was used as the secret name of the City in wide circles in ancient times),[27] which is also used in the plural form to indicate love affairs or sexual adventures. This same root also produces amicus—"friend"—and amicitia, "friendship" (often based to mutual advantage, and corresponding sometimes more closely to "indebtedness" or "influence"). Cicero wrote a treatise called On Friendship (de Amicitia), which discusses the notion at some length. Ovid wrote a guide to dating called Ars Amatoria (The Art of Love), which addresses, in depth, everything from extramarital affairs to overprotective parents.

Latin sometimes uses amāre where English would simply say to like. This notion, however, is much more generally expressed in Latin by placere or delectāre, which are used more colloquially, the latter used frequently in the love poetry of Catullus. Diligere often has the notion "to be affectionate for," "to esteem," and rarely if ever is used for romantic love. This word would be appropriate to describe the friendship of two men. The corresponding noun diligentia, however, has the meaning of "diligence" or "carefulness," and has little semantic overlap with the verb. Observare is a synonym for diligere; despite the cognate with English, this verb and its corresponding noun, observantia, often denote "esteem" or "affection." Caritas is used in Latin translations of the Christian Bible to mean "charitable love"; this meaning, however, is not found in Classical pagan Roman literature. As it arises from a conflation with a Greek word, there is no corresponding verb.

Chinese and other Sinic cultures


"Ai," the traditional Chinese character for love (愛) consists of a heart (心, middle) inside of "accept," "feel," or "perceive," (受) which shows a graceful emotion. It can also be interpreted as a hand offering one's heart to another hand.

Two philosophical underpinnings of love exist in the Chinese tradition, one from Confucianism which emphasized actions and duty while the other came from Mohism which championed a universal love. A core concept to Confucianism is Ren ("benevolent love", 仁), which focuses on duty, action and attitude in a relationship rather than love itself. In Confucianism, one displays benevolent love by performing actions such as filial piety from children, kindness from parent, loyalty to the king and so forth.

The concept of Ai (愛) was developed by the Chinese philosopher Mozi in the 4th century BC in reaction to Confucianism's benevolent love. Mozi tried to replace what he considered to be the long-entrenched Chinese over-attachment to family and clan structures with the concept of "universal love" (jiān'ài, 兼愛). In this, he argued directly against Confucians who believed that it was natural and correct for people to care about different people in different degrees. Mozi, by contrast, believed people in principle should care for all people equally. Mohism stressed that rather than adopting different attitudes towards different people, love should be unconditional and offered to everyone without regard to reciprocation, not just to friends, family and other Confucian relations. Later in Chinese Buddhism, the term Ai (愛) was adopted to refer to a passionate caring love and was considered a fundamental desire. In Buddhism, Ai was seen as capable of being either selfish or selfless, the latter being a key element towards enlightenment.

In contemporary Chinese, Ai (愛) is often used as the equivalent of the Western concept of love. Ai is used as both a verb (e.g. wo ai ni 我愛你, or "I love you") and a noun (such as aiqing 愛情, or "romantic love"). However, due to the influence of Confucian Ren, the phrase ‘Wo ai ni’ (I love you) carries with it a very specific sense of responsibility, commitment and loyalty. Instead of frequently saying "I love you" as in some Western societies, the Chinese are more likely to express feelings of affection in a more casual way. Consequently, "I like you" (Wo xihuan ni, 我喜欢你) is a more common way of expressing affection in Chinese; it is more playful and less serious.[28] This is also true in Japanese (suki da, 好きだ). The Chinese are also more likely to say "I love you" in English or other foreign languages than they would in their mother tongue.

Persian

Rumi, Hafiz and Sa'di are icons of the passion and love that the Persian culture and language present.
The Persian word for love is eshgh,[citation needed] derived from the Arabic ishq, however is considered by most to be too stalwart a term for interpersonal love and is more commonly substituted for 'doost dashtan' ('liking').[citation needed] In the Persian culture, everything is encompassed by love and all is for love, starting from loving friends and family, husbands and wives, and eventually reaching the divine love that is the ultimate goal in life .[citation needed] Over seven centuries ago, Sa'di wrote:
The children of Adam are limbs of one body
Having been created of one essence.
When the calamity of time afflicts one limb
The other limbs cannot remain at rest.
If you have no sympathy for the troubles of others
You are not worthy to be called by the name of "man".

