data/train/batch_000019.jsonl

{"text": "apr 7, 2011 graphene transistor shines on diamond - like substrate diamond - like carbon could be an ideal substrate for graphene transistors. so say researchers in the us who have made advanced devices with a record - high cut - off frequency of 155 ghz and the shortest gate length ever of just 40 nm. the field - effect transistors, which also function all of the way down to temperatures as low as 4. 3 k, operate at radio frequencies and so could be used in wireless communications. graphene is a flat sheet of carbon just one atom thick that conducts electrons at extremely high speeds. indeed, the electrons behave like relativistic particles with no rest mass. this, and other unusual physical properties, means that graphene is often touted to replace silicon as the electronic material of choice and might be used to make faster transistors than any that exist today. transistors made from graphene could be used in radio - frequency microelectronic devices for wireless communications. these devices can be made by transferring high - quality graphene sheets, produced by a technique called chemical vapour deposition ( cvd ), onto a suitable, insulating substrate \u2013 such as silicon dioxide. however, the problem is that the substrate can severely degrade the electronic properties of graphene because of scattering of charge carriers ( electrons and holes ) in graphene. this scattering, which drastically limits the speed of the electrons and holes, comes about due to interactions between graphene and the dielectric substrate material. diamond - like, but cheap now, phaedon avouris and colleagues at the ibm thomas j. watson research center, new york, may now have come up with an answer to this challenge. the team used diamond - like carbon as the top layer of the substrate, with the carbon atop a standard silicon wafer. diamond - like carbon is already widely used in the semiconductor industry and is created by chemical vapour deposition ( cvd ). it is a non - polar dielectric material, which means that it does not trap charges nor does it scatter charge as much as silicon dioxide does. it is also cheap to make in large areas ; does not absorb much water ; and has excellent thermal conductivity. \u201c the cut - off frequency we obtained is the highest so far for transistors made from cvd - graphene, \u201d avouris said. \u201c however, it is not, by far, the limit of what can be achieved because the quality of the cvd -", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6446905758951087, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:5082ec95-285d-4f28-8f4c-1bc5f99ac6f2>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:18.580812"}
{"text": "the following html text is provided to enhance online readability. many aspects of typography translate only awkwardly to html. please use the page image as the authoritative form to ensure accuracy. science evolution and creationism biological evolution is the centralorganizing principle of modern biology. the study of biological evolution has transformed our understanding of life on this planet. evolution provides a scientific explanation for why there are so many different kinds of organisms on earth and how all organisms on this planet are part of an evolutionary lineage. it demonstrates why some organisms that look quite different are in fact related, while other organisms that may look similar are only distantly related. it accounts for the appearance of humans on earth and reveals our species \u2019 biological connections with other living things. it details how different groups of humans are related to each other and how we acquired many of our traits. it enables the development of effective new ways to protect ourselves against constantly evolving bacteria and viruses. [ trait : a physicalor behavioralcharacteristic ofan organism. ] biological evolution refers to changes in the traits of organisms over multiple generations. until the development of the science of genetics at the beginning of the 20th century, biologists did not understand the mechanisms responsible for the inheritance of traits from parents to offspring. the study of genetics showed that heritable traits originate from the dna that is passed from one generation to the next. dna contains segments called genes that direct the production of proteins required for the growth and function of cells. genes also orchestrate the development of a single - celled egg into a multicellular organism. dna is therefore responsible for the continuity of biological form and function across generations. [ dna : deoxyribonucleic acid. a biological molecule composedof subunits knownas nucleotides strungtogether in long chains. the sequences of thesenucleotides contain theinformation that cellsneed in order to grow, to divide into daughtercells, and to manufacture new proteins. ] [ protein : a largemolecule consisting ofa chain of smaller molecules called aminoacids. the sequenceof amino acids andthe molecule \u2019 s three - dimensional structuredetermine a protein \u2019 sspecific function incells or organisms. ] however, offspring are not always exactly like their parents. most organisms in any species, including humans, are genetically variable to some extent. in sexually reproducing species, where each parent contributes only one - half of its genetic information to its offspring ( the offspring receives the full amount of genetic information", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6037120930791806, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:eabf8cb2-6ab2-4c5f-a4fd-88dbb6c0d8b0>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:18.588068"}
{"text": "| abstract | | this paper focuses on the relation between logic and ontology. in particular, it demonstrates how classical logical theory can clarify the ontological part of ludwig wittgenstein \u2019 s tractatus logico - philosophicus. to this end, the work examines the adequacy of a formal system that was devised by the polish logician, mathematician and philosopher roman suszko ( 1919 \u2013 1979 ) as a model for the tractatus. following a brief explanation of the tractarian ontology, the main ideas of suszko \u2019 s system and its philosophical significance will be considered. the latter will be illustrated in the context of central tractarian concepts. finally, two implications for a better understanding of the tractarian ontology will be pointed out. | | keywords | | no keywords specified ( fix it ) | | through your library | | configure | similar books and articles maria cerezo ( 2005 ). the possibility of language : internal tensions in wittgenstein ' s tractatus. center for the study of language and information. colin johnston ( 2007 ). the unity of a tractarian fact. synthese 156 ( 2 ) : 231 - 251. leo k. c. cheung ( 2008 ). the disenchantment of nonsense : understanding wittgenstein ' s tractatus. philosophical investigations 31 ( 3 ) : 197 \u2013 226. barry smith & david murray ( 1981 ). logic, form and matter. aristotelian society supplementary volume 55 : 47 - 74. maria cerezo ( 1998 ). nombrar kripkeano versus nombrar tractariano : un intento de demarcacion ( tractarian naming versus kripkean naming : similarities and differences ). theoria 13 ( 3 ) : 427 - 444. colin johnston ( 2009 ). tractarian objects and logical categories. synthese 167 ( 1 ) : 145 - 161. colin johnston ( 2007 ). symbols in wittgenstein ' s tractatus. european journal of philosophy 15 ( 3 ) : 367 - 394. e. d. klemke ( 1971 ). essays on wittgenstein. urbana, university of illinois press. hugh miller ( 1995 ). tractarian semantics for predicate logic. history and philosophy of logic 16 ( 2 ) : 197 - 215. added to index2009 - 01 - 28 total downloads28 ( # 44, 043 of 549, 014 ) recent downloads ( 6 months )", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6168189427285863, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:f539fe79-810d-4571-ba59-76bc94341769>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:18.868122"}
{"text": ", contradiction, cause and effect, means and end, genus and species, part and whole, substance and property, early and late, large and small, landlord and tenant, master and servant, - - heaven knows what, for the list is literally inexhaustible. the only simplification which could possibly be aimed at would be the reduction of the relations to a smaller number of types, like those which such authors as kant and renouvier call the ' categories ' of the understanding. according as we followed one category or another we should sweep, with our thought, through the world in this way or in that. and all the categories would be logical, would be relations of reason. they would fuse the items into a continuum. were this the sort of connection sought between one moment of our thinking and another, our chapter might end here. for the only summary description of these infinite possibilities of transition, is that they are all acts of reason, and that the mind proceeds from one object to another by some rational path of connection. the trueness of this formula is only equalled by its sterility, for psychological purposes. practically it amounts to simply referring the inquirer to the relations between facts or things, and to telling him that his thinking follows them. but as a matter of fact, his thinking only sometimes follows them, and these so - called ' transitions of reason ' are far from being all alike reasonable. if pure thought runs all our trains, why should she run some so fast and some so slow, some through dull flats and some through [ p. 552 ] gorgeous scenery, some to mountain - heights and jewelled mines, others through dismal swamps and darkness? - - and run some off the track altogether, and into the wilderness of lunacy? why do we spend years straining after a certain scientific or practical problem, but all in vain - - thought refusing to evoke the solution we desire? and why, some day, walking in the street with our attention miles away from that quest, does the answer saunter into our minds as carelessly as if it had never been called for - - suggested, possibly, by the flowers on the bonnet of the lady in front of us, or possibly by nothing that we can discover? if reason can give us relief then, why did she not do so earlier? the truth must be admitted that thought works under conditions imposed ab extra. the great law of habit itself - - that twenty experiences make us recall a thing better than one, that", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.610684549897703, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:fc8cb935-8609-49f0-9ed8-3770f1d83e4b>", "chunk_index": 1, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:19.076858"}
{"text": "of thought, the obstructive preprocessions, the frustrations of reason. this they found in the law of habit, or what we now call association by contiguity. but it never occurred to these writers that a process which could go the length of actually producing some ideas and sequences in the mind might safely be trusted to produce others too ; and that those habitual associations which further thought may also come from the same mechanical source as those which hinder it. hartley accordingly suggested habit as a sufficient explanation of all connections of our thoughts, and in so doing planted himself squarely upon the properly psychological aspect of the problem of connection, and sought to treat both rational and irrational connections from a single point of view. the problem which he essayed, however lamely, to answer, was that of the connection between our psychic states considered purely as such, regardless of the objective connections of which they might take cognizance. how does a man come, after thinking of a, to think of b the next moment? or how does he come to think a and b always together? these were the phenomena which hartley undertook to explain by cerebral physiology. i believe that he was, in many essential respects, on the right track, and i propose simply to revise his conclusions by the aid of distinctions which he did not make. but the whole historic doctrine of psychological association is tainted with one huge error - - that of the construction of our thoughts out of the compounding of themselves together of immutable and incessantly recurring ' simple ideas. ' it is the cohesion of these which the ' principles of [ p. 554 ] association ' are considered to account for. in chapters vi and ix we saw abundant reasons for treating the doctrine of simple ideas or psychic atoms as mythological ; and, in all that follows, our problem will be to keep whatever truths the associationist doctrine has caught sight of without weighing it down with the untenable incumbrance that the association is between ' ideas. ' association, so far as the word stands for an effect, is between things thought of - - it is things, not ideas, which are associated in the mind. we ought to talk of the association of objects, not of the association of ideas. and so far as association stands for a cause, it is between processes in the brain - - it is these which, by being associated in certain ways, determine what successive objects shall be thought. let us proceed towards our final generalization by surveying first a few familiar", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6103797487521267, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:fc8cb935-8609-49f0-9ed8-3770f1d83e4b>", "chunk_index": 3, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:19.079161"}
{"text": "of their appearance complete, so soon as we think of any one of their component parts. some persons, in reciting printed matter by heart, will seem to see each successive word, before they utter it, appear in its order on an imaginary page. a certain chess - player, one of those heroes who train themselves to play several games at once blindfold, is reported to say that in bed at night after a match the games are played all over again before his mental eye, each board being pictured as passing in turn through each of its successive stages. in this case, of course, the intense previous voluntary strain of the power of visual representation is what facilitated the fixed order of revival. association occurs as amply between impressions of different senses as between homogeneous sensations. seen things and heard things cohere with each other, and with odors and tastes, in representation, in the same order in which they cohered as impressions of the outer world. feelings of contact reproduce similarly the sights, sounds, and tastes with which experience has associated them. in fact, the ' objects ' of our perception, as trees, men, houses, microscopes, of which the real world seems composed, are nothing but clusters of qualities which through simultaneous stimulation have so coalesced that the moment one is excited actually it serves as a sign or cue for the idea of the others to arise. let a person enter his room in the [ p. 556 ] dark and grope among the objects there. the touch of the matches will instantaneously recall their appearance. if his hand comes in contact with an orange on the table, the golden yellow of the fruit, its savor and perfume will forthwith shoot through his mind. in passing the hand over the sideboard or in jogging the coal - scuttle with the foot, the large glossy dark shape of the one and the irregular blackness of the other awaken like a flash and constitute what we call the recognition of the objects. the voice of the violin faintly echoes through the mind as the hand is laid upon it in the dark, and the feeling of the garments or draperies which may hang about the room is not understood till the look correlative to the feeling has in each case been resuscitated. smells notoriously have the power of recalling the other experiences in whose company they were wont to be felt, perhaps long years ago ; and the voluminous emotional character assumed by the images which suddenly pour into the mind at such a time forms one of the staple topics of", "subdomain_id": "subdomain_quantum_optics", "similarity_score": 0.6131373093276534, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:fc8cb935-8609-49f0-9ed8-3770f1d83e4b>", "chunk_index": 5, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:19.081463"}
{"text": "power of recalling the other experiences in whose company they were wont to be felt, perhaps long years ago ; and the voluminous emotional character assumed by the images which suddenly pour into the mind at such a time forms one of the staple topics of popular psychologic wonder - - \" lost and gone and lost and gone! a breath, a whisper - - some divine farewell - - desolate sweetness - - far and far away. \" we cannot hear the din of a railroad train or the yell of its whistle, without thinking of its long, jointed appearance and its headlong speed, nor catch a familiar voice in a crowd without recalling, with the name of the speaker, also his face. but the most notorious and important case of the mental combination of auditory with optical impressions originally experienced together is furnished by language. the child is offered a new and delicious fruit and is at the same time told that it is called a ' fig. ' or looking out of the window he exclaims, \" what a funny horse! \" and is told that it is a ' piebald ' horse. when learning his letters, the sound of each is repeated to him whilst its shape is before his eye. thenceforward, long as he may live, he will never see a fig, a piebald horse, or a letter of the alphabet without the name which he first heard in conjunction with each clinging to it in his mind ; and inversely he will [ p. 557 ] never hear the name without the faint arousal of the image of the object. the rapidity of association. reading exemplifies this kind of cohesion even more beautifully. it is an uninterrupted and protracted recall of sounds by sights which have always been coupled with them in the past. i find that i can name six hundred letters in two minutes on a printed page. five distinct acts of association between sight and sound ( not to speak of all the other processes concerned ) must then have occurred in each second in my mind. in reading entire words the speed is much more rapid. valentin relates in his physiology that the reading of a single page of the proof, containing 2629 letters, took him 1 minute and 32 seconds. in this experiment each letter was understood in 1 / 28 of a second, but owing to the integration of letters into entire words, forming each a single aggregate impression directly associated with a single acoustic image, we need not suppose as many as 28 separate associations in a sound. the figures, however, suffi", "subdomain_id": "subdomain_quantum_optics", "similarity_score": 0.6162299002228214, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:fc8cb935-8609-49f0-9ed8-3770f1d83e4b>", "chunk_index": 6, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:19.083085"}
{"text": "system, when any single point or group of points is touched off. but where the original impressions were successive - - the conjugation of [ p. 563 ] a greek verb, for example - - awakening nerve - tracts in a definite order, they will now, when one of them awakens, discharge into each other in that definite order and in no other way. the reader will recollect all that has been said of increased tension in nerve - tracts and of the summation of stimuli ( p. 82 ff. ). we must therefore suppose that in these ideational tracts as well as elsewhere, activity may be awakened, in any particular locality, by the summation therein of a number of tensions, each incapable alone of provoking an actual discharge. suppose for example the locality m to be in functional continuity with four other localities, k, l, n, and o. suppose moreover that on four previous occasions it has been separately combined with each of these localities in a common activity. m may then be indirectly awakened by any cause which tends to awaken either k, l, n, or o. but if the cause which awakens k, for instance, be so slight as only to increase its tension without arousing it to full discharge, k will only succeed in slightly increasing the tension of m. but if at the same time the tensions of l, n, and o are similarly increased, the combined effects of all four upon m may be so great as to awaken an actual discharge in this latter locality. in like manner if the paths between m and the four other localities have been so slightly excavated by previous experience as to require a very intense excitement in either of the localities before m can be awakened, a less strong excitement than this in any one will fail to reach m. but if all four at once are mildly excited, their compound effect on m may be adequate to its full arousal. the psychological law of association of objects thought of through their previous contiguity in thought or experience would thus be an effect, within the mind, of the physical fact that nerve - currents propagate themselves easiest through those tracts of conduction which have been already most in use. descartes and locke hit upon this explanation, which modern science has not yet succeeded in improving. \" custom, \" says locke, \" settles habits of thinking in the understanding, as well as of determining in the will, and of motions in the body ; all which seem to be but trains of motion in the animal spirits", "subdomain_id": "subdomain_quantum_mechanics", "similarity_score": 0.6559768923414311, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:fc8cb935-8609-49f0-9ed8-3770f1d83e4b>", "chunk_index": 11, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:19.091175"}
{"text": "yet succeeded in improving. \" custom, \" says locke, \" settles habits of thinking in the understanding, as well as of determining in the will, and of motions in the body ; all which seem to be but trains of motion in the animal spirits [ p. 564 ] [ by this locke meant identically what we understand by neural processes ] which, once set agoing, continue in the same steps they have been used to, which by often treading are worn into a smooth path, and the motion in it becomes easy and, as it were, natural. \" hartley was more thorough in his grasp of the principle. the sensorial nerve - currents, produced when objects are fully present, were for him ' vibrations, ' and those which produce ideas of objects in their absence were ' miniature vibrations. ' and he sums up the cause of mental association in a single formula by saying : \" any vibrations, a, b, c, etc., by being associated together a sufficient number of times, get such a power over a, b, c, etc., the corresponding miniature vibrations, that any of the vibrations a, when impressed alone, shall be able to excite b, c, etc., the miniatures of the rest. \" it is evident that if there be any law of neural habit similar to this, the contiguities, coexistences, and successions, met with in outer experience, must inevitably be copied more or less perfectly in our thought. if a b c d e be a sequence of outer impressions ( they may be events [ p. 565 ] or they may be successively experienced properties of an object ) which once gave rise to the successive ' ideas, ' a b c d e, then no sooner will a impress us again and awaken the a, than b c d e will arise as ideas even before b c d e have come in as impressions. in other words, the order of impressions will the next time be anticipated ; and the mental order will so far forth copy the order of the outer world. any object when met again will make us expect its former concomitants, through the overflowing of its brain - tract into the paths which lead to theirs. and all these suggestions will be effects of a material law. where the associations are, as here, of successively appearing things, the distinction i made at the outset of the chapter, between a connection thought of and a connection of thoughts, is unimportant. for the connection thought of is", "subdomain_id": "subdomain_quantum_mechanics", "similarity_score": 0.6038596953574187, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:fc8cb935-8609-49f0-9ed8-3770f1d83e4b>", "chunk_index": 12, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:19.092276"}
