data/train/batch_000018.jsonl

{"text": "below are the first 10 and last 10 pages of uncorrected machine - read text ( when available ) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole. intended to provide our own search engines and external engines with highly rich, chapter - representative searchable text on the opening pages of each chapter. because it is uncorrected material, please consider the following text as a useful but insufficient proxy for the authoritative book pages. do not use for reproduction, copying, pasting, or reading ; exclusively for search engines. ocr for page 33 33 glossary advected plume - - wind - transported exhaust plume, subject to local and airport - related hazardous air pollutants : research needs and meteorological conditions analysis ) aircraft gas turbine engine1 - - any gas turbine engine used for aircraft line loss - - percent of particles lost during transit through a given sam - propulsion or for power generation on an aircraft, including those ple line ; particle loss mechanisms include impaction, diffusion, commonly called turbojet, turbofan, turboprop, or turboshaft type settling ( gravitational ), and thermophoresis ( thermodiffusion ) engines lognormal3 - - a normal distribution that is the distribution of the black carbon - - nonvolatile diesel particulate matter, often used inter - logarithm of a random variable changeably with soot or elemental carbon ( see below ), although it normal distribution2 - - a probability density function that approximates is most often used when discussing optical properties the distribution of many random variables ( as the proportion of out - classical aerodynamic diameter1 - - diameter of an equivalent unit den - comes of a particular sort in a large number of independent repeti - sity sphere with the same settling velocity in still air as the particle tions of an experiment in which the probabilities remain constant in question from trial to trial ) and that has the form f ( x ) = ( 1 / ( 2 ) ) coarse particle2 - - particle with a classical aerodynamic diameter be - e ( - 1 / 2 [ ( x - \u00b5 ) / ] 2 where \u00b5 is the mean and is the standard deviation tween 2. 5 and 10 m nonroad - - mobile emission sources not commonly operated on pub - deposition - - an airborne pollutant that reaches the ground by force of lic roadways such as airport ground support equipment, lawn gravity, rain, or by attaching to other particles mowers", "subdomain_id": "subdomain_quantum_thermodynamics", "similarity_score": 0.6119165295841216, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:57188dc8-dfd8-413e-8177-390729fd02be>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:06:31.481039"}
{"text": "| san jose state university | & tornado alley the equipment for demonstrating the aharonov - bohm effect consists of a source of uniform energy electrons, a screen with two slits in it, a screen to capture the interference pattern and a solenoid. the solenoid is an electromagnet encased in an iron tube. the iron tube captures all of the magnetic field created by the electromagnet. outside of the tube the magnetic field zero. without the electromagneti on, the equipment generates the standard interference pattern for the two - slit experiment. a schematic diagram for the experiment is shown below. when the current in the solenoid is increased there is a shift in the interference pattern on the screen. this is quite surprising because the iron shielding of electromagnet confines the magnetic field entirely to the solenoid itself. the magnet field in the paths of the electrons is zero. in any real experiment the magnetic field would be zero except for background levels. paul a. m. dirac proved in 1931 that in such arrangement there would be a phase shift for the wave function of the electron based not upon the level of the magnet field for the region through which it passes but upon the level of the vector potential function. if b ( x ) is the magnetic field function then the vector potential function is such that for any a ( x ) equal to the gradient of a scalar function \u2207g the curl is zero, thus the vector potential function in a region can be nonzero even though the magnetic field is zero. the wave function \u03c8 ( x ) is a complex - valued function of the point in space x. the magnitude squared of the wave function | \u03c8 ( x ) | 2 is the probability density for the electron at point x. a wave function can be multiplied by a function of the form exp ( - i\u03c6 ) without affecting the magnitude and thus without affecting the probabilities of the electron being found in any region of space. the quantity \u03c6 is called the phase angle. it was generally thought before the aharonov - bohm experiment that changes in phase angle do not affect the behavior of electrons. the experiment showed that the phase angle of electrons could be modified even though the magnetic field through which they pass is zero, and that the modification can be detected. what dirac showed is that the change in phase angle of an electron passing through a path s is where e is the charge of the electron, h is planck ' s constant divided by 2\u03c0 and j is", "subdomain_id": "subdomain_quantum_optics", "similarity_score": 0.6265332370960826, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:8bb68c4a-91f9-40f5-919f-3a7a122fd716>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:06:32.055463"}
{"text": "and that the modification can be detected. what dirac showed is that the change in phase angle of an electron passing through a path s is where e is the charge of the electron, h is planck ' s constant divided by 2\u03c0 and j is the line integral where a is the vector potential for the magnetic field. the phase difference between electrons traveling on path 1 compared to path 2 is thus based upon the difference in the line integrals. this is equivalent to computing the line integral forward on path 1 and then backward on path 2. this in turn is equivalent to computing the line integral around the path created by path 2 to path 1 in a reverse direction. this creates a closed path. by stoke ' s theorem the line integral around a closed path is equal to the integral of the curl of the vector quantity over the surface enclosed by the path. in this case the curl of the vector potential is the magnet field and this is nonzero for the cross - section of the solenoid. what the aharonov - bohm experiment established is that it is not only the electric and magnetic field that can have observable effects. the vector potential can also produce observable effects. originally the vector potential function was only a mathematical artifact, a convenience. what the aharonov - bohm effect shows is that the vector potential function has a primacy, an existence in its own right. home page of thayer watkins", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6473941079919727, "token_count": 288, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:8bb68c4a-91f9-40f5-919f-3a7a122fd716>", "chunk_index": 1, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:06:32.056169"}
{"text": "phenomena described by geophysicist in non - technical terms as alaska \u2019 s billion lakes become colder and harder, some of them will sport mysterious, spidery cracks extending from small holes in the ice. this phenomenon inspired a geophysicist to figure out what he calls \u201c lake stars. \u201d \u201c i thought something so pretty and relatively commonly observed should be understandable, so i pursued it, \u201d said victor tsai, who wrote perhaps the only paper in existence on lake stars. tsai, a geophysicist with the seismological laboratory at the california institute of technology, developed a mathematical model to explain how the stars form. he recently gave a less technical description of the conditions needed for lake stars to blossom. \u201c you need relatively thin ice, and a thick snow cover, \u201d he said. \u201c the lake needs to have just frozen over and then had a heavy enough snow to weigh the ice down enough that the snow can become wet from lake water. \u201d tsai became interested in lake stars when he spent a summer at woods hole oceanographic institution in massachusetts. there, he found that, while many people had guessed at what caused lake stars, there was no established theory to explain them. he set up a lab experiment in which he created the stars indoors, using a plate cooled below freezing. through a dish of slush, he fed a steady drip of water one degree above freezing. narrow channels formed in all of his attempts, and he wrote a 13 - page paper on \u201c the formation of radial fingers emanating from a central source. \u201d he provides here a non - technical version on how the stars form : from a hole in the ice, relatively warm lake water flows upward and infiltrates the slushy snow on top. water then flows outwards through the slush. some areas of slush melt more due to variations in water flow, allowing an arm of the star to grow faster. as the arms grow, cold robs the water of heat, slowing the growth of some arms and allowing others to sprout. lake stars are somewhat reminiscent of a feature familiar to most alaskans, windshield cracks. michael marder, a physicist at the university of texas in austin, once explained to me how they happen. a windshield, he said, isn ' t one solid piece of glass, it \u2019 s two layers pressed around a layer of plastic, which keeps glass from flying during an accident. the entire windshield is about as thick as a pile of five dimes. during windshield manufacture, a machine", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6020926713869862, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:703f01c6-a707-4a42-9d1a-30047283dc45>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:06:32.426762"}
{"text": "objectivity is both a metaphysical and an epistemological concept. it pertains to the relationship of consciousness to existence. metaphysically, it is the recognition of the fact that reality exists independent of any perceiver \u2019 s consciousness. epistemologically, it is the recognition of the fact that a perceiver \u2019 s ( man \u2019 s ) consciousness must acquire knowledge of reality by certain means ( reason ) in accordance with certain rules ( logic ). this means that although reality is immutable and, in any given context, only one answer is true, the truth is not automatically available to a human consciousness and can be obtained only by a certain mental process which is required of every man who seeks knowledge \u2014 that there is no substitute for this process, no escape from the responsibility for it, no shortcuts, no special revelations to privileged observers \u2014 and that there can be no such thing as a final \u201c authority \u201d in matters pertaining to human knowledge. metaphysically, the only authority is reality ; epistemologically \u2014 one \u2019 s own mind. the first is the ultimate arbiter of the second. the concept of objectivity contains the reason why the question \u201c who decides what is right or wrong? \u201d is wrong. nobody \u201c decides. \u201d nature does not decide \u2014 it merely is ; man does not decide, in issues of knowledge, he merely observes that which is. when it comes to applying his knowledge, man decides what he chooses to do, according to what he has learned, remembering that the basic principle of rational action in all aspects of human existence, is : \u201c nature, to be commanded, must be obeyed. \u201d this means that man does not create reality and can achieve his values only by making his decisions consonant with the facts of reality. objectivity begins with the realization that man ( including his every attribute and faculty, including his consciousness ) is an entity of a specific nature who must act accordingly ; that there is no escape from the law of identity, neither in the universe with which he deals nor in the working of his own consciousness, and if he is to acquire knowledge of the first, he must discover the proper method of using the second ; that there is no room for the arbitrary in any activity of man, least of all in his method of cognition \u2014 and just as he has learned to be guided by objective criteria in making his physical tools, so he must be guided by objective criteria in forming his tools of cognition : his concepts. it is axiomatic concepts that identify the precon", "subdomain_id": "subdomain_quantum_mechanics", "similarity_score": 0.617007113192987, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:f245e2b8-8a0e-442d-9a17-5d34ee8844b7>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:06:33.225375"}
