Datasets:

konsman
/

quantum-physics-0.6

+{"text": "vacuum expectation value | quantum field theory | in quantum field theory the vacuum expectation value ( also called condensate or simply vev ) of an operator is its average, expected value in the vacuum. the vacuum expectation value of an operator o is usually denoted by. one of the best known examples of an observable physical effect that results from the vacuum expectation value of an operator is the casimir effect. - the higgs field has a vacuum expectation value of 246 gev ( amsler, c. ; doser, m. ; antonelli, m. ; asner, d. ; babu, k. ; baer, h. ; band, h. ; barnett, r. et al. ( 2008 ). \" review of particle physics \". physics letters b 667 : 1. doi : 10. 1016 / j. physletb. 2008. 07. 018. ) this nonzero value underlies the higgs mechanism of the standard model. - the chiral condensate in quantum chromodynamics, about a factor of a thousand smaller than the above, gives a large effective mass to quarks, and distinguishes between phases of quark matter. this underlies the bulk of the mass of most hadrons. - the gluon condensate in quantum chromodynamics may also be partly responsible for masses of hadrons. the observed lorentz invariance of space - time allows only the formation of condensates which are lorentz scalars and have vanishing charge. thus fermion condensates must be of the form, where \u03c8 is the fermion field. similarly a tensor field, g\u03bc\u03bd, can only have a scalar expectation value such as. - wightman axioms and correlation function ( quantum field theory ) - vacuum energy or dark energy - spontaneous symmetry breaking | this quantum mechanics - related article is a stub. you can help wikipedia by expanding it. |", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6969356218982887, "token_count": 399, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:2cd5024e-3744-4b88-a7b7-5bb7e567484c>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:54:44.719344"}
+{"text": "what is meant by \u201c seeing \u201d in this context? seeing \u2014 true seeing, genuine seeing \u2014 is seeing that transcends the ordinary experience of seeing. the ordinary experience of seeing gets lost in conventions. people scarcely notice the things around them. as soon as a thing is seen, it is immediately assigned to some familiar category and no more attention is paid to. in this way, seeing becomes an exercise in identification, and identification draws upon a familiar conceptual scheme, a weltanschauung in which there is a place for everything and everything is to be found in its place. such \u201c seeing \u201d is little more than an excuse to dismiss things with a glance, to ignore the world. to see is to forget the name of the thing one sees. this encapsulation of an extraordinary kind of seeing immediately suggests another kind of seeing, the kind of seeing that is ordinary seeing. what is ordinary experience? what defines the mundane? there is a passage from a posthumously published fragment of wittgenstein that comes to mind : \u201c nothing could be more remarkable than seeing a man who thinks he is unobserved performing some quite simple everyday activity. let us imagine a theatre ; the curtain goes up and we see a man alone in a room, walking up and down, lighting a cigarette, sitting down, etc. so that suddenly we are observing a human being from outside in a way that ordinarily we can never observe ourselves ; it would be like watching a chapter of biography with our own eyes, \u2014 surely this would be uncanny and wonderful at the same time. we should be observing something more wonderful than anything a playwright could arrange to be acted or spoken on the stage : life itself. \u2014 but then we do see this every day without its making the slightest impression on us! true enough, but we do not see it from that point of view. \u201d wittgenstein here observes an unexpected coincidence of ordinary and extraordinary experience. for wittgenstein, extraordinary seeing is simply a shift in perspective away from ordinary seeing. and ordinary seeing is not an excuse to ignore the world, as i wrote above, but is an immersion in the world. the wittgensteinian conception of extraordinary experience is immanent ; wittgenstein rejects the transcendent as a source of the extraordinary. i can imagine someone not getting the point of wittgenstein \u2019 s example ; it is more in the nature of a parable than an argument. and like most parables, it is inherently ambiguous. wittgens", "subdomain_id": "subdomain_quantum_optics", "similarity_score": 0.6100692954922964, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:94f22f8e-c218-4d84-bbff-a7193cd276f6>", "chunk_index": 24, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:54:44.925362"}
+{"text": "doe openness : human radiation experiments : roadmap to the project 3 the positively charged mass within an atom, composed of neutrons and protons and possessing most of the mass but occupying only a small fraction of the volume of the atom. physicists sought to release enormous quantities of energy by splitting the nucleus of a hydrogen atom, generating a chain reaction. 5for more than a half - century, herbert m. parker was a leading force in radiological physics. he was codeveloper of a systematic dosimetry scheme for implant therapy and the innovative proposer of radiological units with unambiguous physical and biological bases. he made seminal contributions to the development of scientifically based radiation protection standards and helped the hanford laboratories achieve prominence in radiation biology, radioactive waste disposal, and characterization of environmental radioactivity. for his inside view of the maturation of medical physics and the birth and evolution of the parallel field of health physics, see r. l. kathren, r. w. baalman, and w. j. bair ; herbert m. parker : publications and other contributions to radiological and health physics ; columbus, ohio : battelle press ; 1986 ; isbn 0 - 935470 - 36 - 0 ; 864 pages. 6a unit of radiation dosage equal to the amount of ionizing radiation required to produce one electrostatic unit of charge of either sign per cubic centimeter of air ; named for wilhelm konrad roentgen, 18451923, german physicist, who discovered x rays in 1895 and received the nobel prize in physics 11a related account of the work and personalities of this instrumentation group can be found in \" determining safe doses for ionizing radiation at chicago ( 1943 ) \" and \" developing new dosimetry instrumentation \" in doe / eh - 0475, human radiation studies : remembering the early years ; oral history of health physicist karl z. morgan, ph. d. ( june 1995 ). 12e. i. du pont de nemours and company constructed and operated the hanford site in washington state from 1943 to 1946 for the manhattan project. the x - 10 facility in oak ridge, a pilot reactor and plutonium production plant, was also built by du pont. du pont and the harshaw chemical company of cleveland produced uranium hexafluoride on a scale sufficient to keep the vital isotope separation research going. 13during world war ii, the manhattan project had built a vast complex of highly classified facilities in and near oak ridge, tennessee, to process uranium", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6342074449007788, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:24f2c5e2-1e73-42cf-be7a-4b2c0defe1dd>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:54:45.073002"}
+{"text": "source : richard rhodes ; the making of the atomic bomb ; new york : simon and schuster ; 1986, p. 547 ) 31according to karl morgan in his oral history, dr. wollan spent most of his time developing fiber dosimeterssmall electrometers with a fiber that moves across the scale proportional to the dose administered to the instrument. 32karl morgan recalls, in \" creating a health physics division ( 194344 ) \" : \" the nobel prize in physics was given to one of [ wollan ' s ] students there who he educated and trained in neutron diffraction techniques. had he lived and were he alive today, he would be the principal recipient of that nobel prize in physics. of course, that has been acknowledged. \" ( morgan transcript, doe / eh - 0475 ) 33a noble gas ; symbol xe. the isotope 135xe is created as a fission product in some reactors. xenon - 135 nuclei absorb neutrons. the presence of 135xe in a reactor will slow down the chain reaction, until the isotope decays. this effect is known as \" xenon poisoning. \" 34the national laboratory near santa fe, new mexico, where nuclear bombs were assembled before and during the cold war ; operated by the university of california for the u. s. department of energy. since world war ii, los alamos has been a research and development center for nuclear weapon designs and other scientific studies. 36a professor of radiology at the university of rochester ( rochester, new york ), site of research involving plutonium and human subjects, dr. warren left rochester to work on the manhattan project in oak ridge as head of the medical section and headed an intramedical advisory committee. after world war ii, he became dean of the university of california, los angeles medical school. 37in 1943 friedell became the executive officer of the manhattan engineer district medical division. for the transcript of the january 28, 1995 interview with friedell, see doe / eh - 0466, human radiation studies : remembering the early years ; oral history of radiologist hymer l. friedell, m. d., ph. d. ( july 1995 ). 42a millirem is one - thousandth of a rem. a rem is a unit of radiation dose equivalent, or \" rads times the quality factor, q. \" the limits for occupational exposure of workers to radiation range from 2 to 5 rem per year for most countries. 43scientists at", "subdomain_id": "subdomain_quantum_metrology", "similarity_score": 0.6062656871561883, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:24f2c5e2-1e73-42cf-be7a-4b2c0defe1dd>", "chunk_index": 2, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:54:45.075327"}