{"text": "material law. where the associations are, as here, of successively appearing things, the distinction i made at the outset of the chapter, between a connection thought of and a connection of thoughts, is unimportant. for the connection thought of is concomitance or succession ; and the connection between the thoughts is just the same. the ' objects ' and the ' ideas ' fit into parallel schemes, and may be described in identical language, as contiguous things tending to be thought again together, or contiguous ideas tending to recur together. now were these cases fair samples of all association, the distinction i drew might well be termed a spitzfindigkeit or piece of pedantic hair - splitting, and be dropped. but as a matter of fact we cannot treat the subject so simply. the same outer object may suggest either of many realities formerly associated with it - - for in the vicissitudes of our outer experience we are constantly liable to meet the same thing in the midst of differing companions - - and a philosophy of association that should merely say that it will suggest one of these, or even of that one of them which it has oftenest accompanied, would go but a very short way into the rationale of the subject. this, however, is about as far as most associationists have gone with their ' principle of contiguity. ' granted an object, a, they never tell us beforehand which of its associates it will suggest ; their wisdom is limited to showing, after it has suggested a second object, that that object was once an associate. they have had to supplement their principle of contiguity by other princi - [ p. 566 ] ples, such as those of similarity and contrast, before they could begin to do justice to the richness of the facts. the elementary law of association. i shall try to show, in the pages which immediately follow, that there is no other elementary causal law of association than the law of neural habit. all the materials of our thought are due to the way in which one elementary process of the cerebral hemispheres tends to excite whatever other elementary process it may have excited at some former time. the number of elementary processes at work, however, and the nature of those which at any time are fully effective in rousing the others, determine the character of the total brain - action, and, as a consequence of this, they determine the object thought of at the time. according as this resultant object is one thing or another, we", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6348186807800056, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:fc8cb935-8609-49f0-9ed8-3770f1d83e4b>", "chunk_index": 13, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:19.093254"}
{"text": "time are fully effective in rousing the others, determine the character of the total brain - action, and, as a consequence of this, they determine the object thought of at the time. according as this resultant object is one thing or another, we call it a product of association by contiguity or of association by similarity, or contrast, or whatever other sorts we may have recognized as ultimate. its production, however, is, in each one of these cases, to be explained by a merely quantitative variation in the elementary brain - processes momentarily at work under the law of habit, so that psychic contiguity, similarity, etc., are derivatives of a single profounder kind of fact. my thesis, stated thus briefly, will soon become more clear ; and at the same time certain disturbing factors, which co - operate with the law of neural habit, will come to view. let us then assume as the basis of all our subsequent reasoning this law : when two elementary brain - processes have been active together or in immediate succession, one of them, on reoccurring, tends to propagate its excitement into the other. but, as a matter of fact, every elementary process has found itself at different times excited in conjunction with many other processes, and this by unavoidable outward causes. which of these others it shall awaken now becomes a problem. shall b or c be aroused next by the present a? we must make a further postulate, based, however, on the fact of tension in nerve - tissue, and on the fact [ p. 567 ] of summation of excitements, each incomplete or latent in itself, into an open resultant. the process b, rather than c, will awake, if in addition to the vibrating tract a some other tract d is in a state of sub - excitement, and formerly was excited with b alone and not with a. in short, we may say : the amount of activity at any given point in the brain - cortex is the sum of the tendencies of all other points to discharge into it, such tendencies being proportionate ( 1 ) to the number of times the excitement of each other point may have accompanied that of the point in question ; ( 2 ) to the intensity of such excitements ; and ( 3 ) to the absence of any rival point functionally disconnected with the first point, into which the discharges might be diverted. expressing the fundamental law in this most complicated way leads to the greatest ultimate simplification. let us, for", "subdomain_id": "subdomain_quantum_optics", "similarity_score": 0.6343636245065071, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:fc8cb935-8609-49f0-9ed8-3770f1d83e4b>", "chunk_index": 14, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:19.094229"}
{"text": "and ( 3 ) to the absence of any rival point functionally disconnected with the first point, into which the discharges might be diverted. expressing the fundamental law in this most complicated way leads to the greatest ultimate simplification. let us, for the present, only treat of spontaneous trains of thought and ideation, such as occur in revery or musing. the case of voluntary thinking toward a certain end shall come up later. take, to fix our ideas, the two verses from ' locksley hall ' : \" i, the heir of all the ages in the foremost files of time, \" \" for i doubt not through the ages one increasing purpose runs. \" why is it that when we recite from memory one of these lines, and get as far as the ages, that portion of the other lines which follows, and, so to speak, sprouts out of the ages, does not also sprout out of our memory, and confuse the sense of our words? simply because the word that follows the ages has its brain - process awakened not simply by the brain - process of the ages alone, but by it plus the brain - processes of all the words preceding the ages. the word ages at its moment of strongest activity would, per se, indifferently discharge into either ' in ' or ' one. ' so would the previous words ( whose tension is momentarily much less stronger than that of ages ) each of them indifferently dis - [ p. 568 ] charge into either of a large number of other words with which they have been at different times combined. but when the processes of ' i, the heir of all the ages, ' simultaneously vibrate in the brain, the last one of them in a maximal, the others in a fading phase of excitement ; then the strongest line of discharge will be that which they all alike tend to take. ' in ' and not ' one ' or any other word will be the next to awaken, for its brain - process has previously vibrated in unison not only with that of ages, but with that of all those other words whose activity is dying away. it is a good case of the effectiveness over thought of what we called on p. 258 a ' fringe. ' but if some one of these preceding words - - ' heir, ' for example - - had an intensely strong association with some brain - tracts entirely disjoined in experience from the poem of ' locksley hall ' - - if the reciter, for instance, were tremulous", "subdomain_id": "subdomain_quantum_mechanics", "similarity_score": 0.6210748035715999, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:fc8cb935-8609-49f0-9ed8-3770f1d83e4b>", "chunk_index": 15, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:19.095616"}
{"text": "past experience, it must still be confessed that an immense number of terms in the linked chain of our representations fall outside of all assignable rule. to take the instance of the clock given on page 586. why did the jeweller ' s shop suggest the shirt - studs rather than a chain which i had brought there more recently, which had cost more, and whose sentimental associations were much more interesting? both chain and studs had excited brain - tracts simultaneously with the shop. the only reason why the nerve - stream from the shop - tract switched off into the stud - tract rather than into the chain - tract must be that the stud - tract happened at that moment to lie more open, either because of some accidental alteration in its nutrition or because the incipient sub - conscious tensions of the brain as a whole had so distributed their equilibrium that it was more unstable here than in the chain - tract. any reader ' s introspection will easily furnish similar instances. it thus remains true that to a certain extent, even in those forms of ordinary mixed association which lie nearest to impartial redintegration, which associate of the interesting item shall emerge must be called largely a matter of accident - - accident, that is, for our intelligence. no doubt it is determined by cerebral causes, but they are too subtile and shifting for our analysis. [ p. 578 ] association by similarity. in partial or mixed associations we have all along supposed the interesting portion of the disappearing thought to be of considerable extent, and to be sufficiently complex to constitute by itself a concrete object. sir william hamilton relates, for instance, that after thinking of ben lomond he found himself thinking of the prussian system of education, and discovered that the links of association were a german gentleman whom he had met on ben lomond, germany, etc. the interesting part of ben lomond, as he had experienced it, the part operative in determining the train of his ideas was the complex image of a particular man. but now let us suppose that that selective agency of interested attention, which may thus convert impartial redintegration into partial association - - let us suppose that it refines itself still further and accentuates a portion of the passing thought, so small as to be no longer the image of a concrete thing, but only of an abstract quality or property. let us moreover suppose that the part thus accentuated persists in consciousness ( or, in cerebral terms, has its brain - process continue ) after the other portions of the thought", "subdomain_id": "subdomain_quantum_mechanics", "similarity_score": 0.6315440847804388, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:fc8cb935-8609-49f0-9ed8-3770f1d83e4b>", "chunk_index": 25, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:19.110190"}
{"text": "image of a concrete thing, but only of an abstract quality or property. let us moreover suppose that the part thus accentuated persists in consciousness ( or, in cerebral terms, has its brain - process continue ) after the other portions of the thought have faded. this small surviving portion will then surround itself with its own associates after the fashion we have already seen, and the relation between the new thought ' s object and the object of the faded thought will be a relation of similarity. the pair of thoughts will form an instance of what is called ' association by similarity. ' the similars which are here associated, or of which the first is followed by the second in the mind, are seen to be compounds. experience proves that this is always the [ p. 579 ] case. there is no tendency on the part of simple ' ideas, ' attributes, or qualities to remind us of their like. the thought of one shade of blue does not remind us of that of another shade of blue, etc., unless indeed we have in mind some general purpose like naming the tint, when we should naturally think of other blues of the scale, through ' mixed association ' of purpose, names, and tints, together. but there is no elementary tendency of pure qualities to awaken their similars in the mind. we saw in the chapter on discrimination that two compound things are similar when some one quality or group of qualities is shared alike by both, although as regards their other qualities they may have nothing in common. the moon is similar to a gas - jet, it is also similar to a football ; but a gas - jet and a foot - ball are not similar to each other. when we affirm the similarity of two compound things, we should always say in what respect it obtains. moon and gas - jet are similar in respect of luminosity, and nothing else ; moon and foot - ball in respect of rotundity, and nothing else. foot - ball and gas - jet are in no respect similar - - that is, they possess no common point, no identical attribute. similarity, in compounds, is partial identity. when the same attribute appears in two phenomena, though it be their only common property, the two phenomena are similar is so far forth. to return now to our associated representations. if the thought of the moon is succeeded by the thought of a foot - ball, and that by the thought of one of mr. x ' s railroads, it is because the attribute rotundity in the moon broke", "subdomain_id": "subdomain_quantum_optics", "similarity_score": 0.6445166405140996, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:fc8cb935-8609-49f0-9ed8-3770f1d83e4b>", "chunk_index": 26, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:19.112035"}
{"text": "now to our associated representations. if the thought of the moon is succeeded by the thought of a foot - ball, and that by the thought of one of mr. x ' s railroads, it is because the attribute rotundity in the moon broke away from all the rest and surrounded itself with an entirely new set of companions - - elasticity, leathery integument, swift mobility in obedience to human caprice, etc. ; and because the last - named attribute in the foot - ball in turn broke away from its companions, and, itself persisting, surrounded itself with such new attributes as make up the notions of a ' railroad king, ' of a rising and falling stock - market, and the like. the gradual passage from impartial redintegration to similar association through what we have called ordinary mixed association may be symbolized by diagrams. fig. 41 is impartial redintegration, fig. 42 is mixed, and fig. 43 [ p. 580 ] similar association. a in each is the passing, b the coming thought. in ' impartial, ' all parts of a are equally operative in calling up b. in ' mixed, ' most parts of a are inert. the part m alone breaks out and awakens b. in ' similar, ' the focalized part m is much smaller than in the previous case, and after awakening its new set of associates, instead of fading out itself, it continues persistently active along with them, forming an identical part in the two ideas, and making these, pro tanto, resemble each other. why a single portion of the passing thought should break out from its concert with the rest and act, as we say, on its own hook, why the other parts should become inert, are mysteries which we can ascertain but not explain. possibly a minuter insight into the laws of neural action will [ p. 581 ] some day clear the matter up ; possibly neural laws will not suffice, and we shall need to invoke a dynamic reaction of the form of consciousness upon its content. but into this we cannot enter now. to sum up, then, we see that the difference between the three kinds of association reduces itself to a simple difference in the amount of that portion of the nerve - tract supporting the going thought which is operative in calling up the thought which comes. but the modus operandi of this active part is the same, be it large or be it small. the items constituting the", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6328389525646989, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:fc8cb935-8609-49f0-9ed8-3770f1d83e4b>", "chunk_index": 27, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:19.113676"}
{"text": "of that portion of the nerve - tract supporting the going thought which is operative in calling up the thought which comes. but the modus operandi of this active part is the same, be it large or be it small. the items constituting the coming object waken in every instance because their nerve - tracts once were excited continuously with those of the going object or its operative part. this ultimate physiological law of habit among the neural elements is what runs the train. the direction of its course and the form of its transitions, whether redintegrative, associative, or similar, are due to unknown regulative or determinative conditions which accomplish their effect by opening this switch and closing that, setting the engine sometimes at half - speed, and coupling or uncoupling cars. this last figure of speech, into which i have glided unwittingly, affords itself an excellent instance of association by similarity. i was thinking of the deflections of the course of ideas. now, from hobbes ' s time downward, english writers have been fond of speaking of the train of our representations. this word happened to stand out in the midst of my complex thought with peculiarly sharp accentuation, and to surround itself with numerous details of railroad imagery. only such details became clear, however, as had their nerve - tracts besieged by a double set of influences - - those from train on the one hand, and those from the movement of thought on the other. it may possibly be that the prepotency of the suggestions of the word train at this moment were due to the recent excitation of the railroad brain - tract by the instance chosen a few pages back of a railroad king playing foot - ball with the stock - market. it is apparent from such an example how inextricably complex are all the contributory factors whose resultant is the line of our reverie. it would be folly in most cases to [ p. 582 ] attempt to trace them out. from an instance like the above, where the pivot of the similar association was formed by a definite concrete word, train, to those where it is so subtile as utterly to elude our analysis, the passage is unbroken. we can form a series of examples. when mr. bagehot says that the mind of the savage, so far from being in a state of nature, is tattooed all over with monstrous superstitions, the case is very like the one we have just been considering. when sir james stephen compares our belief", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6121689973785227, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:fc8cb935-8609-49f0-9ed8-3770f1d83e4b>", "chunk_index": 28, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:19.114877"}
{"text": "or c. if, for instance, i think of paris whilst i am hungry, i shall not improbably find that its restaurants have become the pivot of my thought, etc., etc. but in the theoretic as well as in the practical life there are interests of a more acute sort, taking the form of definite images of some achievement, be it action or acquisition, which we desire to effect. the train of ideas arising under the influence of such an interest constitutes usually the thought of the means by which the end shall be attained. if the end by its simple presence does not instantaneously suggest the means, the search for the latter becomes an intellectual problem. the solution of problems is the most characteristic and peculiar sort of voluntary thinking. where the end thought of is some outward deed or gain, the solution is largely composed of the actual motor processes, walking, speaking, writing, etc., which lead up to it. where the end is in the first instance only ideal, as in laying out a place of operations, the steps are purely imaginary. in both of these cases the discovery of the means may form a new sort of end, of an entirely peculiar nature, an end, namely, which we intensely desire before we have attained it, but of the nature of which, even whilst most strongly craving it, we have no distinct imagination whatever. such an end is a problem. the same state of things occurs whenever we seek to recall something forgotten, or to state the reason for a judgment which we have made intuitively. the desire strains and presses in a direction which it feels to be right but towards a point which it is unable to see. in short, the absence of an item is a determinant of our representations quite as positive as its presence can ever be. the gap becomes no mere void, but what is called an aching void. if we try to explain in terms of brain - action how a thought which only potentially exists can yet be effective, we seem driven to believe that the brain - tract thereof must actually be excited, but only in a minimal and sub - conscious way. try for instance, to symbolize what goes on in a man who is racking his brains to remember a thought which occurred to him last week. the associates of the [ p. 585 ] thought are there, many of them at least, but they refuse to awaken the thought itself. we cannot suppose that they do not irradiate at all into its brain - tract, because his mind quiver", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6096868227681738, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:fc8cb935-8609-49f0-9ed8-3770f1d83e4b>", "chunk_index": 31, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:19.118485"}
{"text": "successively that when we had the thought in question we were at the dinner - table ; then that of our friend j. d. was [ p. 586 ] there ; then that the subject talked about was so and so ; finally, that the thought came a propos of a certain anecdote, and then that it had something to do with a french quotation. now all these added associations arise independently of the will, by the spontaneous process we know so well. all that the will does is to emphasize and linger over those which seem pertinent, and ignore the rest. through this hovering of the attention in the neighborhood of the desired object, the accumulation of associates becomes so great that the combined tensions of their neural processes break through the bar, and the nervous wave pours into the tract which has so long been awaiting its advent. and as the expectant, sub - conscious itching there, bursts into the fulness of vivid feeling, the mind finds an inexpressible relief. the whole process can be rudely symbolized in a diagram. call the forgotten thing z, the first facts with which we felt it was related, a, b, and c, and the details finally operative in calling it up, l, m, and n. each circle will then stand for the brain - process underlying the thought of the object denoted by the letter contained within it. the activity in z will at first be a mere tension ; but as the activities in a, b, and c little by little irradiate into l, m, and n, and as all these processes are somehow connected with z, their combined irradiations upon z, represented by the centripetal arrows, succeed in helping the tension there to overcome the resistance, and in rousing z also to full activity. [ p. 587 ] the tension present from the first in z, even though it keep below the threshold of discharge, is probably to some degree co - operative with a, b, c in determining that l, m, n shall awake. without z ' s tension there might be a slower accumulation of objects connected with it. but, as aforesaid, the objects come before us through the brain ' s own laws, and the ego of the thinker can only remain on hand, as it were, to recognize their relative values and brood over some of them, whilst others are let drop. as when we have lost a material object we cannot recover it by a direct effort, but only through moving", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6183762421091608, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:fc8cb935-8609-49f0-9ed8-3770f1d83e4b>", "chunk_index": 33, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:19.123917"}
