data/train/batch_000042.jsonl

{"text": "$ 12 sale happening now. the quantum internet is born \u201c years from now it may be said that the quantum internet was born today. \u201d of course, the quantum internet is just in the baby stages now - but when it matures, it will be able to process ridiculous amounts of data at blaring speed, and never be hacked. the system, developed by physicists stephan ritter and gerhard rempe at the max planck institute of quantum optics in germany, has two nodes. although this is small, the internet you \u2019 re on right now started in the 1960s in a similar process. this first quantum network was built by utilizing two atoms of rubidium which exchange photons. each atom is placed inside an individual \u2018 room \u2019 with highly reflective mirrors surrounding it, and at a short distance from its sister atom. these rooms, called optical cavities, are connected by an optical fiber. first, scientists aim a laser at the first rubidium atom, which induces an emission of a single photon. that photon travels along the optical fiber to the other optical cavity, containing the other atom. thanks to the mirrors, the photon bounces off the mirrors thousands of times, and is absorbed by the atom upon collision. this absorption transmits information about the first atom \u2019 s quantum state - and voila, a transfer of information. the two rubidium atoms were entangled beforehand, which effectively means that they were linked together. during entanglement ( read more about entanglement here ), certain properties of the atoms are linked, and measuring one instantaneously produces the same result in the other atom. during this experiment, the atoms were entangled for 100 microseconds - a long time in quantum physicists. entanglement what renders any form of hacking impossible - as soon as a would - be hacker tapped into the quantum network, the quantum states of the atoms would no longer match up. this is the first step towards something great. i love physics interviewer : and we \u2019 re hoping that at some point we can get rid of the hungry and sleepy problem. jason silva : exactly, because that \u2019 s really the point, right? we want to transcend our biological limitations. we don \u2019 t want biology or entropy to interrupt the ecstasy of consciousness. consciousness, when it \u2019 s unburdened by the body, is something that \u2019 s ecstatic ; we use the mind to watch the mind, and that \u2019 s the meta - nature of our consciousness, we know that we know that we", "subdomain_id": "subdomain_quantum_cryptography", "similarity_score": 0.6847224257622966, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:78ddec35-cc06-4dfa-a375-2b3f9e733efa>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:29.202247"}
{"text": "in physics, length contraction \u2013 according to hendrik lorentz \u2013 is the physical phenomenon of a decrease in length detected by an observer of objects that travel at any non - zero velocity relative to that observer. this contraction ( more formally called lorentz contraction or lorentz \u2013 fitzgerald contraction ) is usually only noticeable at a substantial fraction of the speed of light ; the contraction is only in the direction parallel to the direction in which the observed body is travelling. this effect is negligible at everyday speeds, and can be ignored for all regular purposes. only at greater speeds does it become important. at a speed of 13, 400, 000 m / s ( 30 million mph, 0. 0447c ), the length is 99. 9 % of the length at rest ; at a speed of 42, 300, 000 m / s ( 95 million mph, 0. 141c ), the length is still 99 %. as the magnitude of the velocity approaches the speed of light, the effect becomes dominant, as can be seen from the formula : - l0 is the proper length ( the length of the object in its rest frame ), - l is the length observed by an observer in relative motion with respect to the object, - v is the relative velocity between the observer and the moving object, - c is the speed of light, and the lorentz factor, \u03b3 ( v ), is defined as in this equation it is assumed that the object is parallel with its line of movement. for the observer in relative movement, the length of the object is measured by subtracting the simultaneously measured distances of both ends of the object. for more general conversions, see the lorentz transformations. an observer at rest viewing an object travelling very close to the speed of light would observe the length of the object in the direction of motion as very near zero. length contraction was postulated by george fitzgerald ( 1889 ) and hendrik antoon lorentz ( 1892 ) to explain the negative outcome of the michelson - morley experiment and to rescue the hypothesis of the stationary aether ( lorentz \u2013 fitzgerald contraction hypothesis ). although both fitzgerald and lorentz alluded to the fact that electrostatic fields in motion were deformed ( \" heaviside - ellipsoid \" after oliver heaviside, who derived this deformation from electromagnetic theory in 1888 ), it was considered an ad hoc hypothesis, because at this time there was no sufficient reason to assume that intermolecular forces behave the same way as electromagnetic ones. in 1897 joseph larmor", "subdomain_id": "subdomain_quantum_optics", "similarity_score": 0.6342009356974471, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:2fbe42aa-32a3-4846-ad95-4d4d73815482>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:29.546281"}
{"text": "who derived this deformation from electromagnetic theory in 1888 ), it was considered an ad hoc hypothesis, because at this time there was no sufficient reason to assume that intermolecular forces behave the same way as electromagnetic ones. in 1897 joseph larmor developed a model in which all forces are considered as of electromagnetic origin, and length contraction appeared to be a direct consequence of this model. yet it was shown by henri poincare ( 1905 ) that electromagnetic forces alone cannot explain the electron ' s stability. so he had to introduce another ad - hoc hypothesis : non - electric binding forces ( poincare stresses ) that ensure the electron ' s stability, give a dynamical explanation for length contraction, and thus hide the motion of the stationary aether. eventually, albert einstein ( 1905 ) was the first who completely removed the ad - hoc character from the contraction hypothesis, by demonstrating that this contraction was no dynamical effect in the aether, but rather a kinematic effect due to the change in the notions of space, time and simultaneity brought about by special relativity. einstein ' s view was further elaborated by hermann minkowski and others, who demonstrated the geometrical meaning of all relativistic effects in spacetime. so length contraction is not of dynamic, but kinematic origin. basis in relativity first it is necessary to carefully consider the methods for measuring the lengths of resting and moving objects, where \" object \" simply means a distance with endpoints that are always mutually at rest, i. e., that are at rest in the same inertial frame of reference. if the relative velocity between an observer ( or his measuring instruments ) and the observed object is zero, then the proper length of the object can simply be determined by directly superposing a measuring rod. however, if the relative velocity > 0, then one can proceed as follows : the observer installs a row of clocks that either are synchronized a ) by exchanging light signals according to the poincare - einstein synchronization, or b ) by \" slow clock transport \", that is, one clock is transported along the row of clocks in the limit of vanishing transport velocity. now, when the synchronization process is finished, the object is moved along the clock row and every clock stores the exact time when the left or the right end of the object passes by. after that, the observer only has to look after the position of a clock a that stored the time when the left end of the object was passing by, and a", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6165331523767728, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:2fbe42aa-32a3-4846-ad95-4d4d73815482>", "chunk_index": 1, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:29.548957"}
{"text": "stores the exact time when the left or the right end of the object passes by. after that, the observer only has to look after the position of a clock a that stored the time when the left end of the object was passing by, and a clock b at which the right end of the object was passing by at the same time. it ' s clear that distance ab is equal to length of the moving object. thus the definition of simultaneity is crucial for measuring the length of moving objects. in newtonian mechanics, simultaneity is absolute and therefore and are always equal. yet in relativity theory the constancy of light velocity in all inertial frames in connection with the relativity of simultaneity destroys this equality. so if an observer in one frame claims to have measured the object ' s endpoints simultaneously, the observers in all other inertial frames will argue that the object ' s endpoints were not measured simultaneously. the deviation between the measurements in all inertial frames is given by the lorentz transformation. as the result of this transformation ( see derivation ), the proper length remains unchanged and always denotes the greatest length of an object, yet the length of the same object as measured in another inertial frame is shorter than the proper length. this contraction only occurs in the line of motion, and can be represented by the following relation ( where is the relative velocity and the speed of light ) for example, a train at rest in s ' and a station at rest in s with relative velocity of are given. in s ' a rod with proper length is located, so its contracted length in s is given by : then the rod will be thrown out of the train in s ' and will come to rest at the station in s. its length has to be measured again according to the methods given above, and now the proper length will be measured in s ( the rod has become larger in that system ), while in s ' the rod is in motion and therefore its length is contracted ( the rod has become smaller in that system ) : thus, as it is required by the principle of relativity ( according to which the laws of nature must assume the same form in all inertial reference frames ), length contraction is symmetrical : if the rod is at rest in the train, it has its proper length in s ' and its length is contracted in s. however, if the rod comes to rest relative to the station, it has its proper length in s and its length is contracted in s '", "subdomain_id": "subdomain_quantum_metrology", "similarity_score": 0.6181686144926872, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:2fbe42aa-32a3-4846-ad95-4d4d73815482>", "chunk_index": 2, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:29.550743"}
{"text": "at rest in the train, it has its proper length in s ' and its length is contracted in s. however, if the rod comes to rest relative to the station, it has its proper length in s and its length is contracted in s '. lorentz transformation in an inertial reference frame s ', and shall denote the endpoints for an object of length at rest in this system. the coordinates in s ' are connected to those in s by the lorentz transformations as follows : as this object is moving in s, its length has to be measured according to the above convention by determining the simultaneous positions of its endpoints, so we have to put. because and, we obtain thus the length as measured in s is given by according to the relativity principle, objects that are at rest in s have to be contracted in s ' as well. for this case the lorentz transformation is as follows : by the requirement of simultaneity and by putting and, we actually obtain : thus its length as measured in s ' is given by : so ( 1 ), ( 3 ) give the proper length when the contracted length is known, and ( 2 ), ( 4 ) give the contracted length when the proper length is known. time dilation length contraction can also be derived from time dilation, according to which the rate of a single \" moving \" clock ( indicating its proper time ) is lower with respect to two synchronized \" resting \" clocks ( indicating ). time dilation was experimentally confirmed multiple times, and is represented by the relation : suppose a rod of proper length at rest in and a clock at rest in are moving along each other. the respective travel times of the clock between the rod ' s endpoints are given by in and in, thus and. by inserting the time dilation formula, the ratio between those lengths is : therefore, the length measured in is given by so the effect that the moving clock indicates a lower travel time in due to time dilation, is interpreted in as due to length contraction of the moving rod. likewise, if the clock were at rest in and the rod in, the above procedure would give geometrical representation the lorentz transformation geometrically corresponds to a rotation in four - dimensional spacetime, and it can be illustrated by a minkowski diagram : if a rod at rest in s ' is given, then its endpoints are located upon the ct ' axis and the axis parallel to it. in this frame the simultaneous ( parallel to the axis of x ' ) positions of", "subdomain_id": "subdomain_quantum_metrology", "similarity_score": 0.6059153489710666, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:2fbe42aa-32a3-4846-ad95-4d4d73815482>", "chunk_index": 3, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:29.553507"}
{"text": "- relativistic physics the ability should decrease at high speed, however, the lorentz contraction of the coulomb field leads to an increase of the electrical field strength normal to the line of motion, which leads to the actually observed increase of the ionization ability. lorentz contraction is also necessary to understand the function of free - electron lasers. relativistic electrons were injected into an undulator, so that synchrotron radiation is generated. in the proper frame of the electrons, the undulator is contracted which leads to an increased radiation frequency. additionally, to find out the frequency as measured in the laboratory frame, one has to apply the relativistic doppler effect. so, only with the aid of lorentz contraction and the rel. doppler effect, the extremely small wavelength of undulator radiation can be explained. another example is the observed lifetime of muons in motion and thus their range of action, which is much higher than that of muons at low velocities. in the proper frame of the atmosphere, this is explained by the time dilation of the moving muons. however, in the proper frame of the muons their lifetime is unchanged, but the atmosphere is contracted so that even their small range is sufficient to reach the surface of earth. reality of lorentz contraction another issue that is sometimes discussed concerns the question whether this contraction is \" real \" or \" apparent \". however, this problem only stems from terminology, as our common language attributes different meanings to both of them. yet, whatever terminology is chosen, in physics the measurement and the consequences of length contraction with respect to any reference frame are clearly and unambiguously defined in the way stated above. in 1911 vladimir varicak asserted that length contraction is \" real \" according to lorentz, while it is \" apparent or subjective \" according to einstein. einstein replied : the author unjustifiably stated a difference of lorentz ' s view and that of mine concerning the physical facts. the question as to whether the lorentz contraction really exists or not is misleading. it doesn ' t \" really \" exist, in so far as it doesn ' t exist for a comoving observer ; though it \" really \" exists, i. e. in such a way that it could be demonstrated in principle by physical means by a non - comoving observer. \u2014 albert einstein, 1911 due to superficial application of the contraction formula some paradoxes can occur. for examples see the ladder paradox or bell ' s spaceship paradox", "subdomain_id": "subdomain_quantum_optics", "similarity_score": 0.6277948187107886, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:2fbe42aa-32a3-4846-ad95-4d4d73815482>", "chunk_index": 6, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:29.560560"}
{"text": "way that it could be demonstrated in principle by physical means by a non - comoving observer. \u2014 albert einstein, 1911 due to superficial application of the contraction formula some paradoxes can occur. for examples see the ladder paradox or bell ' s spaceship paradox. however, those paradoxes can simply be solved by a correct application of relativity of simultaneity. another famous paradox is the ehrenfest paradox, which proves that the concept of rigid bodies is not compatible with relativity, and reduces the applicability of born rigidity. it also shows that for a co - rotating observer the geometry is in fact non - euclidean. visual effects length contraction refers to measurements of position made at simultaneous times according to a coordinate system. this could naively lead to a thinking that if one could take a picture of a fast moving object, that the image would show the object contracted in the direction of motion. however, it is important to realize that such visual effects are completely different measurements, as such a photograph is taken from a distance, while length contraction can only directly be measured at the exact location of the object ' s endpoints. in 1959 roger penrose and james terrell published papers demonstrating that length contraction instead actually shows up as elongation or even a rotation in a photographic image. this kind of visual rotation effect is called penrose - terrell rotation. see also - time dilation - ehrenfest paradox - ladder paradox - lorentz transformation - relativity of simultaneity - kennedy \u2013 thorndike experiment - trouton \u2013 rankine experiment - michelson \u2013 morley experiment three plane trigonometries trigonometry circular parabolic hyperbolic kleinian geometry euclidean plane galilean plane minkowski plane symbol e2 e0, 1 e1, 1 quadratic form positive definite degenerate non - degenerate but indefinite isometry group e ( 2 ) e ( 0, 1 ) e ( 1, 1 ) isotropy group so ( 2 ) so ( 0, 1 ) so ( 1, 1 ) type of isotropy rotations shears boosts cayley algebra complex numbers dual numbers split - complex numbers \u03b52 - 1 0 1 spacetime interpretation none newtonian spacetime minkowski spacetime slope tan \u03c6 = m tanp \u03c6 = u tanh \u03c6 = v \" cosine \" cos \u03c6 = ( 1 + m2 ) - 1 / 2 cosp \u03c6 = 1 cosh \u03c6 = ( 1 - v2 ) - 1 / 2 \" sine \" sin \u03c6 = m (", "subdomain_id": "subdomain_quantum_optics", "similarity_score": 0.6591648371318366, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:2fbe42aa-32a3-4846-ad95-4d4d73815482>", "chunk_index": 7, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:29.562686"}
{"text": "physics, chapters 33 - 37, john wiley & son, pp. 1032f, isbn 0470547944 - the physics of rhic - relativistic heavy ion collisions - gsi : heavy - ion induced electromagnetic interactions - simon hands, the phase diagram of qcd, contemp. phys. 42 : 209 - 225, 2001, arxiv : physics / 0105022 - sexl, roman & schmidt, herbert k. ( 1979 ), raum - zeit - relativitat, braunschweig : vieweg, isbn 3 - 528 - 17236 - 3 - flash the free - electron laser in hamburg ( pdf 7. 8mb ) - see for example physics faq : \" people sometimes argue over whether the lorentz - fitzgerald contraction is \" real \" or not... here ' s a short answer : the contraction can be measured, but the measurement is frame dependent. whether that makes it \" real \" or not has more to do with your choice of words than the physics. \" - einstein, albert ( 1911 ). \" zum ehrenfestschen paradoxon. eine bemerkung zu v. varicaks aufsatz \". physikalische zeitschrift 12 : 509 \u2013 510. ; original : der verfasser hat mit unrecht einen unterschied der lorentzschen auffassung von der meinigen mit bezug auf die physikalischen tatsachen statuiert. die frage, ob die lorentz - verkurzung wirklich besteht oder nicht, ist irrefuhrend. sie besteht namlich nicht \u201e wirklich \u201c, insofern sie fur einen mitbewegten beobachter nicht existiert ; sie besteht aber \u201e wirklich \u201c, d. h. in solcher weise, da\u00df sie prinzipiell durch physikalische mittel nachgewiesen werden konnte, fur einen nicht mitbewegten beobachter. - james terrell ( 1959 ). \" invisibility of the lorentz contraction \". physical review 116 ( 4 ) : 1041 \u2013 1045. bibcode : 1959phrv.. 116. 1041t. doi : 10. 1103 / physrev.", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6625680509534614, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:2fbe42aa-32a3-4846-ad95-4d4d73815482>", "chunk_index": 9, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:29.566948"}
{"text": "briefly, the csa breaks up the input ciphertext into a list of words, and recursively tries to fit as much of the list as possible to the words in a fairly long list of english words, longest word first. it tries to find the trial solution with the maximum number of words fitted with the same key, among all the recursive tree walks made. the csa is very strongly dependent on the input having the word boundaries and lengths correct, so that, for example, a ciphergram redivided into five letter groups will not work. it is a little less dependent on having no wrong letters in the text, but it thinks words of three letters or less are all exact and in its word list, so a mistake in a short word will almost surely cause it to fail. two newspaper cryptoquotes in 1997 had the word \" oh \" in them, and because that word was not in the known word list, they failed, so now the list contains \" oh \". the \" los \" of los angeles tripped the csa once. nearly all cases that take a long time are caused by input having a letter left out of a word, or a wrong letter in a short word. the csa knows no grammar or word meanings. it is merely a brute - force pattern matching algorithm. the upside is that you could replace the word list with, for example, a fairly complete and very accurate german list, and the csa would solve german ciphergrams. the csa usually does not get stumped on the cryptoquotes in the newspapers ; that ' s probably because those have to be relatively easy. last updated 2002 september 17", "subdomain_id": "subdomain_quantum_cryptography", "similarity_score": 0.6069907768577629, "token_count": 334, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:bf9e0271-aaa2-4020-9647-8372c07cd99e>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:29.835211"}