Japanese


Ohatsu and Tokubei, characters of Sonezaki Shinjū

The Japanese language uses three words to convey the English equivalent of "love". Because "love" covers a wide range of emotions and behavioral phenomena, there are nuances distinguishing the three terms.[29][30] The term ai (?), which is often associated with maternal love[29] or selfless love,[30] originally referred to beauty and was often used in religious context. Following the Meiji Restoration 1868, the term became associated with "love" in order to translate Western literature. Prior to Western influence, the term koi (?) generally represented romantic love, and was often the subject of the popular Man'yōshū Japanese poetry collection.[29] Koi describes a longing for a member of the opposite sex and is typical interpreted as selfish and wanting.[30] The term's origins come from the concept of lonely solitude as a result of separation from a loved one. Though modern usage of koi focuses on sexual love and infatuation, the Manyō used the term to cover a wider range of situations, including tenderness, benevolence, and material desire.[29] The third term, renai (恋愛?), is a more modern construction that combines the kanji characters for both ai and koi, though its usage more closely resembles that of koi in the form of romantic love.[29][30]

Turkish (Shaman and Islamic)

In Turkish, the word "love" comes up with several meanings. A person can love a god, a person, parents, or family. But that person can "love" just one special person, which they call the word "aşk." Aşk (a word of Arabic origin) is a feeling for to love, or being "in love" (Aşık), as it still is in Turkish today. The Turks used this word just for their loves in a romantic or sexual sense. If a Turk says that he is in love (Aşık) with somebody, it is not a love that a person can feel for his or her parents; it is just for one person, and it indicates a huge infatuation. The word is also common for Turkic languages, such as Azerbaijani (eşq) and Kazakh (ғашық).

Religious views

Abrahamic religions


Robert Indiana's 1977 Love sculpture spelling ahava.

Christianity

The Christian understanding is that love comes from God. The love of man and woman—eros in Greek—and the unselfish love of others (agape), are often contrasted as "ascending" and "descending" love, respectively, but are ultimately the same thing.[31]

There are several Greek words for "love" that are regularly referred to in Christian circles.
  • Agape: In the New Testament, agapē is charitable, selfless, altruistic, and unconditional. It is parental love, seen as creating goodness in the world; it is the way God is seen to love humanity, and it is seen as the kind of love that Christians aspire to have for one another.
  • Phileo: Also used in the New Testament, phileo is a human response to something that is found to be delightful. Also known as "brotherly love."
  • Two other words for love in the Greek language, eros (sexual love) and storge (child-to-parent love), were never used in the New Testament.
Christians believe that to Love God with all your heart, mind, and strength and Love your neighbor as yourself are the two most important things in life (the greatest commandment of the Jewish Torah, according to Jesus; cf. Gospel of Mark chapter 12, verses 28–34). Saint Augustine summarized this when he wrote "Love God, and do as thou wilt."

Sacred Love Versus Profane Love (1602–03) by Giovanni Baglione. Intended as an attack on his hated enemy the artist Caravaggio, it shows a boy (hinting at Caravaggio's homosexuality) on one side, a devil with Caravaggio's face on the other, and between an angel representing pure, meaning non-erotic, love.

The Apostle Paul glorified love as the most important virtue of all. Describing love in the famous poem in 1 Corinthians, he wrote, "Love is patient, love is kind. It does not envy, it does not boast, it is not proud. It is not rude, it is not self-seeking, it is not easily angered, it keeps no record of wrongs. Love does not delight in evil but rejoices with the truth. It always protects, always trusts, always hopes, and always perseveres." (1 Cor. 13:4–7, NIV)

The Apostle John wrote, "For God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life. For God did not send his Son into the world to condemn the world, but to save the world through him." (John 3:16–17, NIV) John also wrote, "Dear friends, let us love one another for love comes from God. Everyone who loves has been born of God and knows God. Whoever does not love does not know God, because God is love." (1 John 4:7–8, NIV)

Saint Augustine says that one must be able to decipher the difference between love and lust. Lust, according to Saint Augustine, is an overindulgence, but to love and be loved is what he has sought for his entire life. He even says, “I was in love with love.” Finally, he does fall in love and is loved back, by God. Saint Augustine says the only one who can love you truly and fully is God, because love with a human only allows for flaws such as “jealousy, suspicion, fear, anger, and contention.” According to Saint Augustine, to love God is “to attain the peace which is yours.” (Saint Augustine's Confessions)

Augustine regards the duplex commandment of love in Matthew 22 as the heart of Christian faith and the interpretation of the Bible. After the review of Christian doctrine, Augustine treats the problem of love in terms of use and enjoyment until the end of Book I of De Doctrina Christiana (1.22.21-1.40.44;).[32]

Christian theologians see God as the source of love, which is mirrored in humans and their own loving relationships. Influential Christian theologian C.S. Lewis wrote a book called The Four Loves. Benedict XVI wrote his first encyclical on "God is love". He said that a human being, created in the image of God, who is love, is able to practice love; to give himself to God and others (agape) and by receiving and experiencing God's love in contemplation (eros). This life of love, according to him, is the life of the saints such as Teresa of Calcutta and the Blessed Virgin Mary and is the direction Christians take when they believe that God loves them.[31]

In Christianity the practical definition of love is best summarised by St. Thomas Aquinas, who defined love as "to will the good of another," or to desire for another to succeed.[12] This is the explanation of the Christian need to love others, including their enemies. As Thomas Aquinas explains, Christian love is motivated by the need to see others succeed in life, to be good people.