{"text": "it must contain an attribute common to two items, or it must be a uniform concomitant, or what not. we know, in short, a lot about it, whilst as yet we have no knowledge of acquaintance with it ( see p. 221 ), or in mr. hodgson ' s language, \" we know what we want to find beforehand, in a certain sense, in its second intention, and do not know it, in another sense, in its first intention. \" our intuition that one of the ideas which turn up is, at last, our qusitum, is due to our recognition that its relations are identical with those we had in mind, and this may be a rather slow act of judgment. in fact, every one knows that an object may be for some time present to his mind before its relations to other matters are perceived. to quote hodgson again : \" the mode of operation is common to voluntary memory and reason.... but reasoning adds to memory the function of comparing or judging the images which arise.... memory aims at filling the gap with an image which has at some particular time filled it before, reasoning with one which bears certain time - and space - relations to the images before and after \" - - or, to use perhaps clearer language, one which stands in determinate logical relations to those data round about the gap which filled our mind at the start. this feeling of the blank form of relationship before we get the material quality [ p. 589 ] of the thing related will surprise no one who has read chapter ix. from the guessing of newspaper enigmas to the plotting of the policy of an empire there is no other process than this. we trust to the laws of cerebral nature to present us spontaneously with the appropriate idea : \" our only command over it is by the effort we make to keep the painful unfilled gap in consciousness.... two circumstances are important to notice : the first is, that volition has no power of calling up images, but only of rejecting and selecting from those offered by spontaneous redintegration. but the rapidity with which this selection is made, owing to the familiarity of the ways in which spontaneous redintegration runs, gives the process of reasoning the appearance of evoking images that are foreseen to be conformable to the purpose. there is no seeing them before they are offered ; there is no summoning them before they are seen. the other circumstance is, that every kind of reasoning is nothing, in its", "subdomain_id": "subdomain_quantum_mechanics", "similarity_score": 0.6168715866362586, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:fc8cb935-8609-49f0-9ed8-3770f1d83e4b>", "chunk_index": 35, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:19.126247"}
{"text": "images that are foreseen to be conformable to the purpose. there is no seeing them before they are offered ; there is no summoning them before they are seen. the other circumstance is, that every kind of reasoning is nothing, in its simplest form, but attention. \" it is foreign to our purpose here to enter into any detailed analysis of the different classes of mental pursuit. in a scientific research we get perhaps as rich an example as can be found. the inquirer starts with a fact of which he seeks the reason, or with an hypothesis of which he seeks the proof. in either case he keeps turning the matter incessantly in his mind until, by the arousal of associate upon associate, some habitual, some similar, one arises which he recognizes to suit his need. this, however, may take years. no rules can be given by which the investigator may proceed straight to his result ; but both here and in the case of reminiscence the accumulation of helps in the way of associations may advance more rapidly by the use of certain routine methods. in striving to recall a thought, for example, we may of set purpose run through the successive classes of circumstances with which it may [ p. 590 ] possibly have been connected, trusting that when the right member of the class has turned up it will help the thought ' s revival. thus we may run through all the places in which we may have had it. we may run through the persons whom we remember to have conversed with, or we may call up successively all the books we have lately been reading. if we are trying to remember a person we may run through a list of streets or of professions. some item out of the lists thus methodically gone over will very likely be associated with the fact we are in need of, and may suggest it or help to do so. and yet the item might never have arisen without such systematic procedure. in scientific research this accumulation of associates has been methodized by mill under the title of ' the four methods of experimental inquiry. ' by the ' method of agreement, ' by that of ' difference, ' by those of ' residues ' and ' concomitant variations ' ( which cannot here be more nearly defined ), we make certain lists of cases ; and by ruminating these lists in our minds the cause we seek will be more likely to emerge. but the final stroke of discovery is only prepared, not effected, by them. the brain - tracts must, of their own accord,", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6002290113808881, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:fc8cb935-8609-49f0-9ed8-3770f1d83e4b>", "chunk_index": 36, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:19.127400"}
{"text": "cases ; and by ruminating these lists in our minds the cause we seek will be more likely to emerge. but the final stroke of discovery is only prepared, not effected, by them. the brain - tracts must, of their own accord, shoot the right way at last, or we shall still grope in darkness. that in some brains the tracts do shoot the right way much oftener than in others, and that we cannot tell why, - - these are ultimate facts to which we must never close our eyes. even in forming our lists of instances according to mill ' s methods, we are at the mercy of the spontaneous workings of similarity in our brain. how are a number of facts, resembling the one whose cause we seek, to be brought together in a list unless the one will rapidly suggest the other through association by similarity? similarity no elementary law. such is the analysis i propose, first of the three main types of spontaneous association, and then of voluntary association. it will be observed that the object called up may bear any logical relation whatever to the one which suggested it. the law requires only that one condition should be fulfilled. the fading object must be due to a brain - process some of whose elements awaken through habit [ p. 591 ] some of the elements of the brain - process of the object which comes to view. this awakening is the operative machinery, the causal agency, throughout, quite as much so in the kind of association i have called by the name of similarity, as in any other sort. the similarity between the objects, or between the thoughts ( if similarity there be between these latter ), has no causal agency in carrying us from one to the other. it is but a result - - the effect of the usual causal agent when this happens to work in a certain particular and assignable way. but ordinary writers talk as if the similarity of the objects were itself an agent, co - ordinate with habit, and independent of it, and like it able to push objects before the mind. this is quite unintelligible. the similarity of two things does not exist till both things are there - - it is meaningless to talk of it as an agent of production of anything, whether in the physical or the psychical realms. it is a relation which the mind perceives after the fact, just as it may perceive the relations of superiority, of distance, of causality, of container and content, of substance and accident, or of contrast, between an object and some second object which the", "subdomain_id": "subdomain_quantum_optics", "similarity_score": 0.6161852163549794, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:fc8cb935-8609-49f0-9ed8-3770f1d83e4b>", "chunk_index": 37, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:19.128570"}
{"text": "relation which the mind perceives after the fact, just as it may perceive the relations of superiority, of distance, of causality, of container and content, of substance and accident, or of contrast, between an object and some second object which the associative machinery calls up. there are, nevertheless, able writers who not only insist on preserving association by similarity as a distinct elementary law, but who make it the most elementary law, and seek to derive contiguous association from it. their reasoning is as follows : when the present impression a [ p. 592 ] awakens the idea b of its past contiguous associate b, how can this occur except through first reviving an image a of its own past occurrence. this is the term directly connected with b ; so that the process instead of being simply a - - b is a - - a - - b. now a and a are similars ; therefore no association by contiguity can occur except through a previous association by similarity. the most important supposition here made is that every impression on entering the mind must needs awaken an image of its past self, in the light of which it is ' apperceived ' or understood, and through the intermediation of which it enters into relation with the mind ' s other objects. this assumption is almost universally made ; and yet it is hard to find any good reason for it. it first came before us when we were reviewing the facts of aphasia and mental blindness ( see p. 50 ff. ). but we then saw no need of optical and auditory images to interpret optical and auditory sensations by. on the contrary, we agreed that auditory sensations were understood by us only so far as they awakened non - auditory images, and optical sensations only so far as they awakened non - optical images. in the chapters on memory, on reasoning, and on perception the same assumption will meet us again, and again will have to be rejected as groundless. the sensational process a and the ideational process a probably occupy essentially the same tracts. when the outer stimulus comes and those tracts vibrate with the sensation a, they discharge as directly into the paths which lead to b as when there is no outer stimulus and they only vibrate with the idea a. to say that the process a can only reach these paths by the help of the weaker process a is like saying that we need a candle to see the sun by. a replaces a, does all that a does and more ; and there is no intel", "subdomain_id": "subdomain_quantum_optics", "similarity_score": 0.6273229687545974, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:fc8cb935-8609-49f0-9ed8-3770f1d83e4b>", "chunk_index": 38, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:19.129813"}
{"text": "to say that the process a can only reach these paths by the help of the weaker process a is like saying that we need a candle to see the sun by. a replaces a, does all that a does and more ; and there is no intelligible meaning, to my mind, in saying that the weaker process coexists with the stronger. i therefore consider that these writers are altogether wrong. the only plausible proof they give of the coexistence of a with a is when a gives us a sense of familiarity but fails to awaken any distinct thought of past contiguous associates. in a later chapter i shall consider this case. here i content myself with saying that it does not seem conclusive as to the point at issue ; [ p. 593 ] and that i still believe association of coexistent or sequent impressions to be the one elementary law. contrasthas also been held to be an independent agent in association. but the reproduction of an object contrasting with one already in the mind is easily explained on our principles. recent writers, in fact, all reduce it either to similarity or contiguity. contrast always presupposes generic similarity ; it is only the extremes of a class which are contrasted, black and white, not black and sour, or white and prickly. a machinery which reproduces a similar at all, may reproduce the opposite similar, as well as any intermediate term. moreover, the greater number of contrasts are habitually coupled in speech, young and old, life and death, rich and poor, etc., and are, as dr. bain says, in everybody ' s memory. i trust that the student will now feel that the way to a deeper understanding of the order of our ideas lies in the direction of cerebral physiology. the elementary process of revival can be nothing but the law of habit. truly the day is distant when physiologists shall actually trace from cell - group to cell - group the irradiations which we have hypothetically invoked. probably it will never arrive. the schematism we have used is, moreover, taken immediately from the analysis of objects into their elementary parts, and only extended by analogy to the brain. and yet it is only as incorporated in the brain that such a schematism can represent anything causal. this is, to my mind, the conclusive reason for saying that the order of presentation of the mind ' s materials is due to cerebral physiology alone. the law of accidental prepotency of certain processes over others falls also", "subdomain_id": "subdomain_quantum_optics", "similarity_score": 0.6338928149629601, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:fc8cb935-8609-49f0-9ed8-3770f1d83e4b>", "chunk_index": 39, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:19.133703"}
{"text": "that which we aim at ; and from the thought of that, the thought of means to that mean ; and so continually, till we come to some beginning within our own power. and because the end, by the greatness of the impression, comes often to mind, in case our thoughts begin to wander, they are quickly again reduced into the way : which observed by one of the seven wise men, made him give men this precept, which is now worn out, respice finem ; that is to say, in all your actions, look often upon what you would have, as the thing that directs all your thoughts in the way to attain it. \" the train of regulated thoughts is of two kinds ; one, when of an effect imagined we seek the causes, or means that produce it : and this is common to man and beast. the other is, when imagining anything whatsoever, we seek all the possible effects that can by it be produced ; that is to say, we imagine what we can do with it, when we have it. of which i have not at any time seen any sign, but in man only ; for this is a curiosity hardly incident to the nature of any living creature that has no other passion but sensual, such as are hunger, thirst, lust, and anger. in sum, the discourse of the mind, when it is governed by design, is nothing but seeking, or the faculty of invention, [ p. 596 ] which the latins called sagacitas, and sollertia ; a hunting out of the causes, of some effect, present or past ; or of the effects, of some present or past cause. \" the most important passage after this of hobbes is hume ' s : \" as all simple ideas may be separated by the imagination, and may be united again in what form it pleases, nothing would be more unaccountable than the operations of that faculty, were it not guided by some universal principles, which render it, in some measure, uniform with itself in all times and places. were ideas entirely loose and unconnected, chance alone would join them ; and ' tis impossible the same simple ideas should fall regularly into complex ones ( as they commonly do ) without some bond of union among them, some associating quality, by which one idea naturally introduces another. this uniting principle among ideas is not to be considered as an inseparable connection ; for that has been already excluded from the imagination. nor yet are we to conclude that without it", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6063823420504739, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:fc8cb935-8609-49f0-9ed8-3770f1d83e4b>", "chunk_index": 42, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:19.141254"}
{"text": "some associating quality, by which one idea naturally introduces another. this uniting principle among ideas is not to be considered as an inseparable connection ; for that has been already excluded from the imagination. nor yet are we to conclude that without it the mind cannot join two ideas ; for nothing is more free than that faculty : but we are only to regard it as a gentle force, which commonly prevails, and is the cause why, among other things, languages so nearly correspond to each other ; nature in a manner pointing to every one those simple ideas which are most proper to be united in a complex one. the qualities from which this association arises, and by which the mind is after this manner conveyed from one idea to another, are three, viz., resemblance, contiguity in time or place, and cause and effect. \" i believe it will not be very necessary to prove that these qualities produce an association among ideas, and upon the appearance of one idea naturally introduce another. ' tis plain that in the course of our thinking, and in the constant revolution of our ideas, our imagination runs easily from one idea to any other that resembles it, and that this quality alone is to the fancy a sufficient bond and association. ' tis likewise evident, that as the senses, in changing their objects, are necessitated to change them regularly, and take them as they lie contiguous to each other, the imagination must by long custom acquire the same method of thinking, and run along the parts of space and time in conceiving its objects. as to the connection that is made by the relation of cause and effect, we shall have occasion afterwards to examine it to the bottom, and therefore shall not at present insist upon it. ' tis sufficient to observe that there is no relation which produces a stronger connection in the fancy, and makes one idea more readily recall another, that the relation of cause and effect betwixt their objects.... these are therefore the principles of union or cohesion among our simple ideas, and in the imagination supply the place of that inseparable connection by which they are united in our memory. here is a kind of attraction, which in the mental world will be found [ p. 597 ] to have as extraordinary effects as in the natural, and to show itself in as many and as various forms. its effects are everywhere conspicuous ; but as to its causes, they are mostly unknown, and must be resolved into original qualities of human nature, which i pretend not to explain. \" hume did", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6199874328243161, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:fc8cb935-8609-49f0-9ed8-3770f1d83e4b>", "chunk_index": 43, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:19.142313"}
{"text": "theory of faculties. the most [ p. 598 ] extended usage consists, as we know, in dividing intellectual phenomena into classes, in separating those which differ, in grouping together those of the same nature and in giving to these a common name and in attributing them to the same cause ; it is thus that we have come to distinguish those diverse aspects of intelligence which are called judgment, reasoning, abstraction, perception, etc. this method is precisely the one followed in physics, where the words caloric, electricity, gravity, designate the unknown causes of certain groups of phenomena. if one thus never forgets that the diverse faculties are only the unknown causes of known phenomena, that they are simply a convenient means of classifying the facts and speaking of them, if one does not fall into the common fault of making out of them substantial entities, creations which now agree, now disagree, so forming in the intelligence a little republic ; then, we can see nothing reprehensible in this distribution into faculties, conformable as it is to the rules of a sound method and of a good natural classification. in what then is mr. bain ' s procedure superior to the method of the faculties? it is that the latter is simply a classification while his is an explanation. between the psychology which traces intellectual facts back to certain faculties, and that which reduces them to the single law of association, there is, according to our way of thinking, the same difference that we find in physics between those who attribute its phenomena to five or six causes, and those who derive gravity caloric, light, etc., from motion. the system of the faculties explains nothing because each one of them is only a flatus vocis which is of value merely through the phenomena which it contains, and signifies nothing more than these phenomena. the new theory, on the contrary, shows that the different processes of intelligence are only diverse cases of a single law ; that imagination, deduction, induction, perception, etc., are but so many determinate ways in which ideas may combine with each other ; and that the differences of faculties are only differences of association. it explains all intellectual facts, certainly not after the manner of metaphysics which demands the ultimate and absolute reason of things ; but after the manner of physics which seeks only their secondary and immediate cause. \" the inexperienced reader may be glad of a brief indication of the manner in which all the different mental operations may be conceived to consist of images of sensation associated together. memory is the association of a present image with others", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6588589190543095, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:fc8cb935-8609-49f0-9ed8-3770f1d83e4b>", "chunk_index": 45, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:19.144524"}
{"text": "only their secondary and immediate cause. \" the inexperienced reader may be glad of a brief indication of the manner in which all the different mental operations may be conceived to consist of images of sensation associated together. memory is the association of a present image with others known to belong to the past. expectation the same, with future substituted for past. fancy, the association of images without temporal order. belief in anything not present to sense is the very lively, [ p. 599 ] strong, and steadfast association of the image of that thing with some present sensation, so that as long as the sensation persists the image cannot be excluded from the mind. judgment is ' transferring the idea of truth by association from one proposition to another that resembles it. ' reasoning is the perception that \" whatever has any mark has that which it is a mark of \" ; in the concrete case the mark or middle term being always associated with each of the other terms and so serving as a link by which they are themselves indirectly associated together. this same kind of transfer of a sensible experience associated with another to a third also associated with that other, serves to explain emotional facts. when we are pleased or hurt we express it, and the expression associates itself with the feeling. hearing the same expression from another revives the associated feeling, and we sympathize, i. e. grieve or are glad with him. the other social affections, benevolence, conscientiousness, ambition, etc., arise in like manner by the transfer of the bodily pleasure experienced as a reward for social service, and hence associated with it, to the act of service itself, the link of reward being dropped out. just so avarice when the miser transfers the bodily pleasures associated with the spending of money to the money itself, dropping the link of spending. fear is a transfer of the bodily hurt associated by experience with the thing feared, to the thought of the thing, with the precise features of the hurt left out. thus we fear a dog without distinctly imagining his bite. love is the association of the agreeableness of certain sensible experiences with the idea of the object capable of affording them. the experiences themselves may cease to be distinctly imagined after the notion of their pleasure has been transferred to the object, constituting love there - for. volition is the association of ideas of muscular motion with the ideas of those pleasures which the motion produces. the motion at first occurs automatically and results [ p. 600 ] in a pleasure unforeseen", "subdomain_id": "subdomain_quantum_optics", "similarity_score": 0.607867957309215, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:fc8cb935-8609-49f0-9ed8-3770f1d83e4b>", "chunk_index": 46, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:19.147626"}