{"text": "the inquiry project research addresses three main questions : - what changes occur as children move from judgments based on their direct experiences and their perception to a model - mediated understanding of matter? - how does quantitative reasoning play a role in students \u2019 changing understanding of matter? - how effective is the inquiry curriculum in promoting such developments? the longitudinal research focuses on students \u2019 developing concepts of material, weight, volume, density, matter and state of matter from ages 8 \u2013 11 ( see curriculum grade 3, grade 4, and grade 5 ). students at the same grade level, who received their school \u2019 s regular science instruction, serve as a control group for evaluating the impact of the inquiry project. our work builds on a long term learning progression for matter and the atomic - molecular theory showing that children \u2019 s initial concepts of object, material, size, and weight - - each grounded in direct perceptual experience - - must undergo major adjustments to become consistent what scientists now know about matter ( smith, wiser, anderson, & krajcik, 2006 ; wiser & smith, 2008 ). for example, - young children initially believe that tiny objects have no weight. - they fail to realize that liquids, solids and gases are made up of the same, invisibly small, building blocks. - more generally, they believe that their unaided senses provide a trustworthy account of scientific phenomena. this overreliance on perceptual appearances interferes with learning about atoms, molecules and processes that cannot be directly observed. our work also builds on prior studies of the development of quantitative reasoning ( schliemann & carraher, 1992 ; carraher, 1996 ) showing that : - people \u2019 s reasoning about physical quantities often differ in significant ways from reasoning about numbers. - proportional reasoning relies on a shift from numbers as counts to numbers as measures and as ratios. here we provide an initial glimpse into what we are learning from our longitudinal study about how elementary children begin to construct meaningful models of matter and materials both with and without the support of the inquiry curriculum. carraher, d. w. \" learning about fractions. \" ( 1996 ) in theories of mathematical learning, edited by leslie p. steffe, perla nesher, gerald goldin, paul cobb and brian greer. hillsdale, nj : erlbaum. schliemann, a. d. and d. w. carraher ( 1992 ). proportional reasoning in and out of school. in p. light and g. butterworth ( eds.", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.675173955927495, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:defaea9b-a8c9-45c3-9631-236ebf96c0b9>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:29.899245"}
{"text": "he1327 - 2326 with the least heavy elements. the top panel shows the low - dispersion spectrum while the bottom panel is the high dispersion spectrum captured by subaru telescope ' s hds ( high dispersion spectrograph ). the solar spectrum has many absorption lines that are caused by the heavy elements at its surface. in contrast, the spectrum of he1327 - 2326 shows almost no absorption lines due to the lack of heavy elements. in the milky way galaxy, there survives a type of star that was born very early in the history of the universe. how did it form? just after the \" big bang, \" the universe consisted of only hydrogen and helium. the first stars were thought to contain no heavy elements. subaru telescope has discovered such a primordial stars having lowest content of heavy elements known to date. its chemical composition may hold information that could lead us to a better understanding of what the first stars were like. commentary from dr. nobuo arimoto, professor at naoj : subaru telescope excels at extensive imaging, and succeeded in discovering the halo structure of a dwarf galaxy for the first time. due to this discovery we can understand that even a dwarf galaxy has a complex history of formation. it is expected that in the future, further systematic research of this halo structure will show that it is an attribute of many galaxies that exist in our local group.", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6010102170521602, "token_count": 287, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:165dc187-2b42-4695-a026-239367bb4b97>", "chunk_index": 1, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:30.085649"}
{"text": "one of the unwritten rules of physics says you can ' t get something for nothing ; at best, you can manage a fair exchange rate between how much energy you pump into a system and how much you coax out of it. consider your car : on average, only 12. 6 percent of the chemical energy you pump in at $ 3. 50 - plus ( or whatever you pay ) per gallon translates into motion. the rest goes to overcoming drag, inertia and other mechanical inefficiencies, with a whopping 62. 4 percent consumed by engine friction, air pumps and waste heat [ source : california energy commission ]. heat crops up in all sorts of systems. like an energy embezzler, it skims off the top of chemical reactions, physical systems and electrical circuits. whether it ' s the consequence of lost efficiency or its cause, the upshot is you ' re taking a loss in the deal. heat is why we can ' t achieve perpetual motion ( or movement that never ceases ). it ' s also the reason power plants must amp up current to high voltages when transmitting it across country : to overcome energy lost to resistance - - friction ' s electrical counterpart. imagine if we could find a way to remove resistance, thereby eradicating energy loss : no service charges, no taxes and no protection money. energy in = energy out. enter superconductors. if the three laws of thermodynamics say that there ' s no such thing as a free lunch, then superconductors have their cake and eat it, too. send current through a superconducting wire, and it loses no energy to resistance. bend the wire into a loop, and it will hold charge indefinitely. levitate it above a magnet, and the sun will devour the earth before it will fall. soon after its discovery in 1911 by dutch physicist heike kamerlingh onnes and his collaborators, cornelis dorsman, gerrit jan flim and gilles holst, superconductivity inspired dreams of no - loss electrical transmission. unfortunately, there was a catch. superconductors require very cold temperatures, on the order of 39 kelvins ( minus 234 c, minus 389 f ) for conventional superconductors. the solid mercury wire that kamerlingh onnes used required temperatures below 4. 2 k ( minus 269. 0 c, minus 452. 1 f ). even so - called high - temperature supercondu", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6411664870153176, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:9d6f0d52-ccc7-40c4-a4aa-856701c7b98d>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:30.314351"}
{"text": "unless otherwise indicated, all glossary content is : ( c ) copyright 2008 - 2013 dominic john repici ~ all rights reserved ~ no part of this content may be copied without the express written permision of dominic john repici. also known as a neurode, or artificial neuron when used in the context of an artificial neural network ( ann ). in essence, a neuron ' s primary function is to receive a multitude of input signals from external sources, or from other neurons in the neural network, and produce an output signal. a typical neuron in an ann produces a single output value ( called an axon level in netlab ) that roughly represents the weighted combination of the values on its inputs, called synapses. the neuron ' s axon can be connected to the inputs of other neurons, or to outside processes. other neurons ( and input devices ) are connected through the neuron ' s input synapses. these synapses modulate, or gate, the input signals connected to them by weight values before combining them together to form the neuron ' s output. in floating point math, the input values are simply multiplied by the weight values to gate them. because weight values can be adjusted in response to stimuli, the output represented on the neuron ' s axon is further modified by changes the weight values undergo during training. in essence, weight - values represent connection strengths between the neuron and the connected axon, which are the primary mechanism for providing memory in neural networks. neurons in netlab also contain adaptive inputs, which are not shown in the above diagram........ in biological nervous systems, a neuron is a single cell with exaggerated signaling capabilities. the output values are represented by all - or - nothing pulses, called action potentials. in artificial neural networks a neuron is a process element that mimics some aspects and characteristics of a biological neuron. in essence, a neuron, whether biological or simulated, comprises inputs called synapses which are connection - points that connect signals from other neurons and external sources. neurons also have outputs called axons, which carry the neuron ' s output signals to other neurons and external sources.", "subdomain_id": "subdomain_quantum_computing", "similarity_score": 0.6233035623618506, "token_count": 449, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:594aea9d-9d09-405c-9087-38ddcd72a8dc>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:30.636054"}
{"text": "set or another, when it \u2019 s really just a slot in the system of natural numbers. the peano axioms don \u2019 t talk about \u201c cardinality \u201d, and we can \u2019 t build a definition of such a purely set - theoretical concept out of what properties it does discuss. the answer to the question is \u201c! \u201d ( \u201c mu \u201d ). the bourbaki definition doesn \u2019 t define the natural numbers, but merely shows that within the confines of set theory one can construct a model satisfying the given abstract axioms. this is how mathematics works at its core. we define a system, including basic pieces and relations between them. we can use those pieces to build more complicated relations, but we can only make sense of those properties inside the system itself. we can build models of systems inside of other systems, but we should never confuse the model with the structure \u2014 the map is not the territory. this point of view seems to fetishize abstraction at first, but it \u2019 s really very freeing. i don \u2019 t need to know \u2014 or even care \u2014 what particular set and functions define a given model of the natural numbers. anything i can say about one model works for any other model. as long as i use the properties as i \u2019 ve defined them everything will work out fine, and whether i use bourbaki \u2019 s model or not. sooner or later i \u2019 ll have to use relations, so i may as well get the basics nailed down now. a relation between two sets and is just a subset of their cartesian product. that is, it \u2019 s a collection of pairs. often we \u2019 ll write when is in the relation. a function is a special kind of relation where each element of shows up on the left of exactly one pair in. in this case if is in the relation we write. remember from our discussion of functions that i was saying every element of has to show up both at least once and at most once ( that is, exactly once ). a surjection is when every element of shows up on the right side of a pair in at least once, and an injection is when each element in shows up at most once. also interesting are the following properties a relation between a set and itself might have : - a relation is \u201c reflexive \u201d if for every in. - a relation is \u201c irreflexive \u201d if is never true. - a relation is \u201c symmetric \u201d if whenever then also. - a relation is \u201c antisymmetric \u201d if", "subdomain_id": "subdomain_quantum_cryptography", "similarity_score": 0.6169704564740708, "token_count": 511, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:89284d3d-c966-4bb7-855e-d5fcd98c7096>", "chunk_index": 9, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:30.836502"}
{"text": "( from www. soilhealth. com ) ave : class of animals that are referred to as \u201c true birds \u201d, including domesticated poultry. biodiversity ( or biological diversity ) : the variation of life forms within a given ecosystem, biome or for the whole planet. it exists at three main levels : 1. the combinations of species that make up different ecosystems ; 2. the number of different species ; and 3. the different combinations of genes in species ( adapted from bioversity www. bioversity. org ). biodynamic ( bd ) agriculture : based on a series of lectures and conversations with austrian philosopher rudolf steiner, this approach to agriculture relates the ecology of the earth - organism to that of the entire cosmos. the farm is seen as a \" living organism \" and an important core concept is the necessity to take care of the living soil. ( for more information and linked resources, see the website of the biodynamic farming and gardening association in north america, at : www. biodynamics. com ) bioenergy : energy derived from biomass - based fuels. many processes are available for producing bioenergy. these range from conventional ( direct ) uses of biomass such as burning of sticks and branches to generate energy for cooking and heating, to modern ( indirect ) production processes involved in biofuels ( see definition below ), such as converting sugar and starch crops to ethanol to even more advanced technologies such as gasification of wood chips for transport fuel production ( fao ). biofuel : solid, liquid or gaseous fuel obtained from relatively recently lifeless biological material ( biomass ) and is different from fossil fuels, which are derived from biological material that has been dead for a long time. biofuels based on plants can be produced in two main ways : one is to grow crops high in sugar ( e. g. sugar cane, sweet sorghum ) or starch ( maize ), to be fermented to produce ethyl alcohol ( ethanol ) ; the second is to grow plants that contain high amounts of vegetable oil ( e. g. oil palm, soybean, jatropha ). heating these oils allows them to be burned directly in a diesel engine, or they can be chemically processed to produce fuels such as biodiesel. biogas : typically refers to a gas produced by the biological breakdown of organic matter in the absence of oxygen. biogas is a type of biofuel. bio - intensive agriculture : a sustainable 8 - step food - raising", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6184228381677628, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:164a18d0-9d50-4859-9796-8550195b0da6>", "chunk_index": 2, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:31.213724"}
{"text": "that capture carbon dioxide and store it in such a way that it cannot be released into the atmosphere. carrying capacity : refers to the number of individuals who can be supported in a given area within natural resource limits, and without degrading the natural social, cultural and economic environment for present and future generations. the carrying capacity for any given area is not fixed. it can be altered by improved technology, but mostly it is changed for the worse by pressures which accompany a population increase. as the environment is degraded, carrying capacity actually shrinks, leaving the environment no longer able to support even the number of people who could formerly have lived in the area on a sustainable basis. no population can live beyond the environment ' s carrying capacity for very long ( definition from urban environmental management webpage on ecological footprints ). cash crop : a commercial crop as opposed to a subsistence crop, which is used for the family \u2019 s own consumption needs. catchment : see definition for \" watershed \". cellulose : main component of the primary cell wall of green plants civil society : includes all actors in the public domain ( except the government and the military ) grouped together. examples are networks and groups such as farmers ' organisations, associations, non - governmental organisations and unions, etc. by forming farmers ' organisations, whether they are co - operatives, unions or associations, ( small - scale ) farmers can influence policies and governance in their countries by entering into civil society platforms. having a strong civil society is an important part of working towards good governance in our countries - to get farmers ' rights, needs and concerns addressed by those in power. climate change : otherwise known as \" global warming \" or the \" greenhouse effect \", this is based on consistent observations that the earth is warming up : global temperatures are rising much more quickly than normal, snow and ice is melting, and the global average level of the sea is rising. because of global warming, more frequent and intense heat waves, storms, flooding and drought are projected around the world. this has a great impact on the further loss of biodiversity and degradation of land, soil, forest, freshwater and oceans ( see leisa magazine \" dealing with climate change \" volume 24 no. 3 ). collateral : proof of security in obtaining a loan - for small - scale farmers this is a problem as it involves needing to hold capital in their farms ( e. g. land, machinery, cattle ) or that someone outside the household be willing to provide the security for the farmer. commodity : an economic term, referring to a good for which", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.60212163363096, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:164a18d0-9d50-4859-9796-8550195b0da6>", "chunk_index": 4, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:31.215781"}
{"text": "problem as it involves needing to hold capital in their farms ( e. g. land, machinery, cattle ) or that someone outside the household be willing to provide the security for the farmer. commodity : an economic term, referring to a good for which there is demand that but which is equivalent no matter who produces it. commodities are basic resources ( e. g. iron ore, crude oil, copper, gold and aluminum ) and agricultural products ( e. g. salt, sugar, coffee beans, soyabeans, wheat, rice ). commensalism : the symbiotic relationship where one organism benefits and the other is unaffected. an example is found in spiders that benefit from plant leaves in spinning a web on them, while the plant remains unharmed by the presence of the spider. common pool resources : the broad diversity of collectively inherited or produced resources ( and resource systems ) which citizens have a political and moral interest in controlling and managing within their communities. these resources can be natural ( e. g. groundwater, surface water, oceans, mineral resources, genes the atmosphere ), social or cultural ( e. g. traditional know - how and practices, seeds and herbs ). a common pool resource is based on a number of ideal principles : fair access, equitably shared benefits, mutual responsibility for preserving the resources, and democratic and transparent decision - making. it is also referred to as \" common property \" or simply \" the commons \". companion planting : see inter - cropping. competition : an association between two organisms in which both become harmed. an example is when plants compete for water and nutrients, but survive in weakened states as both have too little of the resources they need for good growth. complementarity : relates to different elements helping other to grow better ( e. g. when one crop provides protection against pests, or increase the availability of nutrients, for another crop - these can be planted close together to enhance the beneficial elements ). concession : a business operated under a contract or license associated with a degree of exclusivity in business within a certain geographical area. the owner of the concession either pays a fixed sum or a percentage of revenue to the entity with the ability to assign exclusive rights for an area or facility. examples of concessions include deforestation companies, mining companies - or sports arenas or public parks with concession stands. public services such as water supply may also be operated as concessions. conservation agriculture : ( also known as conservation farming or conservation tillage ) : this is a concept for resource - saving", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6314280645218104, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:164a18d0-9d50-4859-9796-8550195b0da6>", "chunk_index": 5, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:31.216778"}