Judaism

In Hebrew, Ahava is the most commonly used term for both interpersonal love and love between God and God's creations. Chesed, often translated as loving-kindness, is used to describe many forms of love between human beings.

The commandment to love other people is given in the Torah, which states, "Love your neighbor like yourself" (Leviticus 19:18). The Torah's commandment to love God "with all your heart, with all your soul and with all your might" (Deuteronomy 6:5) is taken by the Mishnah (a central text of the Jewish oral law) to refer to good deeds, willingness to sacrifice one's life rather than commit certain serious transgressions, willingness to sacrifice all of one's possessions, and being grateful to the Lord despite adversity (tractate Berachoth 9:5). Rabbinic literature differs as to how this love can be developed, e.g., by contemplating divine deeds or witnessing the marvels of nature. As for love between marital partners, this is deemed an essential ingredient to life: "See life with the wife you love" (Ecclesiastes 9:9). The biblical book Song of Solomon is considered a romantically phrased metaphor of love between God and his people, but in its plain reading, reads like a love song. The 20th-century Rabbi Eliyahu Eliezer Dessler is frequently quoted as defining love from the Jewish point of view as "giving without expecting to take" (from his Michtav me-Eliyahu, Vol. 1).

Islam

Love encompasses the Islamic view of life as universal brotherhood that applies to all who hold faith. Amongst the 99 names of God (Allah), there is the name Al-Wadud, or "the Loving One," which is found in Surah [Quran 11:90] as well as Surah [Quran 85:14]. God is also referenced at the beginning of every chapter in the Qur'an as Ar-Rahman and Ar-Rahim, or the "Most Compassionate" and the "Most Merciful", indicating that nobody is more loving, compassionate and benevolent than God. The Qur'an refers to God as being "full of loving kindness."

The Qur'an exhorts Muslim believers to treat all people, those who have not persecuted them, with birr or "deep kindness" as stated in Surah [Quran 6:8-9]. Birr is also used by the Qur'an in describing the love and kindness that children must show to their parents.

Ishq, or divine love, is the emphasis of Sufism in the Islamic tradition. Practitioners of Sufism believe that love is a projection of the essence of God to the universe. God desires to recognize beauty, and as if one looks at a mirror to see oneself, God "looks" at himself within the dynamics of nature. Since everything is a reflection of God, the school of Sufism practices to see the beauty inside the apparently ugly. Sufism is often referred to as the religion of love.[citation needed] God in Sufism is referred to in three main terms, which are the Lover, Loved, and Beloved, with the last of these terms being often seen in Sufi poetry. A common viewpoint of Sufism is that through love, humankind can get back to its inherent purity and grace. The saints of Sufism are infamous for being "drunk" due to their love of God; hence, the constant reference to wine in Sufi poetry and music.[33]

Bahá’í Faith

In his Paris Talks, `Abdu'l-Bahá described four types of love:[1]
  1. The love that flows from God to human beings
  2. The love that flows from human beings to God
  3. the love of God towards the Self or Identity of God
  4. the love of human beings for human beings

Eastern religions

Buddhism

In Buddhism, Kāma is sensuous, sexual love. It is an obstacle on the path to enlightenment, since it is selfish. Karuṇā is compassion and mercy, which reduces the suffering of others. It is complementary to wisdom and is necessary for enlightenment. Adveṣa and mettā are benevolent love. This love is unconditional and requires considerable self-acceptance. This is quite different from ordinary love, which is usually about attachment and sex and which rarely occurs without self-interest. Instead, in Buddhism it refers to detachment and unselfish interest in others' welfare.

The Bodhisattva ideal in Mahayana Buddhism involves the complete renunciation of oneself in order to take on the burden of a suffering world. The strongest motivation one has in order to take the path of the Bodhisattva is the idea of salvation within unselfish, altruistic love for all sentient beings.

Hinduism


Kama (left) with Rati on a temple wall of Chennakesava Temple, Belur

In Hinduism, kāma is pleasurable, sexual love, personified by the god Kamadeva. For many Hindu schools, it is the third end (Kama) in life. Kamadeva is often pictured holding a bow of sugar cane and an arrow of flowers; he may ride upon a great parrot. He is usually accompanied by his consort Rati and his companion Vasanta, lord of the spring season. Stone images of Kamadeva and Rati can be seen on the door of the Chennakeshava temple at Belur, in Karnataka, India. Maara is another name for kāma.