{"text": "object, constituting love there - for. volition is the association of ideas of muscular motion with the ideas of those pleasures which the motion produces. the motion at first occurs automatically and results [ p. 600 ] in a pleasure unforeseen. the latter becomes so associated with the motion that whenever we think of it the idea of the motion arises ; and the idea of the motion when vivid causes the motion to occur. this is an act of will. nothing is easier than for a philosopher of this school to explain from experience such a notion as that of infinitude. \" he sees in it an ordinary manifestation of one of the laws of the association of ideas, - - the law that the idea of a thing irresistibly suggests the idea of any other thing which has been often experienced in close conjunction with it, and not otherwise. as we have never had experience of any point of space without other points beyond it, nor of any point of time without others following it, the law of indissoluble association makes it impossible for us to think of any point of space or time, however distant, without having the idea irresistibly realized, in imagination, of other points still more remote. and thus the supposed original and inherent property of these two ideas is completely explained and accounted for by the law of association ; and we are enabled to see that if space or time were really susceptible of termination, we should be just as unable as we now are to conceive the idea. \" these examples of the associationist psychology are with the exception of the last, very crudely expressed, but they suffice for our temporary need. hartley and james mill improved upon hume so far as to employ but a single principle of association, that of contiguity or habit. hartley ignores resemblance, james mill expressly repudiates it in a passage which is assuredly one of the curiosities of literature : \" i believe it will be found that we are accustomed to see like things together. when we see a tree, we generally see more trees than one ; a sheep, more sheep than one ; a man, more men than one. from this observation, i think, we may refer resemblance to the law of frequency [ i. e., contiguity ], of which it seems to form only a particular case. \" mr. herbert spencer has still more recently tried to construct a psychology which ignores association by similarity, and in a chapter, which also is a curiosity, he tries [", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6001867514257704, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:fc8cb935-8609-49f0-9ed8-3770f1d83e4b>", "chunk_index": 47, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:19.149637"}
{"text": "difference between a horse, a steam - engine, and a waterfall, when our minds are engrossed with the one circumstance of moving power. the diversity in these had no doubt for a long time the effect of keeping back their first identification ; and to obtuse intellects, this identification might have been for ever impossible. a strong concentration of mind upon the single peculiarity of mechanical force, and a degree of indifference to the general aspect of the things themselves, [ p. 602 ] must conspire with the intellectual energy of resuscitation by similars, in order to summon together in the view three structures so different. we can see, by an instance like this, how new adaptations of existing machinery might arise in the mind of a mechanical inventor. when it first occurred to a reflecting mind that moving water had a property identical with human or brute force, namely, the property of setting other masses in motion, overcoming inertia and resistance, - - when the sight of the stream suggested through this point of likeness the power of the animal, - - a new addition was made to the class of prime movers, and when circumstances permitted, this power could become a substitute for the others. it may seem to the modern understanding, familiar with water - wheels and drifting rafts, that the similarity here was an extremely obvious one. but if we put ourselves back into an early state of mind, when running water affected the mind by its brilliancy, its roar, and irregular devastation, we may easily suppose that to identify this with animal muscular energy was by no means an obvious effect. doubtless when a mind arose, insensible by natural constitution to the superficial aspects of things, and having withal a great stretch of identifying intellect, such a comparison would then be possible. we may pursue the same example one stage further, and come to the discovery of steam power, or the identification of expanding vapor with the previously known sources of mechanical force. to the common eye, for ages, vapor presented itself as clouds in the sky ; or as a hissing noise at the spout of a kettle, with the formation of a foggy curling cloud at a few inches ' distance. the forcing up of the lid of a kettle may also have been occasionally observed. but how long was it ere any one was struck with the parallelism of this appearance with a blast of wind, a rush of water, or an exertion of animal muscle? the discordance was too great to be broken through by such", "subdomain_id": "subdomain_quantum_thermodynamics", "similarity_score": 0.6347015826276461, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:fc8cb935-8609-49f0-9ed8-3770f1d83e4b>", "chunk_index": 49, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:19.155249"}
{"text": "how long was it ere any one was struck with the parallelism of this appearance with a blast of wind, a rush of water, or an exertion of animal muscle? the discordance was too great to be broken through by such a faint and limited amount of likeness. in one mind, however, the identification did take place, and was followed out into its consequences. the likeness had occurred to other minds previously, but not with the same results. such minds must have been in some way or other distinguished above the millions of mankind ; and we are now endeavoring to give the explanation of their superiority. the intellectual character of watt contained all the elements preparatory to a great stroke of similarity in such a case ; - - a high susceptibility, both by nature and by education, to the mechanical properties of bodies ; ample previous knowledge or familiarity ; and indifference to the superficial and sensational effects of things. it is not only possible, however, but exceedingly probable, that many men possessed all these accomplishments ; they are of a kind not transcending common abilities. they would in some degree attach to a mechanical education almost as a matter of course. that the discovery was not sooner made supposes that something farther, and not of common occurrence, was necessary ; and this additional endowment appears to be the identifying power of similarity in general ; the tendency to detect likeness in the midst of disparity and disguise. this [ p. 603 ] supposition accounts for the fact, and is consistent with the known intellectual character of the inventor of the steam - engine. \" dr. hodgson ' s account of association is by all odds the best yet propounded in english. all these writers hold more or less explicitly to the notion of atomistic ' ideas ' which recur. in germany, the same mythological supposition has been more radically grasped, and carried out to a still more logical, if more repulsive, extreme, by herbart and his followers, who until recently may be said to have reigned almost supreme in their native country. for herbart each idea is a permanently existing entity, the entrance whereof into consciousness is but an accidental determination of its being. so far as it succeeds in occupying the theatre of consciousness, it crowds out another idea previously there. this act of inhibition gives it, however, a sort of hold on the other representation which on all later occasions facilitates its following the other into the mind. the ingenuity with which most special cases of association are formulated in this mechanical language of", "subdomain_id": "subdomain_quantum_optics", "similarity_score": 0.6208786737410881, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:fc8cb935-8609-49f0-9ed8-3770f1d83e4b>", "chunk_index": 50, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:19.156244"}
{"text": ". this act of inhibition gives it, however, a sort of hold on the other representation which on all later occasions facilitates its following the other into the mind. the ingenuity with which most special cases of association are formulated in this mechanical language of struggle and inhibition, is great, and surpasses in analytic thoroughness anything that has been done by the british school. this, however, is a doubtful merit, in a case where the elements dealt with are artificial ; and i must confess that to my mind there is something almost hideous in the glib herbartian jargon about vorstellungsmassen and their hemmungen and hemmungssummen, and sinken and erheben and schweben, and verschmelzungen and complexionen. herr lipps, the most recent systematic german psychologist, has, i regret to say, carried out the theory of ideas in a way which the great originality, learning, and acuteness he [ p. 604 ] shows make only the more regrettable. such elaborately artificial constructions are, it seems to me, only a burden and a hindrance, not a help, to our science. in french, m. rabier in his chapter on association, handles the subject more vigorously and acutely than any one. his treatment of it, though short, seems to me for general soundness to rank second only to hodgson ' s. in the last chapter we already invoked association to account for the effect of use in improving discrimination. in later chapters we shall see abundant proof of the immense part which it plays in other processes, and shall then readily admit that few principles of analysis, in any science, have proved more fertile than this one, however vaguely formulated it often may have been. our own attempt to formulate it more definitely, and to escape the usual confusion between causal agencies and relations merely known, must not blind us to the immense services of those by whom the confusion was unfelt. from this practical point of view it would be a true ignoratio elenchi to flatter one ' s self that one has dealt a heavy blow at the psychology of association, when one has exploded the theory of atomistic ideas, or shown that contiguity and similarity between ideas can only be there after association is done. the whole body of the associationist psychology remains standing after you have translated ' ideas ' into ' objects, ' on the one hand, and ' brain - processes ' on the other ; and the analysis", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6058409682658956, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:fc8cb935-8609-49f0-9ed8-3770f1d83e4b>", "chunk_index": 51, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:19.158806"}
{"text": "little to the one side or the other ; for this reason the animal spirits, falling into the contiguous traces, present other related ideas in lieu of that which the mind desired at first to survey. this change we are not always sensible of ; but continuing still the same train of thought, make use of the related idea which is presented to us, and employ it in our reasoning, as if it were the same with what we demanded. this is the cause of many mistakes and sophisms in philosophy ; as will naturally be imagined, and as it would be easy to show, if there was occasion. \" op. cit. prop. xi. see chapter iii, p. 82 - 5. i strongly advise the student to read his senses and intellect, pp. 544 - 556. time and space, p. 266. compare coleridge : \" the true practical general law of association is this : that whatever makes certain parts of a total impression more vivid or distinct than the rest will determine the mind to recall these, in preference to others equally linked together by the common condition of contemporaeity or of contiguity. but the will itself, by confining and intensifying the attention, may arbitrarily give vividness or distinctness to any object whatsoever. \" ( biographia litteraria, chap. v. ) leviathan, pt. i. chap. iii., init. i refer to a recency of a few hours. mr. galton found that experiences from boyhood and youth were more likely to be suggested by words seen at random than experiences of later years. see his highly interesting account of experiments in his inquiries into human faculty, pp. 191 - 203. for other instances see wahle, in vierteljsch f. wiss. phil., ix. 144 - 417 ( 1885 ). i retain the title of association by similarity in order not to depart from common usage. the reader will observe, however, that my nomenclature is not based on the same principle throughout. impartial redintegration connotes neural processes ; similarity is an objective relation perceived by the mind ; ordinary or mixed association is a merely denotative word. total recall, partial recall, and focalized recall, of associates, would be better terms. but as the denotation of the latter word is almost identical with that of association by similarity, i think it better to sacrifice propriety to popularity, and to keep the latter well - worn", "subdomain_id": "subdomain_quantum_mechanics", "similarity_score": 0.6206856590180674, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:fc8cb935-8609-49f0-9ed8-3770f1d83e4b>", "chunk_index": 56, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:19.166226"}
{"text": "february 22, 2012 \u2014 \" religion today \" is contributed by the university of wyoming ' s religious studies program to examine and promote discussion of religious issues. the goal of the enlightenment, that intellectual movement of the 18th century, was to establish human reason as the highest arbiter of knowledge, as opposed to divine revelation, the christian church ' s source of truth. although the accuracy of this claim is still debated among philosophers and theologians, it is clear that reason and its offspring, \" science, \" have become important arenas of knowledge in our intellectual and cultural worlds. indeed, wherever religion and science have offered differing explanations of the natural world, or even the cosmos, our society nearly always treats the scientific view more seriously than the religious one. but even as religion ' s descriptions of the world have seemingly been beaten back before the unrelenting onslaught of science, there is one question where the roles are absolutely reversed. this is the question of meaning. put in large - scale terms, what meaning does nature, the universe and the cosmos, hold? placed in a smaller scale, what is the meaning of a flower ' s blooming in the spring? science can answer the questions of how a flower blooms, why a flower blooms, and even why it blooms in the spring. but it cannot assign an ultimate meaning or purpose to that event. in fact, science cannot even assign ultimate meaning to its own explanations. the theory of evolution, for example, gives strong explanatory power to biology, enabling it to tell us why and how new species of animals and plants develop, why some disappear, and so on. but evolution does not, even cannot, reveal its own ultimate purpose. this inability is not restricted to biology. astronomy, for instance, can describe the formation of black holes and develop a theory of gravitation to explain it, but trying to specify the purpose of a black hole is almost nonsensical in scientific terms. physics can explain why water is the only compound that expands as a solid form rather than contracts, but it does not tell us what that means. does this mean that \" life, the universe, and everything \" ( as douglas adams would describe it ) is meaningless? absolutely not. instead, meaning must come from outside of science itself. it turns out that religions have been doing a pretty good job at answering the question of ultimate meaning. as the biologist kenneth miller argues in his book, \" finding darwin ' s god \" ( cliff street books, 2000 ), \" our human tendency to assign meaning and value", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.604628154934651, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:9a63b3c5-a976-4db9-b76d-0932676fc9c1>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:19.266535"}
{"text": "new technique advances carbon - fiber composites. a revised view of continental tectonics is emerging from the research of an mit professor who has made the first statistical evaluation in the west of long - secret gravity - field data for a large section of the former soviet union. dr. marcia k. mcnutt of the department of earth, atmospheric and planetary sciences, played a leading role, in collaboration with mikhail g. kogan of the institute of physics of the earth, moscow, in making the russian data available to colleagues throughout the world. they published their findings in a recent issue of science magazine. gravity - field data help geologists understand the nature of the various layers deep below the earth ' s surface, giving clues to the influence those layers have on the formation of mountain ranges and other surface features, like the tibetan plateau. the data also have important economic and strategic values which lead many nations to keep information for their territories under wraps. the information is of vital importance in finding and extracting mineral resources, oil and gas, especially for terrain where surface features are obscured by forests. information on gravity - field data can also be used to measure subsurface stress. some nations believe that a knowledge of gravity data can aid the targeting of intercontinental ballistic missiles. this was the original reason for the classification of the soviet data, but now a more important russian imperative has led to the release of the data to help stimulate the economy. the basic geologic question professor mcnutt sought to answer in reviewing the russian data was : when continental blocks such as italy, arabia and india collided with the southern border of eurasia why were narrow mountain belts created in the west and very broad ones in the east? her conclusion : differences in the lateral strength of the upper mantle control intracontinental deformation. the difference between western and eastern eurasia, she found, can be explained by the presence of a low - viscosity zone in the uppermost mantle beneath eastern eurasia that is absent in the west. professor mcnutt ' s statistical analysis of the russian data shows that the location of the change in viscosity corresponds with the geologic boundary between the older shields and platforms of the baltics, russia and siberia with the younger, geologically active mountain belts of eastern asia. \" our conclusions from dynamic modeling of gravity and seismic velocity anomalies from northern eurasia point to a revised view of continental tectonics according to which the physical properties of the upper mantle to depths as great as 400 km ( 248 miles ) are affected by the thermal structure and", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6181099485728561, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:e0c19b09-c970-465b-9e34-28c06e22a019>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:19.904955"}
{"text": "new technologies make new ways of learning possible. with computational technologies, ideas of control, sensing, and feedback can be made accessible and exciting to learners as young as six or eight years old. this talk presents a brief history of the ideas, prototypes, and research that led to lego mindstorms, the immensely popular robot construction kit, launched just two years ago but easily thirty years in the making. lego mindstorms has its roots in the pioneering work on the logo programming language begun by dr. seymour papert in the 1960s. papert was perhaps the first to suggest that children should program computers, then an absurdly radical idea. this notion led to papert ' s theory of learning called \" constructionism \" which suggests both that ( 1 ) learning is an active process of building ideas which is unique and personal for each learner, and ( 2 ) this journey can be greatly facilitated when the learner builds things - in - the - world which become social and shared objects of reflection. papert ' s logo programming language, the later lego / logo system, and ultimately lego mindstorms all inherit from this set of ideas. the talk will conclude with a technological discussion of mit crickets, the latest in this line of design toys for learners. crickets are tiny programmable bricks that can interconnect in myriad ways, and employ an unusual virtual machine / compiler architecture that will be described in detail. - \" metacricket : a designer ' s kit for making computational devices, \" f. martin, b. mikhak, and b. silverman, ibm systems journal, volume 39 numbers 3 - 4, 2000. presents the mit cricket, a tiny embedded controller created for kids but valuable as a prototyping tool for professional designers who aren ' t necessarily engineers. full published paper available at - \" to mindstorms and beyond : evolution of a construction kit for magical machines, \" f. martin et. al, in \" robots for kids : exploring new technologies for learning, \" a. druin & j. hendler, editors, morgan kaufman, 2000. the paper from which this talk takes its name, describing the history of the ideas and prototypes which led to the lego mindstorms product, and our further work and motivations behind developing the crickets. a pre - publication draft is available from - \" design, story - telling, and robots in irish primary education, \" f. martin, d. butler, and w. gleason, presented at the ieee systems, man,", "subdomain_id": "subdomain_quantum_computing", "similarity_score": 0.6100034015028366, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:d40b340c-6475-4385-97bd-86747100b13f>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:20.015910"}