+{"text": "scientists produce transparent, light - harvesting material - james e. rickman - communications office - ( 505 ) 665 - 9203 breakthrough could lead to solar - power - generating windows los alamos, new mexico, november 3, 2010 \u2014 scientists at the u. s. department of energy ' s los alamos national laboratory and brookhaven national laboratory have fabricated transparent thin films capable of absorbing light and generating electric charge over a relatively large area. the material, described in the journal chemistry of materials, could be used in development of transparent solar panels. \" potentially, with future refinement of this technology, windows in a home or office could generate solar power, \" said hsing - lin wang, a co - corresponding author of the paper and a researcher in the chemistry division at los alamos. the new material is a semiconducting polymer spiked with \" fullerenes \" \u2014 soccer - ball - shaped, cage - like molecules composed of 60 carbon atoms. when applied to a surface under carefully controlled conditions, the material self - assembles in a repeating pattern of micron - sized hexagonal - shaped cells resembling a honeycomb. researchers created reproducible films of up to several square millimeters in area. the material is largely transparent because the polymer chains pack together at the edges of the hexagons, remaining loosely packed and relatively thin across the centers. the densely packed edges strongly absorb light and could facilitate electrical conductivity, according to the researchers. \" though such honeycomb - patterned thin films have previously been made using conventional polymers like polystyrene, this is the first report of such a material that blends semiconductors and fullerenes to absorb light and efficiently generate charge and charge separation, \" said lead scientist mircea cotlet, a physical chemist at brookhaven ' s center for functional nanomaterials ( cfn ). perfecting large - scale application of the material could enable a wide range of practical applications, such as energy - generating solar windows, or new types of optical displays. the researchers fabricated the thin films by creating a flow of micron - sized ( about 1 / 100th the width of a human hair ) water droplets across a thin layer of the polymer - fullerene solution. the droplets assembled themselves into arrays within the polymer solution. once the water evaporated, the scientists were left with thin films of polymer in a honeycomb pattern. the deposition method is cost effective and potentially scalable to industrial size. the research was supported at los alamos by the doe office of science.", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6730257933953198, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:6f6cfa7b-3694-4cd5-8e36-cecebaf4f69c>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:54:45.173980"}
+{"text": "the water evaporated, the scientists were left with thin films of polymer in a honeycomb pattern. the deposition method is cost effective and potentially scalable to industrial size. the research was supported at los alamos by the doe office of science. the work was also carried out in part at office of science user facilities cfn and the center for integrated nanotechnologies. the brookhaven team included mircea cotlet, zhihua xu, and ranjith krishna pai. collaborators from los alamos include hsing - lin wang and hsinhan tsai, who are both users of the cfn facilities at brookhaven, andrew dattelbaum from the center for integrated nanotechnologies, and project leader andrew shreve of the materials physics and applications division. the center for functional nanomaterials at brookhaven national laboratory and the center for integrated nanotechnologies are two of the five doe nanoscale science research centers ( nsrcs ), premier national user facilities for interdisciplinary research at the nanoscale. together the nsrcs comprise a suite of complementary facilities that provide researchers with state - of - the - art capabilities to fabricate, process, characterize and model nanoscale materials, and constitute the largest infrastructure investment of the national nanotechnology initiative. the nsrcs are located at doe ' s argonne, brookhaven, lawrence berkeley, oak ridge and sandia and los alamos national laboratories. for more information aboutthe doe nsrcs, please visit http : / / nano. energy. gov. note to editors and reporters : the research team ' s paper can be found at : http : / / pubs. acs. org / doi / abs / 10. 1021 / cm102160m los alamos national laboratory, a multidisciplinary research institution engaged in strategic science on behalf of national security, is operated by los alamos national security, llc, a team composed of bechtel national, the university of california, the babcock & wilcox company, and urs for the department of energy ' s national nuclear security administration. los alamos enhances national security by ensuring the safety and reliability of the u. s. nuclear stockpile, developing technologies to reduce threats from weapons of mass destruction, and solving problems related to energy, environment, infrastructure, health, and global security concerns.", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.64067413570896, "token_count": 484, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:6f6cfa7b-3694-4cd5-8e36-cecebaf4f69c>", "chunk_index": 1, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:54:45.174947"}
+{"text": "? \u201d make sense for a reductionist, but questions such as \u201c what is human nature? \u201d and \u201c how should we live? \u201d \u2014 if they have any meaning at all \u2014 have to be reframed as questions about moving or material physical causes. now let \u2019 s consider a nonreductionist alternative : there are a great many different kinds of beings, with different natures. reality is messy and diverse, with lumps and gaps, peaks and valleys. but what would account for these differences in kind? the traditional western answer is that there is a highest being who is responsible for giving created beings their natures and their very existence. today this traditional answer doesn \u2019 t seem as convincing as it once did. as nietzsche complains in \u201c twilight of the idols \u201d ( 1889 ), in the traditional view \u201c the higher is not allowed to develop from the lower, is not allowed to have developed at all. \u201d but darwin has helped us see that new species can develop from simpler ones. nietzsche abandoned not just traditional creationism but god as well ; others find evolution compatible with monotheism. the point for our present purposes is that nietzsche is opposing not only the view that things require a top - down act of creation, but also reductionists who flatten everything down to the same level ; he suggests that reality has peaks and valleys, and the higher emerges from the lower. some call such a view emergentism. an emergentist account of reality could go something like this. over billions of years, increasingly complex beings have evolved from simpler ones. but there isn \u2019 t just greater complexity \u2014 new kinds of beings emerge, living beings, and new capacities : feeling pleasure and pain, instead of just interacting chemically and physically with other things ; becoming aware of other things and oneself ; and eventually, human love, freedom and reason. reality isn \u2019 t flat. higher beings continue to have lower dimensions. people are still animals, and animals are still physical things \u2014 throw me out a window and i \u2019 ll follow the law of gravity, with deleterious consequences for my freedom and reason. so we can certainly study ourselves as biological, chemical and physical beings. we can correctly reconstruct the moving causes that brought us about, and analyze our material causes. however, these findings aren \u2019 t enough for a full understanding of what humans are. we must also understand our formal cause \u2014 what \u2019 s distinctive about us in our evolved state. thanks to the process of emergence, we have become something more than other animals.", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.606553227677835, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:e32664bc-7960-4c74-8699-99a672164295>", "chunk_index": 2, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:54:45.438433"}
+{"text": "this is a clear and concise treatise on phase transition, written by leo kadanoff, one of the leading figures today in condensed matter physics. even if you don ' t understand the mathematics, the written description of phase transition is very well presented, so i highly recommend this for everyone to read. abstract : this paper looks at the early theory of phase transitions. it considers a group of related concepts derived from condensed matter and statistical physics. the key technical ideas here go under the names of \" singularity \", \" order parameter \", \" mean field theory \", and \" variational method \". in a less technical vein, the question here is how can matter, ordinary matter, support a diversity of forms. we see this diversity each time we observe ice in contact with liquid water or see water vapor, \" steam \", come up from a pot of heated water. different phases can be qualitatively different in that walking on ice is well within human capacity, but walking on liquid water is proverbially forbidden to ordinary humans. these differences have been apparent to humankind for millennia, but only brought within the domain of scientific understanding since the 1880s. a phase transition is a change from one behavior to another. a first order phase transition involves a discontinuous jump in a some statistical variable of the system. the discontinuous property is called the order parameter. each phase transitions has its own order parameter that range over a tremendous variety of physical properties. these properties include the density of a liquid gas transition, the magnetization in a ferromagnet, the size of a connected cluster in a percolation transition, and a condensate wave function in a superfluid or superconductor. a continuous transition occurs when that jump approaches zero. this note is about statistical mechanics and the development of mean field theory as a basis for a partial understanding of this phenomenon.", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.711447046160131, "token_count": 386, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:0ccff45f-bf53-4ad6-a679-cbd515f50430>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:54:45.514417"}