{"text": "explains nothing ; a hazy tautology \u2013 vital - force is the thing that makes living things living \u2013 designed simply to justify our intuitions. ultimately haldane came to reject vitalism, preferring to see life as a multifaceted phenomenon. this appealed to philosopher henry woodger who urged scientists to abandon the word life, instead sticking to listing the properties of living organisms. the laboured definition has now become paradigmatic, turning biologists away from the big philosophical questions concerning life. this is seen in the introduction to most biology textbooks. but the problem with the listing method is that it pretends to tell us what life is, but really only gives us a shopping list of things to look for in living things, ignoring the deeper question of how these properties make things living. furthermore, lists almost always disagree, being dependent on the author \u2019 s personal prejudices. hiding behind our intuition, steven pinker says, is a subjective tick - box of properties which the professional biologist merely couches in technical language. the most important of these properties is the idea that each life - form, besides being self - propelled, contains an essence \u2013 a caterpillar may change into a chrysalis, and then into a butterfly, but despite these huge anatomical changes we feel it is still the same animal. non - living objects lack this essential identity which goes unchanged during the life - cycles of living things. taxonomist ernst mayr believes that essentialism is just as dangerous as vitalism when defining life. he blames plato \u2019 s perfect forms and their overbearing influence on western philosophy. we divide organisms into broad taxonomic categories, specifying the ideal ( average! ) ant or panda \u2013 knowledge we can then use to generalize and make predictions about nature. but therein lies the rub : mayr says \u201c generalizations in biology are almost invariably of a probabilistic nature. \u201d science, as a product of our essentialist intuitions, has been dominated by the search for strict definitions and universal laws. when defining life, however, we must embrace what mayr calls \u2018 population thinking. \u2019 we must see each individual in the population as unique, rejecting the idea of the typical tiger. because \u201c variation is attributed to the imperfect manifestation of the underlying essences, \u201d many intuitive essentialists struggle to accept evolution by natural selection. consider the creationists \u2019 mocking demands for a \u2018 fronkey \u2019, halfway between frog and monkey \u2013 they see species as inviolate categories. they imagine evolutionary change as being a pokemon - like transformation", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6130732065510862, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:c4f0e4f8-98bf-4ccf-b7b6-5c90e6dcef18>", "chunk_index": 1, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:06:33.471963"}
{"text": "the force that binds neutrons to an atom ' s nucleus could be used to create clocks that are 100 times more accurate than today ' s best atomic clocks, say physicists at the university of new south wales ( unsw ). the nuclear clock outlined in a paper accepted for publication in physics letters review would neither lose nor gain 1 / \u2026 why is it that historically the clocks have gotten more accurate, but the trains have been getting later and later? by improvements in ( time ) management? ah yes, but we can measure the lateness of said trains with unprecedented accuracy and thus employ ' atomic timing train advisory consultants ' ( attac ' s ), to burn through a few billion advising the clueless as to how they could reduce said lateness by one orbit of a neutron. quantum uncertainty : the product of the error on the clock and the error in the train schedule is constant. because of heisenberg ' s trains : the more accurately you know the time, the less accurately you know where the fragging train is. how on earth did we, way back when, define such a unit as a second if we couldn ' t even measure it accurately? how do we know it ' s 2012 if we ' ve never had an accurate timepiece? how do we know existing clocks are fast or slow? what do we use to measure the inaccuracy? how hard is it to use w * kipedia to answer your questions, unless they were purely rhetorical? here, have this one on me. http : / / en. wikipedia. org / wiki / second we * define * the second by using atomic clocks, ergo, an average reading of many clocks can never be \" slow \" or \" fast \". if you do something odd with a single atomic clock like take it up a mountain, launch it in a satellite, etc, then it will drift, but that ' s relativity for you. why use atomic clock definition? the definition of a second came about because pendulums, the earth ' s rotation rate and the tropical year cannot be measured with anything like the same accuracy. a physical principle that nothing can ever be exactly measured. nb : the measurement of metre is now defined by the speed of light ( a defined constant ) and the definition of a second rather than by using a platinum bar, or measurements of spectral lines, for much the same reasons - we can measure time far more accurately. > how on earth did we, way back when, define such a unit as a second", "subdomain_id": "subdomain_quantum_metrology", "similarity_score": 0.7033368317176926, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:bf180c42-2615-4c25-bb2e-c1a44b37e0a0>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:06:34.072071"}
{"text": "definition of a second rather than by using a platinum bar, or measurements of spectral lines, for much the same reasons - we can measure time far more accurately. > how on earth did we, way back when, define such a unit as a second if we couldn ' t even measure it accurately? the same way we defined every unit of measurement we had at the time, as best we could. > how do we know it ' s 2012 if we ' ve never had an accurate timepiece? because 430 years ago pope gregory xiii decided that that year should be called 1582 and everybody agreed with him. since then the earth has orbited the sun 430 times making this year 2012. it doesn ' t matter how accurate your second is, it is easy to count years which is how we know it is 2012. > how do we know existing clocks are fast or slow? what do we use to measure the inaccuracy? up until 1967 a second was defined in terms of the earth revolving around the sun. since then it has been define as : \" the duration of 9, 192, 631, 770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium 133 atom. \" purely rhetorical, but i did wonder who would come it with the most condescending reply. as it turns out, you,. until this reply, of course. you sound exactly like my three year old nephew. do you want to build some lego? > because 430 years ago pope gregory xiii decided that that year should be called 1582 and everybody agreed with him. not quite. that ' s only true if you live in catholic country. the uk in common with most protestant countries didn ' t adopt his idea until 1752. the russians didn ' t adopt it until the early 20th century. i read up on this stuff back at the turn of the millennium. a very interesting book - when it comes down to it it ' s all very arbitrary. roman emperors for instance sometimes removed a month in order to bring tax collections in a bit early. maybe that ' s an idea the condem coalition could look as an alternative to spending cuts : ) something about the old way seems easier. we don ' t need to know the time accurately. what mankind really needs is a good excuse for being late. 1 second = the time it takes to grab the remote and change channel when jedward appear on tv. too slow old man, i have a panic button that cuts the power and self", "subdomain_id": "subdomain_quantum_metrology", "similarity_score": 0.6367674212102244, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:bf180c42-2615-4c25-bb2e-c1a44b37e0a0>", "chunk_index": 1, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:06:34.073109"}
{"text": "diamond anvil cells can apply millions of atmospheres of pressure to a solid or liquid, while allowing it to be observed through the diamond \u201c windows. \u201d for the first time, researchers have introduced optical tweezers into one of these cells in order to trap sample particles. the experiment, described in physical review letters, directly measured the viscosity of the water surrounding the particles. further development of this technique could permit investigations of the mechanical changes in biological cells and other soft materials placed under high pressure. a diamond anvil cell ( dac ) is a sealed volume sandwiched between the flat, millimeter - wide tips of two diamonds. when squeezed, the pressure in the cell can reach levels found in the core of the earth. diamonds are not only strong enough to handle these pressures, but they are also transparent to optical and x - ray probes. however, studying certain mechanical properties requires the controlled application of localized forces, which has been difficult to realize in a dac. for their force \u201c handle, \u201d richard bowman of the university of glasgow, in the uk, and his colleagues chose optical tweezers, which are highly focused lasers that trap particles. to overcome the spatial constraints of a dac, the team used part of their laser to create a second beam that reflected back on the cell. the combined beams trapped micron - sized silica beads suspended in a water sample. because the optical forces were known, the random vibrations of trapped beads provided a direct measure of the water viscosity. the team recorded a threefold increase in viscosity for a pressure rise of atmospheres \u2014 a result that agrees well with previous measurements and builds confidence in the new technique. \u2013 michael schirber", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6216611038792608, "token_count": 345, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:8238d2d8-6334-43a0-a3d0-3e6f29acb91c>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:06:34.679860"}
{"text": "quantum system can emit only photons with energy equal ( within the uncertainty ) to the difference between two energy states. even if the atom is in a superposition of energy states \\ left | \\ psi \\ right > = c _ 0 \\ left | 0 \\ right > + c _ 1 \\ left | 1 \\ right > + c _ 2 \\ left | 2 \\ right > + \\ ldots \\ qquad ( 1 ) with average energy somewhere between the levels, it can emit only certain set of photons : $ e _ 1 - e _ 0 $, $ e _ 2 - e _ 0 $, $ e _ 2 - e _ 1 $ etc. emission of a photon is an act of measurement since the energy of the emitted particle contains information about the atom. if the energy of the photon is $ e _ 2 - e _ 1 $ then the energy of the electron in the atom is $ e _ 1 $ - the energy of the final state of the transition. the next photon emitted by this atom will have energy equal to $ e _ 1 - e _ 0 $ for sure. if one observe photons emitted by an ensemble of atoms in state ( 1 ) he will see $ e _ 1 - e _ 0 $ photons with probability $ \\ left | c _ 1 \\ right | ^ 2 $, any of $ e _ 2 - e _ 0 $ and $ e _ 2 - e _ 1 $ with probability $ \\ left | c _ 2 \\ right | ^ 2 $ and so on. the total energy emitted by the system while it is coming to ground state is equal to average energy of state ( 1 ) multiplied by the number of atoms in the ensemble. energy conservation is not violated. the same is true for mixed states for which the probability of certain photon is determined by the density matrix of the system.", "subdomain_id": "subdomain_quantum_optics", "similarity_score": 0.6736675062381443, "token_count": 376, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:b33feb16-7bb6-42d7-8b99-6b9496ca2c1b>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:06:34.683751"}
{"text": "| the h2 double - slit experiment : where quantum and classical physics meet | for the first time, an international research team carried out a double - slit experiment in h2, the smallest and simplest molecule. thomas young ' s original experiment in 1803 passed light through two slits cut in a solid thin plate. in the groundbreaking experiment performed at als beamlines 4. 0 and 11. 0. 1, the researchers used electrons instead of light and the nuclei of the hydrogen molecule as the slits. the experiment revealed that only one \" observing \" electron suffices to induce the emergence of classical properties such as loss of coherence. present - day single photoionization experiments demonstrate double - slit self - interference for a single particle fully isolated from the classical environment. but if quantum particles were put in contact with the classical world in a controlled manner, at what scale would quantum interference begin to diminish and particles start to behave classically? the team decided to study the double photoionization ( complete fragmentation ) of h2, creating two repelling protons acting as a double slit, a fast interfering electron, and a second electron behaving as an active or inactive observer. experiments were performed at two different photon energies : = 240 and 160 ev, leaving about 190 and 110 ev to be shared between the two electrons, respectively. at these high photon energies, double photoionization of h2 led in most cases to one fast and one slow electron. the fast electron ' s energies were 185 to 190 ev ; the slow electron \u2019 s were 5 ev or less ( corresponding to an inactive observer ). the interference pattern of the fast electron was conditioned by the presence and velocity of the other : the greater the difference in their speeds, the less their interaction and the more visible the interference patterns. both electrons were isolated from their surroundings, and quantum coherence prevailed, revealed by the fast electron ' s wavelike interference pattern at the two protons. however, at high photon - energy levels, the fast electron absorbed almost all the energy of the incident single photon, leaving the system too rapidly for interaction with the slow electron. yet the slow electron was also ejected from the molecule through the mysterious process of electron \u2013 electron correlation. this \" secret entanglement \" allows two electrons to remain connected even though far apart. the researchers now had what they needed to build their classical / quantum interface. they choose ionization events where the slow electron had a bit more energy ( 5 \u2013 25 ev ) allowing it act as the classical environment ( an", "subdomain_id": "subdomain_quantum_optics", "similarity_score": 0.6757807674160088, "token_count": 511, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:d5a97766-4890-4e47-b8ad-668a033e2f72>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:06:35.189113"}