{"text": "to which it is linked, such as a share or a currency. a derivative is not a stand - alone asset, since it has no value of its own. however, more common types of derivatives have been traded on markets before their expiration date as if they were assets. among the oldest of these are rice futures, which have been traded on the dojima rice exchange ( in japan ) since the eighteenth century. desertification : persistent degradation of land in dry regions because of climatic variations and human activities. diversification : in terms of income, this refers to the situation of having a number of different income sources in order to decrease risks of depending on only one source ; in terms of diversification in farming, it also refers to spreading risks by having a number of different strategies and products in the farming system. diversity : essentially, this refers to differences ; in farming this relates to different elements ( e. g. crop or livestock varieties ) performing the same function. see also definition for biodiversity above. ( see leisa magazine \" farming diversity \" march 2009 vol 25 no. 1 ) documentation : see \u201c systematisation \u201d. double - cropping : a second crop is planted immediately after the first has been harvested ; this differs from relay cropping ( see below ) in timing of the second planting. ecoagriculture : a concept coined by sara scherr and jeffrey mcneely in a report that includes three pillars ( 1. enhance rural lively hoods ; 2. conserve or enhance biodiversity and ecosystem services ; and 3. develop more sustainable and productive agricultural systems ). it calls for agriculture to be looked at from the landscape scale rather than at individual farm level, in order to be able to become sustainable. ( for more information and links to resources, see the ecoagriculture website at : www. ecoagriculture. org ) ecological footprint : a measure of human demand on the earth ' s resources and ecosystems. it compares human demand with the capacity for the planet to regenerate the ecological resources used. ecology : the study of how organisms interact with each other and with the environment. ecosystem : a dynamic complex of plants, animals and micro - organism communities and their non - living environment interacting as a functional unit in a certain place ( from convention on biological diversity ). ecosystems make up big natural systems such as grasslands, mangroves, coral reefs and tropical forests, but also agro - ecosystems, which are highly dependent on human activities for their existence and maintenance. el nino : a situation when the the", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6024210048721519, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:164a18d0-9d50-4859-9796-8550195b0da6>", "chunk_index": 8, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:31.221474"}
{"text": "the small - scale farmers ' global advocacy organisation, la via campesina ( http : / / viacampesina. org / main _ en / ). free trade : an agreement between countries or regions that remove restrictions on trade transactions, such as tariffs or barriers to trade, import duties or protective measures. futures contracts : a financial term, this is a standardised contract between two parties to buy or sell a specified asset ( eg. oranges, oil, gold ) of standardised quantity and quality at a specified future date at a price agreed today ( the futures price ). the contracts are traded on a \" futures exchange \". gene revolution : a term for the large scale application of biotechnologies in food production, for example thought the development and use of gmos. like with the green revolution, there is much faith in new technologies. its use is seen as the panacea to world hunger, disregarding the many disadvantages concerning loss of biodiversity, environmental degradation and social implications. gene sequences : genes are long strings of instructions for making proteins ( which are the building blocks of life ). these instructions are coded by a 4 - letter alphabet, the dna bases, which are called \" gene sequences \". genetically modified organism ( gmo ) : an organism whose genes have been altered using \" genetic engineering \" techniques that transfer dna molecules from different sources into an organism, giving it modified or new genes. genetic diversity : the total number of genetic characteristics in the genetic makeup of a species. genetic engineering ( ge ) : the alteration of genetic code by artificial means, and is therefore different from traditional selective breeding, in which the organism ' s genes are manipulated indirectly. although scientists knew about the existence of genes and dna earlier, it was not until the 1970s that gene sequences and the fact that genes could be split into segments were discovered. these discoveries made ge possible. genetics : the science of heredity and variation in living organisms. globalisation : the integration of markets and cultures across countries and continents. glut : when there is an oversupply of a good such that the market supply is greater than the demand. good governance : good governance primarily has to do with how effectively a government functions, and serves all of its citizens. it refers to rules and how agreements are made between a government, its citizens as well as businesses. good governance exists if citizens have a say in how their country is governed - such that even the views of minorities are taken into account and the voices of the most vulnerable in society are heard", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6199532805371519, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:164a18d0-9d50-4859-9796-8550195b0da6>", "chunk_index": 12, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:31.225903"}
{"text": "environmental policy tool that is becoming increasingly important in developing and developed countries. ( definition from fao : see the fao webpage devoted to this subject for more information : http : / / www. fao. org / es / esa / pesal / index. html ) percolation : the movement and filtering of fluids through porous materials, such as the movement of water through the soil. perishable food : food that can decay or rot quickly if not refrigerated or taken care of in another way ( e. g. through drying, salting, canning, etc. ). permaculture : the term \" permaculture \", coined by bill mollison and david holmgren, is a blend of \" permanent agriculture \" and \u201c permanent culture \u201d. the goal is perennial agricultural systems that mimic the structure and interrelationships found in natural ecologies. originating as an agroecological design theory, it freely borrows techniques and cultural systems from organic agriculture, sustainable forestry, horticulture, agroforestry and the land management systems of indigenous peoples, developing organising principles that are transferred through two - week intensive permaculture design courses around the world. ( for more information and links to resources, see the permaculture research institute of australia \u2019 s website at : www. permaculture. org. au ) pests : unwanted animals that limit crop production potential. usually this refers to insects but it also includes larger animals such as birds or rabbits that cause damage to crop growth. ph : in agriculture, soil ph is an important measure of nutrient availability. the ph scale, running from 0 to 14, measures how acid or alkaline the soil is. ph is the concentration of hydrogen ( h ) ions - - the more hydrogen ions there are, the more acid the soil is. many environmental factors, including amount of rainfall, vegetation type and temperature can affect soil ph. the ideal ph for most plants and the soil food web is between 6. 5 and 7. sources : wikipedia and acid or alkaline? what ph means in gardenspeak, at www. plantea. com / ph. htm ( blog by marion owen ). photosynthesis : process by which plants convert carbon dioxide into organic compounds, especially sugars, using energy from sunlight. phytosanitary standards : in order to import products, export country governments must be able to satisfy import regulations of the import government with a certificate that indicates that the shipment has", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6132336538278346, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:164a18d0-9d50-4859-9796-8550195b0da6>", "chunk_index": 23, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:31.237630"}
{"text": "is then fed back and used to make decisions about actions to be implemented to improve project performance. the lessons learnt are shared with others. ( from selener, purdy & zapata, 1998 ) systems thinking : a framework for understanding how things work, as well as problems that may need to be solved. it is based on the belief that the different parts that make up a system can best be understood by looking at them in relation to each other and to other systems, rather than in isolation. the only way to fully understand why a problem or element occurs and persists is to understand the part in relation to the whole. another way of describing systems thinking is as a framework for seeing interrelationships rather than things, for seeing patterns of change rather than static \" snapshots \" ( from the fifth discipline, the art and practice of the learning organization, senge, ( doubleday : 1990 ) ). tariff : a kind of tax is usually imposed on imported goods as a way of controlling trade between nations. when shipments of goods arrive at a border crossing or port, customs officers inspect the contents and charge a tax according to the tariff formula. since the goods cannot continue on their way until the duty is paid, it is the easiest duty to collect, and the cost of collection is small ( modified from wikipedia ). \" terminator \" and \" traitor \" seed : these are two controversial biotechnologies owned by major agrochemical companies, relating to genetically modified organisms. the former relates to modified seed of first generation crops that yield sterile seeds in the second generation. traitor technology relates to \" genetic use restriction technology \" which requires farmers to apply a chemical to gm crops to be able to reactivate desired engineered traits. these technologies are intended to both limit the spread of gm plants, and to require farmers to pay for new seed every year, and in the latter case to pay for the required chemicals as well. terms of trade ( or tot ) : in international economics and international trade, this refers to a country \u2019 s exports ( price ) divided by imports ( price ). an improvement in a nation ' s terms of trade is good for that country in the sense that it has to pay less for the products it imports. terms of trade are therefore widely used as an instrument to measure the benefits derived by a nation from international trade. tillage : the disturbance of soil to create the best conditions for seed germination and eventual plant growth. topography : the physical features of land, including terrain relief. transaction :", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6280404632366079, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:164a18d0-9d50-4859-9796-8550195b0da6>", "chunk_index": 28, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:31.242641"}
{"text": "an instrument to measure the benefits derived by a nation from international trade. tillage : the disturbance of soil to create the best conditions for seed germination and eventual plant growth. topography : the physical features of land, including terrain relief. transaction : is basically any sort of activity involving a change of money in an account ( e. g. putting money into or withdrawing money from an account, adding interest to an account or deducting bank charges are all transactions ). transboundary breed : a breed that is found in several country. transboundary species of the five major livestock species ( cattle, sheep, goats, pigs and chickens ), have been developed for a century or more in intensive production systems, and have spread globally. they are generally bred to provide a single product for the market and require high levels of modern inputs and technologies. a very small number of international transboundary breeds accounts for an ever - increasing share of total global production of animal products. yet it is only in north america and the southwest pacific that the number of transboundary breeds exceeds that of local breeds. transboundary disease : as the name suggests, transboundary diseases can easily spread across national and international borders. however, the classification generally focuses on diseases that have a significant economic impact and the ability to disrupt national and international trade. turgidity : the pressure inside a plant \u2019 s cells, that shows it to be growing strong and healthily. ungulate : hoofed animals including domesticated livestock such as cows, goats, camels, horses that are herbivores with vegetable - based diets. pigs are also ungulates, but have a mixed diet. urbanisation : is defined by the united nations as movement of people from rural to urban areas with population growth equating to urban migration. the united nations projected that half of the world ' s population would live in urban areas at the end of 2008. value - based management : a structured approach to measure the performance of a firm ' s unit managers or products in terms of the net benefit they provide to shareholders. value chain : refers to the entire system of production, processing and marketing of a particular product, from inception to the finished product. a value chain consists of a series of chain actors, linked together by flows of products, finance, information and services. variety : genetic variation within a species. vesicles : structures formed inside the plants ' roots, by three of the five genera of arbuscular mycorrhizas. they look like", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6046297074867525, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:164a18d0-9d50-4859-9796-8550195b0da6>", "chunk_index": 29, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:31.243591"}
{"text": "by flows of products, finance, information and services. variety : genetic variation within a species. vesicles : structures formed inside the plants ' roots, by three of the five genera of arbuscular mycorrhizas. they look like an oval bag and most people believe that they are used for storing nutrients. ( from http : / / www. soilhealth. com ) volatilisation of nutrients : chemical process through which gaseous forms of nutrients ( e. g. nitrogen as ammonia ) are directly lost from the soil and into the air. water - logging : saturation of the soil by groundwater such that agriculture is prevented or hindered. watershed : simply put, a watershed refers to an area of land where all of the water that is flowing over or under it drains into the same place. it includes rain ( or snow melt ), streams, groundwater, lakes, ponds, aquifers and wetlands. a watershed is separated from adjacent watersheds by a geographical barrier such as a hill or a mountain, which is known as a \" water divide \". weed : unwanted plant that limits crop production potential. wellbeing : this indicator of quality of life is difficult to measure as it depends on many things such as culture, level of education and personality, but at least one \u2019 s basic human needs, such as food, water and shelter need to be met, while also having certain access to health care, education and political freedoms are also part of wellbeing. wholesaler : a trader that deals with large volumes of different commodities. wilting point : the minimal point of soil moisture that a plant requires not to wilt. if moisture decreases below this point, a plant wilts and can no longer recover its turgidity ( the pressure inside the plant cells ) even when soil moisture is replenished. the wilting point is a constant ( characteristic ) of a particular soil. worldview : a term for the overall perspective from which a person or group sees and interprets the world, and their collection of beliefs about life and the universe. it refers to assumptions and images that have an effect on people ' s motivations in life and in our case their farming goals. world view also refers to how people view their position in terms of gender equality, relationship with nature, etc. ( for more on worldview : the compas network for endogenous development specifically devotes attention to this subject ( www. compasnet. org ) ). zero - grazing : confining rumina", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6058570423397447, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:164a18d0-9d50-4859-9796-8550195b0da6>", "chunk_index": 30, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:31.244751"}
{"text": "material because fibers composed of more than one type of biomolecule are difficult to produce. using a water - based chemical process, ibn scientists were able to construct tissue fibers from two biomolecular materials - peptides and dna. the researchers flanked two droplets of the oppositely charged peptide and dna molecules after it has been dissolved in water. upon contact, the droplets zipped together to form a two - component fiber. fiber formation presumably occurs from the electrostatic interaction between the positively charged peptide molecule and the negatively charged dna molecule. through the same procedure, baculoviral vectors were added to the dna solution to coat the virus with the fibers. dr shu wang shared, \" for the very first time, we have shown that two biomolecules, namely peptides and dna, can interact with each other to form structured fibers in a test tube. since these biomolecules are readily metabolized in the human body to naturally occurring molecules and have no adverse toxicity, they hold strong biomedical potential for the delivery of therapeutic drugs, genes, proteins and viruses to combat cancer. \" \" this innovative application of microfibers with viral vectors is an exciting development for gene therapy that was made possible through multidisciplinary collaboration between biologists, chemists and materials scientists at ibn. our fibrous materials are also of great interest as biocompatible tissue engineering scaffolds for applications in regenerative medicine, \" said professor jackie y ying, executive director, ibn.", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6030210418557125, "token_count": 306, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:c75edecd-c4bc-4b81-8212-c2a2fabab16b>", "chunk_index": 1, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:31.696038"}
{"text": "1. a flat wing - shaped process or winglike part of an organism. 4. the doctrine that reality consists of a single basic substance or element. 10. ( computer science ) a computer that is running software that allows users to leave messages and access information of general interest. 13. an informal term for a father. 14. the mountain peak that noah ' s ark landed on as the waters of the great flood receded. 15. a reproach for some lapse or misdeed. 16. title for a civil or military leader ( especially in turkey ). 17. relating to the blood vessels or blood. 19. a genus of ploceidae. 21. surveying instrument consisting of the upper movable part of a theodolite including the telescope and its attachments. 22. an associate degree in nursing. 26. mild yellow dutch cheese made in balls. 27. fatty pinkish flesh of small salmon caught in the pacific and great lakes. 31. a large fleet. 33. a small asian country high in the himalayas between india and tibet. 34. the cry made by sheep. 35. lacking or deprive of the sense of hearing wholly or in part. 37. the compass point midway between northeast and east. 39. a gradual decline ( in size or strength or power or number ). 42. a loloish language. 45. conforming to truth. 46. a class of proteins produced in lymph tissue in vertebrates and that function as antibodies in the immune response. 47. a meeting of spiritualists. 50. cut the head of. 54. ( psychology ) an urge to withdraw or avoid a situation or an object. 56. genus of western united states annuals with showy yellow or white flowers. 57. a coenzyme derived from the b vitamin nicotinic acid. 58. german romantic poet ( 1787 - 1862 ). 61. a condition ( mostly in boys ) characterized by behavioral and learning disorders. 62. a loose sleeveless outer garment made from aba cloth. 63. united states writer remembered as the secretary and companion of gertrude stein ( 1877 - 1967 ). 64. relating to or characteristic of or occurring on the sea or ships. 1. ( babylonian ) a demigod or first man. 2. goods ( or wreckage ) on the sea bed that is attached to a buoy so that it can be recovered. 3. ( babylonian ) god of storms and wind. 4. a member of the siouan people formerly living in", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6114539438413009, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:e014b6c4-5565-4f68-b938-cd2fc659cf02>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:31.919824"}
{"text": "##s of dimension a by b plus a square of side ( b - a ). this is the previously used pyfudgerean hop likewise, figure 4 is a visual representation of the theorem of pyfudgerous. the large square of side h is of the same area, h\u00b2, as the four triangles, \u00bdab each, plus the small square, ( b - a ) \u00b2. one of the interesting features of figure 4 is the fact that it is a square expressed in terms of a ring of four triangles plus a smaller square. there must be some reduction factor, r, that will shrink figure 4 into its own central square. figure 5 shows one such shrinkage and figure 6 shows an infinity of such stepped shrinkages. this is a fascinating picture. it spirals inwards and indefinite zooming in upon the centre reveals an unending, repeating structure. i am going to call figure 6 the fractile of pyfudgerous. ( a fractile is a fractal that tiles the plane ) the mathematical principle behind this process is outlined in box 1. notice that it could be applied to any ringed square such as figure 3, for example. in fact, it can be applied to any ringed shape, as illustrated by figures 7 and 8. box 1 reveals that all such diagrams represent the sum to infinity of a geometric progression, a topic tackled early on in all a - level mathematics courses. mathematics review, november 1993, volume 4, number 2. \u00a9 philip allan publishers limited. issn 0957 - 1280 the following figure was submitted with the article but not published. bonus figure not used by the publisher all images, text and file downloads \u00a9 2004 - 2012, the mathmagical software company.", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6071071174515907, "token_count": 358, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:d549566b-e6e9-4008-8719-66f3335e174c>", "chunk_index": 2, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:33.066482"}