In contrast to kāma, prema – or prem – refers to elevated love. Karuna is compassion and mercy, which impels one to help reduce the suffering of others. Bhakti is a Sanskrit term, meaning "loving devotion to the supreme God." A person who practices bhakti is called a bhakta. Hindu writers, theologians, and philosophers have distinguished nine forms of bhakti, which can be found in the Bhagavata Purana and works by Tulsidas. The philosophical work Narada Bhakti Sutras, written by an unknown author (presumed to be Narada), distinguishes eleven forms of love.

In certain Vaishnava sects within Hinduism, attaining unaldulterated, unconditional and incessant love for Godhead is considered the foremost goal of life. Gaudiya Vaishnavas who worship Krishna as the Supreme Personality of Godhead and the cause of all causes consider Love for Godhead (Prema) to act in two ways: sambhoga and vipralambha (union and separation)—two opposites .[34]

In the condition of separation, there is an acute yearning for being with the beloved and in the condition of union there is supreme happiness and nectarean. Gaudiya Vaishnavas consider that Krishna-prema (Love for Godhead) is not fire but that it still burns away one's material desires. They consider that Kṛṣṇa-prema is not a weapon, but it still pierces the heart. It is not water, but it washes away everything—one's pride, religious rules, and one's shyness. Krishna-prema is considered to make one drown in the ocean of transcendental ecstasy and pleasure. The love of Radha, a cowherd girl, for Krishna is often cited as the supreme example of love for Godhead by Gaudiya Vaishnavas. Radha is considered to be the internal potency of Krishna, and is the supreme lover of Godhead. Her example of love is considered to be beyond the understanding of material realm as it surpasses any form of selfish love or lust that is visible in the material world. The reciprocal love between Radha (the supreme lover) and Krishna (God as the Supremely Loved) is the subject of many poetic compositions in India such as the Gita Govinda and Hari Bhakti Shuddhodhaya.

In the Bhakti tradition within Hinduism, it is believed that execution of devotional service to God leads to the development of Love for God (taiche bhakti-phale krsne prema upajaya), and as love for God increases in the heart, the more one becomes free from material contamination (krishna-prema asvada haile, bhava nasa paya). Being perfectly in love with God or Krishna makes one perfectly free from material contamination. and this is the ultimate way of salvation or liberation. In this tradition, salvation or liberation is considered inferior to love, and just an incidental by-product. Being absorbed in Love for God is considered to be the perfection of life.[35]

Political views

Free love

Lovers kissing on the street

The term free love has been used [36] to describe a social movement that rejects marriage, which is seen as a form of social bondage. The Free Love movement’s initial goal was to separate the state from sexual matters such as marriage, birth control, and adultery. It claimed that such issues were the concern of the people involved, and no one else.[37]

Many people in the early 19th century believed that marriage was an important aspect of life to "fulfill earthly human happiness." Middle-class Americans wanted the home to be a place of stability in an uncertain world. This mentality created a vision of strongly defined gender roles, which provoked the advancement of the free love movement as a contrast.[38]

The term "sex radical" is also used interchangeably with the term "free lover", and was the preferred term by advocates because of the negative connotations of "free love".[citation needed] By whatever name, advocates had two strong beliefs: opposition to the idea of forceful sexual activity in a relationship and advocacy for a woman to use her body in any way that she pleases.[39] These are also beliefs of Feminism.

Philosophical views


The philosophy of love is a field of social philosophy and ethics that attempts to explain the nature of love. The philosophical investigation of love includes the tasks of distinguishing between the various kinds of personal love, asking if and how love is or can be justified, asking what the value of love is, and what impact love has on the autonomy of both the lover and the beloved.

Many different theories attempt to explain the nature and function of love. Explaining love to a hypothetical person who had not himself or herself experienced love or being loved would be very difficult because to such a person love would appear to be quite strange if not outright irrational behavior. Among the prevailing types of theories that attempt to account for the existence of love are: psychological theories, the vast majority of which consider love to be very healthy behavior; evolutionary theories which hold that love is part of the process of natural selection; spiritual theories which may, for instance consider love to be a gift from a god; and theories that consider love to be an unexplainable mystery, very much like a mystical experience.

Meteor / Meteriod


From Wikipedia, the free encyclopedia
 

A slice of a pallasite meteorite fragment of what was once a meteoroid before it collided with Earth, discovered in Esquel, Argentina; on display at the Canadian Museum of Nature in Ottawa, Canada.