{"text": "connected even though far apart. the researchers now had what they needed to build their classical / quantum interface. they choose ionization events where the slow electron had a bit more energy ( 5 \u2013 25 ev ) allowing it act as the classical environment ( an active observer ). the quantum system of the fast electron now interacted with the slow electron and began to decohere, its interference pattern disappearing. however, the overall coherence was still hidden in the two electrons ' entanglement. the dielectron ' s wavelength was short enough to still interfere ( the sum energy of the two electrons was high enough ), and there was no environment to disturb the interference as the two electrons were now combined into one quasiparticle. thus, interference between the entangled electrons could be reconstructed by graphing their correlated momenta from the angles at which they were ejected. two waveforms appeared in the graph, either of which could be projected to show an interference pattern. because the two waveforms were out of phase with each other, when viewed simultaneously, the interference vanished. if the two - electron system is split into its subsystems and one is thought of as the environment of the other, it becomes evident that classical properties such as loss of coherence can emerge even when only four particles are involved. yet because the two electrons ' subsystems are entangled in a tractable way, their quantum coherence can be reconstructed. in solid - state \u2013 based quantum computing devices, such electron \u2013 electron interaction represents a key challenge as decoherence and loss of information occur on the tiny scale of a single hydrogen molecule. the good news, however, is that, in theory, the information is not completely lost. research conducted by d. akoury, th. weber ( university frankfurt, germany, and berkeley lab, u. s. ) ; k. kreidi, t. jahnke, a. staudte, m. schoffler, n. neumann, j. titze, l. ph. h. schmidt, a. czasch, o. jagutzki, r. a. costa fraga, r. e. grisenti, h. schmidt - bocking, r. dorner ( university frankfurt, germany ) ; t. osipov, h. adaniya, m. h. prior, a. belkacem, ( berkeley lab, ca, u. s. ) ; r. diez muino ( centro de fisica de", "subdomain_id": "subdomain_quantum_mechanics", "similarity_score": 0.7011435932132714, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:d5a97766-4890-4e47-b8ad-668a033e2f72>", "chunk_index": 1, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:06:35.190095"}
{"text": "science fair project encyclopedia this page explains commonly used terms in chess in alphabetical order. some of these have their own pages, like fork and pin. for a list of unorthodox chess pieces, see fairy chess piece ; for a list of terms specific to chess problems, see chess problem terminology. see also : sample chess game - adjournment : suspension of a long chess game with the intention to continue later, usually another day. - algebraic notation : a way of recording a chess game using alphanumeric codes for the squares. - annotation : commentary on a game using a combination of written comments, chess symbols or notation. - arbiter : a tournament official who arbitrates disputes and performs other duties such as keeping the score when players are under time pressure. - armageddon : a game which white must win to win the match, but which black only needs to draw to win the match. white has more time than black : the discrepency can vary, but in fide world championships, white has six minutes, black five. typically used in playoff tie - breakers where shorter blitz games have not resolved the tie. - back rank : a player ' s first rank ( the one on which the pieces stand in the initial array ) ; white ' s back rank is black ' s eighth rank and vice versa. - back rank mate : a checkmate delivered by a rook or queen along a back rank in which the mated king is unable to move up the board because the king is blocked by friendly pieces ( usually pawns ) on the second rank. - bad bishop : a bishop which is hemmed in by pawns of its own color. - battery : two or more pieces of the same color supporting each other on the same file, rank or diagonal. only queens, rooks and bishops can be part of a battery. - bishop : see bishop - bishops on opposite colors : a situation in which one side has only its white - squared bishop remaining while the other has only its black - squared bishop remaining. in endgames, this often results in a draw if there are no other pieces ( only pawns ), even if one side has one or two pawns extra, since the bishops control different squares ; in the middlegame, however, the presence of opposite colored bishops can give an attack an extra edge, since one bishop can attack squares which cannot be covered by the other. - bishop pair : in open positions, two bishops are considered to have an advantage over two knights or a knight", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6140732287813885, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:9c64fd6d-d073-454e-9e83-892f742d231f>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:06:35.289287"}
{"text": "the presence of opposite colored bishops can give an attack an extra edge, since one bishop can attack squares which cannot be covered by the other. - bishop pair : in open positions, two bishops are considered to have an advantage over two knights or a knight and a bishop. ( in closed positions knights may be more valuable than bishops. ) the player with two bishops is said to have the bishop pair. - blindfold chess : a form of chess in which one or both players is not allowed to see the board. - blitz chess : a form of chess with a very small time limit, usually 3 or 5 minutes per player for the entire game. with the advent of electronic chess clocks, it is often the case that the time remaining is incremented by 1 or 2 seconds per move. - blunder : a very bad move, an oversight ( indicated by \"?? \" in notation ). - book move : an opening move found in the standard reference books on opening theory. a game is said to be \" in book \" when both players are playing moves found in the opening references. a game is said to be \" out of book \" when the players have reached the end of the variations analyzed in the opening books or if one of the players deviates with a novelty. - bullet chess : a form of chess in which each side has less than 3 minutes for the entire game. - castling : a special move involving the king and one rook. - centre / center : the 4 squares in the middle of the board. - checkmate : a position in which a player ' s king is in check and the player has no legal move ( i. e cannot move out of check ). a player whose king is checkmated loses the game. - closed game : any chess opening that begins with the moves 1. d4 d5. see also open game and semi - open game. - combination : a clever sequence of moves, often involving a sacrifice, to gain the advantage. the moves of the other player are usually forced, i. e. a combination does not rely on the opponent to make a mistake. - diagonal : a line of squares along which a bishop moves. - discovered attack : an attack made by a queen, rook or bishop when another piece or pawn moves out of its way. - discovered check : a check delivered by a piece when another piece or pawn has moved out of its way. - domination : a situation whereby capture of a piece is unavoidable despite it having wide freedom of movement", "subdomain_id": "subdomain_quantum_cryptography", "similarity_score": 0.6125645786859142, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:9c64fd6d-d073-454e-9e83-892f742d231f>", "chunk_index": 1, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:06:35.290389"}
{"text": "moves out of its way. - discovered check : a check delivered by a piece when another piece or pawn has moved out of its way. - domination : a situation whereby capture of a piece is unavoidable despite it having wide freedom of movement. - double attack : two attacks made with one move : these attacks may be made by the same piece ( in which case it is a fork ) ; or by different pieces ( a situation which may arise via a discovered attack in which the moved piece also makes a threat ). the attacks may directly threaten opposing pieces, or may be threats of another kind : for instance, to capture the queen and deliver checkmate. - double check : a check delivered by two pieces at the same time. - doubled pawns : a pair of pawns of the same color on the same file. - doubled rooks : two of a player ' s rooks placed on the same ( open ) file or rank. this is a battery of rooks. - draw : a game that ends without victory for either player. most drawn games are draws by agreement. the other ways that a game can end in a draw are stalemate, three - fold repetition, the fifty - move rule, and insufficient material. - en passant ( \" in the act of passing \" ; derived from french ) : the rule that allows a pawn that has just advanced two squares to be captured by a pawn on the same rank and adjacent file. - en prise ( from french ) : a piece that can be captured. usually used of a piece that is undefended and can be captured. - endgame : the stage of the game when there are few pieces left on the board. the endgame follows the middlegame. - the capture of a pair of pieces, one white and the other black, usually of the same type ( i. e rook for rook, knight for knight etc ). - the advantage of a rook over a minor piece. the player who captures a rook while losing a minor piece is said to have won the exchange, and the opponent is said to have lost the exchange. - exchange sacrifice : giving up a rook for a minor piece ( knight or bishop ). - expanded centre : the central sixteen squares on the board. - family fork, family check : a knight fork that attacks more than two opposing pieces concomitantly. - fianchetto : the development of the bishop to the second square on the file of the adjacent knight ( that is, b2 or g2 for", "subdomain_id": "subdomain_quantum_cryptography", "similarity_score": 0.6409615658550678, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:9c64fd6d-d073-454e-9e83-892f742d231f>", "chunk_index": 2, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:06:35.291342"}
{"text": "bishop : a fianchettoed bishop, characteristic of the indian defenses ( king ' s indian defense and queen ' s indian defense ). - insufficient material : an endgame scenario in which all pawns have been captured, and one side has only its king remaining while the other is down to a king plus one knight or a king plus one bishop. the position is a draw because it is impossible for the dominant side to force checkmate ( in the event of a king plus two knights versus a lone king, checkmate is possible only if the player with the lone king blunders by moving the king to one of the four corner squares when an alternate move would always be available ). - isolated pawn : a pawn with no pawn of the same color on an adjacent file. - italian bishop : a white bishop developed to the c4 square or a black bishop developed to c5. this development is characteristic of the giuoco piano opening, also called the italian game. - j ' adoube ( from french ) : \" i adjust \". a player says \" j ' adoube \" as the international signal that he intends to adjust the position of a piece on the board without being subject to the touched piece rule. - king : see king - king - side : the side of the board where the kings are at the start of the game, as opposed to the queen - side. - knight : see knight - lightning chess : a form of chess with an extremely small time limit, usually 1 or 2 minutes per player for the entire game. - long diagonal : one of the two diagonals with eight squares ( a1 - h8 or h1 - a8 ). - luft ( from the german for air ) : space made for a castled king to give it a flight square to prevent a back rank mate. usually luft is made by moving a pawn on the second rank in front of the king. - major piece : a queen or rook. - majority : a larger numbers of pawns on one flank opposed by a smaller number of the opponent ' s ; often a player with a majority on one flank has a minority on the other. - mate : short for checkmate. - material : all of a player ' s pieces and pawns on the board. the player with pieces and pawns of greater value is said to have a \" material advantage \". - middlegame : the part of a chess game that follows the opening and comes before the endgame, beginning after the pieces are developed in", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6078835938465099, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:9c64fd6d-d073-454e-9e83-892f742d231f>", "chunk_index": 4, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:06:35.293277"}