{"text": "part of the whole. frail, delicate, easily broken. a part broken away from a whole. a detached, incomplete part. 1. the basic, skeletal structural around which a building is built and which gives it its shape or form. 2. the border or case into which a window or door is set which serves as a structural support. 3. to enclose in or to provide a border for. the skeletal structure of a building. construction of the framework of a house. also referred to as framing clips, these metal fasteners connect the framework and reinforce joints of a building. also referred to as framing anchors, these metal fasteners connect the framework and reinforce joints of a building. type of framing used in two - story homes where one - piece studs extend from the foundation to the roof and form the walls of both stories. the completion or finishing of structural framework. used to lock framing pieces together, these fasteners are made of 16 or 18 gauge zinc - coated metal with pre - punched nail holes. they are set between the pieces of frame and attached with either nails or screws, locking the members together. this method is faster than using nails along. also called a carpenter ' s square, this flat l - shaped measuring tool, also called a framing square, is used to calculate lengths and lay out angles. the legs of the l, which come together at a right angle, have measuring tables and marks for rafter cuts etched into them. markers and attachments, which can be used on a framing, square for making repeat measurements accurately. the intentional use of deception to cause another to suffer loss. federal home loan mortgage corporation ( fhlmc ). commonly known as freddie mac. the company buys mortgages from lending institutions, pools them with other loans and sells shares to investors. property title which has no encumbrances, including mortgages, judgments, and financial liens the entire area of an inlet / outlet opening that is used for air passage in an hvac system. open and competitive trading. estate in which ownership is for an indeterminate length of time. unlimited interest in a property. freehold estates include freehold in deed, a fee simple estate ; freehold in law, an inheritable estate ; and determinable freeholds, a life estate. fine - grained stone that is even in texture that can be worked with masonry tools without splitting along a particular line. a condition that occurs when ice forms at the edge of the roofline, forcing water", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.600230301603571, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:45f6211c-bff4-44a7-b216-f54cd1ae40c2>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:33.145629"}
{"text": "padd : see petroleum administration for defense district ( below ). parallel path flow : as defined by north american electric reliability council, this refers to the flow of electric power on an electric system ' s transmission facilities resulting from scheduled electric power transfers between two other electric systems. ( electric power flows on all interconnected parallel paths in amounts inversely proportional to each path ' s resistance. ) particulate matter ( pm ) : unburned fuel particles that form smoke or soot and stick to lung tissue when inhaled. a chief component of exhaust emissions from heavy \u2013 duty diesel engines. passive solar energy : use of the sun to help meet a building ' s energy needs by means of architectural design such as arrangement of windows and materials such as floors that store heat, or other thermal mass. passive solar system : a solar heating or cooling system that uses no external mechanical power to move the collected solar heat. peak demand : peak demand is the maximum electric load or demand during a specified period of time. see peak load ( below ). peak load : the electric load that corresponds to a maximum level of electric demand in a specified time period. peak periods during the day usually occur in the morning hours from 6 to 9 a. m. and during the afternoons from 4 to about 8 or 9 p. m. the afternoon peak demand periods are usually higher, and they are highest during summer months when air \u2013 conditioning use is the highest. annual peaks generally occur on hot summer days. peak load power plant : a power generating station that is normally used to produce extra electricity during peak load times. peaking unit : a power generator used by a utility to produce extra electricity during peak load times. peat : a heterogeneous mixture of partly decomposed organic matter that has accumulated in a water saturated environment over a very long period of time. peat geologically is considered a very young form of coal and has a heating value of 6, 600 btu / pound. perm : the measurement of water vapor through different materials measured in perm \u2013 inch ( mass of water vapor moving through a unit area in unit time ). personal income : personal income is defined as the income that is received by a person from all sources. it is calculated as the sum of wage and salary disbursements, supplements to wages and salaries, proprietors ' income with inventory valuation and capital consumption adjustments, rental income of persons with capital consumption adjustment, personal dividend income, personal interest income, and personal current transfer receipts, less contributions for government social insurance. personal income is reported", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.603989245168725, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:924b75ad-2e04-4003-b4bd-38123181254a>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:33.254105"}
{"text": "and salaries, proprietors ' income with inventory valuation and capital consumption adjustments, rental income of persons with capital consumption adjustment, personal dividend income, personal interest income, and personal current transfer receipts, less contributions for government social insurance. personal income is reported in current dollars ( no adjustment is made for price changes ). petrochemicals : chemicals made from oil. petrochemical feedstocks : chemical feedstocks derived from petroleum principally for the manufacture of chemicals, synthetic rubber, and a variety of plastics. the categories reported are \" naphthas less than 401 degrees fahrenheit endpoint \" and \" other oils equal to or greater than 401 degrees fahrenheit endpoint \". petrodollars : money paid to other countries for oil imported to the united states. petroleum administration for defense district ( padd ) : the u. s. department of energy divides the united states into regions for planning purposes. the result is a geographic aggregation of the 50 states and the district of columbia into five districts, with padd i further split into three subdistricts. a map is available. the padds include the states listed below : photocell : a device that produces an electric reaction to visible radiant energy ( light ). photosynthesis : a process by which green plants change carbon dioxide into oxygen and organic materials. the energy for this process comes from sunlight. photovoltaic and solar thermal energy : energy radiated by the sun as electromagnetic waves that is converted into electricity by means of solar ( photovoltaic ) cells or concentrating ( focusing ) collectors. photovoltaic cell : a semiconductor that converts light directly into electricity. pipeline : a line of pipe with pumping machinery and apparatus ( including valves, compressor units, metering stations, regulator stations, etc. ) for conveying a liquid or gas. polychloronated biphenyls ( pcbs ) : a group of organic compounds used in the manufacture of plastics and formerly used as a coolant in electric transformers. in the environment, pcbs are highly toxic to aquatic life. they persist in the environment for long periods of time and are biologically accumulative. population \u2013 weighted degree days : heating or cooling degree days weighted by the population in the area in which the degree days are recorded. for example, to calculate the state population \u2013 weighted degree days, the state is divided into nine climatically similar divisions that are assigned weights based on the ratio of the population of the division to the total population of the state. degree day readings", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6104528369773304, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:924b75ad-2e04-4003-b4bd-38123181254a>", "chunk_index": 1, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:33.255219"}
{"text": "recorded. for example, to calculate the state population \u2013 weighted degree days, the state is divided into nine climatically similar divisions that are assigned weights based on the ratio of the population of the division to the total population of the state. degree day readings for each division are multiplied by the corresponding population weight for each division, and these products are then summed to arrive at the state population \u2013 weighted degree day figure. pounds per square inch : a unit of pressure, which is a unit measuring force per unit area. also see psi. power : the rate at which energy is produced, used, or converted from one form to another. power authorities and power districts : quasi \u2013 governmental agencies that perform all or some of the functions of a public utility. power plant : a central station generating facility that produces energy. power pool : 1 ) an entity established to coordinate short \u2013 term operations to maintain system stability and achieve least \u2013 cost dispatch. the dispatch provides backup supplies, short \u2013 term excess sales, reactive power support, and spinning reserve. historically, some of these services were provided on an unpriced basis as part of the members ' utility franchise obligations. coordinating short \u2013 term operations includes the aggregation and firming of power from various generators, arranging exchanges between generators, and establishing ( or enforcing ) the rules of conduct for wholesale transactions. the pool may own, manage and / or operate the transmission lines ( \" wires \" ) or be an independent entity that manages the transactions between entities. often, the power pool is not meant to provide transmission access and pricing, or settlement mechanisms if differences between contracted volumes among buyers and sellers exist. 2 ) two or more interconnected utilities that plan and operate to supply electricity in the most reliable, economical way to meet their combined load. ppm ( parts per million ) : the unit commonly used to represent the degree of pollutant concentration where the concentrations are small. pressurized water reactor ( pwr ) : a nuclear power unit cooled by water that is pressurized to keep it from boiling when it reaches high temperatures. primary energy resources : resources that produce energy. primary energy resources are petroleum, natural gas, coal, hydroelectric power, nuclear electric power, wood and waste, geothermal energy, solar thermal and photovoltaic energy, and wind energy. electricity is a secondary energy resource because generating plants use primary energy resources to generate electricity. primary fuel : fuel consumed in the original production of energy, before conversion takes place. prime supplier : a firm that produces, imports, or transports selected petroleum products across state", "subdomain_id": "subdomain_quantum_thermodynamics", "similarity_score": 0.6438388319544686, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:924b75ad-2e04-4003-b4bd-38123181254a>", "chunk_index": 2, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:33.256346"}
{"text": "an out - of - body experience or sometimes oobe ), is an experience that typically involves a sensation of floating outside of one ' s body and, in some cases, perceiving one ' s physical body from a place outside one ' s body ( autoscopy ). about one in ten people has an out - of - body experience at some time in their lives. scientists know little about the phenomenon. obes are often part of the near - death experience, and reportedly may also lead to astral projection. it is claimed that those experiencing an obe sometimes observe details which were unknown to them beforehand. in some cases the phenomenon appears to occur spontaneously ; in others it is associated with a physical or mental trauma, use of psychedelic drugs, dissociative drugs, or a dream - like state. many techniques aiming to induce the experience deliberately have been developed, for example visualization while in a relaxed, meditative state. recent ( 2007 ) studies have shown that experiences somewhat similar to obes can be induced by direct brain stimulation. relatively little is known for sure about obes. some of those who experience obes claimed to have willed themselves out of their bodies, while others report having found themselves being pulled from their bodies ( usually preceded by a feeling of paralysis ). in other accounts, the feeling of being outside the body was suddenly realized after the fact, and the experiencers saw their own bodies almost by accident. obes often occur during the borderline stage between rem sleep and arousal when sleep paralysis may persist and dream imagery may mingle with sensory input. some neurologists have suspected that the event is triggered by a mismatch between visual and tactile signals. they used a virtual reality setup to recreate an obe. the subject looked through goggles and saw his own body as it would appear to an outside observer standing behind him. the experimenter then touched the subject at the same time as a rod appeared to touch the virtual image. the experiment created an illusion of being behind and outside one ' s body. types of obe obes are sometimes reported to be preceded by and initiated from a lucid dream state, though other types of immediate and spontaneous experience are also reported. in many cases, people who claimed to have had an obe reported being asleep, on the verge of sleep, or already asleep shortly before the experience. a large percentage of these cases referred to situations where the sleep was not particularly deep ( due to illness, noises in other rooms, emotional stress, exhaustion from overworking, frequent", "subdomain_id": "subdomain_quantum_optics", "similarity_score": 0.6334853727611709, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:8932ea81-6368-4eb1-bb79-49f324163ac1>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:33.717452"}
{"text": "slipping is the act of leaving the physical body. some consider progressive relaxation a passive form of sensory deprivation. - waking up mentally but not physically. this related technique is typically achieved through the practice of lucid dreaming. once inside a lucid dream, the dreamer either shifts the subject matter of the dream in an obe direction or banishes the dream imagery completely, in doing so gaining access to the underlying state of sleep paralysis ideal for visualisation of separation from the body. - deep trance and visualization. the types of visualizations vary ; some common imageries used include climbing a rope to \" pull out \" of one ' s body, floating out of one ' s body, getting shot out of a cannon, and other similar approaches. this technique is considered hard to use for people who cannot properly relax. a good example of such a technique consists of the popular \" golden dawn body of light technique \". - brainwave synchronization via audio / visual stimulation. binaural beats can be used to induce specific brain wave frequencies, notably those predominant in various mind awake / body asleep states. binaural induction of the \" body asleep \" theta brain wave frequencies characteristic of dreaming rem sleep was observed as effective by the monroe institute ( and corroborated by others ). simultaneous introduction of \" mind awake \" beta frequencies ( detectable in the brains of normal, relaxed awakened individuals ) was also observed as constructive. another popular technology uses sinusoidal wave pulses to achieve similar results, and the drumming accompanying native american religious ceremonies is also believed to have heightened receptivity to \" other worlds \" through brainwave entrainment mechanisms. - magnetic stimulation of the brain, as with the helmet developed by michael persinger. - electrical stimulation of the brain, particularly the temporoparietal junction ( see below ). - sensory deprivation. this approach aims to cause intense disorientation by removal of space and time references, hoping the brain will fill in the gaps in sensory input. flotation tanks or pink noise played through headphones are often employed for this purpose. obes have been by reported those practicing sense - depriving forms of bdsm such as extreme bondage ( mummification ). - sensory overload, the opposite of sensory deprivation. the subject can for instance be rocked for a long time in a specially designed cradle, or submitted to light forms of torture, to cause the brain to shut itself off from all sensory input. both conditions tend to cause confusion and this disorientation", "subdomain_id": "subdomain_quantum_optics", "similarity_score": 0.6142787828573925, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:8932ea81-6368-4eb1-bb79-49f324163ac1>", "chunk_index": 2, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:33.719761"}
{"text": "type can be frightening as intense physiological sensations may be perceived, such as electrical tingling, full body vibrations and racing heartbeat. confusion is common in spontaneous locale 1 experiences ; the person can believe he has awakened ( or died ) physically and panic can be caused by the realization that limbs appear to be penetrating objects. locale 2 experiences are less overtly physical in nature and have much subjective overlap with lucid dreaming. the subject is immersed in unrealistic worlds, modified forms of reality exhibiting physically impossible or inconsistent features. bright and vivid colours are a common feature of this form. robert bruce ( author ) considers this type of obe to be an astral projection. the obe may or may not be followed by other experiences which are self - reported as being \" as real \" as the obe feeling ; alternatively, the subject may fade into a state self - reported as dreaming, or they may awake completely. the obe is sometimes ended due to a fearful feeling of getting \" too far away \" from the body. many end with a feeling of suddenly \" popping \" or \" snapping \" and sometimes a \" pulling \" back into their bodies ; some even report being \" sucked back \" into physical form. a majority describe the end of the experience by saying \" then i woke up \". however it ' s worth noting that even those who describe the experience as something fantastic that occurs during sleep, and who describe the end of the experience by saying \" and then i woke up \", are very specific in describing the experience as one which was clearly not a dream ; many described their sense of feeling more awake than they felt when they were normally awake. one compared the experience to that of lucid dreaming, but said that it was \" more real \". the phenomenology of an nde usually includes additional physiological, psychological and transcendental factors beyond those of typical obes ( parnia, waller, yeates & fenwick, 2001 ), such as visions of deceased relatives and religious figures, transcendence of ego and spatiotemporal boundaries and other transcendental experiences ( lukoff, lu & turner, 1998 ; greyson, 2003 ). typically the experience follows a distinct progression, starting with the sensation of floating above one ' s body and seeing the surrounding area, followed by the sensation of passing through a tunnel, meeting deceased relatives, and concluding with encountering a being of light ( morse, conner & tyler, 1985 ). studies of obes the first extensive scientific study of obes was made by celia green ( 1968 )", "subdomain_id": "subdomain_quantum_optics", "similarity_score": 0.6016212326410425, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:8932ea81-6368-4eb1-bb79-49f324163ac1>", "chunk_index": 4, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:33.721661"}