{"text": "possible to arrive at it, would consist in two principal things : the one, in employing no term the meaning of which had not first been clearly explained ; the other, in never advancing any proposition which could not be demonstrated by truths already known ; that is, in a word, in defining every term, and in proving every proposition. but to follow the same order that i am explaining, it is necessary that i should state what i mean by definition. the only definitions recognized in geometry are what the logicians call definitions of name, that is, the arbitrary application of names to things which are clearly designated by terms perfectly known ; and it is of these alone that i speak. their utility and use is to elucidate and abbreviate discourse, in expressing by the single name that has been imposed what could otherwise be only expressed by several terms ; so that nevertheless the name imposed remains divested of all other meaning, if it has any, having no longer any than that for which it is alone designed. here is an example : if we are under the necessity of discriminating numbers that are divisible equally by two from those which are not, in order to avoid the frequent repetition of this condition, a name is given to it in this manner : i call every number divisible equally by two, an even number. this is a geometrical definition ; because after having clearly designated a thing, namely, every member divisible equally by two, we give it a name divested of every other meaning, if it has any, in order to give it that of the thing designated. hence it appears that definitions are very arbitrary, and that they are never subject to contradiction ; for nothing is more permissible than to give to a thing which has been clearly designated, whatever name we choose. it is only necessary to take care not to abuse the liberty that we possess of imposing names, by giving the same to two different things. but if we fall into this error, we can oppose to it a sure and infallible remedy : that of mentally substituting the definition in the place of the thing defined, and of having the definition always so present, that every time we speak, for example, of an even number, we mean precisely that which is divisible into two equal parts, and that these two things should be in such a degree joined and inseparable in thought, that as soon as the discourse expresses the one, the mind attaches it immediately to the other. for geometricians, and all", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6673799291244031, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:1684fc30-175e-468b-a3ff-19ceee683983>", "chunk_index": 1, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:20.290657"}
{"text": "into two equal parts, and that these two things should be in such a degree joined and inseparable in thought, that as soon as the discourse expresses the one, the mind attaches it immediately to the other. for geometricians, and all those who proceed methodically, only impose names on things to abbreviate discourse, and not to diminish or change the idea of the things of which they are discoursing. and they pretend that the mind always supplies the full definition to the concise terms, which they only employ to avoid the confusion occasioned by the multitude of words. nothing more promptly and more effectually removes the captious cavils of sophists than this method, which it is necessary to have always present, and which alone suffices to banish all kinds of difficulties and equivocations. this method would certainly be beautiful, but it is abso - lutely impossible ; for it is evident that the first terms that we wished to define would imply precedents to serve for their explanation, and that in the same manner, the first propositions that we wished to prove would imply others which had preceded them ; and thus it is clear that we should never reach the first. thus, in pushing our researches further and further, we arrive necessarily at primitive words which can no longer be defined, and at principles so clear that we can find no others that can serve as a proof of them. for there is one, and it is that of geometry, which is in truth inferior in that it is less convincing, but not in that it less is certain. it does not define every thing and does not prove every thing, and it is in this that it is inferior ; but it assumes nothing but things clear and constant by natural enlightenment, and this is why it is perfectly true, nature sustaining it in default of discourse. this order, the most perfect of any among men, consists not at all in defining every thing or in demonstrating every thing, nor in defining nothing or in demonstrating nothing, but in adhering to this middle course of not defining things clear and understood by all mankind, and of defining the rest ; of not proving all the things known to mankind, and of proving all the rest. against this order those sin alike who undertake to define everything and to prove every thing, and who neglect to do it in those things which are not evident of themselves. this is what is perfectly taught by geometry. she does not define any of these things, space, time, motion,", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6409743245605258, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:1684fc30-175e-468b-a3ff-19ceee683983>", "chunk_index": 2, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:20.291763"}
{"text": "undertake to define everything and to prove every thing, and who neglect to do it in those things which are not evident of themselves. this is what is perfectly taught by geometry. she does not define any of these things, space, time, motion, number, equality, and similar things which exist in great number, because these terms so naturally designate the things that they mean, to those who understand the language, that their elucidation would afford more obscurity than instruction. for there is nothing more feeble than the discourse of those who wish to define these primitive words. what neces - sity is there, for example, of explaining what is understood by the word man? do we not know well enough what the thing is that we wish to designate by this term? and what advantage did plato think to procure us in saying that he was a two - legged animal without feathers? as though the idea that i have of him naturally, and which i cannot express, were not clearer and surer than that which he gives me by his useless and even ridiculous explanation ; since a man does not lose humanity by losing the two legs, nor does a capon acquire it by losing his feathers. there are those who are absurd enough to explain a word by the word itself. i know some who have defined light in this wise : light is a luminary movement of luminous bodies, as though we could understand the words luminary and luminous without the word light. 2 we cannot undertake to define being without falling into the same absurdity : for we cannot define a word without beginning with the word it is, either expressed or understood. to define being therefore, it is necessary to say it is, and thus to employ the word defined in the definition. we see clearly enough from this that there are some words incapable of being defined ; and, if nature had not supplied this defect by a corresponding idea which she has given to all mankind, all our expressions would be confused ; whilst we use them with the same assurance and the same certainty as though they were explained in a manner perfectly exempt from ambiguities : because nature herself has given us, without words, a clearer knowledge of them than art could acquire by our explanations. for, for example, time is of this sort. who can define it? and why undertake it, since all men conceive what is meant in speaking of a time, without any further definition? nevertheless there are many different opinions touching the essence of time. some say that it is the movement of", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6412172325961882, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:1684fc30-175e-468b-a3ff-19ceee683983>", "chunk_index": 3, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:20.292710"}
{"text": "who can define it? and why undertake it, since all men conceive what is meant in speaking of a time, without any further definition? nevertheless there are many different opinions touching the essence of time. some say that it is the movement of created thing ; others, the measure of the movement, etc. thus it is not the nature of these things that i say is known to all ; it is simply the relation between the name and the thing ; so that at the expression time, all direct their thoughts towards the same object ; which suffices to cause this term to have no need of being defined, though afterwards, in examining what time is, we come to differ in sentiment after having been led to think of it ; for definitions are only made to designate the things that are named, and not to show the nature of them. but after this definition there will be two things that will be called by the name of time : the one is what the whole world understands naturally by this word and what all those who speak our language call by this term ; the other will be the movement of a created thing, for this will also called by his name, according to this new definition. it is necessary therefore to shun ambiguities and not to confound consequences. for it will not follow from this that the thing that is naturally understood by the word time is in fact the movement of a created thing. it has been allowable to name these two things the same ; but it will not be to make them agree in nature as well as in name. thus, if we advance this propositiontime is the movement of a created thing, it is necessary to ask what is meant by this word time, that is, whether the usual and generally received meaning is left to it, or whether it is divested of this meaning in order to give to it on this occasion that of the movement of a created thing. for if it be stripped of all other meaning, it cannot be contradicted, and it will become an arbitrary definition, in consequence of which, as i have said, there will be two things that will have the same name. but if its ordinary meaning be left to it, and it be pretended nevertheless that what is meant by this word is the movement of a created thing, it can be contradicted. it is no longer an arbitrary definition, but a proposition that must be proved, if it is not evident of itself ; and this will then be a principle or an axiom, but never a definition", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6294862726417556, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:1684fc30-175e-468b-a3ff-19ceee683983>", "chunk_index": 4, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:20.293629"}
{"text": "created thing, it can be contradicted. it is no longer an arbitrary definition, but a proposition that must be proved, if it is not evident of itself ; and this will then be a principle or an axiom, but never a definition, since in this enunciation it is not understood that the word time signifies the same thing as the movement of a created thing, but it is understood that what is conceived by the term time is this supposed movement. if i did not know how necessary it is to understand this perfectly, and how continually occasions like this, of which i give the example, happen both in familiar and scientific discourses, i should not dwell upon it. but it seems to me, by the experience that i have had from the confusion of controversies, that we cannot too fully enter into this spirit of precision, for the sake of which i write this treatise rather than the subject of which i treat in it. for how many persons are there who fancy that they have defined time, when they have said that it is the measure of movement, leaving it, however, its ordinary meaning! and nevertheless they have made a proposition and not a definition. how many are there, in the like manner, who fancy that they have defined movement, when they have said : motus nec simpliciter motus, non mera potentia est, sed actus entis in potentia! and nevertheless, if they leave to the word movement its ordinary meaning as they do, it is not a definition but a proposition ; and confounding thus the definitions which they call definitions of name, which are the true arbitrary definitions permissible and geometrical, with those which they call definitions of thing, which, properly speaking, are not at all arbitrary definitions but are subject to contradiction, they hold themselves at liberty to make these as well as others ; and each defining the same things in his own way, by a liberty which is as unjustifiable in this kind of definitions as it is permissible in the former, they perplex every thing, and losing all order and all light, become lost themselves and wander into inextricable embarrassments. we shall never fall into such in following the order of geometry. this judicious science is far from defining such primitive words as space, time motion, equality, majority, diminution, whole, and others which every one understands. but apart from these, the rest of the terms that this science employs are to such a degree elucidated and defined", "subdomain_id": "subdomain_quantum_mechanics", "similarity_score": 0.6691674315228803, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:1684fc30-175e-468b-a3ff-19ceee683983>", "chunk_index": 5, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:20.294643"}
{"text": "primitive words as space, time motion, equality, majority, diminution, whole, and others which every one understands. but apart from these, the rest of the terms that this science employs are to such a degree elucidated and defined that we have no need of a dictionary to understand any of them ; so that in a word all these terms are perfectly intelligible, either by natural enlightenment or by the definitions that it gives of them. this is the manner in which it avoids all the errors that may be encountered upon the first point, which consists in defining only the things that have need of it. it makes use of it in the same manner in respect to the other point, which consists in proving the propositions that are not evident. for, when it has arrived at the first known truths, it pauses there and asks whether they are admitted, having nothing clearer whereby to prove them ; so that all that is proposed by geometry is perfectly demonstrated, either by natural enlightenment or by proofs. it will perhaps be found strange that geometry does not define any of the things that it has for its principal objects ; for it can neither define motion, numbers, nor space ; and nevertheless these three things are those of which it treats in particular, and according to the investigation of which it takes the three different names of mechanics, arithmetic, and geometry, this last name belonging to the genus and species. but this will not surprise us if we remark that, this admirable science only attaching itself to the simplest things, this same quality which renders them worthy of being its objects renders them incapable of being defined ; so that the lack of definition is a perfection rather than a defect, since it does not come from their obscurity, but on the contrary from their extreme obviousness, which is such that though it may not have the conviction of demonstrations, it has all their certainty. it supposes therefore that we know what is the thing that is understood by the words motion, number, space ; and without stopping to define them to no purpose, it penetrates their nature and discovers their marvellous properties. these three things which comprehend the whole universe, according to the words : deus fecit omnia in pondere, in numero, et mensura, 4 have a reciprocal and necessary connection. for we cannot imagine motion without something that moves ; and this thing being one, this unity is the origin of all numbers ; and lastly, motion not being able to exist without space, we see these three", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6579387742202034, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:1684fc30-175e-468b-a3ff-19ceee683983>", "chunk_index": 6, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:20.295753"}
{"text": ", 4 have a reciprocal and necessary connection. for we cannot imagine motion without something that moves ; and this thing being one, this unity is the origin of all numbers ; and lastly, motion not being able to exist without space, we see these three things included within the first. for however quick a movement may be, we can conceive of one still more so ; and so on ad infinitum, without ever reaching one that would be swift to such a degree that nothing more could be added to it. and, on the contrary, however slow a movement may be, it can be retarded still more ; and thus ad infinitum, without ever reaching such a degree of slowness that we could not thence descend into an infinite number of others, without falling into rest. in the same manner, however great a number may be, we can conceive of a greater ; and thus ad infinitum, without ever reaching one that can no longer be increased. and on the contrary, however small a number may be as, the hundredth or ten thousandth part, we can still conceive of a less ; and so on ad infinitum, without ever arriving at zero or nothingness. however a great space may be, we can conceive of a greater ; and thus ad infinitum, without ever arriving at one which can no longer be increased. and, on the contrary, however, small a space may be, we can still imagine a smaller ; and so on ad infinitum, without ever arriving at one indivisible, which has no longer any extent. that is, in a word, whatever movement, whatever number, whatever space, whatever time there may be, there is always a greater and a less than these : so that they all stand betwixt nothingness and the infinite, being always infinitely distant from these extremes. all these truths cannot be demonstrated ; and yet they are the foundations and principles of geometry. but as the cause that renders them incapable of demonstration is not their obscurity, but on the contrary their extreme obviousness, this lack of proof is not a defect, but rather a perfection. from which we see that geometry can neither define objects nor prove principles ; but for this single and advantageous reason that both are in an extreme natural clearness, which convinces reason more powerfully than discourse. for what is more evident than this truth, that a number, whatever it may be, can be increasedcan", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6277614876351052, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:1684fc30-175e-468b-a3ff-19ceee683983>", "chunk_index": 7, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:20.296719"}
{"text": "; but for this single and advantageous reason that both are in an extreme natural clearness, which convinces reason more powerfully than discourse. for what is more evident than this truth, that a number, whatever it may be, can be increasedcan be doubled? again, may not the speed of a movement be doubled, and may not a space be doubled in the same manner? and who too can doubt that a number, whatever it may be, may not be divided into a half, and its half again into another half? for would this half be a nothingness? and would these two halves, which would be two zeros, compose a number? in the same manner, may not a movement, however slow it may be, be reduced in speed by a half, so that it will pass over the same space in double the time, and this last movement again? for would this be a perfect rest? and would these two halves of velocity, which would be two rests, compose again the first velocity? lastly, may not a space, however small it may be, be divided into two, and these halves again? and how could these two halves become indivisible without extent, which joined together made the former extent? there is no natural knowledge in mankind that precedes this, and surpasses it in clearness. nevertheless, in order that there may be examples for every thing, we find minds excellent in all things else, that are shocked by these infinities and can in no wise assent to them. i have never known any person who thought that a space could not be increased. but i have seen some, very capable in other respects, who affirmed that a space could be divided into two indivisible parts, however absurd the idea may seem. i have applied myself to investigating what could be the cause of this obscurity, and have found that it chiefly consisted in this, that they could not conceive of a continuity divisible ad infinitum, whence they concluded that it was not divisible. it is an infirmity natural to man to believe that he possesses truth directly ; and thence it comes that he is always disposed to deny every thing that is incomprehensible to him ; whilst in fact he knows naturally nothing but falsehood, and whilst he ought to receive as true only those things the contrary of which appear to him as false. and hence, whenever a proposition is inconceivable, it is necessary to suspend the judgment", "subdomain_id": "subdomain_quantum_information_theory", "similarity_score": 0.6369651838763986, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:1684fc30-175e-468b-a3ff-19ceee683983>", "chunk_index": 8, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:20.297654"}
{"text": "fact he knows naturally nothing but falsehood, and whilst he ought to receive as true only those things the contrary of which appear to him as false. and hence, whenever a proposition is inconceivable, it is necessary to suspend the judgment on it and not to deny it from this indication, but to examine its opposite ; and if this is found to be manifestly false, we can boldly affirm the former, however incomprehensible it may be. let us apply this rule to our subject. there is no geometrician that does not believe space divisible ad infinitum. he can no more be such without this principle than man can exist without a soul. and nevertheless there is none who comprehends an infinite division ; and he only assures himself of this truth by this one, but certainly sufficient reason, that he perfectly comprehends that it is false that by dividing a space we can reach an indivisible part, that, is, one that has no extent. for what is there more absurd than to pretend that by continually dividing a space, we shall finally arrive at such a division that on dividing it into two, each of the halves shall remain indivisible and without any extent, and that thus these two negations of extensions will together compose an extent? for i would ask those who hold this idea, whether they conceive clearly two indivisibles being brought into contact ; if this is throughout, they are only the same thing, and consequently the two together are indivisible ; and if it is not throughout, it is then but in a part ; then they have parts, therefore they are not indivisible. if they confess, as in fact they admit when pressed, that their proposition is as inconceivable as the other, they acknowledge that it is not by our capacity for conceiving these things that we should judge of their truth, since these two contraries being both inconceivable, it is nevertheless necessarily certain that one of the two is true. but as to these chimerical difficulties, which have relation only to our weakness, they oppose this natural clearness and these solid truths : if it were true that space was composed of a certain finite number of indivisibles, it would follow that two spaces, each of which should be square, that is, equal and similar on every side, being the one the double of the other, the one would contain a number of these indivisi", "subdomain_id": "subdomain_quantum_mechanics", "similarity_score": 0.605269542596151, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:1684fc30-175e-468b-a3ff-19ceee683983>", "chunk_index": 9, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:20.298586"}