{"text": "board. the player with pieces and pawns of greater value is said to have a \" material advantage \". - middlegame : the part of a chess game that follows the opening and comes before the endgame, beginning after the pieces are developed in the opening. this is usually roughly moves 20 through 40. - minor piece : a bishop or knight. - minority attack : an advance of pawns on the side of the board where one has fewer pawns than the opponent, usually carried out to provoke a weakness. - novelty : a new move in the opening. - open file : a file on which there are no pawns. a file on which only one player has no pawns is said to be half - open. - open game : any chess opening that begins with the moves 1. e4 e5. also called a double king pawn opening. see also closed game and semi - open game. - opening : the beginning moves of the game, usually roughly the first 20 moves. in the opening players set up their pawn structures and develop their pieces. the opening precedes the middle game. see chess opening. - opposite color bishops : the situation in which each player has only one bishop remaining and these bishops travel on opposite color squares ( white and black both have king ' s bishops remaining or both have queen ' s bishops ). although there are many exceptions, opposite color bishops can provide opportunities for attack in the middle game but are usually drawish in the endgame. - opposition : a situation in which two kings stand on the same rank or file with one empty square between them. the player on move may be forced to move the king to a less advantageous square. a particularly important concept in endgames. - outside passed pawn : a passed pawn that is near the edge of the board and far away from other pawns. in the endgame, usually a strong advantage for the side possessing such a pawn. - passed pawn : a pawn that has no pawn of the opposite color on its file or on any adjacent files on its way to queening. - pawn : see pawn - pawn structure : pawns being the least mobile of the pieces and the only pieces unable to move backwards, the position of the pawns influences the character of the game. the placement of the pawns is known as the pawn structure. - perpetual check : a draw forced by one player putting the opponent ' s king in a potentially endless series of checks. - piece : this term can mean either any chess piece including pawns ( as", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6203854454496525, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:9c64fd6d-d073-454e-9e83-892f742d231f>", "chunk_index": 5, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:06:35.294233"}
{"text": "which the study seeks to clarify. when looking at results, the p value is important. p stands for probability. it measures the likelihood that a particular finding or observed difference is due to chance. the p value is between 0 and 1. the closer the result is to 0, the less likely it is that the observed difference is due to chance. the closer the result is to 1, the greater the likelihood that the finding is due to chance ( random variation ) and that there is no difference between the groups / variables. qualitative research is the approach usually associated with the social constructivist paradigm which emphasises the socially constructed nature of reality. it is about recording, analysing and attempting to uncover the deeper meaning and significance of human behaviour and experience, including contradictory beliefs, behaviours and emotions. researchers are interested in gaining a rich and complex understanding of people \u2019 s experience and not in obtaining information which can be generalized to other larger groups. the approach adopted by qualitative researchers tends to be inductive which means that they develop a theory or look for a pattern of meaning on the basis of the data that they have collected. this involves a move from the specific to the general and is sometimes called a bottom - up approach. however, most research projects also involve a certain degree of deductive reasoning ( see section on quantitative research for more details ). qualitative researchers do not base their research on pre - determined hypotheses. nevertheless, they clearly identify a problem or topic that they want to explore and may be guided by a theoretical lens - a kind of overarching theory which provides a framework for their investigation. the approach to data collection and analysis is methodical but allows for greater flexibility than in quantitative research. data is collected in textual form on the basis of observation and interaction with the participants e. g. through participant observation, in - depth interviews and focus groups. it is not converted into numerical form and is not statistically analysed. data collection may be carried out in several stages rather than once and for all. the researchers may even adapt the process mid - way, deciding to address additional issues or dropping questions which are not appropriate on the basis of what they learn during the process. in some cases, the researchers will interview or observe a set number of people. in other cases, the process of data collection and analysis may continue until the researchers find that no new issues are emerging. researchers will tend to use methods which give participants a certain degree of freedom and permit spontaneity rather than forcing", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6027862767205538, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:94d60efc-a3a5-4d31-851b-0e4acb07a418>", "chunk_index": 2, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:06:35.330684"}
{"text": "data intelligence, business analytics as i mentioned in my previous article of \u201c fuzzy delphi method to design a strategic plan \u201d, i would like to continue the debate on distance method. but before going to the distance method, let me explain my story as follows : while i was working on discrepancy between basic and distance method on driving forces, i encountered to a phenomena. now, let me depict this phenomenon in the framework of a theorem below cited : inequality theorem in fuzzy logic assume, there is the fuzzy subset a of x where x is a universal set. then, we define the fuzzy set of a by its membership function ( mf = membership function ) as follows : mfa : x - - - - - - - [ 0, 1 ] it means that a real number mfa ( x ) in the interval [ 0, 1 ] is assigned to each element x where x is a member of x and also the value of mfa ( x ) at x presents the grade of membership of x in a. we consider below conditions for the fuzzy set a : - fuzzy set a is a convex and normalized fuzzy set in which we can say the fuzzy set a is a fuzzy number. - fuzzy set a is a central triangular fuzzy number where we have : for central triangular fuzzy number a = ( a, b, c ) : mfa ( x ) = 2 ( x - a ) / c - a if a < x < b mfa ( x ) = 2 ( x - c ) / a - c if b < x < c b = ( a + c ) / 2 now, we assume the set of s is included all central triangular fuzzy numbers as follows : s = [ ai ], i = 1, 2, 3, \u2026 \u2026. n in fact, we have : you can review the continuation of this article on below link :", "subdomain_id": "subdomain_quantum_simulation", "similarity_score": 0.6154887910995793, "token_count": 374, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:ccc5c55a-3cfc-40e8-be5a-7752e5762b27>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:06:35.384940"}
{"text": "arenas instead of the killing fields. variety is indeed the spice of life. a little girl in a pink blouse with the word sweet embroidered across its front appeared with her mother at the starbucks on south pointe \u2013 the south end of miami beach. she had her mom \u2019 s facial features and her dour expression as well. her mother got her a glazed donut, a bottle of orange juice, and a plastic cup of ice. as the tot chewed on her donut, without much interest despite her serious countenance, her mom offered her orange juice from the plastic bottle ; but she reached for the ice instead, picked up and popped a cube in her mouth. instead of pouring the juice into the container with the ice, her mother starting dropping cubes into the bottle, as if to show her child what should be done with ice cubes if picked up one by one. but the girl did not have that objective : she insisted on pressing the plastic lid on the bottle ; then she took another ice cube from the glass and popped it into her mouth, whereupon her face lit up with delight. she did not want the liquid ; she wanted the ice : she appreciated the sensational difference of form, and no doubt she appreciated the fact that she had obtained it for herself. again, nothing in particular would exist without differences ; nothing exists within the simple unity and absolute self - identity of the perfect wholeness sometime called the final cause or the end for which all things were created and in which they are presumably perfected and therefore have their truth and beauty ; to wit : good. all existents in unity have hypothetically canceled each other out ; nothing but infinity remains once the vanities are consumed by the bonfire ; but that would be nothing in itself, which is to say nothing in particular. on the verge of the abyss, then, we might say \u201c from nothing to nothing \u201d instead of \u201c from dust to dust. \u201d we find variations of such nonsensical nihilism or idiotic iconoclasm at the esoteric or occluded core of several religions. religious ascetics whose sacrificial religion constitutes the good death or virtual suicide, and who identify absolute being with nothingness, might deny the charge of negativity by stating that the affirmation of what is tantamount to nothing is in fact an affirmation of the all ; for example : empty space is the positive permanent fact ; the forms of space are ephemeral negations. in any event one might want", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6245112250119141, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:724ab179-6ea5-4035-9070-1731e634b37e>", "chunk_index": 10, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:06:35.660596"}
{"text": "a single object. the addition operator \u2018 + \u2019 no longer models this situation well because when we place a new object in the bag it does not always increase the number of objects contained in the bag by one. it is not terribly difficult to annihilate the relationship between the equation 3 + 2 = 5 and the other real world situations given above. for example, einstein \u2019 s theory of relativity tells us ( in contradiction to the more intuitive but less accurate equations of newtonian mechanics ) that when a person on a train which is moving three miles per hour ( with respect to the ground ) throws a ball at two miles per hour ( with respect to the train ), then the speed of the ball with respect to the ground is actually very slightly less than 5 miles per hour, not equal to 5 miles per hour. what \u2019 s more, if i had three dollars worth of goods yesterday and then borrow two dollars worth of goods from you today, the total number of dollars worth of goods that i have possession of will not necessarily be five dollars if the value of my original goods changed between yesterday and today ( as can happen in real economic markets ). what these examples show us is that the only reason to say that grouping balls or combining velocities or aggregating wealth encapsulates the idea of mathematical addition is because most of the time the addition operator \u2018 + \u2019 provides a good model for these scenarios. we can no more conclude that 3 + 2 = 5 is a true statement simply because putting two balls into a bag that already has three balls generally produces a bag with five balls, then we can conclude that 3 + 2 = 5 is false simply because velocities have been proven not to add. in other words, while real world situations can motivate the equations of mathematics and provide justifications for applying them, they cannot prove that those equations are actually true. we have stared at equations like 3 + 2 = 5 so many times in our lives that it can be difficult to consider them with fresh eyes in order to ask ourselves what it really is that they are saying. clearly \u2019 3 \u2032, \u2018 + \u2019, \u2019 2 \u2032, \u2018 = \u2019 and \u2019 5 \u2032 are not objects in the physical universe. you can go to the zoo and see three bears, or see the numeral \u2019 3 \u2032 printed on a sign, or perform arithmetic on paper using the symbol \u2019 3 \u2032, but nowhere in the universe can you find the actual ( metaphysical ) number \u2019 3 \u2032. this is hardly surprising, since", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6117146307820538, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:7e60be39-5ae5-486f-84a5-f0cf36a5f3c1>", "chunk_index": 1, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:06:36.153683"}