A meteoroid is a small rocky or metallic body travelling through space. Meteoroids are significantly smaller than asteroids, and range in size from small grains to 1 meter-wide objects. Smaller objects than this are classified as micrometeoroids or space dust.[1][2][3][4] Most are fragments from comets or asteroids, while others are collision impact debris ejected from bodies such as the Moon or Mars.[5][6][7][8]

When such an object enters the Earth's atmosphere at a speed typically in excess of 20 km/s, aerodynamic heating produces a streak of light, both from the glowing object and the trail of glowing particles that it leaves in its wake. This phenomenon is called a meteor, or colloquially a "shooting star" or "falling star". A series of many meteors appearing seconds or minutes apart, and appearing to originate from the same fixed point in the sky, is called a meteor shower. Incoming objects larger than several meters (asteroids or comets) can explode in the air. If a meteoroid, comet or asteroid or a piece thereof withstands ablation from its atmospheric entry and impacts with the ground, then it is called a meteorite.

Around 15,000 tonnes of meteoroids, micrometeoroids and different forms of space dust enter Earth's atmosphere each year.[9]

Meteoroids


Animated illustration of different phases as a meteoroid enters the Earth's atmosphere to become visible as a meteor and land as a meteorite

2008 TC3 meteorite fragments found on February 28, 2009 in the Nubian Desert, Sudan.

In 1961, the International Astronomical Union defined a meteoroid as "a solid object moving in interplanetary space, of a size considerably smaller than an asteroid and considerably larger than an atom".[10][11] In 1995, Beech and Steel, writing in Quarterly Journal of the Royal Astronomical Society, proposed a new definition where a meteoroid would be between 100 µm and 10 meters across.[12] Following the discovery of asteroids below 10 m in size,[clarification needed] Rubin and Grossman refined the Beech and Steel definition of meteoroid to objects between 10 µm and 1 m in diameter.[2] According to Rubin and Grossman the minimum size of an asteroid is given by what can be discovered from Earth-bound telescopes, so the distinction between meteoroid and asteroid is fuzzy. The smallest asteroid ever discovered (based on absolute magnitude) is 2008 TS26 with an absolute magnitude of 33.2,[13] and an estimated size of 1-meter.[14] Objects smaller than meteoroids are classified as micrometeoroids and cosmic dust. The Minor Planet Center does not use the term "meteoroid".

Meteoroid composition

Almost all meteoroids contain extraterrestrial nickel and irons. They have three main classifications, irons, stones and stony-irons. Some stone meteoroids contain grain-like inclusions known as "chondrules" and are called "chondrites." Stoney meteoroids without these features are called "achondrites", which are typically formed from extraterrestrial igneous activity; they contain little or no extraterrestrial iron.[15] The composition of meteoroids can be inferred as they pass through the Earth's atmosphere from their trajectories and the light spectra of the resulting meteor. Their effects on radio signals also give information, especially useful for daytime meteors which are otherwise very difficult to observe. From these trajectory measurements, meteoroids have been found to have many different orbits, some clustering in streams (see Meteor showers) often associated with a parent comet, others apparently sporadic. Debris from meteoroid streams may eventually be scattered into other orbits. The light spectra, combined with trajectory and light curve measurements, have yielded various compositions and densities, ranging from fragile snowball-like objects with density about a quarter that of ice,[16] to nickel-iron rich dense rocks. The study of meteorites also gives insights into the composition of non-ephemeral meteoroids.

Meteoroids in the Solar System

Meteoroids travel around the Sun in a variety of orbits and at various velocities. The fastest ones move at about 42 kilometers per second through space in the vicinity of Earth's orbit.[citation needed] The Earth travels at about 29.6 kilometers per second. Thus, when meteoroids meet Earth's atmosphere head-on (which only occurs when meteors are in a retrograde orbit such as the Eta Aquarids, which are associated with the retrograde Halley's Comet), the combined speed may reach about 71 kilometers per second. Meteoroids moving through Earth's orbital space average about 20 km/s.[17]

On January 17, 2013 at 05:21 PST, a 1 meter-sized comet from the Oort cloud entered Earth atmosphere over a wide area in California and Nevada.[18] The object had a retrograde orbit with perihelion at 0.98 ± 0.03 AU. It approached from the direction of the constellation Virgo, and collided head-on with Earth atmosphere at 72 ± 6 km/s[18] vapourising more than 100 km above ground over a period of several seconds.

Meteoroid collisions with Earth and its atmosphere


Meteor seen from the site of the Atacama Large Millimeter Array.[19]

When meteoroids intersect with the Earth's atmosphere at night, they are likely to become visible as meteors. If meteoroids survive the entry through the atmosphere and reach the Earth's surface, they are called meteorites. Meteorites are transformed in structure and chemistry by the heat of entry and force of impact. A noted meteoroid, 2008 TC3, was observed in space on a collision course with Earth on 6 October 2008 and entered the Earth's atmosphere the next day, striking a remote area of northern Sudan. It was the first time that a meteoroid had been observed in space and tracked prior to impacting Earth.[10]

Meteor


A Leonid meteor, seen in the 2009 Leonid meteor shower.