{"text": "better remedy than to make them look through glasses that magnify this delicate point to a prodigious mass ; whence they will easily conceive that by the aid of another glass still more artistically cut, they could be magnified so as to equal that firmament the extent of which they admire. and thus these objects appearing to them now easily divisible, let them remember that nature can do infinitely more than art. for, in fine, who has assured them that these glasses change the natural magnitude of these objects, instead of re - establishing, on the contrary, the true magnitude which the shape of our eye may change and contract like glasses that diminish? it suffices to say to minds clear on this matter that two negations of extension cannot make an extension. but as there are some who pretend to elude this light by this marvellous answer, that two negations of extension can as well make an extension as two units, neither of which it is a number, can make a number by their combination ; it is necessary to reply to them that they might in the same manner deny that twenty thousand men make an army, although no single one of them is an army ; that a thousand houses make a town, although no single one is a town ; or that the parts make the whole, although no single one is the whole ; or, to remain in the comparison of numbers, that two binaries make a quaternary, and ten tens a hundred, although no single one is such. but it is not to have an accurate mind to confound by such unequal comparisons the immutable nature of things with their arbitrary and voluntary names, names dependent upon the caprice of the men who invented them. for it is clear that to facilitate discourse the name of army has been given to twenty thousand men, that of town to several houses, that of ten to ten units ; and that from this liberty spring the names of unity, binary, quaternary, ten, hundred, different through our caprices, although these things may be in fact of the same kind by their unchangeable nature, and are all proportionate to each other and differ only in being greater or less, and although, as a result of these names, binary may not be a quaternary, nor the house a town, any more than the town is a house. but again, although a house is not a town, it is not however a negation of a town ; there", "subdomain_id": "subdomain_quantum_optics", "similarity_score": 0.6210233898933661, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:1684fc30-175e-468b-a3ff-19ceee683983>", "chunk_index": 11, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:20.300745"}
{"text": "these names, binary may not be a quaternary, nor the house a town, any more than the town is a house. but again, although a house is not a town, it is not however a negation of a town ; there is a great difference between not being a thing, and being a negation of it. for, in order to understand the thing to the bottom, it is necessary to know that the only reason why unity is not in the ranks of numbers, is that euclid and the earliest authors who treated of arithmetic, having several properties to give that were applicable to all the numbers except unity, in order to avoid often repeating that in all numbers except unity this condition is found, have excluded unity from the signification of the word number, by the liberty which we have already said can be taken at will with definitions. thus, if they had wished, they could in the same manner have excluded the binary and ternary, and all else that it pleased them ; for we are master of these terms, provided we give notice of it ; as on the contrary we may place unity when we like in the rank of numbers, and fractions in the same manner. and, in fact, we are obliged to do it in general propositions, to avoid saying constantly, that in all numbers, as well as in unity and in fractions, such a property is found ; and it is in this indefinite sense that i have taken it in all that i have written on it. but the same euclid who has taken away from unity the name of number, which it was permissible for him to do, in order to make it understood nevertheless that it is not a negation, but is on the contrary of the same species, thus defines homogeneous magnitudes : magnitudes are said to be of the same kind, when one being multiplied several times may exceed the other ; and consequently, since unity can, be - ing multiplied several times, exceed any number whatsoever, it is precisely of the same kind with numbers through its essence and its immutable nature, in the meaning of the same euclid who would not have it called a number. it is not the same thing with an indivisible in respect to an extension. for it not only differs in name, which is voluntary, but it differs in kind, by the same definition ; since an indivisible, multiplied as many times as we like, is so far from being able to exceed an extension, that it can never", "subdomain_id": "subdomain_quantum_cryptography", "similarity_score": 0.600240978324269, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:1684fc30-175e-468b-a3ff-19ceee683983>", "chunk_index": 12, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:20.303364"}
{"text": "and then we shall find a perfect correspondence between these things ; for all these magnitudes are divisible ad infinitum, without ever falling into their indivisibles, so that they all hold a middle place between infinity and nothingness. such is the admirable relation that nature has established between these things, and the two marvellous infinities which she has proposed to mankind, not to comprehend, but to admire ; and to finish the consideration of this by a last remark, i will add that these two infinites, although infinitely different, are notwithstanding relative to each other, in such a manner that the knowledge of the one leads necessarily to the knowledge of the other. for in numbers, inasmuch as they can be continually augmented, it absolutely follows that they can be continually diminished, and this clearly ; for if a number can be multiplied to 100, 000, for example, 100, 000th part can also be taken from it, by dividing it by the same number by which it is multiplied ; and thus every term of augmentation will become a term of division, by changing the whole into a fraction. so that infinite augmentation also includes necessarily infinite division. and in space the same relation is seen between these two contrary infinites ; that is, that inasmuch as a space can be infinitely prolonged, it follows that it may be infinitely diminished, as appears in this example : if we look through a glass at a vessel that recedes continually in a straight line, it is evident that any point of the vessel observed will continually advance by a perpetual flow in proportion as the ship recedes. therefore if the course of the vessel is extended ad infinitum, this point will continually recede ; and yet it will never reach that point in which the horizontal ray carried from the eye to the glass shall fall, so that it will constantly approach it without ever reaching it, unceasingly dividing the space which will remain under this horizontal point without ever arriving at it. from which is seen the necessary conclusion that is drawn from the infinity of the extension of the course of the vessel to the infinite and infinitely minute division of this little space remaining beneath this horizontal point. those who will not be satisfied with these reasons, and will persist in the belief that space is not divisible ad infinitum, can make no pretensions to geometrical demonstrations, and although they may be enlightened in other things, they will be very little in this ; for one can easily be", "subdomain_id": "subdomain_quantum_mechanics", "similarity_score": 0.6109999560019922, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:1684fc30-175e-468b-a3ff-19ceee683983>", "chunk_index": 14, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:20.305732"}
{"text": "belief that space is not divisible ad infinitum, can make no pretensions to geometrical demonstrations, and although they may be enlightened in other things, they will be very little in this ; for one can easily be a very capable man and a bad geometrician. but those who clearly perceive these truths will be able to admire the grandeur and power of nature in this double infinity that surrounds us on all sides, and to learn by this marvellous consideration to know themselves, in regarding themselves thus placed between infinitude and a negation of extension, between an infinitude and a negation of number, between an infinitude and a negation of movement, between an infinitude and a negation of time. from which we may learn to estimate ourselves at our true value, and to form reflections which will be worth more than all the rest of geometry itself. i have thought myself obliged to enter into this long discussion for the benefit of those who, not comprehending at first this double infinity, are capable of being persuaded of it. and although there may be many who have sufficient enlightenment to dispense with it, it may nevertheless happen that this discourse which will be necessary to the one will not be entirely useless to the other. note 1. after this paragraph occur in the ms. the following lines, written in a finer hand, and inclosed in parenthesis : is much more to succeed in the one than the other, and i have chosen this science to attain it only because it alone knows the true rules of reasoning, and, without stopping at the rules of syllogisms which are so natural that we cannot be ignorant of them, stops and establishes itself upon the true method of conducting reasoning in all things, which almost every one is ignorant of, and which it is so advantageous to know, that we see by experience that among equal minds and like circumstances, he who possesses geometry bears it away, and acquires a new vigor. i wish, therefore, to explain what demonstrations are by the example of those of geometry, which is almost the only one of the human sciences that produces infallible ones, because she alone observes the true method, whilst all the others are, through a natural necessity, in a sort of confusion, which the geometricians alone know exceedingly well how to comprehend. on the margin of this fragment is in the ms. the following note : that which is in small characters was hidden under a paper, the edges of which were glued,", "subdomain_id": "subdomain_quantum_mechanics", "similarity_score": 0.6166401013448262, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:1684fc30-175e-468b-a3ff-19ceee683983>", "chunk_index": 15, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:20.306742"}
{"text": "of confusion, which the geometricians alone know exceedingly well how to comprehend. on the margin of this fragment is in the ms. the following note : that which is in small characters was hidden under a paper, the edges of which were glued, and upon which was written the article beginning : i cannot better explain, etc. faugere. [ back ] note 2. pascal alludes here to father noel, a jesuit, with whom he had had a warm discussion on the subject of his experiences touchant le vide. in a letter that he wrote to father noel in 1647, he said : the sentence which precedes your closing compliments defines light in these terms : light is a luminous motion of rays composed of lucid, that is, luminous bodies ; upon which, i have to tell you that it seems to me that you ought first to have defined what luminous is, and what a lucid or luminous body is, for till then, i cannot understand what light is. and as we never make use in definitions of the term of the thing defined, i should have difficulty in conforming to yours which says : light is a luminary motion of a luminous body. faugere. [ back ] note 3. here the ms. adds in parenthesis : ( but as nature punishes all that science does not bestow, its order in truth does not give a superhuman perfection, but it has all that man can attain. it has seemed to me proper to give from the beginning of this discourse this, etc. ). faugere. [ back ] note 4. god has made all things in weight, number and proportion. [ back ]", "subdomain_id": "subdomain_quantum_optics", "similarity_score": 0.6144066868290322, "token_count": 340, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:1684fc30-175e-468b-a3ff-19ceee683983>", "chunk_index": 16, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:20.307350"}
{"text": "27 - 10 - 2008 : an international team of scientists has performed the ultimate miniaturisation of computer memory : storing information inside the nucleus of an atom. this breakthrough is a key step in bringing to life a quantum computer - a device based on the fundamental theory of quantum mechanics which could crack problems unsolvable by current technology. in the quantum world, objects such as atoms are allowed to exist in multiple states simultaneously - that is, they could literally be in two places at once or possess a number of other seemingly mutually exclusive properties. quantum computing is seen as the holy grail of computing because each individual piece of information, or \u2018 bit \u2019, can have more than one value at once, as opposed to current technology which is limited to either 1s or 0s. this yields unprecedented processing power and thus dramatically widens the scope of what computers can do. the problem : how do you isolate a quantum bit from a noisy environment to protect the delicate quantum information, while at the same time allowing it to interact with the outside world so that it can be manipulated and measured? the team, with scientists and engineers from oxford and princeton universities and lawrence berkeley national laboratory, reported a solution to this problem in nature. the team \u2019 s plan was to devise a hybrid system using both the electron and nucleus of an atom of phosphorous embedded in a silicon crystal. each behaves as a tiny quantum magnet capable of storing quantum information, but inside the crystal the electron is more than a million times bigger than the nucleus, with a magnetic field that is a thousand times stronger. this makes the electron well - suited for manipulation and measurement, but not so good for storing information, which can become rapidly corrupted. this is where the nucleus comes in : when the information in the electron is ready for storage, it is moved into the nucleus where it can survive for much longer times. the experiments were made possible by the use of silicon enriched with the single 28si iso - tope, painstakingly grown by the berkeley team into large crystals while keeping the material ultra - pure and free from contaminants. \u201c the electron acts as a middle - man between the nucleus and the outside world. it gives us a way to have our cake and eat it - fast processing speeds from the electron, and long memory times from the nucleus, \u201d said john morton, a research fellow at st. john \u2019 s college, oxford and lead author of the letter to nature. crucially, the information stored in the nucleus had a lifetime of about 1 and", "subdomain_id": "subdomain_quantum_computing", "similarity_score": 0.7133743218328776, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:6ea99552-cdce-47d9-94ec-d724100cd258>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:20.546244"}
{"text": "and long memory times from the nucleus, \u201d said john morton, a research fellow at st. john \u2019 s college, oxford and lead author of the letter to nature. crucially, the information stored in the nucleus had a lifetime of about 1 and 3 / 4 seconds, exceeding a recently calculated target for quantum computing in silicon beyond which known error correction techniques could then protect the data for an arbitrarily long period of time. without this technique the longest researchers had been able to preserve quantum information in silicon was a few tens of milliseconds. \u201c nobody really knew how long a nucleus might hold quantum information in this system. with the crystals from lawrence berkeley and very careful measurements we were delighted to see memory times exceeding the threshold, \u201d said steve lyon, leader of the princeton team. many different approaches to building a quantum computer are being studied, however one great advantage of the model used here is that it is based on silicon technology, which makes it more compatible with today \u2019 s computers. this is where you can add this news to your personal favourites for nature and chemists alike, making atmospheric nitrogen available for the formation of more complex nitrogen compounds is both essential and difficult. paul chirik and scott semproni at princeton university, usa, report the first examples of the use of group 4 metallocene complexes for b... more us and german scientists have used laser light to guide micro - particles through a solution towards a target. the technique could be applied to transport the particles to specific locations inside living cells, they say. these so - called \u2018 micro - swimmers \u2019 consist of a polystyrene sphere with o... more the max planck society is strengthening its commitment to the development of a sustainable energy supply and has joined forces with internationally renowned princeton university to establish the max planck princeton research center for plasma physics. shirley m. tilghman, the president of p... more researchers with the u. s. department of energy ( doe ) \u2019 s lawrence berkeley national laboratory ( berkeley lab ) have once again demonstrated the incredible capabilities of metamaterials \u2013 artificial nanoconstructs whose optical properties arise from their physical structure rather than their ch... more exactly how a crystal forms from solution is a problem that has occupied scientists for decades. researchers at eindhoven university of technology ( tu / e ), together with researchers from germany and the usa, are now presenting the missing piece. this classical theory of crystal formation, wh... more the phenomenon in ferromagne", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6348814042693585, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:6ea99552-cdce-47d9-94ec-d724100cd258>", "chunk_index": 1, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:20.547333"}
{"text": "4 - wheeled motor vehicle. 6. a stock exchange in new york. 7. includes some plants usually placed in e. g. genus dicksonia. 8. any group or radical of the form rco - where r is an organic group. 9. ( informal ) being satisfactory or in satisfactory condition. 10. the seventh month of the moslem calendar. 11. a means of serving. 12. a unit that is part of some military service. 18. ( botany ) of or relating to the axil. 20. the branch of computer science that deal with writing computer programs that can solve problems creatively. 24. type genus of the cariamidae comprising only the crested cariama. 26. by bad luck. 27. the basic unit of electric current adopted under the system international d ' unites. 28. ( astronomy ) the angular distance of a celestial point measured westward along the celestial equator from the zenith crossing. 30. type genus of the family arcidae. 31. the battle in 1806 in which napoleon decisively defeated the prussians. 33. a fixed charge for a privilege or for professional services. 34. a constellation in the southern hemisphere near telescopium and norma. 35. any of numerous hairy - bodied insects including social and solitary species. 37. a bantu language spoken by the kamba people in kenya. 39. a burn cause by hot liquid or steam. 41. manufactured in standard sizes to be shipped and assembled elsewhere. 42. a city of southeastern mexico. 46. a light springing movement upwards or forwards. 47. a very poisonous metallic element that has three allotropic forms. 48. the basic unit of money in bangladesh. 49. very dark black. 50. a challenge to do something dangerous or foolhardy. 52. the rate at which heat is produced by an individual in a resting state. 53. top part of an apron. 54. a unit of conductance equal to the reciprocal of an ohm. 58. a hard gray lustrous metallic element that is highly corrosion - resistant. 59. the blood group whose red cells carry both the a and b antigens.", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6087972245237364, "token_count": 438, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:1cccff50-3ffd-4bb3-bae2-e4a5fb979da2>", "chunk_index": 1, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:20.673335"}
{"text": "210 suppliers ) condensers are devices which accept a vapor stream and convert it to a liquid using heat transfer and / or compression. they are used in steam turbines for power plants, in cooling units for in - process fluids, and in air conditioning systems for buildings and automobiles. search by specification | learn more about condensers cooling towers ( 243 suppliers ) cooling towers are defined as any open water recirculation device that uses fans or natural draft to draw or force air to contact and cool water by evaporation. search by specification | learn more about cooling towers cooling tunnels ( 35 suppliers ) cooling tunnels ensure controlled temperature reduction in both batch and continuous process systems. they are similar to air convention ovens, but have no heating capacity. learn more about cooling tunnels crucibles ( 150 suppliers ) cryogenic equipment ( 141 suppliers ) cryogenic equipment produces or is used in the production of very low temperature materials or processes. learn more about cryogenic equipment cryostats and dewars ( 53 suppliers ) cryostats and dewars are used to keep sensors and store samples at very cold temperatures. learn more about cryostats and dewars dampers and louvers ( 264 suppliers ) dampers and louvers are used to control the flow of air in a process system or enclosed area. dampers are usually motorized or manually - adjustable for flow control. louvers are often fixed for a constant flow rate. learn more about dampers and louvers deaerators ( 61 suppliers ) deaerators are used to remove dissolved, corrosive gases from boiler feed water. they heat incoming makeup water for injection into the boiler, and return the condensate to a temperature which minimizes the solubility of these gases. learn more about deaerators dehumidifiers ( 181 suppliers ) desuperheaters ( 38 suppliers ) desuperheaters are used to cool steam in power plants. learn more about desuperheaters economizers ( 43 suppliers ) economizers are mechanical devices that are designed to reduce energy consumption, or to perform other useful, energy - related functions ( such as preheating fluids ). learn more about economizers evaporative coolers ( 138 suppliers ) evaporative coolers are cooling devices that use the evaporation of water into the air to cool the air temperature. they are sometimes called air coolers, desert coolers or swamp coolers. learn more about evaporative coolers fans and blowers ( industrial ) ( 1,", "subdomain_id": "subdomain_quantum_thermodynamics", "similarity_score": 0.6142168147116582, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:ef71d290-562a-4249-a0ae-2317a04d9deb>", "chunk_index": 1, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:21.205453"}