+{"text": "methods | statistics | clinical | educational | industrial | professional items | world psychology | religious experience ( sometimes known as a spiritual experience, sacred experience, or mystical experience ) is a subjective experience in which an individual reports contact with a transcendent reality, an encounter or union with the divine. a religious experience is most commonly known as an occurrence that is uncommon in the sense that it doesn \u2019 t fit in with the norm of everyday activities and life experiences, and its connection is with the individual \u2019 s perception of the divine. studying religious experience objectively is a difficult task, as it is entirely a subjective phenomenon. however, commonalities and differences between religious experiences have enabled scholars to categorize them for academic study many religious and mystical traditions see religious experiences as real encounters with god or gods, or real contact with other realities, while some hold that religious experience is an evolved feature of the human brain amenable to normal scientific study. differing religious traditions have described this fundamental religious experience in different ways : - nullification and absorption within god ' s infinite light ( chassidic schools of judaism ) - complete detachment from the world ( kaivalya in some schools of hinduism, including sankhya and yoga ; jhana in buddhism ) - liberation from the cycles of karma ( moksha in sikhism, jainism and hinduism, nirvana in buddhism ) - deep intrinsic connection to the world ( satori in mahayana buddhism, te in taoism ) - union with god ( henosis in neoplatonism and theosis in christianity, brahma - prapti or brahma - nirvana in hinduism ) - innate knowledge ( irfan and fitra in islam ) - experience of one ' s true blissful nature ( samadhi or svarupa - avirbhava in hinduism ) - liberating the individual to return to a natural state ( dionysian mysteries ) william james ' definition edit - transient - - the experience is temporary ; the individual soon returns to a \" normal \" frame of mind. - ineffable - - the experience cannot be adequately put into words. - noetic - - the individual feels that he or she has learned something valuable from the experience. - passive - - the experience happens to the individual, largely without conscious control. although there are activities, such as meditation ( see below ), that can make religious experience more likely, it is not something that can be turned on and off at will. norman habel ' s definition edit habel defines religious experiences as the structured way in which a", "subdomain_id": "subdomain_quantum_optics", "similarity_score": 0.6177744563990532, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:0eb6b0bb-851e-4b8f-be92-d9a65903708d>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:54:45.559518"}
+{"text": "ecstasy and possession are basically one and the same experience, ecstasy being merely one form which possession may take. the outward manifestation of the phenomenon is the same in that shamans appear to be possessed by spirits, act as their mediums, and even though they claim to have mastery over them, can lose that mastery ( lewis : 1986 ). mystical - - mystical experiences are in many ways the opposite of numinous experiences. in the mystical experience, all ' otherness ' disappear and the believer becomes one with the transcendent. the believer discovers that he or she is not distinct from the cosmos, the deity or the other reality, but one with it. zaehner has identified two distinctively different mystical experiences : natural and religious mystical experiences ( charlesworth : 1988 ). natural mystical experiences are, for example, experiences of the ' deeper self ' or experiences of oneness with nature. zaehner argues that the experiences typical of ' natural mysticism ' are quite different from the experiences typical of religious mysticism ( charlesworth : 1988 ). natural mystical experiences are not considered to be religious experiences because they are not linked to a particular tradition, but natural mystical experiences are spiritual experiences that can have a profound effect on the individual. spiritual awakening - - a spiritual awakening is a religious experience involving a realization or opening to a sacred dimension of reality. often a spiritual awakening has lasting effects upon one ' s life. the term \" spiritual awakening \" may be used to refer to any of a wide range of experiences including being born again, near - death experiences, and mystical experiences such as liberation and enlightenment. explanations of religious experience edit scientific studies on religious experience edit transpersonal psychology is a school of psychology that studies the transpersonal, self - transcendent or spiritual aspects of the human experience. the journal of transpersonal psychology describes transpersonal psychology as \" the study of humanity \u2019 s highest potential, and with the recognition, understanding, and realization of unitive, spiritual, and transcendent states of consciousness \" ( lajoie and shapiro, 1992 : 91 ). issues considered in transpersonal psychology include spiritual self - development, peak experiences, mystical experiences, systemic trance and other metaphysical experiences of living. u. s. psychologist and philosopher william james ( 1842 \u2013 1910 ) is regarded by most psychologists of religion as the founder of the field. his varieties of religious experience is considered to be the classic work in the field, and references to james ' ideas are common at professional conferences. james distinguished between institutional religion and personal religion. institutional religion refers", "subdomain_id": "subdomain_quantum_mechanics", "similarity_score": 0.603785160263911, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:0eb6b0bb-851e-4b8f-be92-d9a65903708d>", "chunk_index": 3, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:54:45.564221"}
+{"text": "let \u2019 s see how much we know about it. note the definition, \u2018 appears to attract \u2019 \u2013 we are not sure. einstein \u2019 s views - \u2019 theory of general relativity \u2018 as applied to gravity. space and time, spacetime condition gravity. \u201c general relativity, or the general theory of relativity, is the geometric theory of gravitation published by albert einstein in 1916 and the current description of gravitation in modern physics. general relativity generalises special relativity and newton \u2019 s law of universal gravitation, providing a unified description of gravity as a geometric property of space and time, or spacetime. in particular, the curvature of spacetime is directly related to the energy and momentum of whatever matter and radiation are present. the relation is specified by the einstein field equations, a system of partial differential equations. \u201d \u2026 some predictions of general relativity differ significantly from those of classical physics, especially concerning the passage of time, the geometry of space, the motion of bodies in free fall, and the propagation of light. examples of such differences include gravitational time dilation, gravitational lensing, the gravitational redshift of light, and the gravitational time delay. the predictions of general relativity have been confirmed in all observations and experiments to date. although general relativity is not the only relativistic theory of gravity, it is the simplest theory that is consistent with experimental data. however, unanswered questions remain, the most fundamental being how general relativity can be reconciled with the laws of quantum physics to produce a complete and self - consistent theory of quantum gravity. space is curved ( please read my blogs under astrophysics ). have we defined space, tie? consequently gravitation as influenced by spacetime, at best, remains a conjecture. newton on gravity ( theory discared, yet being used in calculations ) \u201c \u201c i deduced that the forces which keep the planets in their orbs must [ be ] reciprocally as the squares of their distances from the centers about which they revolve : and thereby compared the force requisite to keep the moon in her orb with the force of gravity at the surface of the earth ; and found them answer pretty nearly \u2019 \u2026 although newton \u2019 s theory has been superseded, most modern non - relativistic gravitational calculations are still made using newton \u2019 s theory because it is a much simpler theory to work with than general relativity, and gives sufficiently accurate results for most applications involving sufficiently small masses, speeds and energies. \u2019 irrespective of the fact whether our theory is right or wrong", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.640022842184832, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:2195b4ea-3b90-4842-b377-6dfae66d9f6c>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:54:45.598362"}
+{"text": "newton \u2019 s theory because it is a much simpler theory to work with than general relativity, and gives sufficiently accurate results for most applications involving sufficiently small masses, speeds and energies. \u2019 irrespective of the fact whether our theory is right or wrong, principles of nature work, so much for science. by the way, can some one forward me the exact definition of nature? a ) earth is \u2018 assumed \u2019 to be surrounded by its own gravitational filed, which exerts an attractive force on all objects. assuming a spherically symmetrical planet, the strength of this field at any given point is proportional to the planetary body \u2019 s mass and inversely proportional to the square of the distance from the center of the body \u2026. the fundamental is an assumption. again, \u2018 this means that, ignoring air resistance, an object falling freely near the earth \u2019 s surface increases its velocity by 9. 81 m / s ( 32. 2 ft / s or 22 mph ) for each second of its descent. thus, an object starting from rest will attain a velocity of 9. 81 m / s ( 32. 2 ft / s ) after one second, 19. 62 m / s ( 64. 4 ft / s ) after two seconds, and so on, adding 9. 81 m / s ( 32. 2 ft / s ) to each resulting velocity. also, again ignoring air resistance, any and all objects, when dropped from the same height, will hit the ground at the same time. \u2018 the strength of the gravitational field is numerically equal to the acceleration of objects under its influence, and its value at the earth \u2019 s surface, denoted g, is approximately expressed below as thestandard average. g = 9. 81 m / s2 = 32. 2 ft / s2 \u2032 we want to know earth \u2019 s gravitation, that is what we want to prove. acceleration of bodies is determined the force of gravitation. so when we rely on the acceleration of objects under the influence of the earths \u2019 gravitation, have we not already assumed earth \u2019 s gravity? we also ignore the effect of electromagnetism and other forces at work, em being dependent on gravitation or is the other way around? the theory is riddled with assumptions and leaping to conclusions. chinese scientists have found a way to measure gravity and it throws spanner in the works. \u2018 by conducting six observations of total and annular solar eclipses, as well as earth tides, a team headed by tang keyun,", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6015059215890484, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:2195b4ea-3b90-4842-b377-6dfae66d9f6c>", "chunk_index": 1, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:54:45.599444"}