{"text": ", or see the numeral \u2019 3 \u2032 printed on a sign, or perform arithmetic on paper using the symbol \u2019 3 \u2032, but nowhere in the universe can you find the actual ( metaphysical ) number \u2019 3 \u2032. this is hardly surprising, since \u2019 3 \u2032 is a concept or idea, not a physical thing. but this line of thought implies that 3 + 2 = 5 is a statement about the relationship among the concepts \u2019 3 \u2032, \u2019 2 \u2032, and \u2019 5 \u2032, and not a statement about physical entities that actually exist. but how do we define the word \u201c true \u201d when it comes to relations among abstract concepts? one possible approach is to say that statements about abstract concepts are true if they follows as logical consequence of the definitions of the concepts themselves. this leads us to ask whether 3 + 2 = 5 and all other mathematical statements are simply true by definition as a consequence of our chosen definitions for \u2019 3 \u2032, \u2018 + \u2019, \u2019 2 \u2032, \u2018 = \u2019, \u2019 5 \u2032 and the other mathematical objects. unfortunately, this question cannot be answered without further qualification. to begin with, what do we mean by \u201c mathematical objects \u201d, and how do we choose to define concepts such as \u2019 3 \u2032? various authors have attempted to define mathematics by developing lists of axioms ( which are simply assumed to be true ) and then proving that the basic mathematical objects ( e. g. integers ) and theorems ( e. g. a + b = b + a ) follow from these axioms. unfortunately, there are a variety of different ways that math can be axiomatized ( i. e. built up from basic axioms ). some approaches use sets as the most basic objects ( as is done in what is probably the most popular axiomatization, zermelo - fraenkel set theory ), while others use category theory to provide the basic building blocks, and still other theories attempt to axiomatize only small portions of math, such as euclid \u2019 s axioms of planar geometry, hilbert \u2019 s axiomatization of euclidean geometry and the peano axioms for arithmetic. what is even worse ( when it comes to deciding what is true ) than having so many conflicting viewpoints for constructing math is that the axioms of these viewpoints are themselves not provably true. if you are willing to assume the axioms of math are \u201c true \u201d ( whatever that means ), then all of the resulting theorems that can be derived from those axioms are", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6094089754207694, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:7e60be39-5ae5-486f-84a5-f0cf36a5f3c1>", "chunk_index": 2, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:06:36.154906"}
{"text": "##ual megapixel ( p - mpix ) concept that weights the modulation transfer function ( mtf ) of the lens with the human visual acuity. read more about perceptual megapixels. device or process allowing to start and stop light acquisition on a sensor. process that allows exposing the lines of the sensor one after the other. mechanical device used to block light from or allow light onto a sensor. ratio between the value of a signal and the noise standard deviation. the data showing the signal - to - noise ratio function of the gray level values. the data describing the relative amount of light converted into signal for each wavelength device used to measure the variation of the energy of incident light as a function of wavelength. the data relating any arbitrary wavelength to a numerical value. the expected difference of a signal to its mean value. the process of decreasing the number of pixels of a digital signal. it is commonly used to display an image on a lower resolution device ( screen or print ). a gray level value representing the expected gray level over all possible well exposed photos. tonal range is the effective number of distinguishable gray levels a camera can produce. target illuminated from behind. light beams go through the target to reach the camera. transmission of a photographic lens describes its ability to transmit light from the photographic scene to the sensor surface. lenses consists of many glass elements, each reflecting or absorbing a portion of the light ; therefore the more elements, the lower the transmission. read more about how transmission is defined, measured and scored. travel & family photography involves shooting both indoors and out, and includes landscapes, portraits, group shots, and close - ups when sightseeing. the field of view requirement is very broad, from wide - angle to long telephoto, so photographers typically look for a high - power zoom with a good trade - off between all image quality parameters. read more about lens travel score requirements.", "subdomain_id": "subdomain_quantum_optics", "similarity_score": 0.6293036922318413, "token_count": 392, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:6140431a-c437-4887-8bb2-30c32797f1d9>", "chunk_index": 1, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:06:36.318476"}
{"text": "us 4088828 a a printed circuit board wherein a conductor pattern is printed on an insulating base, first solder resist layers are formed on the surface of the conductor pattern remaining lands which are for soldering thereon, second solder resist layers for prevention of bridging for preventing bridging of solder are formed at least at portions where the gap between the lands is narrow, and thereby electronic parts such as an ic can be reliably assembled on the printed circuit board. 1. a printed circuit board comprising an insulating base, a conductor pattern printed on said insulating base, a first solder resist layer formed on the entire surface of the conductor pattern remaining lands which are for soldering thereon, and a second solder resist layer for prevention of bridging of interland gaps by solder, said second solder resist layer being formed on said first solder resist layer at least over portions thereof where interland gaps are narrow. 2. a printed circuit board according to claim 1, wherein said second solder resist layer is formed over the entire area of the part for mounting electronic parts such as semiconductor integrated circuits. 3. a printed circuit board according to claim 1, wherein said second solder resist layer is printed with a mark print ink simultaneously with the printing of marks or symbols of assembled electronic parts. this invention relates to printed circuit boards suitable for mounting electronic parts such as integrated circuit parts, having lead terminals provided at very small pitch intervals. generally, the surface of a printed circuit board on which surface a conductor pattern of copper or like conductor is formed is dipped through a fused solder bath or in a jet type solder bath after the electronic parts are assembled on the printed circuit board, and solder is attached to the conductive pattern surface. thus, the leads of the electronic parts are electrically and mechanically connected to the conductor pattern. the printed circuit board is used after making these connections. in the conductor pattern as mentioned above a layer for the resisting solder ; that is the so - called solder resist layer, is formed so that solder may be attached to only fixed portions of the conductor pattern. in the meantime, there is a trend for the gap between adjacent lands of the conducting pattern to be reduced with a tendency toward reduction in the size of electric apparatus and the use of many semiconductor integrated circuit parts, which use has been made possible with the progress of techniques concerning electronic parts ; in fact it is often the case in these days that interland gaps less than the minimum gap of 0", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6105849208031316, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:10510f3b-ea31-4a7f-9662-87c2a9c40c7a>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:06:36.643417"}
{"text": "size of electric apparatus and the use of many semiconductor integrated circuit parts, which use has been made possible with the progress of techniques concerning electronic parts ; in fact it is often the case in these days that interland gaps less than the minimum gap of 0. 5 millimeter prescribed in the japanese industrial standard ( jis c - 5010 ) are required. for example, when soldering lead terminals arranged in a row such as those in a semiconductor integrated circuit component arranged at a pitch of 2. 5 millimeters to the circular portion of conductor lands arranged in correspondence with the row, solder resist layers are printed with space between the layers of 0. 5 millimeter or less. fig. 1 is a fragmentary sectional view showing a prior art printed circuit board in the state being used ; fig. 2 is a fragmentary sectional view showing an embodiment of the printed circuit board according to the invention in the state being used ; and figs. 3 and 4 are fragmentary top views showing alternative forms of the same printed circuit board. fig. 1 shows an example of prior art, in which the solder lead terminals of an electronic part such as a semiconductor circuit component are arranged in a row. designated at 1 is an insulating base, at 2 conductors printed on one surface of the insulating base 1, at 3 holes for mounting lead terminals of electronic parts to be provided on the insulating base 1, at 4 solder resist layers, at 5 an electronic part such as a semiconductor integrated circuit, at 6 lead terminals of the electronic part 5, and at 7 solder portions. in this structure, when the gap between adjacent lands of the conductor 2 becomes 0. 5 mm or less, even if the solder resist layer 4 is formed, short - circuiting between the adjacent lands of the conductor or solder portions 7 on the lands occurs often due to bridging of adjacent solder portions 7 over the intervening solder resist layer 4. this is thought to occur as the result of insufficient thickness of the solder resist layer 4. accordingly, it has heretofore been necessary as a correction step to separate the bridging portion 8 by means such as soldering iron, but this has been an extreme disadvantage in view of productivity. besides, when the correction is made in this way, the conductor 2 or electronic part 5 is heated twice, and this causes thermal deterioration of the conductor or electric part and hence reduction of its life ; thus, this correction is one which causes great problems. this invention solves the", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6046933085640951, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:10510f3b-ea31-4a7f-9662-87c2a9c40c7a>", "chunk_index": 1, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:06:36.644407"}
{"text": "made in this way, the conductor 2 or electronic part 5 is heated twice, and this causes thermal deterioration of the conductor or electric part and hence reduction of its life ; thus, this correction is one which causes great problems. this invention solves the above drawbacks inherent in the prior art. the invention will now be described in conjunction with an embodiment thereof with reference to figs. 2 to 4. designated at 9 is an insulating base consisting of a synthetic resin. a pattern of copper conductors 10 is formed by means of etching on one surface of the insulating base 9. in the insulating base 9 holes 13 are provided for receiving lead terminals 12 of an electronic part 11. of course the conductor 10 is formed around the holes 13. a layer 15 for the resisting solder, or so - called solder resist layer, is formed on the surface of the conductor 10 remaining circular lands 14 on which soldering is possible around the respective holes 13. further, a solder resist layer 16 for preventing the bridging is formed where the gap between adjacent lands 14 is small, for example, 0. 5 millimeter. the solder resist layer 16 for the prevention of bridging may be formed only over areas where it is actually required as shown in fig. 3, or it may be formed over the entire area of the part where the semiconductor integrated circuit components are mounted as shown in fig. 4. further, in view of the manufacturing process, in order to avoid an increase in the number of printing step, after the printing of the solder resist layer 15 which is the first layer, the solder resist layer 16 for the prevention of bridging is printed simultaneously with the printing of symbols indicating the mounted electronic parts, using an epoxy resin having the property of resisting solder as the printing ink. in this case, the positional precision is substantially the same as that in the printing of the solder resist layer 15 which is the first layer ; therefore, a sufficient positional precision can be obtained, and also it is possible to print the solder resist layer having substantially the same thickness as that of the solder resist layer 15. of course, the printing ink used must not be inferior in electric properties and moisture resistance to the first solder resist layer 15. by providing these two solder resist layers 15 and 16, even when soldering is done, a solder 17 will never bridge the adjacent solder portions 17. further, for the purpose of preventing bridging, one may", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6274327941290396, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:10510f3b-ea31-4a7f-9662-87c2a9c40c7a>", "chunk_index": 2, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:06:36.645425"}