{"text": "the pseudoscope creates one of the most remarkable of all optical illusions, and was first described by sir charles wheatstone in the 1830s. the pseudoscope swaps the incoming images, so that the right eye sees what the left eye would have seen, and vice versa. the pseudoscope therefore does to front and back what a mirror does to left and right. this means that foreground becomes background and visible background becomes foreground, or more simply, background advances, foreground recedes. when you view objects with this scope, the convex becomes concave. a tree turns inside out as it were - it ' s front branches appear at the back, whilst the back branches come out in front, hanging or suspended in mid - air as their support is eclipsed by branches in front. the scope will suggest to the viewer that a person ' s face is hollow or concave but your brain refuses to accept such nonsence and so peoples ' heads merely appear odd or uncomfortable to look at. it is best then to choose to look at a landscape or tree or anything which may suggest ambiguous perspective. in a real sense pseudoscopic vision fights ` normal vision '. it is, after all, a major alteration to the way information is being presented to the brain for processing, and some people, not all, find there is initially at least, a tendency to suppress the extraordinary interpretation of space it reveals. because of this unfamiliarity, the full pseudoscopic experience might take a little time to assert itself. some people find that they can never see a pseudoscopic image. these pseudoscopes come as a kit form, and require assembly. this is a fairly complex kit, and it will take a number of hours to complete. there are a total of four mirrors. there are two front silvered glass mirrors ( the two small mirrors ) and two acrylic mirrors ( the large ones ) included in the kit. you will need to provide glue. the kit comes from germany, but we provide an english translation of the instructions. experience space on the flipside! suggested age 16 + made in eu", "subdomain_id": "subdomain_quantum_optics", "similarity_score": 0.6190877974961392, "token_count": 422, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:e80b7145-f3d9-417c-95cc-e4e54a6a6e7f>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:21.215725"}
{"text": "abrasion / sanding the wearing away of any part of material by rubbing it against another surface. the term is often used to describe the processes of creating an aged look in denim. abrasion can be achieved through hand rubbing with sandpaper or even washing garments with stones or rubber balls to break down the surface of the fabric. think of the abraded seams and hems on your favorite pair of old jeans. this is the distressed look ( as opposed to worn - out ) that is entirely intentional. agate a semiprecious type of quartz also known as chalcedony ( pronounced kal - sed - nee ). it forms in a wide variety of colors and textures. each individual agate forms by filling a cavity in a host rock. agate was highly valued as a talisman or amulet in ancient times. it was said to quench thirst or protect from fevers. persian magicians used agate to divert storms. amazonite : a semiprecious gemstone that is a variety of green microcline feldspar. it varies in color from apple green to bluish green. also known as amazon stone, it is commonly found in the united states, brazil, zimbabwe, russia, australia and namibia. it is said to enhance clarity and understanding while balancing human energies. antique fleece a mellow blend of cotton and polyester. washed for a soft, lived - in quality. fleece lining lends a warm, cozy feel. applique ( pronounced a - plee - kay ) : material that is cut out and sewn or embroidered and fastened to a fabric. applique comes from the french appliquer, which means to \" put on. \" the art of hand applique covers a wide spectrum, from primitive folk art to the sophistication of baltimore album quilts \u2014 elegant appliqued quilts from the mid - 1800s that were highly sought - after and considered an honor to receive. authentic fit our stretch boot - cut style with a vintage appeal. it sits below the waistline and follows the contours of hips and thighs with its slightly fitted approach. whiskering detail adds to the \" lived - in \" appeal. aventurine ( sometimes known as goldstone ) a shimmering quartz ( crystalline mineral ) stone that ranges in color from yellow and red to light green and light brown. the shimmer is caused by tiny metallic particles ( mica ) within the stone. the mineral aventurine takes its", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.632457689522298, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:5ba29617-694c-47ff-b0ae-824a3e26356a>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:21.507255"}
{"text": "by yan zhang - princeton university the 2008 olympic games in beijing have focused attention on the problems of air quality in urban environments and will serve as an important platform for developing and testing new technologies and procedures for analysis and management of air quality problems. regional decisions concerning industrial development, agricultural practice and urban policy can play important roles in air quality problems linked to fine particulate matter. the olympic games will provide an important research venue for addressing these issues and unique opportunities for advancing novel environmental sensor systems and atmospheric models. in our work, we will deploy two environmental sensor systems at the institute of atmospheric physics, chinese academy of sciences near the olympic stadium in beijing from june to august 2008 for continuous monitoring of trace gases, before, during, and after the olympic games. data from these sensors will be incorporated into analyses using the weather research and forecasting model, a state - of - the - art meteorological model which is coupled with an atmospheric chemistry ( wrf - chem ) module. these analyses will be used to examine air quality problems in the beijing metropolitan region and regional climatology problems linked to trends of decreasing precipitation in the beijing metropolitan region associated with increased aerosol loadings. the environmental sensor systems deployed in beijing use quantum cascade lasers ( qcls ) as the core technology for measuring trace gases from \" remote sensing \" and \" point \" sensors. qcls are tiny, tunable mid - infrared ( mid - ir ) semiconductor laser sources that have extremely broad wavelength coverage ( 3 - 20 \u03bcm ), which includes the wavelength range where trace gases have their strongest absorption features. the lasers are designed to emit at aparticular wavelength ; thus, by knowing where a gas absorbs best, a laser can be designed for detection of that specific gas. as a result of new developments of qcls, laser absorption spectroscopy is becoming aviable alternative to other analytical methods for trace gas sensing. qclops ( quantum cascade laser open path system ) is an \" open path \" remote sensing system that uses two qcls for monitoring multiple trace gases. the principal target gases for qclops are ozone, ammonia, and carbon dioxide. elevated ozone levels in urban regions around the world present one of the greatest air quality and public health challenges associated with industrial and automobile emissions. ammonia plays an important and complex role in aerosol chemistry in urban environments and development of sensor systems for ammonia has proven especially challenging. carbon dioxide is broadly recognized as an important greenhouse gas and its measurement in urban environments is an important goal of qclops. the laser radiation is transmitted through the air and reflected", "subdomain_id": "subdomain_quantum_metrology", "similarity_score": 0.6390028235272458, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:ffb455bb-1631-4101-92b3-6ed60997a9a1>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:21.773872"}
{"text": "in urban environments and development of sensor systems for ammonia has proven especially challenging. carbon dioxide is broadly recognized as an important greenhouse gas and its measurement in urban environments is an important goal of qclops. the laser radiation is transmitted through the air and reflected back by a retro - reflector to a detector. the detector is connected to a data acquisition system and a computer. the computer runs a custom algorithm to calculate concentrations. no and no2 are important ozone precursors and their presence in urban environments is strongly connected to automobile emissions. detection of no and no2 is of great interest for air quality problems linked to elevated ozone concentrations. fast and sensitive detection of no can be realized by faraday rotation spectroscopy. the best no detection limit ( sub - ppbv ; parts per billion by volume ) can be obtained at approximately 5. 3 \u03bcm. an \" externalcavity \" ( ec ) qcl source that precisely coincides withth isoptimum absorption wavelength was developed and a faraday rotation spectrometer based on the ec - qcl was developed for detection of no. the measurement technique will allow for sensitive and selective measurements of no even in the presence of strongly interfering gases ( especially water vapor ). a fully automaticand autonomous ec - qcl faraday rotation spectroscopic sensorsystem will be deployed at the beijing test site for contiuous atnospheric no monitoring. the weather research and forecasting model, coupled with the wrf - chem atmospheric chemistry module ( wrf - chem ), provides a powerful platform for meteorological and air quality forecasting, as well as regional analyses of the impact of anthropogenic emissions on air quality and regional climate. wrf - chem has been used at princeton for analyses of aerosol impacts on regional precipitation climatology in the baltimore and new york city metropolitan region. with the collaboration of the nansen - zhu international center of the institute of atmospheric physics ( iap ), the chinese academy of sciences, wrf - chem will be implemented as a forecasting tool for the beijing olympics. an important element of the forecasting system will be integrating observations from sensor systems like qclops in to the forecasting process. the princeton group will also work closely with iap in studying and understanding how the urban aerosols influence local weather and public health through coupled modeling and monitoring analyses.", "subdomain_id": "subdomain_quantum_metrology", "similarity_score": 0.6360027348928712, "token_count": 477, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:ffb455bb-1631-4101-92b3-6ed60997a9a1>", "chunk_index": 1, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:21.775711"}
{"text": "academic standards correlations on teachers ' domain use the achievement standards network ( asn ) database of state and national standards, provided to nsdl projects courtesy of jes & co. we assign reference terms to each statement within a standards document and to each media resource, and correlations are based upon matches of these terms for a given grade band. if a particular standards document of interest to you is not displayed yet, it most likely has not yet been processed by asn or by teachers ' domain. we will be adding social studies and arts correlations over the coming year, and also will be increasing the specificity of alignment. air is a mixture of different molecules. its composition is the result of chemical reactions, atmospheric motion, and emissions from a variety of sources, both natural and manmade. one of these emissions is carbon dioxide ( co2 ). co2 is a greenhouse gas : it traps the heat from sunlight close to earth ' s surface. in their natural balance, greenhouse gases make earth habitable for humans and other living things. however, a change in their concentration may affect atmospheric temperatures dramatically. in fact, most climate scientists are convinced that an increased concentration of co2 in the atmosphere is one of the leading drivers of global warming today. in this lesson, students will discover how carbon dioxide is added into the atmosphere and the effect it ' s having on environmental public health. the lesson begins with a brief review of the molecules that make up air. students use lego bricks to model these molecules, with individual bricks representing the atoms that make up the molecules. continuing with lego bricks, they investigate how co2 enters the atmosphere through a chemical reaction called combustion. next, students learn about the relationship between air and atmospheric conditions, and watch a video that describes environmental disasters associated with atmospheric warming. they learn how the concentration of co2 in the atmosphere correlates with temperature and then explore an interactive activity that details the potential impact of atmospheric warming on human health. the lesson ends with a class discussion of ways to reduce the concentration of co2 in the air. note : this lesson may be followed up with the understanding air : air pollution and modeling pollutants with lego\u00ae bricks lesson plan, which demonstrates other forms of pollution that result from incomplete combustion and other chemical reactions in the air. climate change and human health interactive printing instructions : set scaling to \" 0 % \" or \" none \" so that the lego bricks on the printouts are actual size. print two - page documents back - to - back and laminate, if possible ; or", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6113612237200039, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:6db3a4d4-5af4-419e-8e43-363bef8176c9>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:22.306587"}
{"text": "change and human health interactive printing instructions : set scaling to \" 0 % \" or \" none \" so that the lego bricks on the printouts are actual size. print two - page documents back - to - back and laminate, if possible ; or print one - sided and use a plastic sleeve. 1. explain that air is a mixture of gases and is essential to life. even though air is invisible, it is all around us. air is made up of molecules ( groups of two or more atoms that are bonded together ). the types and amounts of atoms and molecules in air can impact both environmental and public health. 2. to pique student interest, and to uncover any misconceptions students may have about air, conduct a class survey. hand out the what is air made of? guess! document survey, have students look at it, and then have them vote anonymously by raising their hands with their heads down and eyes closed. before revealing the correct answer ( b ), tally their votes and put them up on the board. note : the answer to the survey question is printed on the back of the handout, so tell students not to turn it over. if time allows, have students debate the question, then vote to see whose answer was most convincing. or, ask students to discuss what they know about air that might help them answer the question. you may reveal the correct answer to the class or allow them to discover it for themselves in the next step. 3. tell students they will now have a chance to make a model of air. distribute one lego\u00ae atoms and molecules layout mat document to each group of two or three students. this document explains the contents of the lego brick set. you may also distribute the lego\u00ae atoms and molecules : chemical reactions student worksheet document to refresh the students ' understanding of the types of matter. explain that they will use the lego bricks to model tiny particles of matter that are too small to be seen. each brick represents an atom, and they will use these atoms to build four types of molecules : nitrogen, oxygen, carbon dioxide, and water. using the back of the what is air made of? guess! document as their guide, have them construct a model of air that reflects the correct components and their concentrations. after they have done this, point out the \" 390 parts per million ( ppm ) \" label under the co2 molecule. have students convert 20 percent oxygen and 80 percent nitrogen into ppm. ( that is, convert the fractions 20 /", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6202262579217248, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:6db3a4d4-5af4-419e-8e43-363bef8176c9>", "chunk_index": 1, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:22.307951"}
{"text": "understanding microelectronics : a top - down approach december 2011, \u00a92011, wiley - blackwell this price is valid for united states. change location to view local pricing and availability. for today \u2019 s students, the most beneficial approach to learning is this top - down method that demonstrates a global view of electronics before going into specifics. franco maloberti uses this approach to explain the fundamentals of electronics, such as processing functions, signals and their properties. here he presents a helpful balance of theory, examples, and verification of results, while keeping mathematics and signal processing theory to a minimum. presents a new learning approach that will greatly improve students \u2019 ability to retain key concepts in electronics studies match the evolution of computer aided design ( cad ) which focuses increasingly on high - level design covers sub - functions as well as basic circuits and basic components provides real - world examples to inspire a thorough understanding of global issues, before going into the detail of components and devices discusses power conversion and management ; an important area that is missing in other books on the subject end - of - chapter problems and self - training sections support the reader in exploring systems and understanding them at increasing levels of complexity a supporting website ( http : / / www. wiley. com / wileycda / wileytitle / productcd - 047074555x, desccd - relatedwebsites. html ) presents the interactive student lab, elvislab, where students can conduct virtual experiments on circuits together with powerpoint slides for lecturers. inside this book you will find a complete explanation of electronics that can be applied across a range of disciplines including electrical engineering and physics. this comprehensive introduction will be of benefit to students studying electronics, as well as their lecturers and professors. postgraduate engineers, those in vocational training, and design and application engineers will also find this book useful.", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6080608897941674, "token_count": 373, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:7f620be6-e083-431f-bfa2-b1d32b644ef1>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:22.474686"}
{"text": "microcalorimetry of macromolecules : the physical basis of biological structures this price is valid for united states. change location to view local pricing and availability. other available formats : e - book examining the physical basis of the structure of macromoleculesproteins, nucleic acids, and their complexesusing calorimetric techniques many scientists working in biology are unfamiliar with the basics of thermodynamics and its role in determining molecular structures. yet measuring the heat of structural change a molecule undergoes under various conditions yields information on the energies involved and, thus, on the physical bases of the considered structures. microcalorimetry of macromolecules offers protein scientists unique access to this important information. divided into thirteen chapters, the book introduces readers to the basics of thermodynamics as it applies to calorimetry, the evolution of the calorimetric technique, as well as how calorimetric techniques are used in the thermodynamic studies of macromolecules, detailing instruments for measuring the heat effects of various processes. also provided is general information on the structure of biological macromolecules, proteins, and nucleic acids, focusing on the key thermodynamic problems relating to their structure. the book covers : - the use of supersensitive calorimetric instruments, including micro and nano - calorimeters for measuring the heat of isothermal reactions ( isothermal titration nano - calorimeter ), the heat capacities over a broad temperature range ( scanning nano - calorimeter ), and pressure effects ( pressure perturbation nano - calorimeter ) - two of the simplest but key structural elements : the \u03b1 and polyproline helices and their complexes, the \u03b1 - helical coiled - coil, and the pyroline coiled - coils - complicated macromolecular formations, including small globular proteins, multidomain proteins and their complexes, and nucleic acids - numerous examples of measuring the ground state of protein energetics, as well as changes seen when proteins interact the book also reveals how intertwined structure and thermodynamics are in terms of a macromolecule ' s organization, mechanism of formation, the stabilization of its three - dimensional structure, and ultimately, its function. the first book to describe microcalorimetric technique in detail, enough for graduate students and research scientists to successfully plumb the structural mysteries of proteins and the double helix, microcalorimetry of macromolecule", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6034261146702924, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:0846fd28-c34b-4d4c-8d6a-50ea0908fb58>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:22.477767"}
{"text": "quicksand and other non - newtonian fluids share properties with both liquids and solids. non - newtonian fluids consist of tiny grains suspended in liquid, with the appearance of a solid or gel. stand on quicksand and you will sink ( though not as rapidly as movies and cartoons suggest ). but strike it quickly and it will briefly harden. previous explanations of quicksand behavior relied on the presence of containment walls and effects like grain dilation under stress. however, a new experimental study challenges prior assumptions, showing that new concepts may be needed to explain non - newtonian fluids. scott r. waitukaitis and heinrich m. jaeger at the university of chicago created a quicksand - like substance called \" oobleck \" out of cornflour and water, which they then struck with an aluminum rod. by measuring the position, speed, and acceleration of the rod as it interacted with the oobleck, they determined that its solidification arises from compression that propagates away from the impact point. by using a huge amount of fluid ( 25 liters ), the researchers showed the bizarre non - newtonian effects were independent of the size of the container, so the presence of confining walls is irrelevant. through x - ray imaging, they discovered a nearly cylindrical solid region forms directly below the impact point. the detailed analysis led the authors to develop a simple model for the impact, which bears striking similarity to models for objects falling into liquids, but produces very different effects. this may have been the most carefully monitored bowl of starch ever devised. in the experiment, the researchers mounted the aluminum rod using guide rails to make sure it impacted along a single axis. for different trials, they either dropped the rod ( free fall ) or used a slingshot to drive it more quickly downward. the rod was fixed with an accelerometer, and the whole process was recorded on high - speed video to measure the instantaneous position, speed, and acceleration. the grains of the cornflour in the oobleck are irregularly shaped and range in size from 5 to 20 microns ( 0. 005 to 0. 02 millimeters ), which is typical of quicksand and other non - newtonian fluids. additionally, the suspension contained tracer particles that could be imaged with x - rays ; motion within the oobleck could be tracked with the tracers. the authors positioned a force sensor directly below the rod at the bottom of the container to examine how the impact", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6065331704371284, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:bec751b6-db43-451c-be44-31f461c3f535>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:22.711327"}