+{"text": "explanation of characteristics of fluids by ron kurtus - succeed in understanding physics. key words : physical science, states of matter, solid, gas, liquid, plasma, shape, container, gravity, sphere, spreading, pour, flow, school for champions. copyright \u00a9 restrictions characteristics of fluids by ron kurtus ( revised 26 march 2007 ) the states of matter are solid, liquid, gas and plasma. a fluid is a subset of the states of matter, consisting of liquids, gases and plasmas. this is because they have common properties that are distinct from solids. a fluid does not have a specific shape as does a solid. instead, fluids take the shape of their containers. they also will flow or pour when under the influence of a force such as gravity. questions you may have include : - what is the natural shape of fluids? - how do fluids take the shape of their containers? - how do fluids flow? this lesson will answer those questions. useful tool : metric - english conversion solids have specific shapes because the molecular forces holding particles in place are stronger than the kinetic energy of the molecules. usually, the molecules just vibrate in place, with little or no other movement. on the other hand, fluids exist at higher temperatures and thus their particles have greater kinetic energy. the shape of a fluid adapts to its environment or container. a liquid in space will form the natural shape of a sphere. this is because the attraction between its atoms or molecules is greater than the forces from their kinetic energy moving outward. a sphere is a shape with the smallest surface area for a given volume of material. a liquid sphere or drop of liquid \u2014 such as water \u2014 that is falling toward the earth through the atmosphere will be a slightly flattened sphere, due to the air resistance. if you spill some water on the floor, it will splash and spread out on the floor. liquids like thin oil will spread out even more than water on the floor. the molecules in a gas have more energy than when the material is in the liquid state, such that they overcome the molecular forces. a gas in space or in the atmosphere will continually spread in a shapeless form. a gas that is heavier than air may gravitate toward the floor, where it then spreads out. the rate that the gas expands is a function of its temperature or kinetic energy of its particles. a plasma is an ionized gas, usually at extremely high temperatures. that means some of its electrons have been stripped off. plasmas have most of the same properties as gases. shape in container", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6308348560534354, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:b04d95f3-6fb6-4aaa-b4a3-010dc6dab246>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:54:45.616791"}
+{"text": "by nick gilbert a study conducted by element six, a specialist in synthetic diamond supermaterials, along with scientists from the departments of chemistry and physics at the university of warwick, has revealed that boron - doped synthetic diamond materials can be suitable for a new generation of electrochemical applications. the research shows that boron - doped synthetic diamond has outstanding electrochemical properties while retaining the full strength and durability of its chemical structure. the study shows that the materials have excellent electrochemical properties and retain the durability and strength of their chemical structure. according to the research findings, the quantity of boron doping in the synthetic diamond together with a decrease in graphitic content, makes the material an ideal choice for the analysis of electrochemical reactions in a broad measurement range. element six developed the high quality synthetic diamond samples that were used in the research by using chemical vapour deposition ( cvd ), and optimized them mainly for electrochemical applications. the collaborative research discovered that it was possible to dope the synthetic diamond material with considerably high levels of boron to allow metal electrode - like behavior, and simultaneously restrain the creation of graphitic carbon elements to below detectable levels. thus, an optimized material is provided by the team which maximizes the series of analytes that can be found in solution along with reduced detection limits. the enhanced boron - doped electrodes will facilitate the development of electrochemical sensors with improved reliability, selectivity and sensitivity. the technical research on synthetic diamond material was performed by the element six \u2019 s uk - based r & d team and the electrochemical studies were conducted by the university of warwick \u2019 s electrochemistry and interfaces group.", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6254388416976027, "token_count": 342, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:08f60681-c089-45ca-accd-609c3fd15cf8>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:54:46.243474"}
+{"text": "just watched an amazing program on the relationship between the senses and how the brain processes information. it appears that optical illusions are in fact beneficial to us and helps us survive. even as they are illusions, they allow us to make sense ( use it in a practical way ) of sensory information. this may be a hardwired genetic benefit. but it is also disconcerting as, even when we know what we are looking at, our brain may reject the \u201c knowledge \u201d and still be fooled by the image. it is physically unable to present us with conflicting results. otoh, it also allows us to \u201c see \u201d smells, sounds, touch. they showed a totally blind ( lost sight a couple of months after he was born ) cyclist who goes bike riding everyday on a narrow forest path. he uses sonar by clicking his tongue continuously and from the echos he forms an actual picture in his brain of the path. tests showed that when he hears sounds his visual cortex is activated, even as he has no memories of actually ever seeing anything with his eyes. we like to think that our senses are seperate and being processed distinct from each other. it appears now that we actually integrate all sensory information, though our visual input is the most influential sense, which may fool our taste or even our hearing. tests on culinary chefs proved that when fruit juices were presented to them but the colors were changed, these chefs had a real problem identifying the taste and definitively identify the taste of the fruit juice. one chef identified a yellow juice as apple juice, but in reality it was strawberry juice. they also showed that sound has a great impact on our taste and touch perception. the same chefs were given a selection of potato chips and had to rate them for crunchiness. but while biting in the chips the sound of the crunch while biting and chewing were modified. it showed clearly that the lower the crunch sound, the more of the chefs rated those chips as very crunchy, even as they were chewing and feeling the crunch itself and the chip physically was not particularly crunchy. it \u2019 s called neural plasticity and shows that the brain, while able to present us with an integrated \u201c result \u201d of our senses is physically ( neural function ) unable to present certain results which are not pertinent to our interaction with the environment per se.", "subdomain_id": "subdomain_quantum_optics", "similarity_score": 0.6106397685334404, "token_count": 469, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:a55196a3-67b4-4f5a-9b60-b35b1b27f387>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:54:46.397004"}
+{"text": "to our survival brains. we get angry, we lash out, we fight, or we run and hide. when we don ' t feel threatened, we love, we care, we grow. throughout our lives, these two brains coexist, side by side, sometimes collaborating, more often struggling for dominance. this struggle is hard work and requires some degree of inner development and self - realization. it has always been so. this work has been the subject of all the great wisdom traditions of the world. they were founded millennia ago, when for most people daily life was a constant struggle, without the technology and convenience we take for granted now. so we mustn ' t imagine that this struggle between old brain and new is a modern thing, a function of our newfound scientific prowess too subtle for the ancients. the tugging match between the survival brain and the mature brain has been going on for thousands of years. it has not been easy. it is still going on. it is work, our whole life ' s work, the one that applies regardless of time, place, or culture. but how do we accomplish it? the purpose of this book is to explore the various dimensions of this question, in all its complexity and variety. for that is the unique condition of the human being : we do not know in advance how to do our deeper work. the cosmic outward bound program that deposited us here has not given us this information. we might say that the question itself is the answer : our work is to find out what our work is. but such a circumlocution provides no real satisfaction. this is an issue that generations of philosophers and religious teachers have tried to unravel, with mixed success. their answers are helpful, up to a point, but they are still their answers, not ours, and for the particulars of our life, the question remains. it may help to consider work in the plural - - works. according to the american heritage dictionary, this means, \" the output of an artist or artisan considered or collected as a whole. \" we go to the library and see the rows of books bound in leather : the complete works of charles dickens, of ernest hemingway. but imagine some cosmic library in which all of us, in the course of our life, are creating the bound volumes that in the end will represent our \" complete works, \" which we shape and develop throughout life. indeed, shaping is yet another meaning of the word work, as when a sculptor \" works \" clay. imagine saying", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6022445699708148, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:d9c1c1a5-ed87-4d10-bf3a-d9eb68b38dbe>", "chunk_index": 2, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:54:46.657612"}
