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Topic Review
Principle of Least Action
The principle of least action – or, more accurately, the principle of stationary action – is a variational principle that, when applied to the action of a mechanical system, can be used to obtain the equations of motion for that system. It was historically called "least" because its solution requires finding the path of motion in space that has the least value. The principle can be used to derive Newtonian, Lagrangian and Hamiltonian equations of motion, and even general relativity (see Einstein–Hilbert action). In relativity, a different action must be minimized or maximized. The classical mechanics and electromagnetic expressions are a consequence of quantum mechanics. The stationary action method helped in the development of quantum mechanics. In 1933, the physicist Paul Dirac demonstrated how this principle can be used in quantum calculations by discerning the quantum mechanical underpinning of the principle in the quantum interference of amplitudes. Subsequently Julian Schwinger and Richard Feynman independently applied this principle in quantum electrodynamics. The principle remains central in modern physics and mathematics, being applied in thermodynamics, fluid mechanics, the theory of relativity, quantum mechanics, particle physics, and string theory and is a focus of modern mathematical investigation in Morse theory. Maupertuis' principle and Hamilton's principle exemplify the principle of stationary action. The action principle is preceded by earlier ideas in optics. In Ancient Greece , Euclid wrote in his Catoptrica that, for the path of light reflecting from a mirror, the angle of incidence equals the angle of reflection. Hero of Alexandria later showed that this path was the shortest length and least time. Scholars often credit Pierre Louis Maupertuis for formulating the principle of least action because he wrote about it in 1744 and 1746. However, Leonhard Euler discussed the principle in 1744,[ and evidence shows that Gottfried Leibniz preceded both by 39 years.
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  • 29 Sep 2022
Topic Review
Project Alpha
Project Alpha was an effort by magician James Randi to test the quality of scientific rigor of a well-known test of paranormal phenomena. In the late 1970s, Randi contacted the newly established McDonnell Laboratory for Psychical Research ("MacLab") with suggestions on how to conduct tests for paranormal phenomena. At the same time, two teenage boys (Steve Shaw, later known as Banachek, and Mike Edwards) independently contacted the McDonnell Laboratory and volenteered as subjects for such tests from 1979 to 1982. They quickly proved to exhibit a range of paranormal abilities far and away better than the other subjects of the experiment. The lab began leaking reports of the pair's capabilities, which were in fact simple magic tricks. When rumors of the test subjects' connection to Randi reached Peter Phillips, head of the MacLab, he instituted tighter protocols for the experiments; the two subjects' results declined sharply. In 1983, Randi held a press conference to expose the deception In the wake of Project Alpha, there were a number of controversies about the ethics of interference in scientific research and the validity of paranormal research as it then existed. It remains a watershed event in the field of parapsychology.
  • 610
  • 28 Nov 2022
Topic Review
Proper Name
In the philosophy of language, a proper name – examples include a name of a specific person or place – is a name which ordinarily is taken to uniquely identify its referent in the world. As such it presents particular challenges for theories of meaning, and it has become a central problem in analytic philosophy. The common-sense view was originally formulated by John Stuart Mill in A System of Logic (1843), where he defines it as "a word that answers the purpose of showing what thing it is that we are talking about but not of telling anything about it". This view was criticized when philosophers applied principles of formal logic to linguistic propositions. Gottlob Frege pointed out that proper names may apply to imaginary and nonexistent entities, without becoming meaningless, and he showed that sometimes more than one proper name may identify the same entity without having the same sense, so that the phrase "Homer believed the morning star was the evening star" could be meaningful and not tautological in spite of the fact that the morning star and the evening star identifies the same referent. This example became known as Frege's puzzle and is a central issue in the theory of proper names. Bertrand Russell was the first to propose a descriptivist theory of names, which held that a proper name refers not to a referent, but to a set of true propositions that uniquely describe a referent – for example, "Aristotle" refers to "the teacher of Alexander the Great". Rejecting descriptivism, Saul Kripke and Keith Donnellan instead advanced causal-historical theories of reference, which hold that names come to be associated with individual referents because social groups who link the name to its reference in a naming event (e.g. a baptism), which henceforth fixes the value of the name to the specific referent within that community. Today a direct reference theory is common, which holds that proper names refer to their referents without attributing any additional information, connotative or of sense, about them.
  • 641
  • 21 Oct 2022
Topic Review
Proximal Sensing
Proximal sensing techniques denote several non-invasive technologies in which the target objects—in the present context, cultural heritage manufacts—are placed within a short distance of the sensor, detector or camera lens collecting the data. Depending on the technology employed and the study purpose, the sensors/detectors work in different portions of the electromagnetic spectrum, from X-ray to ultraviolet (UV), from visible (VIS) to infrared (IR) and, further, from microwave to radio.