{"text": "hz ) over harribance ' s right parieto - occipital region, consistent with neuropsychological evidence of early brain trauma in these regions. in a second study, ingo swann was asked to draw images of pictures hidden in envelopes in another room. individuals with no knowledge of the nature of the study rated swann ' s comments and drawings as congruent with the remotely viewed stimulus at better than chance levels. additionally, on trials in which swann was correct, the duration of 7 hz ( alpha band ) paroxysmal discharges over the right occipital lobe was longer. subsequent anatomical mri examination showed anomalous subcortical white matter signals focused in the perieto - occipital interface of the right hemisphere that were not expected for his age or history. in august 2007 henrik ehrsson, then at the institute of neurology at university college of london ( now at the karolinska institute in sweden ) published research in science demonstrating the first experimental method that, according to the scientist ' s claims in the publication, induced an out - of - body experience in healthy participants. the experiment was conducted in the following way : the study participant sits in a chair wearing a pair of head - mounted video displays. these have two small screens over each eye, which show a live film recorded by two video cameras placed beside each other two metres behind the participant \u2019 s head. the image from the left video camera is presented on the left - eye display and the image from the right camera on the right - eye display. the participant sees these as one \u2018 stereoscopic \u2019 ( 3d ) image, so they see their own back displayed from the perspective of someone sitting behind them. the researcher then stands just beside the participant ( in their view ) and uses two plastic rods to simultaneously touch the participant \u2019 s actual chest out - of - view and the chest of the illusory body, moving this second rod towards where the illusory chest would be located, just below the camera \u2019 s view. the participants confirmed that they had experienced sitting behind their physical body and looking at it from that location. the experiment fits a three - point definition of the out - of - body experience ( obe ). the obe as reported in spontaneous cases can be phenomenologically more complex as commented in slate and elsewhere. dr. sam parnia \u2014 university of southampton study starting in the fall of 2008, 25 uk and us hospitals will participate in a 3 year study", "subdomain_id": "subdomain_quantum_optics", "similarity_score": 0.604764440598239, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:8932ea81-6368-4eb1-bb79-49f324163ac1>", "chunk_index": 8, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:33.727845"}
{"text": "as reported in spontaneous cases can be phenomenologically more complex as commented in slate and elsewhere. dr. sam parnia \u2014 university of southampton study starting in the fall of 2008, 25 uk and us hospitals will participate in a 3 year study, co - ordinated by dr. sam parnia and southampton university. they will examine near - death experiences in 1, 500 cardiac arrest survivors. the study aims to determine if people without a heartbeat or brain activity can have documentable out - of - body experiences. astral projection is a paranormal interpretation of an out - of - body experience achieved either awake or via lucid dreaming or deep meditation. the concept of astral projection assumes the existence of another body, separate from the physical body and capable of traveling to non - physical planes of existence. commonly such planes are called astral, etheric, or spiritual. astral projection is often experienced as the spirit or astral body leaving the physical body to travel in the spirit world or astral plane evidence for objective reality of astral projection is sometimes suggested when people, such as patients during surgery, describe obes in which they see or hear events or objects outside their sensory range ( for instance, pam reynolds reported experiencing an obe during brain surgery and described a surgical instrument she had not seen previously, as well as conversation that occurred while she was under anethesia ). skeptics such as susan blackmore have disputed whether anything leaves the body during an obe. - buhlman, william. adventures beyond the body : astral projection. isbn 0062513710 - robert peterson book on obes ( available online ) - out - of - body experiences and the brain - pritchard, mark h ( 2004 ) \" a course in astral travel and dreams \". isbn 0 - 9740560 - 1 - 4 - review of the tome \" projectiology : a panorama of experiences outside the human body \" by waldo vieira, md journal of parapsychology - out - of - body experiences and the astral hypothesis : part i robert novella, the new england journal of skepticism, volume 5 issue 2, 10 / 1 / 2002 - obes and the astral hypothesis : part ii - lucid dreaming - robert novella, the new england journal of skepticism, volume 6 issue 1, 5 / 1 / 2003 - goa herald ; goan links science, spirituality by out - of - body experience - charles tart ' s original obe experiments - body part - explorations in consciousness a website about", "subdomain_id": "subdomain_quantum_mechanics", "similarity_score": 0.6011122196234837, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:8932ea81-6368-4eb1-bb79-49f324163ac1>", "chunk_index": 9, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:33.729130"}
{"text": "on the tape and decipher them ; and a rule book to tell the machine what to do depending on what symbol the head saw on the tape. these rules would tell the head both what to do in response to a given symbol and then which rules to use next. suppose, for instance, the head detects a 1 on the tape. a possible rule might be to move one square to the left and write a 1 ; or move one square to the right and write a 0 ; or stay on that square, erase the 1 and leave the square blank. by following well - thought - out rules, such a mechanism could compute any number that could be computed ( and write it as a string of 0s and 1s ). one of the prime consequences of turing \u2019 s analysis was his conclusion that some numbers could not be computed. he adopted godel \u2019 s device of assigning a number to every possible mathematical statement and then showed that this inability to compute all numbers implied that the provability of some statements could not be decided. ( and turing showed that his proof of undecidability was also equivalent to church \u2019 s more complicated proof. ) turing \u2019 s result was immediately recognized as exceptional by his professor at the university of cambridge, who advised turing to go to princeton for graduate school and work with church. turing \u2019 s imaginary computer ( christened by church the \u201c turing machine \u201d ) offered additional lessons for future computer scientists. depending on the type of calculation you wanted to perform, you could choose from turing machines with different sets of instructions. but, as turing showed, you have no need for a roomful of machines. a portion of one computer \u2019 s tape could contain the rules describing the operations needed for carrying out any particular computation. in other words, you can just give that machine a rule book ( today, you \u2019 d call it a program ) that tells it what to do. such a \u201c universal turing machine \u201d could then be used to solve any problem that could be solved. during his time at princeton, turing discussed these ideas with the mathematician john von neumann, who later articulated similar principles in describing the stored program general purpose computer, the model for digital computers ever since. today \u2019 s computers, whether macs or pcs or teraflop supercomputers, are all turing machines. \u201c von neumann realized that turing had achieved the goal of defining the notion of universal computing machine, and went on to think about practical implementations of this theoretical computer, \u201d writes miguel angel martin - delgado of universidad com", "subdomain_id": "subdomain_quantum_computing", "similarity_score": 0.6010682887820644, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:939ee34a-3711-4e56-ae18-216fe2c0cf05>", "chunk_index": 2, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:33.845653"}
{"text": "researchers at ge have come up with a way to treat metals so that they repel water. the extreme water - repelling property, called superhydrophobicity, means that water forms drops on the surface instead of spreading and sticking to it. the advance builds on previous work that came out of ge \u2019 s global research center, in niskayuna, ny. two years ago, researchers showed that they could make lexan \u2013 a widely employed plastic that \u2019 s used to create cds, ipods, aircraft windscreens, and car headlamps \u2013 water - repellant. they did this by chemically treating the surface to make it rough. the researchers have now demonstrated the same effect on metal surfaces. many other superhydrophobic materials have been demonstrated, but most have used some kind of plastic. superhydrophobic metals open up many new applications, says jeffrey youngblood, a professor of materials engineering at purdue university. \u201c metallic structures are more robust and can survive in harsher environments, allowing for their use in applications where plastic is infeasible, [ such as in ] planes, trains, automobiles, heavy machinery, and engines, \u201d youngblood says. ge has some ideas about how to use the materials. one possibility is in de - icing aircrafts. ice buildup on engines due to condensation can be catastrophic. right now, aircraft use heat to prevent ice, which requires power. de - icing on the ground, meanwhile, is done with de - icing fluids, which contain toxic chemicals ; spraying aircraft with de - icing fluids on the ground also takes a lot of time. \u201c it would be very desirable if we could \u2026 just be able to have a material on which ice didn \u2019 t stick, \u201d says margaret blohm, advanced technology leader for the nanotechnology program at ge \u2019 s global research center. another application for the metals could be in gas and steam turbines. the superhydrophobic metals could reduce the buildup of moisture and contaminants on the turbines, increasing their efficiency and requiring fewer shutdowns for maintenance. ge researchers have not published their work, and they declined to divulge much about their research achievements. but they do say that their inspiration comes from lotus - plant leaves, which have a nanocrystalline wax structure. on the leaf \u2019 s surface are tiny wax crystals tens of nanometers wide, which hold water drops as almost perfectly spherical beads. blohm says that the team", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6197896220582015, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:5fafd224-2b49-4523-8016-d37ee0d2d94d>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:33.982359"}
{"text": "the definition of a definite integral : requires the interval [ a, b ] be finite. the fundamental theorem of calculus requires that f be continuous on [ a, b ]. in this section, you will be studying a method of evaluating integrals that fail these requirements \u2014 either because their limits of integration are infinite, or because a finite number of discontinuities exist on the interval [ a, b ]. integrals that fail either of these requirements are improper integrals. ( if you are not familiar with l ' hopital ' s rule, it is a good idea to review it before reading this section. ) improper integrals with infinite limits of integration consider the integral assigning a finite upper bound in place of infinity gives this improper integral can be interpreted as the area of the unbounded region between, ( the - axis ), and. 1. suppose exists for all. then we define - = as long as this limit exists and is finite. if it does exist we say the integral is convergent and otherwise we say it is divergent. 2. similarly if exists for all we define 3. finally suppose is a fixed real number and that and are both convergent. then we define we claim that to do this we calculate we claim that the integral this follows as to calculate the integral use integration by parts twice to get now and because exponentials overpower polynomials, we see that and as well. hence, notice that we had to assume that to avoid dividing by zero. however the case was done in a previous example. improper integrals with a finite number discontinuities first we give a definition for the integral of functions which have a discontinuity at one point. definition of improper integrals with a single discontinuity if f is continuous on the interval [ a, b ) and is discontinuous at b, we define : = if the limit in question exists we say the integral converges and otherwise we say it diverges. similarly if f is continuous on the interval ( a, b ] and is discontinuous at a, we define finally suppose f has an discontinuity at a point c in ( a, b ) and is continuous at all other points in [ a, b ]. if and converge we define notice that we had to assume that do avoid dividing by zero. so instead we do the case separately, the integral is improper because the integrand is not continuous at x = 2. however had we not notice that we might have been tempted to", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6156842272883882, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:ddf486eb-51a9-43ee-8e8c-952946bd3b3d>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:36.053046"}
{"text": "notice that we had to assume that do avoid dividing by zero. so instead we do the case separately, the integral is improper because the integrand is not continuous at x = 2. however had we not notice that we might have been tempted to apply the fundamental theorem of calculus and conclude that it equals which is not correct. in fact the integral diverges since and and both diverge. we can also give a definition of the integral of a function with a finite number of discontinuities. definition : improper integrals with finite number of discontinuities suppose f is continuous on [ a, b ] except at points in [ a, b ]. we define as long as each integral on the right converges. notice that by combining this definition with the definition for improper integrals with infinite endpoints, we can define the integral of a function with a finite number of discontinuities with one or more infinite endpoints. there are integrals which cannot easily be evaluated. however it may still be possible to show they are convergent by comparing them to an integral we already know converges. theorem ( comparison test ) let f and g be continuous functions defined for all. - suppose for all. then if converges so does - suppose for all. then if diverges so does a similar theorem holds for improper integrals of the form and for improper integrals with discontinuities. show that converges. for all x we know that so. this implies that we have seen that converges. so putting and into the comparison test we get that the integral converges as well. show that diverges. just as in the previous example we know that for all x. thus we have seen that diverges. so putting and into the comparison test we get that diverges as well. an extension of the comparison theorem to apply the comparison theorem you do not really need for all. what we actually need is this inequality holds for sufficiently large x ( i. e. there is a number c such that for all ). for then so the first integral converges if and only if third does, and we can apply the comparison theorem to the piece. show that converges. the reason that this integral converges is because for large x the factor in the integrand is dominant. we could try comparing with, but as, the inequality is the wrong way around to show convergence. instead we rewrite the integrand as since the limit we know that for x sufficiently large we have. so for large x,", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6006302182185906, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:ddf486eb-51a9-43ee-8e8c-952946bd3b3d>", "chunk_index": 1, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:36.054103"}
{"text": "structural biochemistry / lipids / fluid mosaic model fluid mosaic model the fluid mosaic model is used to describe the interactions of lipids and proteins in biological membranes. this model essentially proclaims the concept of lateral diffusion, stating that proteins can freely move about within a membrane and that such membranes are considered to effectively be two - dimensional. the fluid mosaic model of biological membranes are always fluctuating and adjusting. in 1972, the fluid mosaic model was introduced by s. jonathan singer and garth nicholson. fluid mosaic model of membranes states that membrane components are free to diffuse in the plane of the membrane. some of the membrane proteins are restricted to specific regions of the membrane by interactions with cytoskeletal proteins. also, although many phospholipids and membrane proteins can move laterally within a leaflet, they do not flip - flop from one leaflet of the bilayer to the other. flip - flop of the phospholipids is very rare. the inner and the outer leaflets of the membrane may be made up of different phospholipids. anyways, the membrane fluidity refers to the movement of membrane phospholipids within the plane of the membrane. a decrease in fluidity is associated with decreased transport rates. the length of the fatty acid side chains also affects fluidity. the phospholipids with no hydrocarbon chains have increased hydrophobic interactions with neighboring lipids and thus decreased membrane fluidity. [ microbiology ] some organisms can alter membrane fluidity in response to temperature stress by changing the length and degree of saturation of fatty acids present in membrane phospholipids. cholesterol also influence membrane fluidity. the effects of cholesterol on membrane fluidity are complicated and depend on factors such as the ratio of saturated to unsaturated fatty acids in the membrane. the cholesterol also prevents packing of saturated fatty acids, thus increasing fluidity. proposed by s. j. singer and garth l. nicholson in 1972, the fluid mosaic model provides a reasonable structure and image of the biological membranes in general. one of the most important features of this model is the idea that the phospholipid bilayer is fluid. the phospholipid molecule are free to move laterally. relative to the lateral movement of the phospholipid molecules, there is very little exchange between the two halves of the bilayer. this minimal exchange, or flip flop action, allows asymmetric distribution of phospholi", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6016749476710479, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:3e54e468-21e5-44ff-a541-713f91558e74>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:36.070632"}
{"text": "diminish in color and before you knew it, the area seem to be recoated with green fluorescence. the phenomenon behind this was the aspect of the cell membrane diffusing the bleached hydrophilic heads amongst the rest of the cell membrane. this diffusion allowed for the white bleach to diminish in color by being substituted by green fluorescenced hydrophilic heads. there was found to be two types of diffusion in the cell membrane, lateral diffusion and transverse diffusion. lateral diffusion is the switching of positions in a side by side manner without any sort of flipping. this is the fastest mode of diffusion found in the cell. the second diffusion method transverse diffusion, is the flipping of the phospholipid heads to either side of the cell membrane. this method of diffusion however is less likely and happens significantly slower then lateral diffusion. history & development singer ' s studies of membranes started in the 1950s when scientists noticed that many water - soluble proteins ( like those in cells ) were also able to dissolve in nonpolar, nonaqueous solvents and that proteins adopted different shapes in hydrophilic vs. hydrophobic environments. many proteins are found in environments also high in lipid content, and this prompted singer to look into the relationship between proteins and lipid membranes. before singer and nicolson ' s fluid mosaic model of membranes, a triple - layered membrane model was proposed, the davson - danielli - roberston ( ddr ) model. this model proposed a triple - layered membrane, with a lipid layer between two flat protein layers. however, when studied with respect to energetics of hydrophobic / hydrophilic interactions, this model is not feasible. due to hydrophobic and hydrophilic interactions between amino acid residues of a protein, singer therefore proposed that membrane proteins would assume folded conformations, not remain in a flat layer like the ddr model proposed. also in contrast to the ddr model, singer also proposed that logically and for maximum stability membrane proteins would not be separated from the lipid bilayer but rather incorporated as part of the membrane. these conclusions all came together in the fluid mosaic model, where the phospholipid bilayer is a fluid matrix and both lipids and proteins are capable of lateral and rotational movement ( see membrane fluidity ). - nelson, david l, michael m. cox. lehninger principles of biochemistry fourth edition. new york : w. h. freeman, and company 2005. - martin, laura. the", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6009057263083369, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:3e54e468-21e5-44ff-a541-713f91558e74>", "chunk_index": 2, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:36.072835"}
{"text": "object and subject, inphilosophy, the terms used to denote respectively the see also : world and consciousness. the see also : term \" object \" ( from see also : lat. ob, over against, and jacere, to throw ) is used generally in philosophy for that in which an activity of the mind ends, or towards which it is directed. with these may be compared the ordinary uses of the term for \" thing \" simply, or for that after which one strives, or at which one aims. \" subject, \" literally that which is \" thrown under \" ( sub ), is originally the material or content of a discussion or thought, but in philosophy is used for the thought or the thinking see also : person. the relation between the thinking subject and the object thought is analogous to the grammatical antithesis of the same terms : the \" subject \" of a verb is the person or thing from which the see also : action proceeds, while the \" object, \" see also : direct or indirect, is the person or thing affected. the true relation between mind or thought ( subject ) and see also : matter or extension ( object ) is the chief problem of philosophy, and may be investigated from various standpoints ( see psychology and see also : metaphysics ). it should be observed that the philosophical use of \" subject \" is precisely the opposite of the see also : common use. in ordinary language the \" subject \" of discussion, of a poem, of a see also : work of see also : art, is that which the see also : speaker, author or artist treats. objective, or object glass there are no comments yet for this article. do not copy, download, transfer, or otherwise replicate the site content in whole or in part. links to articles and home page are encouraged.", "subdomain_id": "subdomain_quantum_mechanics", "similarity_score": 0.6085292268648578, "token_count": 367, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:62bb74db-e68c-40ae-9161-bb0a7df378be>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:36.252892"}