+{"text": "new brazing alloys improve thermal barrier in jet engine hot section material scientists and ceramics component manufacturers have been developing new materials and processes that let engines run hotter and hotter in response to the aerospace industry \u2019 s focus on higher performance and lower costs. in gas turbine engines a large amount of air from the compressor is used to cool the turbine vane and blades. the amount of air needed is determined by turbine temperature and the materials that need to be cooled. if the turbine materials need less cooling or can be made from materials that can withstand higher temperatures, this would make more air available for propulsion. increasing the turbine \u2019 s temperature capability is thus key to improving engine efficiency. however, engines run hotter as processing temperature is increased, and this increased heat tends to degrade metals. inside turbines, pre - sintered preforms ( psps ) are being used to repair vanes that are breaking down due to excessive heat and wear. psps, with a small amount of braze alloy mixed with the parent metal, are used primarily in the turbine section for repairing vane cracks and wear areas. as temperatures continue to climb in these zones, new materials and technologies are being developed to create a better thermal barrier. this is expected to significantly lower maintenance, repair and overhaul ( mro ) costs. examples include the development of advanced braze alloys, the use of ceramics on high temperature metal to ceramic components, and the introduction of active brazing, which allows metal to be bonded directly to ceramic without metallization. braze alloys developed for high temperature applications braze alloys are used in a variety of advanced military aircraft and commercial aerospace engine components and grades are being developed that directly bond ceramic to metal or other materials. alloy compositions vary and include those designed for functional use in very high - temperature applications ( 750 - 850\u00b0c ). alloys are selected to meet the specific service temperature conditions as well as the requirements of all the components to be joined. examples include alloys used in new turbine hot sections, brazing silicon nitride ceramic to new super alloy engine parts. see table 1 for an overview of available braze alloys, showing the engine part it is used in and the component / base material. click on image to enlarge", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6055923798414811, "token_count": 444, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:97b60ea3-0221-43cb-9652-0c8f4c5b8d6e>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:54:46.820871"}
+{"text": "997438 0. 9999999999 45. 000000 0. 000810 44. 999190 0. 99999999999 45. 000000 0. 000256 44. 999744 0. 999999999999 45. 000000 0. 000081 44. 999919 0. 9999999999999 45. 000000 0. 000026 44. 999974 0. 99999999999999 45. 000000 0. 000008 44. 999992 0. 999999999999999 45. 000000 0. 000002 44. 999998 let ' s board the c - ship bradley to explore relativistic aberration. to avoid being confused by other relativistic effects, we ' ve set the main viewer to compensate for lorentz contraction and doppler shift, leaving only aberration to affect our view. once again, we fly through the lattice, this time arranging our flight profile so as to reach different velocities as we fly through the midpoint of the lattice. a 475k mpeg movie of the following images is available for your viewing pleasure. at rest in the middle of the lattice, we see a normal view, unaffected by aberration. the ship ' s computer displays a graphic to the left of the viewscreen that shows the effect of aberration on light arriving from various directions with respect to the direction we ' re travelling. stationary in the lattice, no aberration is indicated. now we ' ve accelerated to one tenth the speed of light, and already aberration is changing our view. the display on the left shows how light from various directions ( shown on the outer ring ) has been displaced to the apparent directions of the lines radiating from the bradley. at this velocity aberration agrees with the classical prediction to two decimal places ; light is still behaving just like rain. we notice on the main viewer that we ' re seeing more of the lattice, as aberration shifts objects previously outside our field of view into the frame. at a quarter of the speed of light, newton is still firmly in charge ; aberration is behaving linearly, and the contribution of special relativity is less than a quarter of a degree of", "subdomain_id": "subdomain_quantum_optics", "similarity_score": 0.6133387054461366, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:aea03c01-3dcf-4425-a973-d7e4aa959010>", "chunk_index": 4, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:54:46.966131"}
+{"text": "outside our field of view into the frame. at a quarter of the speed of light, newton is still firmly in charge ; aberration is behaving linearly, and the contribution of special relativity is less than a quarter of a degree of the total aberration of more than 11\u00b0. half the speed of light, and we ' re developing eyes in the back of our head - - objects 120\u00b0 from the direction we ' re moving are shifted so they appear to our right and left. still, relativity accounts for only about 10 % of the total aberration. three quarters of the speed of light : relativity now accounts for a substantial fraction of the total aberration, which is already approaching the 45\u00b0 classical physics predicts we ' d measure at the speed of light. nine - tenths of the speed of light : einstein ' s in the driver ' s seat now. light rays coming from our side now appear to come from a direction about 26\u00b0 from the ship ' s bow, compared to the classical prediction of 48\u00b0. more and more of the lattice seems to be before us now, even though we ' re observing from a point in the middle. ninety - five percent of the speed of light : the compression toward our direction of travel continues. relativistic effects now dominate. ninety - nine percent : only objects almost directly astern still appear to be behind us. we ' re now only one part in a thousand slower than light. even objects five degrees from our stern now enter the field of view looking in the direction of travel. extreme distortion of objects behind us becomes apparent. and finally, we view the lattice from the midpoint at a velocity of 0. 9999 of the speed of light. the cell of the lattice directly behind our ship has been distorted by aberration to almost fill the field of view. the rest of the lattice is reduced to a small grid in the centre of the main viewer. the readout to the left of the view shows that even light rays emitted five degrees from our stern appear at an angle to the bow of 15\u00b0.", "subdomain_id": "subdomain_quantum_optics", "similarity_score": 0.6164762830848907, "token_count": 427, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:aea03c01-3dcf-4425-a973-d7e4aa959010>", "chunk_index": 5, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:54:46.966958"}
+{"text": "the field of psychology that studies the ways in which people develop physically, emotionally, intellectually and socially over the course of their lives. developmental psychologists are concerned primarily with how the human mind / personality changes over the course of a lifetime, from its conception and intrauterine development through childhood, adolescence, adulthood, and old age. the field envelops nearly all aspects of life and seeks to understand the factors that influence personality, intelligence, and behavior. initially, developmental psychologists focused primarily on childhood development, believing that with adulthood came a kind of personality stasis. one of the first to question this notion was erik erikson ( 1902 - 1979 ) in his landmark 1950 book eight ages of man, laying out a schema whereby human personality continues to change and evolve throughout the life - cycle. it was chiefly due to erikson ' s work that developmental psychology expanded its view, taking on what is referred to within the field as the lifespan approach. sigmund freud ( 1856 - 1939 ), the first theorist to link childhood experience with adult behavior, proposed what is perhaps the most widely known but least understood theory of childhood development. he saw personality development as consisting primarily of a conflict between biology and culture ; that is, between the genetically programmed needs of the infant / child and the ability or willingness of the parents to satisfy those needs. freud laid out a blueprint of development consisting of four stages : the oral, the anal, the phallic, and latency. at each stage of development, which freud believed occurred at varying ages, infants and children had different needs, all biologically determined. what freud saw as significant was the degree to which those needs were either met or frustrated by the parents : extremes at either end, frustration of gratification, resulted in fixation which stunted development. freud ' s ideas were, and continue to be, highly controversial, mainly because he attributed feelings of sexuality to infants, but also because of his focus on male concepts and imagery to explain his theory. later developmental psychologists would expand on freud ' s work, or propose new schemes of development. one such theorist was the swiss zoologist and psychologist jean piaget, who revolutionized developmental psychology with his theories of intellectual, or cognitive, development. piaget ' s first contribution was to define intelligence as a process of volitional, cognitive endeavor a person undertakes to make sense of the world. he theorized that as a person passes through each of these stages she struggles to internalize or understand the novelties inherent in each stage. this", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6129332335737219, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:86a07726-cfcd-4b9e-b122-2b4d891ee60a>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:54:47.187587"}