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  • 02 Jun 2023
Topic Review
Pseudophilosophy
Pseudophilosophy (or cod philosophy) is a philosophical idea or system which does not meet an expected set of standards.
  • 1.9K
  • 22 Nov 2022
Topic Review
Psychological Effects of Digital Companies’ Employees during COVID-19
The ways people use words online can furnish psychological processes about their beliefs, fears, thinking patterns, and so on. Extracting from online employees’ reviews on the workplace community websites, the psychological effects of employees during the phase of the COVID-19 pandemic can be quantified. Affected by the pandemic after 2020, although the overall evaluation of digital companies employees was tending to be better, were work–life balance, culture and values, senior management, career opportunities, and salary and benefits, which were still getting worse. 
  • 637
  • 07 Mar 2022
Topic Review
Puppets for Autistic Teenagers
The benefits of puppetry for children in therapeutic and educational contexts are well established, with puppets shown to have improved children’s learning, their relationships with adults and other children, and their self-confidence and communication. Adding to this research is an emerging body of evidence that shows the many benefits of puppets for autistic children both as a form of early intervention and as a teaching strategy in the early years of schooling.
  • 515
  • 01 Nov 2023
Topic Review
Rajan Zed Prayer Protest
The Rajan Zed prayer protest were events surrounding the first official offering of a Hindu prayer at the United States Senate. On July 12, 2007, Rajan Zed, a Hindu cleric and a noted leader in Interfaith Relations from the Indian Association of Northern Nevada based in Reno, appeared at the United States Senate as its guest Chaplain.
  • 994
  • 25 Nov 2022
Topic Review
Rangtong-Shentong
Rangtong and shentong are two distinctive views on emptiness (sunyata) and the two truths doctrine within Tibetan Buddhism. Rangtong (Tibetan: རང་སྟོང་, Wylie: rang stong; "empty of self-nature") is a philosophical term in Tibetan Buddhism that is used to distinguish the majority Madhyamaka teaching on the meaning of śūnyatā or "emptiness", namely that all phenomena are empty of an enduring and/or unchanging essence or "self," and that this emptiness is not an absolute reality, but a mere nominal characterisation of phenomena. It is related to the prasangika approach, which argues that no syllogistic forms of reasoning should be used to debate the notion of inherent existence, but only arguments which show the logical implications and absurdity of positions based upon inherent existence. This position is the mainstream Gelugpa interpretation of Madhyamaka, one of the main Mahayana schools, which dominates Vajrayana Buddhism. Shentong (Tibetan: གཞན་སྟོང་, Wylie: gzhan stong, Lhasa dialect: [ɕɛ̃̀tṍŋ], also transliterated zhäntong or zhentong; literally "other-emptiness") is a position within Tibetan Madhyamaka. It applies śūnyatā in a specific way, agreeing that relative reality is empty of self-nature, but stating that absolute reality (Paramarthasatya)[note 1] is "non-dual Buddhajnana"[note 2] and "empty" (Wylie: stong) only of "other," (Wylie: gzhan) relative phenomena, but is itself not empty and "truly existing." This absolute reality is described by positive terms, an approach which helps "to overcome certain residual subtle concepts" and "the habit [...] of negating whatever experience arises in his/her mind." It destroys false concepts, as does prasangika, but it also alerts the practitioner "to the presence of a dynamic, positive Reality that is to be experienced once the conceptual mind is defeated." Shentong was systematized and articulated under that name by Dolpopa Sherab Gyaltsen (1292–1361), who identified absolute reality with the Buddha-nature. Shentong was suppressed by the dominant Gelug school for several hundred years, equally for political reasons as doctrinal reasons. In 1658, the Gelug authorities banned the Jonang school for political reasons, forcibly converting its monks and monasteries to the Gelug school, as well as banning shentong philosophy and books, thus making the rangtong position the overwhelmingly majority one in Tibetan Buddhism. After this suppression various shentong views were propagated mainly by Karma Kagyu and Nyingma lamas. The 19th century saw a revival of Shentong-views, and continued with the Rimé movement. Nowadays Shentong is present primarily as the main philosophical theory of the Jonang school, although it is also taught by the Sakya and Kagyu schools, where it is identified with centerless awareness.
  • 1.0K
  • 20 Oct 2022
Biography
Ravi Shankar
Ravi Shankar (born 13 May 1956) is an Indian yoga guru,[1] a spiritual leader. He is frequently referred to as "Sri Sri" (honorific), Guru ji, or Gurudev.[2] From around the mid 1970s, he worked as an apprentice under Mahesh Yogi, the founder of Transcendental Meditation. In 1981, he split from the Transcendental Meditation (TM) and founded the Art of Living Foundation.[3] Ravi Shankar was bo
  • 1.6K
  • 30 Nov 2022
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