{"text": "stainless steel pipe is the desired material for process piping systems due to ease of maintaining sanitary conditions and corrosion resistant properties. it is the material of choice for food conveying applications which require conformance to fda requirements. a standard benefit of the stainless steel family of materials is that it covers materials of much different chemistry, permitting economical alternatives to higher end materials and providing greater corrosion resistance to a wide variety of chemical services and environments, as well as providing increased strength. the internal pressure capabilities make stainless steel pipe suitable for use in many heavy duty applications. process piping fluids cover a wide range of applications from water to chemical services. for high pressure applications or highly corrosive environments, it may be necessary to utilize a duplex or super duplex stainless steel because of its high physical properties and greater corrosion resistance. duplex stainless steel differs from austenitic stainless steel in chemical make - up ; it has higher quantities of chromium and molybdenum and lower quantities of nickel. duplex stainless steel can be referred to as 2205, and super duplex 2507 because of the percentages of chromium and nickel in their composition. all stainless steels contain a varying percentage of chromium, molybdenum and nickel. the most common stainless steel is austenitic, which includes the stainless steel pipes made to the specifications of astm a312 in types 304 / 304l and 316 / 316l. types 304 / 304l are for general corrosion applications such as process cooling water. types 316 / 316l have a higher corrosion resistance to chlorides and may be desired based upon the chemical composition of the process fluid. the \u201c l \u201d designation means that the stainless steel contains less than 0. 03 % carbon. this is beneficial if the pipe needs to be welded. stainless steel pipe is generally available in diameters up to 36 inches with dimensions ranging from schedule 5s to 160s with schedule 10s being the most readily available. the system working pressure and pipe joining method will determine the required pipe wall thickness for each application. stainless steel pipe may be installed using a variety of joining methods including grooved, welded, flanged, and threaded.", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6110890630813826, "token_count": 439, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:d695bf41-d0af-4c60-ba28-c12d289d1536>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:06:36.892528"}
{"text": "life science : session 1 session 1. what is life? during this session, you will have an opportunity to build understandings to help you : - distinguish between living, dead, and nonliving - define the characteristics of life what is life? this question at first seems deceptively simple \u2014 we all know how to recognize what is living and what is not. or do we? what are the characteristics of all living things, and how do we know if an object really possesses those characteristics? this session explores how the concept \u201c life \u201d can be defined. error - unable to load content - flash we open with a look at environments where you wouldn \u2019 t expect to find life and pose the question : if you are looking for life, what do you look for? dr. herbert thier, representing the science curriculum improvement study ( scis3 + ), emphasizes the importance of building understandings of the concept \u201c life \u201d in the early elementary grades as a foundation for the development of ideas in life science throughout the elementary school years and beyond. the program continues as children in grades two and three are presented with a challenge : group objects as living, dead or nonliving. in what is called the \u201c science studio, \u201d the children are observed and interviewed in a clinical setting to uncover their ideas about these three concepts. throughout the course, the science studio is a place where research on children \u2019 s ideas is brought to life. in brooklyn, new york, we visit laurajo kelly and her second - grade students as they generate their own definitions of living, dead, and nonliving and proceed to design experiments to test whether a \u201c mysterious \u201d object is alive. an interview with dr. gary ruvkun, who is leading a team of researchers to determine whether life exists on mars, tells us what he considers to be the best sign of life. our search for an answer to the question \" what is life? \" leads us to consider five characteristics that are shared by all living things. one characteristic \u2014 cells \u2014 introduces us to the fundamental unit of life. we also look more closely at the matter that composes life and see the role played by organic molecules, such as the hereditary molecule dna. finally, dr. paul williams introduces us to an ongoing web site - based activity \u2014 bottle biology \u2014 that is meant to provide you with an opportunity to apply ideas addressed during this session as well as act as a resource for k - 6 classroom activities. | next : a closer look |", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6211907715330451, "token_count": 503, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:aed078fd-7ec7-4a33-9f68-3e55a22da49c>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:06:37.473411"}
{"text": "fermilab scientists find evidence for significant matter - antimatter asymmetry batavia, ill. \u2014 scientists of the dzero collaboration at the department of energy \u2019 s fermi national accelerator laboratory announced friday, may 14, that they have found evidence for significant violation of matter - antimatter symmetry in the behavior of particles containing bottom quarks beyond what is expected in the current theory, the standard model of particle physics. the new result, submitted for publication in physical review d by the dzero collaboration, an international team of 500 physicists, indicates a one percent difference between the production of pairs of muons and pairs of antimuons in the decay of b mesons produced in high - energy collisions at fermilab \u2019 s tevatron particle collider. \" this exciting new result provides evidence of deviations from the present theory in the decays of b mesons, in agreement with earlier hints, \" said dmitri denisov, co - spokesperson of the dzero experiment, one of two collider experiments at the tevatron collider. last year, physicists at both tevatron experiments, dzero and cdf, observed such hints in studying particles made of a bottom quark and a strange quark. dim lights embed embed this video on your site when matter and anti - matter particles collide in high - energy collisions, they turn into energy and produce new particles and antiparticles. at the fermilab proton - antiproton collider, scientists observe hundreds of millions every day. similar processes occurring at the beginning of the universe should have left us with a universe with equal amounts of matter and anti - matter. but the world around is made of matter only and antiparticles can only be produced at colliders, in nuclear reactions or cosmic rays. \u201c what happened to the antimatter? \u201d is one of the central questions of 21st \u2013 century particle physics. to obtain the new result, the dzero physicists performed the data analysis \" blind, \" to avoid any bias based on what they observe. only after a long period of verification of the analysis tools, did the dzero physicists look at the full data set. experimenters reversed the polarity of their detector \u2019 s magnetic field during data collection to cancel instrumental effects. \u201c many of us felt goose bumps when we saw the result, \u201d said stefan soldner - rembold, co - spokesperson of dzero. \u201c we knew we were seeing", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6322992245449244, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:39b773f0-e015-4c3d-82d8-f87b7ad7d8f0>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:06:37.507286"}
{"text": "detector \u2019 s magnetic field during data collection to cancel instrumental effects. \u201c many of us felt goose bumps when we saw the result, \u201d said stefan soldner - rembold, co - spokesperson of dzero. \u201c we knew we were seeing something beyond what we have seen before and beyond what current theories can explain. \u201d the precision of the dzero measurements is still limited by the number of collisions recorded so far by the experiment. both cdf and dzero therefore continue to collect data and refine analyses to address this and many other fundamental questions. \u201c the tevatron collider is operating extremely well, providing fermilab scientists with unprecedented levels of data from high energy collisions to probe nature \u2019 s deepest secrets. this interesting result underlines the importance and scientific potential of the tevatron program, \u201d said dennis kovar, associate director for high energy physics in doe \u2019 s office of science. the dzero result is based on data collected over the last eight years by the dzero experiment : over 6 inverse femtobarns in total integrated luminosity, corresponding to hundreds of trillions of collisions between protons and antiprotons in the tevatron collider. \u201c tevatron collider experiments study high energy collisions in every detail, from searches for the higgs boson, to precision measurement of particle properties, to searches for new and yet unknown laws of nature. i am delighted to see yet another exciting result from the tevatron, \u201d said fermilab director pier oddone. dzero is an international experiment of about 500 physicists from 86 institutions in 19 countries. it is supported by the u. s. department of energy, the national science foundation and a number of international funding agencies. fermilab is a national laboratory funded by the office of science of the u. s. department of energy, operated under contract by fermi research alliance, llc. the popular movement for reconciliation \" mussalaha \" grows or to know syria is to love syria. recentnews read more 1581 read more 2678 read more 3994 read more 3683 cia mililtary and covert operations in libya from 80s - secret cia base files by ralph mcgehee recentnews read more 2947", "subdomain_id": "subdomain_quantum_metrology", "similarity_score": 0.6219815029722768, "token_count": 463, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:39b773f0-e015-4c3d-82d8-f87b7ad7d8f0>", "chunk_index": 1, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:06:37.508115"}
{"text": "- derived carbon ( cdc ) structures and chmiola ' s on electrochemistry led to the steps to develop the electrochemical capacitors experiment. this turned from a one - year undergraduate project into chmiola ' s doctorate thesis project. an international collaboration with the group of professor patrice simon of the universite paul sabatier in france was the needed catalyst \" to make the synergy complete, \" chmiola says. chmiola ' s discovery was featured in the aug. 18, 2006, edition of the journal science. furthermore, reports about his work have appeared in the journal nature and other print and online international publications. how important are supercapacitors to our everyday lives? supercapacitors are valued for their infinite energy lifespan. traditional power sources and batteries, essential to our personal electronic devices and automobiles, don ' t store that much energy. due to their high storage energy capacity, supercapacitors are finding increased usage in portable electronic devices like mp3 players, mobile phones and palm pilots. other benefits, like short charging times and high performance in low temperatures, could lead to new applications. supercapacitors, as an energy efficient alternative, have limitations in both cost and performance. \" obviously all the pieces are not in place yet to put electrochemical capacitors ( ec ) in every future automobile, \" chmiola asserts, \" but helping to advance the understanding and develop the knowledge base necessary to make this revolution happen is what keeps me going. \" his team has some out - of - the - box ideas to make supercapacitors better, and results are promising, \" but it ' s a bit too early for publication, \" chmiola adds. integrative graduate education and research traineeship program # 0221664 igert : nanoscale engineering and science : one campus, two - university approach nano materials group : http : / / nano. materials. drexel. edu / science magazine : http : / / www. sciencemag. org / cgi / content / abstract / 1132195 nature journal : http : / / www. nature. com / nature / journal / v442 / n7105 / full / 442850a. html", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6217729024074531, "token_count": 456, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:afd629a1-a565-4b1d-8b73-842f3bebebc8>", "chunk_index": 2, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:06:37.669206"}