{"text": "differential absorption lidar ( dial ) light is absorbed by many of the atmospheric components. absorption of light by molecules is the basis for dial which is used to measure the atmospheric concentrations of gases such as water vapor and ozone. dial measurements of water vapor as shown in figure ( a ), water vapor has many discrete absorption lines. in water vapor dial, laser pulses are transmitted at two wavelengths, one on a water vapor absorption line, \u03bbon, and another off - line, \u03bboff. if the two wavelengths are close together, then for both wavelengths the scattering by molecules and particles is essentially equal. the difference in the returns between the two wavelengths is then due entirely to absorption by water vapor molecules, figure ( b ). thus, measurement of the ratio of the backscatter at the two wavelengths as a function of range can be used to calculate the water vapor concentration profile. dial measurements of ozone dial measurements of ozone require less precise laser frequency because ozone has a broad ( ~ 200 nm ) absorption band [ see figure ] instead of narrow lines lines like water vapor. this requires that the on - and off - wavelengths be chosen with sufficient wavelength separation to ensure a significant difference in their absorption. however, uncertainty in the changes of aerosol scattering and patterning between the wavelengths can introduce error. the difference in aerosol scattering at \u03bbon and \u03bboff can be extrapolated from a third measurement taken at a longer wavelength, \u03bba. therefore, dial measurements with three wavelengths can be used to determine ozone concentration profiles to good accuracy.", "subdomain_id": "subdomain_quantum_metrology", "similarity_score": 0.6149802466431995, "token_count": 308, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:2beebe7c-8aaa-4c3d-80fc-4a5dce1df539>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:36.394974"}
{"text": "see also the browse high school definitions stars indicate particularly interesting answers or good places to begin browsing. - phi [ 05 / 18 / 1997 ] what is phi? - pick ' s theorem, lattice points, and area [ 08 / 27 / 1998 ] what is a lattice point, and how does it relate to the area of a triangle, rectangle, and a circle? - point symmetry [ 08 / 19 / 2001 ] what exactly is point symmetry? how can one tell if point symmetry is - polyhedra : classification, theorem [ 02 / 12 / 1998 ] i would like to know how polyhedrons are classified, which figures can be used for the faces, and the theorem relating the faces, edges, and - polyhedra : solids or surfaces? [ 06 / 06 / 2003 ] is a polyhedron always a solid figure? - polynomial basics and terms [ 05 / 20 / 1998 ] i ' m having a lot of trouble understanding polynomials. - polynomial degrees and definition of a field [ 03 / 02 / 1998 ] the degree of polynomials added together, and definition of a field. - polyominoes [ 09 / 08 / 1997 ] i am using polyominos, but i do not know how to tell my dad what they are. how can i tell him so he will know? - power or exponent? [ 10 / 14 / 2003 ] i always thought that ' power ' was just a synonym for ' exponent '. is - principal square root positive [ 10 / 24 / 2002 ] why are we always taught that the principal square root of a number is - product notation [ 10 / 26 / 2000 ] can the pi symbol also be used to mean multiplying all the terms in a - profit margin and percentage markup [ 02 / 16 / 2007 ] i own a small business and am a little confused about the difference between a percentage markup and a profit margin. are they the same thing? if not, how are they different? - pronumerals [ 05 / 14 / 2002 ] what is a ' pronumeral '? - proofs with isosceles triangles [ 10 / 28 / 1998 ] what are altitudes, angle bisectors, and medians? how do you prove that in an isoseles triangle, the altitude is a median and an angle bisector? - proportionality symbol [ 05 / 20 / 2003 ] do you know the name of the little symbol used in the topic of rates and variation that means ' in proportion to '? - pyramid", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6465534981367995, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:4c3e5f8e-59d0-43c4-af99-677609767380>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:36.661361"}
{"text": "and an equilateral - relative and absolute extrema of a function [ 01 / 07 / 2004 ] what is the difference between the absolute extrema and the relative extrema in calculus? - relatively prime [ 10 / 07 / 1999 ] what does the term relatively prime mean, and how can you determine if two numbers are relative primes? - rhombus and square comparison [ 01 / 14 / 2004 ] comparison of the definitions of rhombus and square as a way to answer the questions, ' is a square a rhombus? ' and ' is a rhombus a square? '. - rhombus vs. rhomboid [ 08 / 27 / 2002 ] what is the difference between a rhombus and a rhomboid? - roughing it more rigorously [ 12 / 02 / 2010 ] a physics student wants to make sense of the various symbols used to represent \" approximately equal to \" - - as well as the phrase ' s mathematical meaning. doctor vogler produces two precise definitions while acknowledging that context, and personal preference, rule the day. - scientific notation and engineering notation [ 10 / 22 / 2003 ] what is the difference between scientific notation and engineering - the second octant [ 04 / 03 / 2002 ] where is the second octant? no one seems to know how to count the next octants after the first. - set, subset, element [ 3 / 10 / 1997 ] please define : set, subset, member, element, intersection, union. - significant non - zero digits [ 11 / 27 / 2001 ] how many significant digits are there in a number with no non - zero digits? example : 00. 000 are there any? - the simplex method [ 11 / 2 / 1996 ] how does the simplex method work and what would i use it for?", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6039653461045166, "token_count": 375, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:4c3e5f8e-59d0-43c4-af99-677609767380>", "chunk_index": 2, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:36.663227"}
{"text": "see also the 3d and higher browse middle school definitions stars indicate particularly interesting answers or good places to begin browsing. - circle definitions [ 04 / 29 / 2002 ] define a circle and its parts : diameter, radius, center, - circumference vs. perimeter [ 05 / 09 / 2003 ] technically speaking, can the term ' perimeter ' apply to a circle in a - clarifying percentages vs. percentage points [ 11 / 21 / 2003 ] what is the difference between measuring using percentages versus measuring using percentage points? what is meant by a percentage point? - clockwise and counterclockwise [ 03 / 19 / 2001 ] what does clockwise mean? - a closer look at the definition of median [ 08 / 14 / 2008 ] if you have five numbers like 100, 200, 300, 400, 500, the median or middle number is 300. how does this divide the set of numbers into two equal groups? - comparing transitivity and substitution [ 10 / 01 / 2003 ] what is the difference between transitivity and substitution? - complementary and supplementary angles [ 09 / 30 / 1998 ] why are angles called complementary and supplementary? - complementary and supplementary angles [ 10 / 24 / 1999 ] definitions of complementary and supplementary angles. - complementary or supplementary? [ 04 / 02 / 2001 ] i keep getting complementary and supplementary mixed up. how can i remember which is which? - concave and convex polygons [ 08 / 13 / 2001 ] what ' s the difference between a convex and a concave polygon? - concept of factoring [ 03 / 22 / 1997 ] could you explain the concept of factoring and give examples of its - congruent fractions [ 04 / 03 / 1997 ] what are congruent fractions? - converting to bushels [ 05 / 18 / 2002 ] how can i convert cubic feet to bushels? - convex and concave polygons [ 3 / 23 / 1996 ] what are convex and concave polygons? - correct usage of equal and equivalent in math statements [ 02 / 20 / 2008 ] is there a mathematical difference between \" equal \" and \" equivalent \"? - cubic centimeter, cubic inch [ 08 / 26 / 1997 ] can you help me define these terms? - cubic centimeters and milliliters [ 10 / 29 / 2001 ] i know that cubic centimeters and milliliters are the same thing, but is there any way you can prove it to me? - cute numbers [ 08 / 29 / 2003 ] i have found two definitions of a", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6006529371029075, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:4f3c2039-d54a-4340-a219-fc6dddb346d1>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:36.667941"}
{"text": "of interpolate [ 10 / 27 / 1995 ] could you please define interpolate and give me an example? - definition of mixed number [ 11 / 22 / 2004 ] is 5 a mixed number? why or why not? i think it is, because you can write 5 0 / 3, can ' t you? - definition of negative square roots [ 03 / 08 / 2004 ] i know that the square root of 49 = 7 since 7 x 7 = 49. but the negative square root of 49 is - 7. is this because ( - 7 ) x ( - 7 ) also equals 49 or because the square root of 49 is 7 and the negative stays because it is not involved with the operation? my teacher wrote - sqrt ( 49 ) = - 7 because ( - 7 ) x ( - 7 ) = 49. - definition of opposite sides [ 01 / 18 / 2001 ] what is the formal definition of ' opposite sides ' of a polygon? does a regular pentagon have opposite sides? does a concave polygon have opposite sides? how can we define it consistent with our intuition? - definition of oval [ 06 / 09 / 2002 ] can you give a precise definition of ' oval '? - definition of quotient [ 11 / 13 / 2008 ] if i divide 15 by 2, i always thought that the quotient was 7 and the remainder was 1. but i ' ve seen that the quotient can also be 15 / 2. how can quotient have different meanings? - definition of repetend [ 9 / 17 / 1995 ] what is the definition of repetend? where can i find its definition on - definition of ' solve ' [ 11 / 29 / 2005 ] in algebra class i was told that a problem such as 2 + 2 cannot be solved. in order to ' solve ' a problem there has to be a variable involved. is this correct? - definition of vinculum [ 10 / 21 / 2004 ] is the bar placed over the set of repeated digits in a repeating decimal called a vinculum? i ' ve heard that but i can ' t confirm it. - definitions : average, mean, mode [ 5 / 20 / 1996 ] arithmetic, geometric, harmonic means defined.", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6011925311533839, "token_count": 457, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:4f3c2039-d54a-4340-a219-fc6dddb346d1>", "chunk_index": 2, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:36.669771"}
{"text": "the chemical elements, known and as yet unknown, and energy in all of its forms \u2014 are virtually infinite in their extent. in this sense, nature \u2019 s contribution is boundless. even if we limit our horizon exclusively to the planet earth, which certainly need not be our ultimate limit, the magnitude of natural resources supplied by nature is mind - bogglingly huge. it is nothing less than the entire mass of the earth and all of the energy that goes with it, from thunder storms in the atmosphere, a single one of which discharges more energy than all of mankind produces in an entire year, to the tremendous heat found at the earth \u2019 s core in millions of cubic miles of molten iron and nickel. yes, the natural resources provided by nature in the earth alone extend from the upper limits of the earth \u2019 s atmosphere, four - thousand miles straight down, to its center. this enormity consists of solidly packed chemical elements. there is not one cubic centimeter of the earth, either on its surface or anywhere below its surface, that is not some chemical element or other, or some combination of chemical elements. this is nature \u2019 s contribution to the natural resources contained in this planet. it indicates the incredibly enormous extent of what is out there awaiting transformation by man into natural resources possessing goods - character. and this brings me to what i consider to be the revolutionary view of natural resources that is implied in menger \u2019 s theory of goods. namely, not only does man create the goods - character of natural resources \u2014 by obtaining knowledge of their useful properties and then creating their useability and accessibility by virtue of establishing the necessary command over them \u2014 but he also has the ability to go on indefinitely increasing the supply of natural resources possessing goods - character. he enlarges the supply of useable, accessible natural resources \u2014 that is, natural resources possessing goods - character \u2014 as he expands his knowledge of and physical power over nature. the prevailing view, that dominates the thinking of the environmentalists and the conservationists, that there is a scarce, precious stock of natural resources that man \u2019 s productive activity serves merely to deplete is wrong. seen in its full context, man \u2019 s productive activity serves to enlarge the supply of useable, accessible natural resources by converting a larger, though still tiny, fraction of nature into natural resources possessing goods - character. the essential question concerning natural resources is what fraction of the virtual infinity that is nature does man possess sufficient knowledge concerning and sufficient physical command over to be able to direct it to", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6166320174039304, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:8f8607bf-4d95-4eba-9b86-2481d85430fc>", "chunk_index": 10, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:36.723503"}
{"text": "supports for mine shafts, and modern pumps and engines. today, a single worker operating a bulldozer or steam shovel can move far more earth than hundreds of workers in the past using hand shovels. advances in reduction methods have made it possible to obtain pure ores from compounds previously either altogether impossible to work with or at least too costly to work with. improvements in shipping, railroad building, and highway construction have made possible low - cost access to high - grade mineral deposits in regions previously inaccessible or too costly to exploit. and, i added : there is no limit to the further advances that are possible. reductions in the cost of extracting petroleum from shale and tar sands have the potential for expanding the supply of economically useable petroleum by a vast multiple of what it is today. hydrogen, the most abundant element in the universe, may turn out to be an economical source of fuel in the future. atomic and hydrogen explosives, lasers, satellite detection systems, and, indeed, even space travel itself, open up limitless new possibilities for increasing the supply of economically useable mineral supplies. advances in mining technology that would make it possible to mine economically at a depth of, say, ten thousand feet, instead of the present much more limited depths, or to mine beneath the oceans, would so increase the portion of the earth \u2019 s mass accessible to man that all previous supplies of accessible minerals would appear insignificant in comparison ( p. 64 ). the key point here is that, following menger \u2019 s insights into the nature of goods, the supply of economically useable, accessible natural resources is expandable. it is enlarged as part of the same process by which man increases the production and supply of all other goods, namely, scientific and technological progress and saving and capital accumulation. the fundamental situation is this. nature presents the earth as an immense solidly packed ball of chemical elements. it has also provided comparably incredible amounts of energy in connection with this mass of chemical elements. if, over and against this massive contribution from nature stands motivated human intelligence \u2014 the kind of motivated human intelligence that a free, capitalist society so greatly encourages, with its prospect of earning a substantial personal fortune as the result of almost every significant advance, there can be little doubt as to the outcome : man will succeed in progressively enlarging the fraction of nature \u2019 s contribution that constitutes goods ; that is, he will succeed in progressively enlarging the supply of useable, accessible natural resources. the likelihood of his success is greatly reinforced by two closely related facts : the progressive", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6039733813207655, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:8f8607bf-4d95-4eba-9b86-2481d85430fc>", "chunk_index": 12, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:36.727347"}
{"text": "goods of lower order. all that it is necessary to add to menger \u2019 s view is recognition once again of the fact that the earth is an immense ball of solidly packed chemical elements. now these chemical elements constitute man \u2019 s external material surroundings, i. e., his environment. they are the external material conditions of human life. when these facts are kept in mind, it becomes clear that the process of production, and the whole of economic activity, so far from constituting a danger to man \u2019 s environment, as the environmentalists claim, have the inherent tendency to improve his environment, indeed, that that is their essential purpose. this becomes obvious as soon as one realizes that not only does the entire world physically consist of nothing but chemical elements, but also that these elements are never destroyed. they simply reappear in different combinations, in different proportions, in different places. as i wrote in capitalism : apart from what has been lost in a few rockets, the quantity of every chemical element in the world today is the same as it was before the industrial revolution. the only difference is that, because of the industrial revolution, instead of lying dormant, out of man \u2019 s control, the chemical elements have been moved about, as never before, in such a way as to improve human life and well - being. for instance, some part of the world \u2019 s iron and copper has been moved from the interior of the earth, where it was useless, to now constitute buildings, bridges, automobiles, and a million and one other things of benefit to human life. some part of the world \u2019 s carbon, oxygen, and hydrogen has been separated from certain compounds and recombined in others, in the process releasing energy to heat and light homes, power industrial machinery, automobiles, airplanes, ships, and railroad trains, and in countless other ways serve human life. it follows that insofar as man \u2019 s environment consists of the chemical elements iron, copper, carbon, oxygen, and hydrogen, and his productive activity makes them useful to himself in these ways, his environment is correspondingly improved. consider further examples. to live, man needs to be able to move his person and his goods from place to place. if an untamed forest stands in his way, such movement is difficult or impossible. it represents an improvement in his environment, therefore, when man moves the chemical elements that constitute some of the trees of the forest somewhere else and lays down the chemical elements brought from somewhere else to constitute a road. it is an", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6116791229611754, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:8f8607bf-4d95-4eba-9b86-2481d85430fc>", "chunk_index": 14, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:36.729734"}
{"text": "substitution ciphers that encode a message by substituting one character for another go back at least as far as julius caesar, who used a rotating character scheme to encode military orders. this simple type of encryption is vulnerable to statistical attacks, however, as anyone who has solved cryptogram puzzles can attest. in world war ii, the nazi military employed an encryption scheme that addressed this weakness of simple substitution ciphers. this scheme, implemented by typewriter - sized devices known as enigma machines, gave the nazis a tactical advantage that greatly contributed to their early success in the war. in fact, the eventual breaking of this coding scheme by researchers at bletchley park, england ( including alan turing ) is hailed as one of the turning points of the war. enigma machines used interchangeable rotors that could be placed in different orientations to obtain different substitution patterns. more significantly, the rotors rotated after each character was encoded, changing the substitution pattern and making the code very difficult to break. the behavior of the rotating rotors can be modeled, in a simplified form, by a device consisting of labeled, concentric rings. for example, the model below has three rings labeled with the letters of the alphabet and ' # ' ( representing a space ). to encrypt a character using this model, find the character on the inner rotor ( i. e., the inside ring ) and note the character aligned with it on the outer rotor ( i. e., the outside ring ), then find that character on the middle rotor ( i. e., the middle ring ) and output the one aligned with it on the outer rotor. after a character is encrypted, turn the inner rotor clockwise one step. whenever the inner rotor returns to its original orientation, the middle rotor turns once in lock - step, just like the odometer in a car. for example, in this configuration the character ' a ' would be encrypted as ' n ', since ' a ' on the inner rotor is aligned with ' h ' on the outer rotor, and ' h ' on the middle rotor is aligned with ' n ' on the outer rotor. after performing this encryption, the inner rotor is rotated clockwise, so the letter ' a ' would next be encrypted as ' d '. note that decrypting a message requires following the same steps, only in reverse ( i. e., find the character on the outer rotor, note the character aligned with it on the middle rotor", "subdomain_id": "subdomain_quantum_cryptography", "similarity_score": 0.6294756461720691, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:45b67d2d-1fa1-4c8c-9564-fc656660c09d>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:36.777864"}