Multiple separately occurring meteors photographed over an extended exposure time during a meteor shower.

A meteor or "shooting star" is the passage of a meteoroid or micrometeoroid into the Earth's atmosphere, incandescent from air friction and shedding glowing material in its wake sufficiently to create a visible streak of light.[20][10] Meteors typically occur in the mesosphere at altitudes between 76 to 100 km (47 to 62 mi).[21] The root word meteor comes from the Greek meteōros, meaning "high in the air."[20]

Millions of meteors occur in the Earth's atmosphere daily. Most meteoroids that cause meteors are about the size of a grain of sand. Meteors may occur in showers, which arise when the Earth passes through a stream of debris left by a comet, or as "random" or "sporadic" meteors, not associated with a specific stream of space debris. A number of specific meteors have been observed, largely by members of the public and largely by accident, but with enough detail that orbits of the meteoroids producing the meteors have been calculated. All of the orbits passed through the asteroid belt.[22] The atmospheric velocities of meteors result from the movement of Earth around the Sun at about 30 km/s (18 miles/second),[23] the orbital speeds of meteoroids, and the gravity well of Earth.

Meteors become visible between about 75 to 120 km (47 to 75 mi) above the Earth. They usually disintegrate at altitudes of 50 to 95 km (31 to 59 mi).[24] Meteors have roughly a fifty percent chance of a daylight (or near daylight) collision with the Earth. Most meteors are, however, observed at night, when darkness allows fainter objects to be recognised. For bodies with a size scale larger than (10 cm to several meters) meteor visibility is due to the atmospheric ram pressure (not friction) that heats the meteoroid so that it glows and creates a shining trail of gases and melted meteoroid particles. The gases include vaporized meteoroid material and atmospheric gases that heat up when the meteoroid passes through the atmosphere. Most meteors glow for about a second. A relatively small percentage of meteoroids hit the Earth's atmosphere and then pass out again: these are termed Earth-grazing fireballs (for example The Great Daylight 1972 Fireball). The visible light produced by a meteor may take on various hues, depending on the chemical composition of the meteoroid, and the speed of its movement through the atmosphere. As layers of the meteoroid abrade and ionize, the color of the light emitted may change according to the layering of minerals. Colors of meteors depend on the relative influence of the metallic content of the meteoroid versus the superheated air plasma, which its passage engenders:[25]
  • Orange-yellow (sodium)
  • Yellow (iron)
  • Blue-green (magnesium)
  • Violet (calcium)
  • Red (atmospheric nitrogen and oxygen)

Fireball


Reported Fireballs[26]
Year #
2013 3556
2012 2326
2011 1629
2010 948
2009 692
2008 726
A fireball is a brighter-than-usual meteor. The International Astronomical Union defines a fireball as "a meteor brighter than any of the planets" (magnitude −4 or greater).[27] The International Meteor Organization (an amateur organization that studies meteors) has a more rigid definition. It defines a fireball as a meteor that would have a magnitude of −3 or brighter if seen at zenith. This definition corrects for the greater distance between an observer and a meteor near the horizon. For example, a meteor of magnitude −1 at 5 degrees above the horizon would be classified as a fireball because if the observer had been directly below the meteor it would have appeared as magnitude −6.[28] For 2013 there were 3556 fireballs recorded at the American Meteor Society.[29] There are probably more than 500,000 fireballs a year,[30] but most will go unnoticed because most will occur over the ocean and half will occur during daytime.

Fireballs reaching magnitude −14 or brighter are called bolides.[31] The IAU has no official definition of "bolide", and generally considers the term synonymous with "fireball". Astronomers often use "bolide" to identify an exceptionally bright fireball, particularly one that explodes (sometimes called a detonating fireball). It may also be used to mean a fireball which creates audible sounds. In the late twentieth century, bolide has also come to mean any object that hits the Earth and explodes, with no regard to its composition (asteroid or comet).[32] The word bolide comes from the Greek βολίς (bolis) [33] which can mean a missile or to flash. If the magnitude of a bolide reaches −17 or brighter it is known as a superbolide.[31][34]

Atmospheric remains of meteor passage

Entry of meteoroids into the Earth's atmosphere produces three main effects: ionization of atmospheric molecules, dust that the meteoroid sheds, and the sound of passage.