{"text": "n [ summation summation n. the final argument of an attorney at the close of a trial in which he / she attempts to convince the judge and / or jury of the virtues of the client ' s case. ( see : closing argument ) over ( i ) ] i ( [ y. sub. 1 ] < z ) [ [ ( z - [ y. sub. 1 ] / z ] [. sup. [ alpha ] ], where n is the sample size, i subscript ( 1 ) in word processing and scientific notation, a digit or symbol that appears below the line ; for example, h2o, the symbol for water. contrast with superscript. ( 2 ) in programming, a method for referencing data in a table. is the family or individual, y is the relevant measure of welfare, z is the poverty line, and i is an indicator function in mathematics, an indicator function or a characteristic function is a function defined on a set that indicates membership of an element in a subset that takes the value of one if the statement is true and zero otherwise. when [ alpha ] = 0, the resulting measure is the head count index, or [ p. sub. 0 ]. when [ alpha ] = 1, the fgt index results in the poverty - gap index, or [ p. sub. 1 ], and the squared poverty - gap index ( [ p. sub. 2 ] ) results when [ alpha ] = 2. in order to answer the question of whether poverty is higher in nonmetropolitan than metropolitan areas, or more generally most any question regarding whether poverty has changed over time or varies over some geographic or demographic characteristic, estimates of the sampling variance for the indices are required. kakwani ( 1993 ) provides two asymptotic estimates for the variance of the fgt poverty indices that are easy to calculate and frequently used. the kakwani formula for the variance of p0, the head count index, is [ p. sub. 0 ] ( 1 - [ p. sub. 0 ] ) / ( n - 1 ), where n is the sample size. the formula for all other variance estimates of the fgt indices is ( [ p. sub. 2 [ alpha ] ] - [ p. sup. 2. sub. [ alpha ] ]. ) / ( n - 1 ). the primary disadvantage of the kakwani estimates is that they assume the sample was collected using a simple random draw from the population. as noted in the introduction", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6012020599954143, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:77f6d4b2-18d5-4dca-92f8-673403803ad8>", "chunk_index": 8, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:06:38.196580"}
{"text": "is a list of axioms as that term is understood in mathematics, by wikipedia page. in epistemology, the word axiom is understood differently ; see axiom and self - evidence. individual axioms are almost always part of a larger axiomatic system. of symmetry symmetry, generally speaking, a balance or correspondence between various parts of an object ; the term symmetry is used both in the arts and in the sciences., replication in database management, the ability to keep distributed databases synchronized by routinely copying the entire database or subsets of the database to other servers in the network. there are various replication methods. invariance in \u00b7 var \u00b7 i \u00b7 ant 1. not varying ; constant. 2. mathematics unaffected by a designated operation, as a transformation of coordinates. an invariant quantity, function, configuration, or system., income scale independence, decomposability, and the principle of transfers only if it is a positive multiple of the theil index. ( 20 ) the bootstrap estimates are based on 1, 000 replications. for methodology details and the program used, see jolliffe and krushelnytskyy ( 1999 ). lorenz curves the lorenz curve is a graphical representation of the cumulative distribution function of a probability distribution ; it is a graph showing the proportion of the distribution assumed by the bottom y % of the values. are art alternative way to examine inequality, and zheng ( 2002 ) derives asymptotic covariance covariance a measure of the degree to which returns on two risky assets move in tandem. a positive covariance means that asset returns move together. a negative covariance means returns vary inversely. structure for generalized lorenz curves when the sample is based on a complex design. ( 21 ) the relative difference in poverty uses the metropolitan poverty level as the base and can be expressed as [ ( [ p. sub. [ alpha ] nonmetropolitan ] - [ p. sub. [ alpha ] metropolitan ] ) / [ p. sub. [ alpha ] metropolitan ] ]. ( 22 ) all differences listed in figure 2 are statistically significant with p - values less than 0. 01. ( 23 ) i use ols, rather than a censored regression model censored regression models commonly arise in econometrics in cases where the variable of interest is only observable under certain conditions. a common example is labor supply., because the zero values for each of the [ p. sub. [ alpha ] ] indices are the", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6599996318227305, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:77f6d4b2-18d5-4dca-92f8-673403803ad8>", "chunk_index": 35, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:06:38.228498"}
{"text": "challenger will characterization a rather long and fancy word for analyzing a system or process and measuring its \" characteristics. \" for example, a web characterization would yield the number of current sites on the web, types of sites, annual growth, etc. of the theil measure of income inequality. journal of economic theory 31 : 105 - 21. foster, james, joel greet, and erik thorbecke. 1984. a class of decomposable poverty measures. econometrica 52 : 761 - 5. foster, james, and anthony shorrocks. 1991. subgroup consistent poverty indices. econometrica 59 : 687 - 709. hanratty, maria, and rebecca blank. 1992. down and out in north america north america, third largest continent ( 1990 est. pop. 365, 000, 000 ), c. 9, 400, 000 sq mi ( 24, 346, 000 sq km ), the northern of the two continents of the western hemisphere. : recent trends in poverty rates in the united states and canada. quarterly journal of economics the quarterly journal of economics, or qje, is an economics journal published by the massachusetts institute of technology and edited at harvard university ' s department of economics. its current editors are robert j. barro, edward l. glaeser and lawrence f. katz. 107 : 233 - 54. honig, marjorie, and randall filer. 1993. causes of intercity in \u00b7 ter \u00b7 cit \u00b7 y relating to, involving, or connecting two or more cities : intercity rivalry ; an intercity bus. trademark variations in homelessness. american economic review 83 : 248 - 55. howes, stephen, and jean lanjouw. 1998. does sample design matter for poverty comparisons. review of income and wealth 44 : 99 - 109. jolliffe, dean. 2001. estimating sampling variance from the current population survey : a synthetic design approach to correcting standard errors. economics working paper archive no. ewp - em 0110006. jolliffe, dean. 2002. rural poverty rates stays under 15 percent in 1999. rural america 16 : 39 - 41. jolliffe, dean, gaurav datt, and manohar sharma. in press. robust poverty and inequality measurement in egypt : correcting for spatial - price variation and sample design effects. review of development economics. jolliffe, dean, and bohdan kroshelnytskyy. 1999. bootstrap standard errors for indices of inequality :", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6367481563548576, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:77f6d4b2-18d5-4dca-92f8-673403803ad8>", "chunk_index": 38, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:06:38.231599"}
{"text": "what is science : is science about observation or falsification? by : bruce in previous posts i responded ( or gave other peopleas responses anyhow ) to the ideas that science is primarily about prediction, reductionism, or holism. in those ideas we found some truth, but not the whole truth. another common point of view is that science is really about observation. related to this is the idea that science is primarily about empirical evidence or in other words must be falsifiable. as it turns out, these points of view are somewhat correct, but also misleading. science is not primarily observation i doubt science would have any meaning if we didnat take the ideas of observation and empirical evidence seriously. descarte is rumored to have tried to argue in favor of pure reason, but we know that this doesnat work out in real life. the problem is that our reasoning capacity is too broad. we can think of logical possibilities that just happen to not exist. in a past post ( in the notes ) i hinted at one of these : cartesian dualism a the idea that minds and matter are different things and that minds can exist without matter. ( seemingly contradicted by d & c 131 : 7 ). i can conceive of cartesian dualism, but all the evidence currently points against it. plus cartesian dualism is a classic violation of occamas razor. it only provides explanations by pushing the problems it purports to solve to a new location plus creating new ones. ( this does not rule out the possibility that some form of dualism will turn out to be true, and in fact i believe this will turn out to be the case. but classic cartesian dualism seems a rational non - starter for me. ) therefore we need empiricism and observation to test which of our ideas is correct. observation and empiricism are therefore important parts of science. but the simple truth is that you can have science without these. often you have no choice because the technology hasnat developed yet to observe predictions made by scientific theories. the large hadron collider is a good example of this ; it might cost billions to make an observation. worse yet, some observations may forever be cost prohibitive. furthermore, sometimes the smallest of observations cascade into the largest of ground shaking conclusions. as david deutsch points out, thus observations of ever smaller physical effects have been forcing ever greater changes in our world - view. it may therefore seem that we are inferring ever grander", "subdomain_id": "subdomain_quantum_mechanics", "similarity_score": 0.6044713639000279, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:888799cc-37ab-452e-b4b8-deb53abc5e1d>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:06:38.480784"}
{"text": "observations cascade into the largest of ground shaking conclusions. as david deutsch points out, thus observations of ever smaller physical effects have been forcing ever greater changes in our world - view. it may therefore seem that we are inferring ever grander conclusions from even scantier evidence. what justifies these inferences? ( the fabric of reality, p. 57 ) but this presents a difficult with defining science through observation. science is not always falsifiable karl popper is famous for having introduced the idea that science should be falsifiable. this is often interpreted as a theory not being ascientifica unless itas possible to falsify it. again, i think this is a powerful idea that has a lot of truth to it. is there any doubt that we should not take freudas non - falsifiable theories seriously any more now that we have better falsifiable psychological theories? a falsifiable theory is automatically better than a non - falsifiable one because the most productive theories make falsifiable predictions so that we can, to a degree, check them for verisimilitude. ( i. e. closeness to reality. ) but i doubt this is what really defines science either. it would seem there are too many counter examples. one of my favorite authors, roger penrose, points out that popper - style falsification is simply not enough to exclude a theory from science. askarl popper provided a reasonable - looking criterion for the scientific admissibility of a proposed theory, namely that it be observationally refutable. but i fear that this is too stringent a criterionas take the example of supersymmetry in modern particle physics. asit is a central ingredient of string theory. it status among theoreticians these days is so strong that it is almost considered to be part of todayas astandarda particle - physics model. yet, it has no ( serious ) experimental supportas the theory predicts asuperpartnersa for all the observed fundamental particles of nature, but none of these has so far been observed. the reason [ given ] as is that a symmetry - breaking mechanism ( of unknown nature ) causes the superpartners to be so massive that the energies needed to create them are still beyond the scope of present - day accelerators. with increased energy capabilities, the superpartners might be foundas but suppose that still no superpartners are actually found. would this disp", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6058004679722794, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:888799cc-37ab-452e-b4b8-deb53abc5e1d>", "chunk_index": 1, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:06:38.482628"}