+{"text": "cell system has already seen this threat before and has learnt what to do. this time the igg antibody producing cells proliferate and release igg just as quickly as the igm producing cells. this time around the igm type antibodies are virtually superfluous. the antibody production persists for longer and reaches up to ten times the concentration of antibody produced in the initial antigenic challenge. classic defense against a pathogen involves antibody binding to the pathogens antigens. this signals the immune cells that the substrate the antibodies are bound to should be destroyed. immune cells will link to the antibodies via fc receptors. this receptor linking activates the immune cell into destroying use of x ray crystallography has demonstrated the shape and function of antibody binding sites on the fab arms of the \" y \" shape molecule. shape is what defines which antigen shape the antibody can bind. actual binding is an active process involving several chemical and electrical interactions between the antigen and antibody receptor. chemical binding involves the linking of oxygen or nitrogen molecules in the antigen and antibody to a hydrogen atom ( usually taken from water in the vicinity ). electrical bonding works in two ways. overall, antibodies are negatively charged whereas antigens are frequently positively charged. the electrostatic attraction between the two can help keep them together. a second and stronger electrical method of binding involves \" van der waals \" forces. essentially each atom of a molecule has a net positive or negative charge depending on how many electrons it contains. positive and negative atom charges can provide a quite strong bond between antibody and antigen. finally the strongest form of antigen / antibody bonding is \" hydrophobic bonding \". some parts of molecules don ' t like water ( hydrophobic ) and will physically bond to anything to force water molecules away from the immediate vicinity. antibody binding sites have this property. for all of these attractive forces to work the antigen and antibody molecule must be close to each other. there must be a pretty good fit between the shape of the antigen and shape of the antibody receptor site before the molecules get close enough to each other to form the bonds. it is possible for several antigens to be very similar in shape. perhaps they only have one or two molecules difference between them. it is possible for an antibody to bind to all of these antigens but those that don ' t fit perfectly will have weaker bonding ability. the reduced bonding strength may not be strong enough to overcome repulsive forces that are ever present pushing the antibody and antigen apart. the ability of an antibody to bind a particular antigen is called antibody \" affinity \".", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6005248400507349, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:246bedf4-c568-4faa-ac13-d072f83938b7>", "chunk_index": 1, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:54:47.739654"}
+{"text": "h. after that the foil was taken out from the solution, washed by pure methanol, and dried on the air. the study of concentration dependence was similar. preparation of nanoparticles gold nanoparticles ( aunps ) were obtained by citrate reduction of k [ aucl4 ] described elsewhere. silver nanoparticles ( agnps ) were obtained using similar process of agno3 reduction published by smitha et al.. prepared nanoparticles were characterized by tem and uv - vis absorption spectroscopy. uv - vis absorption spectroscopy was carried out using a varian spectrophotometer, model cary 400 scan, from 200 to 800 nm. the transmission electron microscopy ( tem ) images were recorded using a jeol microscope, model jem - 1010 with accelerating voltage 100 kv. preparation of sandwich structures the sandwich structures were prepared by two procedures. in the first one ( figure 2a ), the gold foils were modified by silver or gold nanoparticles previously covered by biphenyl - 4, 4 ' - dithiol. 1 ml of nanoparticles was added drop - wise at intensive stirring to the 1 ml of biphenyl - 4, 4 ' - dithiol solution with concentration of 5 \u00d7 10 - 2 mol / l. the obtained mixture was purified by centrifugation. ptfe foil with gold layer was placed to the solution of nanoparticles for 12 h. after that the foil was removed from the solution, washed by pure methanol, and dried on the air. figure 2. ( a ) preparation of sandwich structures using modified nanoparticles. ( b ) preparation of sandwich structures using modified gold layer. in the second procedure ( figure 2b ), ptfe foil with gold layer modified by biphenyl - 4, 4 ' - dithiol was prepared. then such modified foil was placed into the solution of 2 ml of nanoparticles for 12 h. after that the foil was removed from the solution, washed by pure methanol, and dried on the air. raman spectral measurements were performed on raman nir advantage spectrograph deltanu with laser excitation line 785 nm, power 100 mw in the range of 100 to 2000 cm - 1 with spectral resolution 4 cm - 1. integration time was 20 s and results spectra are average of five measurements. surface was focused by the nuscope with manual adjustment and field of view was approximately 800 \u03bcm", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6011205766601866, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:bfda52f2-e311-481c-82ab-037f002ffb16>", "chunk_index": 2, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:54:48.583733"}
+{"text": "an excitonic solar cell ( xsc ) is characterized by the formation of an exciton that is produced when a photon from light is adsorbed by the light harvesting molecule. an exciton is a tightly bound electron - hole pair which must be split for charge generation. the exciton dissociation takes place at the interface between the constituent semiconductors. nanostructuration of interfaces is a crucial approach toward highly efficient devices. there are ( among several ) three general types of xscs : organic ( osc ), hybrid ( hsc ) and dye sensitized solar cells ( dsc ). other types are the quantum dot - sensitized solar cells ( qdsc ), the extremely thin absorber solar cell ( eta ) or the solid - state version of the dsc, the solid - state dye sensitized solar cell ( ss - dsc ). xscs can be calssified by the type of material used ( organic semiconductors, inorganic semiconductors, etc ) or by the type of n - p junction ( bi - layer, electrochemical junction, bulk heterojunction, etc ). organic : c60 derivatives ( pcbm ), polymers ( p3ht ), small molecules, etc. inorganic : tio2, zno, cdse, nb2o5, ins3, sb2s3, nio, wo3, moo3, etc. electron transport materials ( etm ) : pcbm, tio2, cds, cdse, etc hole transport materials ( htm ) : p3ht, pedot, spiro - ometad, nio, v2o5, etc light harvesting material ( lhm ) : dyes, qd, polymers like p3ht can also harvest light", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6872213347197546, "token_count": 372, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:58b885d7-6915-4367-8697-2055c74d1961>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:54:48.589294"}
+{"text": "general relativity is a theory which describes space, time and the gravitational field in terms of a lorentzian metric. a complete understanding of the gravitational field requires an understanding of the matter sources which generate it. in the einstein equations,, the left hand side depends only on and is a feature of the geometry alone. on the other hand the right hand side, the energy - momentum tensor, depends not only on the metric but also on some matter fields. the right hand side of einstein \u2019 s equations seems to have suffered from bad press coverage from an early stage. einstein himself is often quoted as having said that the left hand side of his equations is made of marble while the right hand side is made of wood. i do not have a source for this quote \u2013 if anyone reading this does i would be grateful to hear about it. in this post i want to suggest treating that humble right hand side with more respect. if i lived in a palace made of marble with beautiful wooden furniture then i might be more impressed by the marble than by the wood. i would nevertheless do my best to prevent little boys from carving their initials into the furniture with penknives or the cat ( much as i love cats ) from using it as an accessory for the care of its claws. the left hand side of the einstein equations is universal within general relativity \u2013 it is always the same, no matter which type of physical situation is to be described. on the other hand the nature of the matter fields depends very much on what physical situation is to be described and what aspects of it are to be included in the description. it is necessary to make a choice of matter model. what is remarkable is that there is a large variety of choices which, in conjunction with the einstein equations, lead to a consistent closed system of equations which bears no traces of the fact that other physical effects have been omitted. in fact there are three related choices which have to be made to set up the mathematical model in any given case. the first is the matter fields themselves \u2013 what kind of geometrical objects are they? the second is the expression which defines the energy - momentum tensor in terms of the matter fields and the metric. the third is the system of equations of motion which describe the dynamics of the matter. note that in general the energy - momentum tensor depends explicitly on the metric. it is not possible to define an energy - momentum tensor unless the spacetime geometry is given. the same is true in the case of the equations of motion of the matter. they also contain the metric explicitly", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.627681298774248, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:7a8fe757-e6d6-4a38-bbe7-6984253d3f2f>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:54:49.790117"}