During the entry of a meteoroid or asteroid into the upper atmosphere, an ionization trail is created, where the molecules in the upper atmosphere are ionized by the passage of the meteor. Such ionization trails can last up to 45 minutes at a time. Small, sand-grain sized meteoroids are entering the atmosphere constantly, essentially every few seconds in any given region of the atmosphere, and thus ionization trails can be found in the upper atmosphere more or less continuously. When radio waves are bounced off these trails, it is called meteor burst communications. Meteor radars can measure atmospheric density and winds by measuring the decay rate and Doppler shift of a meteor trail. Most meteoroids burn up when they enter the atmosphere. The left-over debris is called meteoric dust or just meteor dust. Meteor dust particles can persist in the atmosphere for up to several months. These particles might affect climate, both by scattering electromagnetic radiation and by catalyzing chemical reactions in the upper atmosphere.[35] Larger meteors can enter dark flight after deceleration where the meteorite (or fragments) fall at terminal velocity.[36] Dark flight starts when the meteorite(s) decelerate to about 2–4 km/s (4,500–8,900 mph).[37] Larger fragments will fall further down the strewn field.

Sounds of meteors

Sound generated by a meteor in the upper atmosphere, such as a sonic boom, typically arrives many seconds after the visual light from a meteor disappears. Occasionally, as with the Leonid meteor shower of 2001,"crackling", "swishing", or "hissing" sounds have been reported,[38] occurring at the same instant as a meteor flare. Similar sounds have also been reported during intense displays of Earth's auroras.[39][40][41][42]

Sound recordings made under controlled conditions in Mongolia in 1998 support the contention that the sounds are real.[43]

Theories on the generation of these sounds may partially explain them. For example, scientists at NASA suggested that the turbulent ionized wake of a meteor interacts with the Earth's magnetic field, generating pulses of radio waves. As the trail dissipates, megawatts of electromagnetic energy could be released, with a peak in the power spectrum at audio frequencies. Physical vibrations induced by the electromagnetic impulses would then be heard if they are powerful enough to make grasses, plants, eyeglass frames, and other conductive materials vibrate.[44][45][46][47] This proposed mechanism, although proven to be plausible by laboratory work, remains unsupported by corresponding measurements in the field.

Seasonal variation in meteor sightings

A meteor shower is the result of an interaction between a planet, such as Earth, and streams of debris from a comet or other source. The passage of the Earth through cosmic debris from comets and other sources is a recurring event in many cases. Comets can produce debris by water vapor drag, as demonstrated by Fred Whipple in 1951,[48] and by breakup. Each time a comet swings by the Sun in its orbit, some of its ice vaporizes and a certain amount of meteoroids will be shed. The meteoroids spread out along the entire orbit of the comet to form a meteoroid stream, also known as a "dust trail" (as opposed to a comet's "dust tail" caused by the very small particles that are quickly blown away by solar radiation pressure).
The frequency of fireball sightings increases by about 10-30% during the weeks of vernal equinox.[49] Even meteorite falls are more common during the northern hemisphere's spring season. Although this phenomenon has been known for quite some time, the reason behind the anomaly is not fully understood by scientists. Some researchers attribute this to an intrinsic variation in the meteoroid population along Earth's orbit, with a peak in big fireball-producing debris around spring and early summer. Research is in progress for mapping the orbits of the meteors to gain a better understanding of the phenomenon.[50]

History

Although meteors have been known since ancient times, they were not known to be an astronomical phenomenon until early in the 19th century. Prior to that, they were seen in the West as an atmospheric phenomenon, like lightning, and were not connected with strange stories of rocks falling from the sky. Thomas Jefferson wrote "I would more easily believe that (a) Yankee professor would lie than that stones would fall from heaven."[51] He was referring to Yale chemistry professor Benjamin Silliman's investigation of an 1807 meteorite that fell in Weston, Connecticut.[51] Silliman believed the meteor had a cosmic origin, but meteors did not attract much attention from astronomers until the spectacular meteor storm of November 1833.[52] People all across the eastern United States saw thousands of meteors, radiating from a single point in the sky. Astute observers noticed that the radiant, as the point is now called, moved with the stars, staying in the constellation Leo.[53]

The astronomer Denison Olmsted made an extensive study of this storm, and concluded it had a cosmic origin. After reviewing historical records, Heinrich Wilhelm Matthias Olbers predicted the storm's return in 1867, which drew the attention of other astronomers to the phenomenon. Hubert A. Newton's more thorough historical work led to a refined prediction of 1866, which proved to be correct.[52] With Giovanni Schiaparelli's success in connecting the Leonids (as they are now called) with comet Tempel-Tuttle, the cosmic origin of meteors was now firmly established. Still, they remain an atmospheric phenomenon, and retain their name "meteor" from the Greek word for "atmospheric".[54]