{"text": "encrypted as ' d '. note that decrypting a message requires following the same steps, only in reverse ( i. e., find the character on the outer rotor, note the character aligned with it on the middle rotor, find that character on the outer rotor, then output the character aligned with it on the inner rotor ). for this assignment, you are to design a java class named enigma that simulates this three - ring model. you may assume that all enigma models have the same outer rotor, as shown in the above diagram. that is, the outer rotor consists of the 26 capital letters and the ' # ' symbol ( representing a space ) in the following clockwise order : # bdfhjlnprtvxzacegikmoqsuwy. since the other rotors are interchangeable, however, their contents and alignment relative to the outer rotor must be specified when constructing an enigma model. for example, the initial settings of the inner and middle rotors in the above diagram are # gnuahovbipwcjqxdkryelszfmt and # ejotychmrwafkpuzdinsxbglqv, respectively. using an enigma object, it should be possible to encode and decode text messages, with the appropriate rotation of the rotors occurring after each character encoding / decoding. you should also design and implement a graphical user interface that makes it simple for the user to specify the rotor settings on an enigma model, and encode or decode text. once you have your model working, test it by decoding the message oknnwrdhgerpilrlamfzf # fmuc using the diagram settings. note : if you would like to make your own 3 - ring enigma model out of paper, download this online form, cut out the rings, and follow the instructions at the site.", "subdomain_id": "subdomain_quantum_cryptography", "similarity_score": 0.6330090368241318, "token_count": 386, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:45b67d2d-1fa1-4c8c-9564-fc656660c09d>", "chunk_index": 1, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:36.778590"}
{"text": "australasian journal of philosophy 84 ( 1 ) : 59 \u2013 73 ( 2006 ) | abstract | | ' philosophy arises through misconceptions of grammar ', said wittgenstein. few people have believed him, and probably none, therefore, working in the area of the philosophy of mathematics. yet his assertion is most evidently the case in the philosophy of set theory, as this paper demonstrates ( see also rodych 2000 ). the motivation for twentieth century set theory has rested on the belief that everything in mathematics can be defined in terms of sets [ maddy 1994 : 4 ]. but not only are there notable items which cannot be so defined, including numbers and mereological sums, the very notion of a set, as formalized within this tradition, is based on a series of grammatical confusions. | | keywords | | no keywords specified ( fix it ) | | through your library | | configure | similar books and articles emily carson ( 1996 ). on realism in set theory. philosophia mathematica 4 ( 1 ) : 3 - 17. john mayberry ( 1994 ). what is required of a foundation for mathematics? philosophia mathematica 2 ( 1 ) : 16 - 35. f. a. muller ( 2001 ). sets, classes, and categories. british journal for the philosophy of science 52 ( 3 ) : 539 - 573. john j. ross ( 2009 ). reading wittgenstein ' s philosophical investigations : a beginner ' s guide. lexington books. siegfried gottwald ( 2006 ). universes of fuzzy sets and axiomatizations of fuzzy set theory. part i : model - based and axiomatic approaches. studia logica 82 ( 2 ) : 211 - 244. jose ferreiros ( 2011 ). on arbitrary sets and zfc. bulletin of symbolic logic 17 ( 3 ) : 361 - 393. emmon bach, actl semantics : compositionality and morphosemantics : ii : words, morphemes, constructions, interpretations. john p. burgess ( 1988 ). sets and point - sets : five grades of set - theoretic involvement in geometry. psa : proceedings of the biennial meeting of the philosophy of science association 1988 : 456 - 463. added to index2009 - 01 - 28 total downloads12 ( # 93, 408 of 549, 122 ) recent downloads ( 6 months ) 1 ( # 63, 361 of 549", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6060071628176851, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:322a8b59-0ebb-4a3d-9dec-564e21a48559>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:36.998017"}
{"text": "a breakthrough in the harnessing of ' t - rays ' - electromagnetic terahertz waves - which could dramatically improve the detecting and sensing of objects as varied as biological cell abnormalities and explosives has been announced. researchers at the university of bath, uk, and in spain have said they have found a way to control the flow of terahertz radiation down a metal wire. their findings are set out in a letter published in the current journal physical review letters. terahertz radiation, whose frequency is around one thousand billion cycles a second, bridges the gap between the microwave and infrared parts of the electromagnetic spectrum. materials interact with radiation at t - ray frequencies in different ways than with radiation in other parts of the spectrum, making t - rays potentially important in detecting and analysing chemicals by analysing how they absorb t - rays fired at them. this would allow quality control of prescribed drugs and detection of explosives to be carried out more easily, as many complex molecules have distinctive signatures in this part of the electromagnetic spectrum. t - ray applications are presently limited by the relatively poor ability to focus the rays, which is achieved using the conventional means of lenses and mirrors to focus the radiation. this limits the spot size of focused t - rays to a substantial fraction of a millimetre and this has made studies of small objects such as biological cells with high resolution are virtually impossible. but in their work the researchers found that although ordinary metal wire would not guide t - rays very well, if a series of tiny grooves was cut into the wire, it would do so much more effectively. if such a corrugated metal wire is then tapered to a point it becomes possible to very efficiently transport radiation to a point as small as a few millionths of a metre across. this might, for example, lead to breakthroughs in examining very small objects such as the interior of biological cells where it might be possible to detect diseases or abnormalities. t - rays could also be directed to the interior of objects which could be useful in applications like endoscopic probing for cancerous cells or explosive detection. \" this is a significant development that would allow unprecedented accuracy in studying tiny objects and sensing chemicals using t - rays \" said dr stefan maier, of the university of bath ' s department of physics, who leads the research. \" metal wire ordinarily has a limited ability to allow t - rays to flow along it, but our idea was to overcome this by corrugating its surface with a series of grooves, in effect creating an artificial material or '", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6028342578582434, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:1486ae3c-fa8c-45ff-84f9-7120159d0fc5>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:37.066903"}
{"text": ", and actors. the term \" stage \" in this context was chosen to allude to the stage theories, but not in the strict definition that includes irreversibility and invariance. the terms \" phase \" or \" mindset \" may be equally suitable for this distinction. the basic idea is that individuals pass through different mindsets on their way to behavior change. thus, interventions may be most efficient when tailored to these particular mindsets. for example, nonintenders are supposed to benefit from confrontation with outcome expectancies and some level of risk communication. they need to learn that the new behavior ( e. g., becoming physically active ) has positive outcomes ( e. g., well - being, weight loss, fun ) as opposed to the negative outcomes that accompany the current ( sedentary ) behavior ( such as developing an illness or being unattractive ). in contrast, intenders should not benefit from such a treatment because, after setting a goal, they have already moved beyond this mindset. rather, they should benefit from planning to translate their intentions into action. finally, actors do not need any treatment at all unless one wants to improve their relapse prevention skills. then, they should be prepared for particular high - risk situations in which lapses are imminent. this can be done by teaching them to anticipate such situations and by acquiring the necessary levels of perceived recovery self - efficacy. there are quite a few randomized controlled trials that have examined the notion of stage - matched interventions based on hapa, for example in the context of dietary behaviors, physical activity, and dental hygiene. - \u2191 conner, m., & norman, p. ( eds. ). ( 2005 ). predicting health behavior : research and practice with social cognition models ( 2nd ed. ). buckingham, england : open university press. - \u2191 sniehotta, f. f. ( 2009 ). towards a theory of intentional behaviour change : plans, planning, and self - regulation. british journal of health psychology, 14, 261 \u2013 273. - \u2191 biddle, s. j. h., & fuchs, r. ( 2009 ). exercise psychology : a view from europe. psychology of sport and exercise, 10, 410 \u2013 419. - \u2191 sutton, s. ( 2005 ). stage models of health behaviour. in m. conner & p. norman ( eds. ), predicting health behaviour : research and practice with social cognition models ( 2nd ed., pp. 223 \u2013 275", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.603989240031529, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:9ca235c5-e093-410a-9e1d-e105975f2c3a>", "chunk_index": 3, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:37.086015"}
{"text": "to improve energy storage technologies, and we ' re confident that substantial progress will be made. we can, however, use thermodynamics to calculate the upper limits of what ' s possible for a variety of technologies. and when we do this, we find that many technologies will never compete with fossil carbon on energy density. let ' s start with batteries. today ' s lead acid batteries can store about 0. 1 mega - joules per kilogram, or about 500 times less than crude oil. those batteries, of course, could be improved, but any battery based on the standard lead - oxide / sulfuric acid chemistry is limited by foundational thermodynamics to less than 0. 7 mega - joules per kilogram. due to the theoretical limits of lead - acid batteries, there has been serious work on other approaches such as lithium - ion batteries, which usually involve the oxidation and reduction of carbon and a transition metal such as cobalt. these batteries have already improved upon the energy density of lead - acid batteries by a factor of about 6 to around 0. 5 mega - joules per kilogram - - a great improvement. but as currently designed, they have a theoretical energy density limit of about 2 mega - joules per kilogram. and if research regarding the substitution of silicon for carbon in the anodes is realized in a practical way, then the theoretical limit on lithium - ion batteries might break 3 mega - joules per kilogram. therefore, the maximum theoretical potential of advanced lithium - ion batteries that haven ' t been demonstrated to work yet is still only about 6 percent of crude oil! but what about some ultra - advanced lithium battery that uses lighter elements than cobalt and carbon? without considering the practicality of building such a battery, we can look at the periodic table and pick out the lightest elements with multiple oxidations states that do form compounds. this thought experiment turns up compounds of hydrogen - scandium. assuming that we could actually make such a battery, its theoretical limit would be around 5 mega - joules per kilogram. so the best batteries are currently getting 10 percent of a physical upper bound and 25 percent of a demonstrated bound. and given other required materials such as electrolytes, separators, current collectors, and packaging, we ' re unlikely to improve the energy density by more than about a factor of 2 within about 20 years. this means hydrocarbons - - including both fossil carbon and biofuels - - are still a factor of 10 better than the physical upper bound,", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6404477075670203, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:6b7ba779-60ae-4245-947f-1023736357ef>", "chunk_index": 1, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:37.509193"}
{"text": "re unlikely to improve the energy density by more than about a factor of 2 within about 20 years. this means hydrocarbons - - including both fossil carbon and biofuels - - are still a factor of 10 better than the physical upper bound, and they ' re likely to be 25 times better than lithium batteries will ever be. what about storing energy in electric fields ( i. e., capacitors ) or magnetic fields ( i. e., superconductors )? while the best capacitors today store 20 times less energy than an equal mass of lithium - ion batteries, one company, eestor, claims a new capacitor capable of 1 mega - joule per kilogram. whether or not this claim proves valid, it ' s within about a factor of 2 of the physical limit based on the bandgap of the dielectric material. electromagnets of high - temperature superconductors could in theory reach about 4 mega - joules per liter similar to our theoretical batteries given a reasonable density ; existing magnetic energy storage systems top out around 0. 01 mega - joules per kilogram, about equal to existing capacitors. here again, both the realized technology and its ultimate physical potential are far behind the energy density of common hydrocarbon fuels. that brings us to the option of storing chemical potential energy as fuel that can be oxidized by atmospheric oxygen. we do it today, but with two differences : we generate this fuel renewably and convert it to work more efficiently than in combustion engines, either by fuel cells or air batteries. zinc air batteries, which involve the oxidation of zinc metal to zinc hydroxide, could reach about 1. 3 mega - joules per kilogram. but if we take elemental zinc all the way to zinc oxide, then we can theoretically beat the best imagined batteries at about 5. 3 mega - joules per kilogram. zinc has proved interesting enough that several writers ( not us ) have imagined a \" zinc economy. \" to get really ambitious, we imagine storing energy as elemental aluminum or elemental lithium. those two highly electro - positive elements yield a theoretical energy density - - when oxidized in air - - of 32 and 43 mega - joules per kilogram. at least now the theoretical limit is between 60 percent and 80 percent to that of hydrocarbons ; we just have to figure out how to extract a large fraction of the energy from that oxidation. a more promising approach is to use fuel cells with liquid and gaseous fuels.", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6388021247794238, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:6b7ba779-60ae-4245-947f-1023736357ef>", "chunk_index": 2, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:37.511571"}
{"text": "| a microscopic double - slit experiment | two centuries ago, thomas young performed the classic demonstration of the wave nature of light. he placed a screen with two tiny slits in front of a single light source, effectively converting it into a two - centered source. on a second screen far away, he saw a pattern of light and dark diffraction fringes, a well - known hallmark of wave interference. along with later studies using particles instead of light, the experiment played a crucial role in establishing the validity of wave \u2013 particle duality, a puzzling concept that has ultimately become central to the interpretation of complementarity in quantum mechnanics. in a new twist on this classic experiment, the double slit ( with light waves ) has been replaced by a diatomic molecule ( with electron waves ). at als beamline 10. 0. 1, researchers have shown that diatomic molecules can serve as two - center emitters of electron waves and that traces of electron - wave interference can be directly observed in precise measurements of vibrationally resolved photoionization spectra. in the 1960s, howard cohen and ugo fano conjectured that it should be possible to conduct a microscopic version of the double - slit experiment by photoionizing homonuclear ( single - element ) diatomic molecules. the emitted electrons, which are initially shared between the two indistinguishable atoms, would be \" coherent \" when their debroglie wavelengths are comparable to the molecule ' s equilibrium interatomic distance. under these conditions, cohen and fano predicted that electron - wave interference should affect the molecule ' s photoionization cross sections ( i. e., the probability of ionization ) for photoionization energies of a few hundred evs ( the extreme ultraviolet regime ). the manifestations of this matter - wave interference have been actively sought in beautiful but time - consuming experiments that require \" fixing in space \" the molecular targets via complex detection schemes. in addition to the practical difficulties, such an approach required the introduction of arbitrary calibration parameters or fitting functions, leading to equivocal interpretations. the work reported here takes another, more direct approach based on an elaborate, first - principles framework developed within the international group led by f. martin ( autonomous university of madrid ). the analysis includes consideration of the vibrational transitions associated with valence - shell photoionization of diatomic molecules. one striking prediction was that values of the photoionization cross - section would oscillate around a value predicted by", "subdomain_id": "subdomain_quantum_optics", "similarity_score": 0.688354614827712, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:b9ad457f-9423-4461-9407-ba95e7a33f7c>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:37.694952"}
{"text": "). the analysis includes consideration of the vibrational transitions associated with valence - shell photoionization of diatomic molecules. one striking prediction was that values of the photoionization cross - section would oscillate around a value predicted by the franck \u2013 condon principle, which governs the likelihood of transitions involving electronic and vibrational states ( \" vibronic \" transitions ). the approach was made experimentally possible by the advent of high - brightness, third - generation light sources as well as significant progress in electron detection techniques able to distinguish the various vibrational states available to diatomic molecules. the unique characteristics of extreme beam stability, powerful photon flux, and high resolving power offered at als beamline 10. 0. 1 allowed the research team to access the underlying structure of the valence photoelectron bands and to reliably extract vibrational cross - sections over a wide photon energy range ( 20 to 300 ev ). the experiments were performed on hydrogen ( h2 ) \u2014 the simplest of all diatomics, homonuclear nitrogen ( n2 ), and even the heteronuclear carbon monoxide ( co ). clear oscillations around the franck \u2013 condon values have been observed and interpreted as the distinct mark of young ' s interferences. they are satisfactorily reproduced by first - principles calculations that do not require the introduction of any external arbitrary parameters or fitting functions. these results on benchmark molecules constitute an important step toward extending this particular combination of detection technique and advanced modeling into a widely applicable structural tool for electron interferometry and holography by capitalizing on coherent photoemission. these multicenter interferences in the continuum are a very sensitive probe of electronic and geometric degrees of freedom. as such, they can track in real time the various couplings at play during the photoionization processes triggered by accelerator - or lab - based light sources that are rapidly developing around the world. research conducted by : s. e. canton ( lund university, sweden ), e. plesiat ( autonomous university of madrid, spain ), j. d. bozek ( slac national accelerator laboratory ), b. s. rude ( als ), p. decleva ( university of trieste and the national research council, institute of materials, italy ), and f. martin ( autonomous university of madrid and the madrid institute for advanced studies in nanoscience, spain ). research funding : ministry of science and innovation ( spain ) and", "subdomain_id": "subdomain_quantum_optics", "similarity_score": 0.6637649997432398, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:b9ad457f-9423-4461-9407-ba95e7a33f7c>", "chunk_index": 1, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:37.696174"}