{"text": "that the energies needed to create them are still beyond the scope of present - day accelerators. with increased energy capabilities, the superpartners might be foundas but suppose that still no superpartners are actually found. would this disprove the supersymmetry idea? not at all. it could ( and probably would ) be argued that there had simply been too much optimism about the smallness of the degree of the symmetry breaking, and even higher energies would be needed to find the missing superpartner. [ so ] we see that it is not so easy to dislodge a popular theoretical idea through the traditional scientific method of crucial experimentation, even if that idea happened actually to be wrong. ( the road to reality, p. 1020 - 1021 ) penrose goes on to use another example. one of our current theories predicts the existence of amonopoles. a imagine a magnet that has only a north or a south pole and not both. if even one exists in the entire universe, this theory has been vindicated. but if we never find any itas not really that shocking because what are the odds weare going to find that one monopole somewhere out there in the entire universe? so here is yet another non - refutable theory. but few would argue it isnat science. even popper seems to disagree with this supposedly popper - inspired idea, or at least he never says something isnat science just because it canat be falsified. rather popper only created a demarcation between what he calls aempirical theoriesa and non - empirical ones. he goes on to say : this criterion of demarcation between empirical and non - empirical theories i have also called the criterion of falsifiability or the criterion of refutability. it does not imply that irrefutable theories are false. nor does it imply that they are meaningless. but it does imply that, as long as we cannot describe what a possible refutation of a certain theory would be like, that theory may be regarded as laying outside the field of empirical science. ( the myth of the framework, p. 88 ) therefore a theory that is not refutable is only outside a category he calls aempirical sciencea not necessarily science in general. in fact, popper points out that one of our most important theories a the theory of evolution a is based on a non - falsifiable core tenant ; namely survival of the fittest : there is a difficulty", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6268096295197055, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:888799cc-37ab-452e-b4b8-deb53abc5e1d>", "chunk_index": 2, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:06:38.484409"}
{"text": "american heritage\u00ae dictionary of the english language, fourth edition - n. a solid with six faces, each a parallelogram and each being parallel to the opposite face. century dictionary and cyclopedia - n. a prism whose bases are parallelograms. - n. in experimental psychology, an outline drawing of a parallelepiped, with one diagonal drawn in, embodying an illusion of reversible perspective. the figure was published by necker in 1832 : the name \u2018 cube \u2019 properly belongs to a similar figure published by wheatstone in 1838. see illusion. 2. - n. geometry solid figure, having six faces, all parallelograms ; all opposite faces being similar and parallel. gnu webster ' s 1913 - n. ( geometry ) a prism whose bases are parallelograms. - n. a prism whose bases are parallelograms - greek parallelepipedon : parallelos, parallel ; see parallel + epipedon, plane surface, from neuter sing. of epipedos, level ( epi -, epi - + pedon, ground ). ( american heritage\u00ae dictionary of the english language, fourth edition ) \u201c remember, the volume of a parallelepiped is the area of its base surface times its height. \u201d \u201c but i wish he would have used the more correct and pretentious ' parallelepiped '. \u201d \u201c the house is a 23m x 7m parallelepiped, made of concrete, steel and glass, embedded in the slope of the terrain. \u201d \u201c this describes the diagonal of a rectangular parallelepiped, where length along the respective axes are : \u201d \u201c the class intimations of these images are plain enough, though polidori in his exhaustive effort of preservation did not scruple to include upper - end or highland stretches \u2014 canal street, say, with its two - storied, sometimes stuccoed domiciles set back on lawns, including a pert example of old - fashioned flat - roofed, parallelepiped - pure modernism, with art deco stripes and a little penthouse. \u201d \u201c compressed earth blocks generally have a rectangular parallelepiped format and are full or perforated with vertical and / or horizontal indentations. \u201d \u201c rectangular parallelepiped format with holes or perforations in combination with indentations on its larger faces ( laying face and bed face ). \u201d \u201c the most common format is a rectangular parallelepiped ( or prism", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6323574374448028, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:dbd73cb2-9f37-4080-814d-6867481e0711>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:06:38.517741"}
{"text": "how does it feel : a study in sensory perception sensory stimulation is a chemical process which occurs between the human body and brain. when we experience sensation, our body is exposed to some type of sensory stimulation. the sensory receptors then receive this information, and transmit it to the brain using neural impulses, or neurotransmitters. there it is interpreted into the correct sensation. sensations are the basic building blocks of perception. perception is the process of organizing and making sense of our sensory input. perception allows us to better interpret the information our sensory receptors receive, and form images of the world around us. transduction is what happens when the receptors transform the energies they receive into a form that can be interpreted and utilized by the nervous system. human beings are able to experience various sensations because the nervous system encodes the messages we are receiving and interpreting. in his doctrine of specific nerve energies, johannes muller theorizes that different sensory modes exist because the information received by our sensory receptors stimulates different synapses when traveling back to the brain. this is known as anatomical encoding. this type of encoding determines which sensory organ is activated by a certain type of stimulation, according to which specific neural pathway it travels. ( wade, tavris, 2006 ). anatomical encoding does not totally explain how or why our different sensory modalities exist independently. scientists found it difficult to link specific skin senses to individual neural pathways ; neither does the doctrine of specific nerve energies explain variations of stimulus within a certain sensory experience, i. e. the softness of an animal ' s fur versus the coarseness of sandpaper, or the distinction between the colors light blue and dark blue. a second type of encoding, called functional encoding, is therefore required to make sense of these differentials in our sensory perception. according to wade and tavris, \" functional...", "subdomain_id": "subdomain_quantum_optics", "similarity_score": 0.6405747380408637, "token_count": 373, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:af6bbce4-2fbc-4198-b794-a2d8201c7fa8>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:06:38.551954"}
{"text": "this module implements an interface to the crypt ( 3 ) routine, which is a one - way hash function based upon a modified des algorithm ; see the unix man page for further details. possible uses include allowing python scripts to accept typed passwords from the user, or attempting to crack unix passwords with a dictionary. notice that the behavior of this module depends on the actual implementation of the crypt ( 3 ) routine in the running system. therefore, any extensions available on the current implementation will also be available on this module. word will usually be a user \u2019 s password as typed at a prompt or in a graphical interface. salt is usually a random two - character string which will be used to perturb the des algorithm in one of 4096 ways. the characters in salt must be in the set [. / a - za - z0 - 9 ]. returns the hashed password as a string, which will be composed of characters from the same alphabet as the salt ( the first two characters represent the salt itself ). since a few crypt ( 3 ) extensions allow different values, with different sizes in the salt, it is recommended to use the full crypted password as salt when checking for a password. a simple example illustrating typical use : import crypt, getpass, pwd def login ( ) : username = input ( ' python login : ' ) cryptedpasswd = pwd. getpwnam ( username ) if cryptedpasswd : if cryptedpasswd = = ' x ' or cryptedpasswd = = ' * ' : raise \" sorry, currently no support for shadow passwords \" cleartext = getpass. getpass ( ) return crypt. crypt ( cleartext, cryptedpasswd ) = = cryptedpasswd else : return 1", "subdomain_id": "subdomain_quantum_cryptography", "similarity_score": 0.6218469314304321, "token_count": 364, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:62708ab8-96b3-462f-9482-87a7af429490>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:06:38.938423"}
{"text": "i read a great article from imprimis, the free publication put out by hillsdale college in michigan, titled the floating dollar as a threat to property rights. the article started out with the curious case of the incredible shrinking kilo ( a problem normally faced only by drug lords that employ users as traffickers ). apparently this one particular metallic cylinder securely housed at the international bureau of weights and measures near paris, france, is the \" reference kilo \" for not only the global metric system, but even the u. s. customary system in which 2. 2 pounds equals this particular kilo. the problem is, it ' s shrinking! so far it has only shrunk by 50 micrograms, about the weight of a fingerprint on earth. but even so, this is a big problem for scientists that deal in exacting calculations that require global standardization. the problem boils down to the definition of a kilogram. the global standard definition of a kilo is this particular cylinder! it was cast in platinum and iridium by johnson matthey in 1879, adopted by the first general conference for weights and measures in 1889, and has been the global reference point for the measurements of mass ever since. but some scientists are now complaining that with the exacting tolerances of today ' s high - tech world, the 21st century kilo needs a new definition. modern science needs a better reference point for mass. this got me thinking about reference points, and how they have all \u2014 in every single case ; temperature, distance, force, pressure, time, etc. \u2014 changed and evolved their definitions throughout history to best fit the cutting - edge needs of the time. this is a trend that always faces the opposing forces of inertia \u2014 the resistance to change \u2014 and progress \u2014 the need for change. another obvious trend in the evolution of reference points, when viewed in a long - line historical context, is the expansion from local to national to regional and finally to global standardization. this trend, especially, faces the opposition of inertia as national reference points have become part of the national identity of their people. the remnants can be seen everywhere. for temperature we have fahrenheit and celsius. for mass we have avoirdupois ounces, troy ounces and metric grams. the world is littered with national currencies. and even foreign languages are a good example of our innate resistance to global standardization. this trend toward global reference points is a practical \u2014 not a moral \u2014 evolution. it will continue", "subdomain_id": "subdomain_quantum_metrology", "similarity_score": 0.6070086414997166, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:34925301-c16a-46c6-ab1d-8b88bd52b70a>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:06:39.249023"}