Notable meteors

1992—Peekskill, New York
The Peekskill Meteorite was filmed on October 9, 1992 by at least 16 independent videographers.[55] Eyewitness accounts indicate the fireball entry of the Peekskill meteorite started over West Virginia at 23:48 UT (±1 min). The fireball, which traveled in a northeasterly direction, had a pronounced greenish colour, and attained an estimated peak visual magnitude of −13. During a luminous flight time that exceeded 40 seconds the fireball covered a ground path of some 700 to 800 km.[56] One meteorite recovered at Peekskill, New York, for which the event and object gained their name, had a mass of 12.4 kg (27 lb) and was subsequently identified as an H6 monomict breccia meteorite.[57]
The video record suggests that the Peekskill meteorite had several companions over a wide area. The companions are unlikely to be recovered in the hilly, wooded terrain in the vicinity of Peekskill.
2009—Bone, Indonesia
A large fireball was observed in the skies near Bone, Indonesia on October 8, 2009. This was thought to be caused by an asteroid approximately 10 meters in diameter. The fireball contained an estimated energy of 50 kilotons of TNT, or about twice the Nagasaki atomic bomb. No injuries were reported.[58]
2009—Southwestern US
A large bolide was reported on 18 November 2009 over southeastern California, northern Arizona, Utah, Wyoming, Idaho and Colorado. At 00:07 local time a security camera at the high altitude W. L. Eccles Observatory (2930 m above sea level) recorded a movie of the passage of the object to the north.[59][60] Of particular note in this video is the spherical "ghost" image slightly trailing the main object (this is likely a lens reflection of the intense fireball), and the bright fireball explosion associated with the breakup of a substantial fraction of the object. An object trail can be seen to continue northward after the bright fireball event. The shock from the final breakup triggered seven seismological stations in northern Utah; a timing fit to the seismic data yielded a terminal location of the object at 40.286 N, -113.191 W, altitude 27 km.[61] This is above the Dugway Proving Grounds, a closed Army testing base.
2013—Chelyabinsk Oblast, Russia
Over 1,500 people were injured mostly by glass from shattered windows caused by a meteoroid explosion during meteor event in Chelyabinsk Oblast, Russia on 15 February 2013, when a meteoroid exploded approx 25 to 30 km above the environs of Chelyabinsk, Russia. An increasingly bright streak was observed during morning daylight with a large contrail lingering behind. At no less than 1 minute and up to at least 3 minutes after the object peaked in intensity (depending on distance from trail), a large concussive blast was heard that shattered windows and set-off car alarms, which was followed by a number of smaller explosions.[62] Scientists at NASA's Jet Propulsion Laboratory (JPL) estimated the meteoroid to have an initial mass of 11,000 tonnes, and to measure approximately 17 to 20 metres across, as it entered the earth's atmosphere.[63][64]

Gallery of meteors

Meteorite and meteoroid impacts

A meteorite is a portion of a meteoroid or asteroid that survives its passage through the atmosphere and hits the ground without being destroyed.[65] Meteorites are sometimes, but not always, found in association with hypervelocity impact craters; during energetic collisions, the entire impactor may be vaporized, leaving no meteorites. Geologists use the term, "bolide", in a different sense from astronomers to indicate a very large impactor. For example, the USGS uses the term to mean a generic large crater-forming projectile in a manner "to imply that we do not know the precise nature of the impacting body ... whether it is a rocky or metallic asteroid, or an icy comet for example".[66]

Meteoroids also hit other bodies in the solar system. On such stony bodies as the moon or Mars with no or little atmosphere, they leave enduring craters.

Frequency of large meteoroid collisions with Earth

The diameter of the biggest impactor to hit Earth on any given day is likely to be about 40 centimeters (16 inches) in a given year about 4 meters, and in a given century about 20 meters. These statistics are obtained by the following:
Over at least the range from 5 centimeters (2.0 inches) to roughly 300 meters (980 feet), the rate at which Earth receives meteors obeys a power-law distribution as follows:
N(>D) = 37 D^{-2.7}\
where N (>D) is the expected number of objects larger than a diameter of D meters to hit Earth in a year.[67] This is based on observations of bright meteors seen from the ground and space, combined with surveys of near Earth asteroids. Above 300 meters in diameter, the predicted rate is somewhat higher, with a two-kilometer asteroid (one million-megaton TNT equivalent) every couple of million years — about 10 times as often as the power-law extrapolation would predict.

Two tektites, molten terrestrial ejecta from a meteorite impact.

Meteorite and meteoroid impact craters

Meteoroid collisions with solid Solar System objects, including the Moon, Mercury, Callisto, Ganymede and most small moons and asteroids, create impact craters, which are the dominant geographic features of many of those objects. On other planets and moons with active surface geological processes, such as Earth, Venus, Mars, Europa, Io and Titan, visible impact craters may become eroded, buried or transformed by tectonics over time. In early literature, before the significance of impact cratering was widely recognised, the terms cryptoexplosion or cryptovolcanic structure were often used to describe what are now recognised as impact-related features on Earth.[68] Molten terrestrial material ejected from a meteorite impact crater can cool and solidify into an object known as a tektite. These are often mistaken for meteorites.

Gallery of meteorites


Probabilistic programming

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