{"text": "graphene is a sheet of carbon, just one atom thick, which is electrically sensitive to mechanical deformation and contact with water. not only this, but it is highly effective at repelling water too. it \u2019 s also far cheaper to obtain than indium, which is used in indium tin oxide ( ito ) for current capacitive touch screen technology. therefore there is a benefit to the environment too, by reducing the demand for industrial mining operations. as explained in our other feature about nokia \u2019 s nano - tech, graphene is a structure made from carbon atoms bonded together in a planar hexagonal pattern. by definition, sheets of graphene are only one atom thick, but have amazing properties. at nokia world 2011, we found a customised nokia 700, whose screen had been given the hydrophobic coating. we were told that the graphene layer is 97 % transparent. indeed, the screen looked just as crisp as an ordinary 700. this is an improvement over current ito technology which is 90 % transparent. a nokia 700 sporting a hydrophobic coating we were told that the coating was made up of a grid of graphene tubes ( i. e. carbon nanotubes ). each line of the grid was made up of multiple nanotube strands, putting their width on the order of micrometers. however, the structure is still only one tube thick, keeping it on the nanometer scale. we were also told that the graphene layer is thinner than the current ito layers, which accounts for the increased transparency. the width of the grid lines are similar to a human hair, and therefore should just be visible to the naked eye. indeed, part of the demonstration apparatus we saw had a sample piece of polymer with a nanotube grid overlaid, on which we could just about see the grid lines. because water cannot interact with graphene, it makes for an ideal water resistant coating. therefore, entire phone bodies could be covered in graphene to make them more resilient in wet environments. the advantage of graphene doesn \u2019 t stop there though. the nanotube grid can be mounted to the phone screen with a microscopic air gap. this configuration then acts as a capacitor, with an air dielectric. as droplets of water touch the graphene layer, the capacitance of the air gap is changed, which can be easily detected and read as input. the demonstration set up : high speed camera, linked to nokia 700 with hydrophobic touch layer, and hydrophobic coated polymer sheet", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6497833549302028, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:d67179bf-5869-402d-820a-9d984bc2222e>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:37.777810"}
{"text": "##ene layer, the capacitance of the air gap is changed, which can be easily detected and read as input. the demonstration set up : high speed camera, linked to nokia 700 with hydrophobic touch layer, and hydrophobic coated polymer sheet as a demonstration of both the water resistant ( hydrophobic ) and electrostatic properties of this coating, the nokia 700 was used to a trigger a high speed camera. the phone was fixed at an angle above the polymer sheet, and when the demonstrator dropped water on the phone, it activated the camera and ran straight off the screen. high speed video was then captured of the water droplet falling on to the hydrophobic coated polymer. the video recording was played back to us, and we could see the droplet hitting the polymer in slow motion. on impact, the droplet spread out under its own momentum. however, because it couldn \u2019 t mix with the graphene, the surface tension of the water pulled it back into a spherical shape. the droplet effectively maintained that shape due to the repulsive forces of the graphene layer. droplet supported by surface tension on a hydrophobic coated piece of polymer this technology has the potential to provide a new form of capacitive touch screen, while making mobile phones more robust. however, nokia still needs to adapt the material so that it reacts to the oils in human skin, instead of water, but still be hydrophobic. another benefit of graphene capacitive technology is that it \u2019 s far cheaper to produce than current capacitive touch screens. the indium in ito is becoming increasingly scarce and expensive. meanwhile, graphene is just an allotrope of carbon and will be far cheaper to obtain, with less polluting byproducts. david gilson ( and photos by steve litchfield ), 08 november 2011", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6143939845090651, "token_count": 374, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:d67179bf-5869-402d-820a-9d984bc2222e>", "chunk_index": 1, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:37.778871"}
{"text": "on the emotional scaffolding of the self, or how the dynamics of temperament fluctuate with social context. we \u2019 ve previously explored what it means to be human and what defines a \u201c person. \u201d much of our understanding of personhood hinges on what we call \u201c character \u201d \u2014 but what, exactly, is it? here is an omnibus of definitions and insights from notable cross - disciplinary thinkers, from philosophy to neuroscience to literature, underpinning which is a shared sentiment that \u201c character \u201d is fluid and responsive to context, rather than a static and unflinching set of traits. a person \u2019 s authentic nature is a series of shifting, variegated planes that establish themselves as he relates to different people ; it is created by and appears within the framework of his interpersonal relationships. biological anthropologist helen fisher in this will make you smarter : new scientific concepts to improve your thinking : personality is composed of two fundamentally different types of traits : those of \u2018 character ; \u2019 and those of \u2018 temperament. \u2019 your character traits stem from your experiences. your childhood games ; your family \u2019 s interests and values ; how people in your community express love and hate ; what relatives and friends regard as courteous or perilous ; how those around you worship ; what they sing ; when they laugh ; how they make a living and relax : innumerable cultural forces build your unique set of character traits. the balance of your personality is your temperament, all the biologically based tendencies that contribute to your consistent patterns of feeling, thinking and behaving. as spanish philosopher, jose ortega y gasset, put it, \u2018 i am, plus my circumstances. \u2019 temperament is the \u2018 i am, \u2019 the foundation of who you are. psychologists thomas lewis, fari amini, and richard lannon in a general theory of love : an infant \u2019 s emotional scaffold provides for temperament and for innate abilities like reading facial expressions. limbic contact with his parents hones that pluripotential structure into the template of emotional life \u2014 the neural core of emotional identity. once this quintessence is firm, we say that a person exists, and we can know the individuated attributes of his emotional self. ongoing experience gradually transforms his neural configuration, changing him from who he was into who he is, one synapse at a time. emotional identity drifts over a lifetime \u2014 if fast and far enough, one might encounter a stranger \u2019 s heart where a friend \u2019 s or a lover \u2019 s once dwelt.", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6027766860171282, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:ef804c09-385f-4189-a137-dc3c37a021f1>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:38.203781"}
{"text": "scie108 discoveries in chemistry : a history department of science, technology, engineering & mathematics : science course number and titlescie108 discoveries in chemistry : a history number of credits3 credits minimum number of instructional minutes per semester2250 other pertinent informationnon - lab course catalog course descriptionthis course examines the historical development of chemistry ; the personalities, stories, and experiments behind modern understanding of matter ( specifically elements and compounds ), and how that understanding has led to practical technologies. in addition, the course explores the nature of scientific thought related to the historic chemical research explored. required course content and direction learning goals : discoveries in chemistry : a history is designed to serve as a one - semester course to meet the science core requirement for the non - science major. discoveries in chemistry : a history covers selected areas of chemistry in a qualitative manner, but not in as much detail as general chemistry for science majors. discoveries in chemistry : a history also illustrates the nature of science by exploring historically important chemical experiments, and how our understanding of the atomic - molecular world was developed from the results of those experiments. this helps the students understand how science works, equipping them to understand and develop informed opinions related to contemporary scientific issues. as one of the natural sciences, chemistry has evolved out of careful observation and experimentation ; as technology evolves, so does the body of chemical knowledge. this course integrates relevant technological advances to illustrate that the methods and practices that allowed chemical knowledge to grow and develop in the past continue to alter and refine our understanding of the physical world. all of these topics are explored from a historical perspective, with examination of the experiments and observations that led to our modern understanding of them. the twofold goal of this approach is to reinforce understanding of the concepts themselves and to illustrate the nature of scientific thought and practice. in addition, historical investigation of scientific developments illustrates how considerations in the wider world \u2014 such as social, economic, and cultural factors \u2014 affect the course of scientific investigations ; how such concerns affect how scientists think, the scientific issues scientists choose to investigate, questions scientists ask, how scientists interpret experimental results and observations, and how scientists develop frameworks for organizing their understanding of the physical world. conversely, the affects of scientific developments on the outside world, its affects on economics, history, society, culture, etc. are explored. - course students will : - demonstrate an understanding of how observations and experimental evidence shape scientific knowledge, and draw a logical conclusion ; - demonstrate basic understanding of the atomic - molecular nature of matter,", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6191345077710293, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:c3d68f76-db81-46c4-aa81-774ea1f1782f>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:38.232363"}
{"text": ", history, society, culture, etc. are explored. - course students will : - demonstrate an understanding of how observations and experimental evidence shape scientific knowledge, and draw a logical conclusion ; - demonstrate basic understanding of the atomic - molecular nature of matter, and how atoms and molecules give rise to macroscopically - observable elements and compounds ; - describe how historical, economic, social, and cultural factors affect the practice of science and the development of scientific ideas, and how science in turn has affected history, economics, society, and culture ; - evaluate scientific evidence in current scientific issues, and shape and express informed opinions on relevant contemporary scientific issues, and defend their opinions on the basis of evidence ; and - define the role of chemistry in relevant modern technologies. - core ( if applicable ) category i : - apply the scientific method by explaining and identifying its components in a variety of situations. - understand and express the meaning and significance of a variety of communications ( interpretation ). mathematics or sciencestudents will be able to : critical thinking / problem solvingstudents will be able to : planned sequence of topics and / or learning activities : - scientific thought : forming and refining ideas with experimental and observational evidence - phlogiston theory develops to explain apparent loss of mass during combustion - priestly discovers oxygen through decomposition of hgo - lavoisier shows combustion products actually have more mass - combustion - as - oxidation replaces phlogiston theory - in the process, lavoisier distinguishes \u201c compounds \u201d from \u201c simple substances \u201d - atoms : how we know they \u2019 re real - lavoisier defines compounds and simple substances, but offers no explanation - davy discovers several oxides of nitrogen - dalton notices mathematical relationships among proportions - the law of definite proportions - dalton proposes atoms as an explanation - also explains compounds and simple substances - development of atomic theory after dalton - gay - lussac \u2019 s law of combining volumes bolsters atomic theory - avogadro explains discrepancies in theory, but is ignored for fifty years - still resistance among some chemists - this was because atoms were not observable - atomic theory was useful, leading to fruitful research, which swayed some ; but even skeptics used the theory - early 1900s : perrin observes brownian motion, providing direct evidence of atoms - today : atomic force microscopy - inside the atom - dalton \u2019 s atoms were immutable until j. j. thomson discovered the electron - rutherford discovers the nucleus, moseley defines atomic number - chadwick discovers neutrons -", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6501033883793877, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:c3d68f76-db81-46c4-aa81-774ea1f1782f>", "chunk_index": 1, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:38.233576"}
{"text": "evidence of atoms - today : atomic force microscopy - inside the atom - dalton \u2019 s atoms were immutable until j. j. thomson discovered the electron - rutherford discovers the nucleus, moseley defines atomic number - chadwick discovers neutrons - meitner, hahn, and strassmann discover fission - hans bethe determines fusion powers the sun - organizing the elements - lavoisier \u2019 s \u201c simple substances \u201d - dalton \u2019 s atoms explain the existence of elements - early attempts at organization fail - development of the modern periodic table - cannizzaro \u2019 s reports more accurate atomic mass values in 1861 - refined atomic mass values allow periodic trends to become clearer to mendeleyev and to meyer : both develop periodic tables - meyer and mendeleyev both make periodic tables for use in textbooks - both developed table to make learning element properties easier - mendeleyev uses periodic table to predict discovery of new elements - de boisbaudran discovers gallium - nilson discovers scandium - winkler discovers germanium - these discoveries bring recognition for mendeleyev, but also priority dispute with meyer - refinements to periodic table - ramsey discovers noble gases - mendeleyev rejects them at first - ramsey shows noble gases to be a new column on the periodic table - discovery of electron explains periodicity - mendeleyev rejects electrons - electrons meant the elements were not the most fundamental form of matter - protons explain te and i discrepancy - structure makes the substance - wohler and von liebig discover isomerism - the development of structural concepts in chemistry - kekule and couper lay down basics of organic structure, explaining isomerism - pasteur discovers chirality - van \u2019 t hoff uses lack of isomerism in ch2cl2 to propose tetrahedral carbon - how are atoms joined in structures? - kossel proposes ionic bonding - lewis proposes covalent bonding > / li > - lonsdale determines benzene bonds are equal in length - pauling proposes resonance on the basis of lonsdale \u2019 s results - epilogue : hodgkin wins nobel prize for vitamin b12 and other structural determinations - reproducing natural structures - wohler synthesizes urea - the vital hypothesis - wohler \u2019 s urea began the overturning of this hypothesis - percy julian synthesizes physostigmine - designing new molecules - hoffmann and eichengrun synthesize aspirin : modifying natural structures - salicylic acid exists", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6545642501880071, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:c3d68f76-db81-46c4-aa81-774ea1f1782f>", "chunk_index": 2, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:38.234766"}
{"text": "s urea began the overturning of this hypothesis - percy julian synthesizes physostigmine - designing new molecules - hoffmann and eichengrun synthesize aspirin : modifying natural structures - salicylic acid exists in nature, but harsh - structural modification produces aspirin - nazis erase eichengrun from aspirin story - carothers invents nylon - staudinger puts forth macromolecular theory to explain natural and synthetic polymers - carothers uses theory to invent nylon - nylon is structurally similar to silk : biomimetics - macromolecular theory prevailed because it produced useful ( and profitable ) products more so than because of the results of any single decisive experiment - elion and hitchings first use rational design to produce chemotherapy drugs ; win nobel prize - understand the nature of scientific knowledge as being based on evidence and observation - understand the nature of scientific knowledge as being testable - examine scientific evidence and draw conclusions based on that evidence - understand that scientific ideas are refined as new evidence emerges, and to be able to recognize moments in history when such revision occurs, and to be able to recognize contemporary changes in scientific understanding when they occur - recognize simple mathematical relationships in scientific observations and be able to draw conclusions from mathematical relationships - grasp the distinction between descriptive scientific laws and explanatory scientific theories - know the evidence that has led us to the basic theories underlying modern chemistry - understand how protons, neutrons, and electrons combine to form the different kinds of atoms that make up all the elements that make up ordinary matter - grasp that periodic relationships among elements arise from mathematical relationships between the numbers of protons and electrons found in various elements - understand the difference between elements and compounds - understand the nature of ionic bonding and covalent bonding in a cursory manner - understand how atoms join to form molecules ( and extended crystals ) and that the nature of these structures gives rise to the macroscopic properties of a substance - understand the concept of chirality in a cursory manner - understand that it is the molecular - level structure of a substance that gives rise to its properties, and not its origin ( i. e. natural vs. synthetic ) - understand that natural substances can be duplicated by synthesizing the same molecular - level structures artificially - grasp the concept of biomimetics in molecular design - understand that chemists can design and prepare new materials with desired properties by understanding how molecular - level structure affects macroscopic properties - understand the macromolecular nature", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6185821652485155, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:c3d68f76-db81-46c4-aa81-774ea1f1782f>", "chunk_index": 3, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:38.235755"}
{"text": "- level structures artificially - grasp the concept of biomimetics in molecular design - understand that chemists can design and prepare new materials with desired properties by understanding how molecular - level structure affects macroscopic properties - understand the macromolecular nature of polymeric materials - understand in a cursory manner the processes of nuclear fission and nuclear fusion assessment methods for core learning goals : - course course learning goals are continuously assessed by : periodic written examinations and quizzes, in - class group work and discussions, and writing assignments. - core ( if applicable ) - category i : mathematics or science - category iii : critical thinking / problem solving written examinations and classroom exercises are used to assess the ability of the student to accurately translate descriptive problems into mathematical formulas and solve them. for example, students are asked to calculate relative atomic masses based on the proportions of elements in a series of compounds. students apply the scientific method in the classroom and are required to discuss observations, and give a reasonable explanation to any changes or deviations from the expected results. critical thinking and problem solving are assessed using written examinations and classroom exercises. the classroom exercises contain components aimed at evaluating application of skills, integration of knowledge to explain phenomena, and reasoning exercises. for example, students are asked to evaluate the merit of competing theories in explaining observations made during historic chemical investigations. reference, resource, or learning materials to be used by students : see course format. the students use approved text, demonstration equipment, the library, science learning center, and computer programs. teaching methods employedsection viii is not being used in new and revised syllabi as of 12 / 10 / 08. revision / approval date : approved 5 / 2012", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6540902734204246, "token_count": 337, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:c3d68f76-db81-46c4-aa81-774ea1f1782f>", "chunk_index": 4, "filtering_threshold": 0.6, "created_at": "2025-12-26T12:16:38.236438"}