+{"text": "- momentum tensor depends explicitly on the metric. it is not possible to define an energy - momentum tensor unless the spacetime geometry is given. the same is true in the case of the equations of motion of the matter. they also contain the metric explicitly. without the metric even the nature of the matter fields themselves can become ambiguous. which positions should we choose for the indices of a tensor occurring in the description of the matter fields? from a physical point of view it is clear why the metric is necessary in so many ways. the mathematical model must be given a physical interpretation which involves the consideration of measurements. in the absence of a given geometry there is no way to talk about measurements. when a matter model has been chosen the basic equations which are to be solved are the einstein - matter equations, i. e the einstein equations coupled to the equations of motion for the chosen type of matter. the unknowns are the metric and the basic matter fields. for any reasonable choice of matter fields the energy - momentum tensor has zero divergence as a consequence of the equations of motion. however the equations of motion in general contain more information than the divergence - free property of the energy - momentum tensor. for more discussion of these things together with examples see chapter 3 of my book. i emphasize that solving the equations describing the physical situation within the given model means solving both the einstein equations and the equations of motion of the matter. this is too often neglected in the literature. a particular danger occurs when the solutions under consideration are of low regularity. if the einstein equations do not make sense pointwise then it should be checked that they hold in the sense of distributions. for solutions which lack regularity on a hypersurface this is expressed in the junction conditions and it is common in the literature to check that they hold. the equations of motion should also be satisfied in the sense of distributions and this is often ignored. when i use the phrase \u2018 in the sense of distributions \u2019 here this is just a shorthand since the equations are nonlinear. the correct statement is that it is necessary to think carefully about the sense in which the equations are satisfied. an example may help to make the importance of the issue clear. at the gr12 conference in boulder in 1989 there was a heated discussion of the question, whether colliding plane waves can give rise to spontaneous creation of matter. ( i emphasize that this discussion was in a purely classical context. quantum theory was not being taken into account. ) this kind of creation of matter sounds ridiculous from a physical point of view.", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.648490770944519, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:7a8fe757-e6d6-4a38-bbe7-6984253d3f2f>", "chunk_index": 1, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:54:49.794734"}
+{"text": "mathematics - filter : if there are seven funds with various charges, how can i work out the allocation to these funds of a fixed amount so that the weighted mean charge is below a certain level and the allocations are of similar sizes? [ more inside ] posted by djgh on dec 31, 2012 - can you cite any examples where a technological breakthrough wasn ' t possible until there was some sort of mathematical breakthrough? [ more inside ] posted by brian puccio on apr 6, 2011 - best books, websites, lecture series on game theory and its applications for smart people who understand mathematics but can ' t stand trawling through pages of unnecessary complex formulae? posted by vizsla on jan 26, 2009 - applied math filter : help me use math! i ' d like to learn more about mathematics and it ' s practical applications - particularly in computer science [ more inside ] posted by dcbarker on aug 1, 2008 - why is it that when i solve the inequality 0 \u2264 arccos ( x ) < > cos ( \u03c0 / 4 )? why do the operators switch direction? > [ more inside ] posted by pugz on oct 19, 2007 - imagine a cube - shaped building, with ten cube - shaped rooms along each side ( 10 rooms long, 10 high & 10 deep ). each cubular room has 4 walls, 1 ceiling and 1 floor. each of the 6 interior surfaces in all 1000 cubular rooms is decorated with a different piece of art. the rooms can be moved around the building, as if it were an enormous rubik ' s cube, but they can also be spun on their axes, so all 6 walls of all 1000 cubes is capable of touching all the others ( if the cube is so arranged ). how many combinations of art within the ' cube gallery ' are possible? if you can run me through the workings of the maths i would be extra grateful. also, what technical words / phrases / language are useful / interesting in expressing this concept? [ more inside ] posted by 0bvious on apr 24, 2007 - mathematical imbecile question : what ' s the simplest, most universal way to add a list of vectors? [ more inside ] posted by jimbob on feb 19, 2005 - how can a major key sound confident and happy, while a minor key can sound sinister or sad? is it just centuries of musical brainwashing, or is there a real mathematical explanation? posted by pretty _ generic on may 7, 2004 -", "subdomain_id": "subdomain_quantum_computing", "similarity_score": 0.6093122086098937, "token_count": 509, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:bff01b08-c9bc-48cd-85a3-46142856ef21>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:54:49.916689"}
+{"text": "about the author my work currently involves developing weldable high strength bainitic steels for use as armour, before this i did various other things with steel and nickel alloys ( mostly steel! ). some details of those things can be found here. my name is mathew peet, i have a webpage at mathewpeet. org which has some more of my stuff. about bainite \u2013 potted history bainite is a microstructure of steel that forms at temperatures intermediate between the formation of pearlite and martensite in many steels. first discovered by davenport and bain who conducted a series of isothermal transformation experiments. historically there has been much discussion in the literature about the mechanism of transformation of bainite, with opinions varying from it being very similar to pearlite, to it being similar to martensite. results of ko and cottrell showed that bainite exhibited a surface relief consistant with a martensitic transformation mechanism. shortly after matas and hehemann introduced the concept of a sub - unit mechanism to explain the apparant inconsistancy between the slow speed of transformation and the high speed the interface would be expected to move. microstructures formed as a result of continuous cooling or by welding are often very complex and this leads to lots of scope for errors in identification of microstructures. this leads to more confusion over the appearance of the microstructure an an urge to classify constituents by appearance rather than transformation mechanism. generally bainitic ferrite forms austenite as plates before carbon is partitioned to the austenite. carbide precipitation can also take place either within the ferrite or between the plates of ferrite due to supersaturation. this distinguishes upper - bainite and lower - bainite. if transformation occurs without the formation of carbides the volume fraction of bainite forming will be limited by thermodynamics. once the carbon in the austenite reaches a concentration were any new bainite that formed would have the same energy as the parent austenite. this is the \u2018 incomplete transformation \u2019 and \u2018 t - zero concept \u2019. you can find more information on the phase transformations and complex properties group \u2019 s page about bainite. about the blog i thought it would be useful and fun for me to write this blog. personally my aim is to develop better writing habits and to document some of the things i think about to render them useful. so far posts have included simple calculations, experimental results, discussion of what is happening in", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6374636564419003, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:7866b026-3ee5-4bf2-9f14-ae72348c72a7>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:54:49.920495"}
+{"text": "alternative conceptions of introductory geoscience students and a method to decrease them college students often leave introductory geoscience courses with alternative conceptions, and these alternative conceptions are a barrier to their grasp of geological conceptions. this dissertation clarifies the problem and suggests pedagogical strategies for correcting it. it is an integration of research on students ' conceptions of geoscience topics with the application of that knowledge to the development of materials to change these conceptions to be more scientifically accurate. this research identifies and documents alternative conceptions students have in several key geoscience topics and the consequences of these alternative conception in terms of preventing understanding. after documenting the alternative conceptions, i investigate their sources. in addition, i develop ways in which the alternative conceptions can be addressed in classrooms in terms of non - traditional teaching techniques, and i assess the success of these methods. ^ chapter 1 addresses alternative conceptions in general introductory geoscience topics. i use known student alternative conceptions to develop a series of interactive materials to help reduce students ' alternative conceptions. after their development, i assess the efficacy of these materials, and my research indicates that they are successful in helping students better learn the geoscience concepts. ^ chapter 2 deals with a particularly difficult topic for students \u2014 that of phylogenetic systematics. students have an intuitive way of categorizing organisms, and this categorization is different from the system used by experts within the field. my investigation indicates the conceptual change required of students to fully understand the topic leads to great difficulties with learning. drawing upon results of the research in chapter 1, i developed and assessed interactive materials to help students better understand phylogenetic systematics. ^ using the insight gained from chapters 1 and 2, chapters 3 and 4 further examine students ' conceptions in an area critical to understanding geology : rocks and their formation. my research indicates that students view rocks as objects independent from the processes that form and change them. in addition, i document students ' alternative conceptions of rocks. using these alternative conceptions, i look more deeply into the underlying factors that cause the difficulties students have with learning rocks, their formation, and their importance to the geosciences. ^ karen melissa kortz, \" alternative conceptions of introductory geoscience students and a method to decrease them \" dissertations and master ' s theses ( campus access ).", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6208546670171681, "token_count": 482, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:641d8413-28ff-48f7-a659-d12f83f8152b>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:54:50.202481"}
+{"text": "extrasensory perception, or esp, refers to the apparent ability of a human being to \" acquire information without using the [ five ] ordinary senses of the body and without depending on logical inference. \" 2 are all subdivisions of the broader esp category. the term was made popular by j. b. rhine in an attempt to separate the phenomena it describes from the mysticism of spiritualism and instead link it with current scientific concepts. in regards to mysticism, esp is commonly referred to as the sixth sense, and can provide an individual with information about the past, present, and future. to some, such information is regarded as having originated in a second, or alternate, in the laboratory, many parapsychologists prefer to use the term general esp ( or gesp ) to avoid having to label a particular experimental result as being caused by telepathy or clairvoyance, since it cannot be stated for certain which of the two caused the result. for example, in many remote - viewing experiments designed to test clairvoyance, it may be that the subject is obtaining the information from the mind of the traveler ( telepathically ). or in other tests, such as the ganzfeld, in which a person tries to send an image to another person, it may be that the receiver is using clairvoyance to view the image. in general, the reported spontaneous cases of esp amongst the public typically consist of information related through dreams ( the most common ), waking impressions, or sensory hallucinations ( the least common ). typically come in two forms : realistic and unrealistic. the most common type of psychic dream is the realistic dream, in which one dreams of something that is currently happening or about to happen. these dreams are often extremely detailed and appear as if the dreamer were watching the events unfold from a particular vantage point. the unrealistic, or symbolic, dream conveys information in symbolic terms or in outright fantasy. while the occurrences in the dream may bear little resemblance to an actual event, the message is conveyed nonetheless. since ordinary dreams are often unrealistic, it is not surprising that psychic dreams will also appear as such. psychic symbolic dreams are typically set apart from common dreams by the fact that they often carry a certain sense of importance to the dreamer. in many cases observed by dr. louisa e. rhine, it was found that realistic and unrealistic elements were rarely mixed in a psychic dream. however, the reason for this, or why some people", "subdomain_id": "subdomain_quantum_optics", "similarity_score": 0.6533932841061538, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:d909c2c6-84a3-45e9-9374-f6b5da459c40>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:54:50.996826"}
+{"text": "death was the predominant theme... and women were receivers twice as often as men, whereas [ men were senders ] in 60 % of the cases. \" 6 other meta - analyses also confirm that the majority of psychic experiences come in the form of dreams, and the majority of these dreams are precognitive, meaning that they convey information about an event not yet taken place. ( many parapsychologists have conjectured that esp is facilitated in the dream state, possibly because the barriers surrounding the conscious mind appear to be thinnest during such altered states of consciousness. ) such experiences, however, raise some difficult questions for parapsychologists, for example, \" can we use the information acquired through psychic experiences to change the future... or prevent a foreseen tragedy? \" other questions ask, \" if the experience in [ genuinely ] paranormal, is it revealing what will inevitably happen, or is it warning what might happen if steps are not taken to avoid it? \" 2 there are no answers to these questions. in some cases people have tried and failed to prevent some kind of tragedy, and in others, they have succeeded. the majority, however, do not try at all for fear of ridicule. away from the subject of spontaneous esp, let us now briefly examine some attempts to bring esp into the laboratory. the foundations for parapsychology as an experimental science were established in the 1930 ' s by dr. j. b. rhine at the duke university parapsychology laboratory in durham, north carolina. beginning with his famous deck of esp cards, rhine attempted to observe and measure esp in the laboratory. variations of rhine ' s original esp - card guessing experiment have been created and tested throughout the years, but perhaps one of the most significant results came from a series of experiments known as the pearce - pratt experiments. this series of experiments took place on duke university ' s west campus under the direction of j. b. rhine. j. gaither pratt, the agent, was located in what was then the physics building. once a minute he picked up a card from a well shuffled deck and, without looking at it, moved the card face - down onto a book. at that very minute, hubert pearce, who was located in a library one hundred yards away and who had a synchronized watch, tried to perceive the card on the book. without meeting, both men deposited sealed records with rhine - - pratt of the targets ( which he recorded after the run )", "subdomain_id": "subdomain_quantum_optics", "similarity_score": 0.6073850297700047, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:d909c2c6-84a3-45e9-9374-f6b5da459c40>", "chunk_index": 3, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:54:51.001023"}
+{"text": "refer to those who were confident about the reality of psi and goats for those who doubted its existence or its pertinence in the context of the test. \" after filling out the questionnaire, schmeidler \" gave the students a classic psi test with esp cards in which they tried to guess sequences of target - cards. [ she then ] compared the results of the psi test [ to ] those of the questionnaire. the remarkable conclusion was that the ' sheep ' had a significant deviation above chance, while ' goats ' were significantly below it. \" this effect, which has been termed the sheep - goat effect and has been confirmed by many independent researchers, demonstrates that \" one ' s attitudes toward psi affects the likelihood that such phenomena will occur in the first place. the more an individual harbors a reductionistic view of the world, the less chance such phenomena will emerge ( let alone be witnessed by them ) ; the more one is interested in interconnectedness, and open to psi experiences, the more likely the world will respond by creating such experiences. \" 6 this now leads us to the question of how such experiences are created in the first place. many theories regarding esp have been formulated over the years, and while the majority have been dismissed by serious researchers ( such as the idea that esp is communicated through a form of radio waves ), a few continue to be entertained. one theory was presented by the famous novelist and muckraker upton sinclair, who reportedly had several psychic experiences of his own. indeed, his wife, mary craig sinclair, was reputed to be a rather talented clairvoyant. when asked what such abilities mean to them, the sinclairs replied that, \" it seems to indicate a common substratum of mind, underlying our individual minds, and which we can learn to tap. we are apparently getting hints of a cosmic consciousness, or cosmic unconsciousness : some kind of mind stuff which is common to us all, and which we can bring into our individual consciousness. why is it not sensible to think that there may be a universal mind - stuff, just as there is a universal body - stuff, of which we are made, and to which we this statement closely resembles psychologist carl jung ' s theory of a collective unconscious into which the conscious mind has subliminal psychic access. during his studies, jung noticed that certain symbols ( such as age for wisdom or serpents for evil ) were interpreted similarly by people of different backgrounds, and were included in the myths and legends of various different cultures.", "subdomain_id": "subdomain_quantum_mechanics", "similarity_score": 0.6043893949125586, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:d909c2c6-84a3-45e9-9374-f6b5da459c40>", "chunk_index": 6, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:54:51.005206"}
+{"text": "berkeley lab physicist challenges speed of gravity claim 18 jun 2003 ( source : lawrence berkeley national laboratory ) public information department lawrence berkeley national laboratory lynn yarris, ( 510 ) 486 - 5375, email @ example. com berkeley, ca - - albert einstein may have been right that gravity travels at the same speed as light but, contrary to a claim made earlier this year, the theory has not yet been proven. a scientist at lawrence berkeley national laboratory ( berkeley lab ) says the announcement by two scientists, widely reported this past january, about the speed of gravity was wrong. stuart samuel, a participating scientist with the theory group of berkeley lab ' s physics division, in a paper published in physical review letters, has demonstrated that an \" ill - advised \" assumption made in the earlier claim led to an unwarranted conclusion. \" einstein may be correct about the speed of gravity but the experiment in question neither confirms nor refutes this, \" says samuel. \" in effect, the experiment was measuring effects associated with the propagation of light, not the speed of gravity. \" according to einstein ' s general theory of relativity, light and gravity travel at the same speed, about 186, 000 miles ( 300, 000 kilometers ) per second. most scientists believe this is true, but the assumption was that it could only be proven through the detection of gravity waves. sergei kopeikin, a university of missouri physicist, and edward fomalont, an astronomer at the national radio astronomy observatory ( nrao ), believed there was an alternative. on september 8, 2002, the planet jupiter passed almost directly in front of the radio waves coming from a quasar, a star - like object in the center of a galaxy billions of light - years away. when this happened, jupiter ' s gravity bent the quasar ' s radio waves, causing a slight delay in their arrival on earth. kopeikin believed the length of time that the radio waves would be delayed would depend upon the speed at which gravity propagates from jupiter. to measure the delay, fomalont set up an interferometry system using the nrao ' s very long baseline array, a group of ten 25 - meter radio telescopes distributed across the continental united states, hawaii, and the virgin islands, plus the 100 - meter effelsberg radio telescope in germany. kopeikin then took the data and calculated velocity - dependent effects. his calculations appeared to show that the speed at which gravity was being propagated from jupiter matched", "subdomain_id": "subdomain_quantum_metrology", "similarity_score": 0.6071364742338794, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:a00a2c12-9afb-4fa3-8d22-722be5b150f3>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:54:51.698496"}