{"text": "| an arrangement of five objects, as trees, in a square or rectangle, one at each corner and one in the middle. | | an extraordinary or unusual thing, person, or event ; an exceptional example or instance. | | weber ( german \u02c8ve\u02d0b\u0259r ) | | 1. | | baron carl maria friedrich ernst von ( karl ma\u02c8ri\u02d0a \u02c8fri\u02d0dr\u026ac \u025brnst f\u0254n ). 1786 - - 1826, german composer and conductor. his three romantic operas are der freischutz ( 1821 ), euryanthe ( 1823 ), and oberon ( 1826 ) | | 2. | | ernst heinrich ( \u025brnst \u02c8hainr\u026ac ). 1795 - - 1878, german physiologist and anatomist. he introduced the psychological concept of the just noticeable difference between stimuli | | 3. | | max ( maks ). 1864 - - 1920, german economist and sociologist, best known for the protestant ethic and the spirit of capitalism ( 1904 - - 05 ) | | 4. | | wilhelm eduard ( \u02c8v\u026alh\u025blm \u02c8e\u02d0duart ). 1804 - - 91, german physicist, who conducted research into electricity and magnetism | weber web \u00b7 er ( web ' \u0259r, va ' b\u0259r ) a unit of magnetic flux in the international system of units equal to the product of one tesla and one square meter. weber we \u00b7 ber ( va ' b\u0259r ), ernst heinrich. 1795 - 1878. german physiologist and psychologist who studied sensory response and is considered a founder of experimental psychology. | weber ( web ' \u0259r, va ' b\u0259r ) pronunciation key the si derived unit of magnetic flux. a magnetic flux of one weber, passing through a conducting loop and reduced to zero at a uniform rate in one second, induces an electric potential of one volt in the loop. one weber is equal to one volt per second, or 108 maxwells. the weber is named after german scientist wilhelm eduard weber ( 1804 - 1891 ). | weber ( va ' b\u0259r ) pronunciation key german physiologist who is noted for his study of sensory response, particularly in the ear and the skin. he also demonstrated that the digestive juices are the specific products of glands.", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6091094106921817, "token_count": 478, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:80b49614-0612-413a-9fb2-254ab3ae48d4>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:22.945984"}
{"text": "to save one ' s self or property from harm or less. [ colloq. ] ba * co \" ni * an (? ), a. of or pertaining to lord bacon, or to his system of philosophy. baconian method, the inductive method. see induction. bac * te \" ri * a (? ), n. p. see bacterium. bac * te \" ri * al (? ), a. ( biol. ) of or pertaining to bacteria. bac * te \" ri * ci ` dal (? ), a. destructive of bacteria. bac * te \" ri * cide (? ), n. [ bacterium + l. caedere to kill ] ( biol. ) same as germicide. bac * te \" ri * o * log ` ic * al (? ), a. of or pertaining to bacteriology ; as, bacteriological studies. bac * te \" ri * ol ` o * gist, n. one skilled in bacteriology. bac * te \" ri * ol ` o * gy (? ), n. [ bacterium + - logy. ] ( biol. ) the science relating to bacteria. bac * te ` ri * o * scop \" ic (? ), a. ( biol. ) relating to bacterioscopy ; as, a bacterioscopic examination. bac * te ` ri * os \" co * pist (? ), n. ( biol. ) one skilled in bacterioscopic examinations. bac * te ` ri * os \" co * py (? ), n. [ bacterium + - scopy ] ( biol. ) the application of a knowledge of bacteria for their detection and identification, as in the examination of polluted water. bac * te \" ri * um (? ), n. ; pl. bacteria ( # ). [ nl., fr. gr.,, a staff : cf. f. bacterie. ] ( biol. ) a microscopic vegetable organism, belonging to the class alg\u00e6, usually in the form of a jointed rodlike filament, and found in putrefying organic infusions. bacteria are destitute of chlorophyll, and are the smallest of microscopic organisms. they are very widely diffused in nature, and multiply with marvelous rapidity, both by fission", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6117256371180709, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:c73db666-dff0-4dcc-b0b4-05cb70f9e703>", "chunk_index": 4, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:23.561898"}
{"text": "chaos, like next year \u2019 s weather, is anything but predictable. so results appearing in the 8 october print issue of prl may seem paradoxical : researchers claim that for the first time, two lasers have been synchronized so that one can anticipate the chaotic fluctuations in the other. some experts are skeptical of the result, but it illustrates some of the challenges in the field of chaos research, where physicists are attempting to understand and make use of nature \u2019 s seeming disorder. the weather is a classic example of chaos. in a perfect world, a computer \u2013 given a complete set of atmospheric data and equations \u2013 should be able to crunch out forecasts for years to come. but in practice, tiny uncertainties in the initial data set eventually lead to completely inaccurate predictions. a laser also becomes very unpredictable if you reflect a small portion of the laser \u2019 s output back into the device. this feedback makes the laser \u2019 s future output \u2013 like next year \u2019 s weather \u2013 strongly dependent on its past. alan shore and his colleagues at the university of wales in bangor, uk, created fluctuations in their first laser \u2013 the \u201c transmitter \u201d \u2013 using this standard feedback technique. they also fed some of the transmitter \u2019 s light into a second, \u201c receiver \u201d laser, which went into fits of intensity fluctuations nearly identical with those of the transmitter. the team arranged the mirrors in a way that gave the transmitter \u2019 s feedback signal a long round trip, so the receiver got the signal earlier and anticipated the transmitter \u2019 s fluctuations by a fixed amount of time. surprisingly, that fixed anticipation time did not depend upon the round - trip time for light to re - enter the transmitter. several researchers have pointed out that even the tiniest amount of accidental light traveling from the receiver back to the transmitter could induce unintended fluctuations in the transmitter. they suggest that the receiver might not be anticipating fluctuations in the transmitter, but rather, causing them. shore says that there is a small amount of feedback from the receiver to the transmitter, but that his team has shown that this feedback is not causing the fluctuations in the transmitter \u2013 a result they will soon publish. although many experts want to consider this result more carefully, they are optimistic about the potential usefulness of chaos synchronization. dan gauthier of duke university in durham, nc, suggests one possible application for anticipating chaos : researchers could maintain an extremely steady laser intensity by using the advanced signal to counter fluctuations quickly. ingo fischer, of the university of darmstadt in germany, still sees open questions in the interpretation", "subdomain_id": "subdomain_quantum_optics", "similarity_score": 0.6301302800785259, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:8011ffe5-2ebf-4135-a85f-8d69d02cabcf>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:23.851252"}
{"text": "stewart, ian. taming the infinite : the story of mathematics from the first numbers to chaos theory. quercus, dist. by trafalgar square. dec. 2011. 384p. illus. index. isbn 9781847247681. pap. $ 14. 95. math have you ever thought of math as terrific fun? stewart ( mathematics, univ. of warwick, uk ; why beauty is truth : the history of symmetry ) makes it that and more. his engaging writing style draws readers into the story of mathematics, giving it an arc and its players charismatic personalities, even when those players are notation systems. in each chapter, stewart chronologically examines a particular area of mathematics. he gives accessible, real - world examples that are easy to visualize and often illustrate the impact of complicated mathematical concepts on our daily lives. from tally marks and numerals, to euclid and pythagoras, to imaginary numbers and chaos theory, to godel and faraday, stewart offers an insightful and clear history of mathematical developments. the diagrams and illustrations are comprehensible for lay readers yet not condescendingly simple. throughout, stewart examines the discoveries of great mathematicians and offers absorbing anecdotes about their lives in special callouts throughout the book. verdict clear and readable, this is an essential title for math, science, and technology buffs and will be intriguing for all. it might even be of interest to teens! highly recommended. \u201a candice kail, columbia univ. libs., new york mount, ian. the vineyard at the end of the world : maverick winemakers and the rebirth of malbec. norton. jan. 2012. c. 288p. illus. bibliog. index. isbn 9780393080193. $ 26. 95. beverages adding to the growing body of work on wine history, wine journalist mount traces the history of argentinian wine from its beginning in the 1700s to the present day. to accomplish this monumental task in a digestible narrative, he focuses on one figure and one region but explains in the epilog that many other people and areas were also important. the result is an artfully written story of how a poorly developed wine culture grew into one of the best wine regions in the world. mount brings to light a lesser - known wine region and explains how cultural contact beginning with spanish explorers contributed to its current wine - producing status. the work is obviously well", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.606287790310867, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:5cf78dbc-4403-4661-8936-679e6890bb01>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:23.999750"}
{"text": "one of the outstanding achievements of 20th century science was the realisation that the great diversity of nature is based on a handful of elementary particles acting under the influence of only a few fundamental forces. this talk aims to give an overview of the natural forces that shape everything around us and outlines current research and what we believe remains to be discovered. prof. peter kalmus is emeritus professor at queen mary, university of london. at various times he has been president of the physics section of the british association, vice president of the institute of physics, and vice president of the royal institution. a distinguished career has seen him awarded the rutherford medal for his outstanding role in the discovery of the w and z particles, an obe for his contributions to physics and only last week the kelvin medal for his role in the public understanding of physics. dramatic advances in the study of stem cells - the precursor cells of blood, skin, bone and nerve cells - could be used one day to help sufferers from parkinson ' s disease, hepatitis, leukaemia, diabetes and rheumatoid arthritis. stem cells hold the key to the ability to grow a patient ' s own tissue for repair, and are central to the cloning debate. potentially they could be used to create unlimited supplies of replacement tissue, including nerve, bone, skin and heart muscle, for repairing injuries and for treating disease - potentially saving millions of lives. cloning offers a way to grow a patient ' s own stem cells but, by perfecting such technology, scientists could accelerate efforts to conduct so - called reproductive cloning. professor richard gardner, who is chairing the royal society ' s working group on stem cells and therapeutic cloning provides a rich overview into the how and why of cloning. professor wolpert ' s thesis is that science is not common sense. common sense is misleading - it can make you accept that a seashell on the top of a mountain is proof of a global flood. in this talk professor wolpert gives one scientist ' s view of the culture of science and why the public ' s understanding of that culture is so much in error. his thoughtful analysis concludes that scientific thought is unnatural. as well as a cbe, professor wolpert is a fellow of the royal society and former chairman of the committee for the public understanding of science. in may he was awarded the royal institution ' s michael faraday award for services to the public understanding of science. the common flu of 1918 spread faster than any disease in history, before orsince, and killed more people", "subdomain_id": "subdomain_quantum_optics", "similarity_score": 0.6157331377228588, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:5c6e8595-d959-401d-8022-7f7225a700c5>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:24.217841"}
{"text": "public understanding of science. in may he was awarded the royal institution ' s michael faraday award for services to the public understanding of science. the common flu of 1918 spread faster than any disease in history, before orsince, and killed more people in less time than all of the great plagues ofhistory, doing so in the presence of relatively ' modern ' medical science. even last year, approximately 20, 000 people in the uk died from what werethought to be flu - related illnesses. yet even this was not an epidemic - the spanish flu pandemic at the close of the first world war is believed tohave accounted for the deaths of well over 20m people worldwide, including280, 000 in the uk. the last official flu epidemic was 11 years ago, butthe fact that there is no way of guessing when the next one might be is avery serious concern. dr elspeth garman will go through at what we know ofthe different strains of flu virus and outline the progress made in thedevelopment of a cure. ref : ` the origin and control of flu pandemics ' laver and garman, science sep 7, 2001, 1776 - 1777. cryptography, the science of encrypting and decrypting information, dates as far back as 1900 bc when a scribe in egypt first used a derivation of the standard hieroglyphics of the day to communicate today cryptography provides the locks and keys to the information age. it is the technology that enables private emails to be sent and secure business transactions to take place over the internet. simon singh, author of fermat ' s last theorem and the code book, will give a brief history of cryptography and then discuss its impact in the 21st century. he will also bring with him a genuine enigma cipher machine. simon singh completed his phd in particle physics at cambridge. in 1991 he joined the bbc science department and worked as a producer and director with ' tomorrow ' s world ' and ' horizon '. he is also the author of ' fermat ' s last theorem ' and ' the code book ', the latter forming the basis for the popular channel 4 series ' the science of secrecy '. this talk is run in conjunction with blackwellscafe scientifique.", "subdomain_id": "subdomain_quantum_cryptography", "similarity_score": 0.6044459644159226, "token_count": 466, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:5c6e8595-d959-401d-8022-7f7225a700c5>", "chunk_index": 1, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:24.220418"}
{"text": "we are remembered by our exaggerations. so at a recent reunion of my former research - group members, several recalled my saying \" when you see a standard deviation in an x - ray crystal structure, multiply it by pi [ \u03c0, 3. 141... ], or if the structure is done by friends, by e [ 2. 718... ]. \" i was talking about structures of molecules \u2014 details of their geometry, also of a particularly fruitful way to gain knowledge of these structures. and of the error estimates in such studies. there is no more basic enterprise in chemistry than the determination of the geometrical structure of a molecule. such a determination, when it is well done, ends speculation and provides us with the starting point for understanding every physical, chemical and biological property of the molecule. indeed, the chemical sciences ( only modestly imperialistic, i take them to range from materials science through molecular biology ) are what they are today largely as the result of careful structure determination. we ' d be still waiting in ignorance if we believed the hype of various microscopies. a few very accurate structures have come to us through ingenious use of electron diffraction and various spectroscopies. but the vast majority of what we know about shapes and metric detail of molecules and extended materials derives from studies of the diffraction of x rays by single crystals of molecules, a technique popularly called \" x - ray crystallography. \" \u00bb post comment", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6287191289344253, "token_count": 302, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:40d9e532-38da-4823-a06a-47ce1c0effc9>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:24.456589"}
{"text": "to use all functions of this page, please activate cookies in your browser. with an accout for my. chemeurope. com you can always see everything at a glance \u2013 and you can configure your own website and individual newsletter. - my watch list - my saved searches - my saved topics - my newsletter syenites are usually peralkaline and peraluminous, with high proportions of alakali elements and aluminium. syenites are formed from alkaline igneous activity, generally formed in thick continental crustal areas, or in cordilleran subduction zones. to produce a syenite, it is necessary to melt a granitic or igneous protolith to a fairly low degree of partial melting. this is required because potassium is an incompatible element and tends to enter a melt first, whereas higher degrees of partial melting will liberate more calcium and sodium, which produce plagioclase, and hence a granite, adamellite or tonalite. syenite is not a common rock, some of the more important occurrences being in new england, arkansas, montana, new york ( syenite gneisses ), switzerland, germany, and norway. the term syenite was originally applied to hornblende granite like that of syene in egypt, from which the name is derived. episyenite ( or epi - syenite ) is a term used in petrology to describe to the result of alteration of a sio2 rich rock to a more sio2 depleted rock. the term stems from \" epi \" and syenite. the process which results in sio2 depletion can be termed episyenitization. this process is only referring to the macroscopic result of relative sio2 depletion in a rock. the actual physical process leading to this sio2 depletion may vary in a given metamorphic environment. diffusion of chemical components in a stagnant fluid, related to differences in chemical potential or pressure as well as advection of a sio2 - undersaturated fluid may lead to the dissolution of quartz from the un - altered rock, thus depleting it of this component. | this article is licensed under the gnu free documentation license. it uses material from the wikipedia article \" syenite \". a list of authors is available in wikipedia. |", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6017682771084738, "token_count": 489, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:d1363d58-3b64-4f0d-ac92-ec5bdb0cc7d9>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:24.681098"}
{"text": "activity 19. 1. 3 \u2013 discovering family similarities dimitri mendeleev, a russian chemist, created the first version of the periodic table of the elements ( figure 19. 3 ) in 1869. when he ordered the elements according to increasing atomic weight in columns so that rows contained analogous elements, he saw patterns that allowed him to predict the properties of elements yet to be discovered. mendeleev \u2019 s task was formidable because there was relatively little data to work with, and no electronic tools to organize it. today, however, we have an abundance of information as well as database tools that allow us to instantly group data by common characteristics. database technology has fueled the information revolution by allowing us to store and examine large amounts of data. in this activity you will use a database program to separate data by groups and summarize your findings. table 19. 2 ( see book ) arranges the elements in terms of increasing atomic number. no patterns or trends are seen when the elements are displayed in this fashion. if, however, elements are arranged as seen in the periodic table, those with similar properties are grouped together. each column represents a family of elements that have similar electron configuration and similar chemical properties. although the periodic table makes it easy to see which elements have similar properties ( those in the same family or column ), it does not allow for an easy comparison of these properties. by contrast, table 19. 2 lists much specific information about the properties of the elements, but does not allow for comparison of family ( group ) data, unless first arranged by group. sort the elements by group, then calculate average group values for heat of fusion, specific heat, thermal conductivity, and other properties of your choice using the subtotal command and average option. list your results. database. ( 1 ) which families are most similar to each other? ( 2 ) which families are most dissimilar to each other?", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6041768399856469, "token_count": 387, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:1c5019d0-c9cf-43f5-8442-58695c0b40a5>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:24.799642"}
{"text": "and so controllable, safe, clean, and irresistible is hydrostatic pressure, either of air or water, that, now our mechanical skill in construction is sufficiently advanced, it must come more and more into use. we might almost anticipate from its wide adoption a perfect utopian system of machine labour, in which human labour would be restricted to the simple direction of the hydraulic pressure. but before indulging in imaginary approximations to perfection, it is well to inquire into the several conditions of possibility. to the capabilities of hydrostatic pressure there is perhaps physically speaking scarcely a limit, but commercially speaking our command of water power, or hydrostatic power, in whatever form, is nearly limited to our command of steam. it is steam that presents us with hydrostatic power in its most abundant and available form. water power in uniform abundance is to be had, in this country at least, only through steam ; and all experience points to the fact that, instead of water being a possible commercial substitute for steam, it is steam that from its first use has been a substitute for water power. a brief consideration of the history of the steam - engine will put this fact in the clearest light. though water power had been in use since the time of the romans, a great want was clearly felt in the seventeenth century of some new power, antithetical to water power, so to speak, and capable of overcoming it, so that drowned mines might be pumped dry, and water might be raised to furnish artificial water power, where a natural supply was not to be had. the earliest explicit patent for a new engine was directed to the raising of water, * 25 and the \" exact and true definition \" of the marquis of worcester ' s engine clearly expressed a similar purpose. \" there being indeed no place but either wanteth water, or is overburdened therewith... by this engine either defect is remediable. \" hence the marquis calls his invention a \" stupendous water commanding engine, \" and truly regarded it as a new primum mobile which was to overcome the force of falling water. his appreciation of the value of water power is shown by his remarkable motto : * 26 \u2014 \" whosoever is master of weight is master of force, \" and consequently, \" said he, \" to him all forcible actions and achievements are easy, which are in any wise beneficial to, or for, mankind. \" savery had no less correct and exalted notions of what his engine", "subdomain_id": "subdomain_quantum_thermodynamics", "similarity_score": 0.6021380491572997, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:41f1cda9-93f9-4ebf-9fea-4816e78066dc>", "chunk_index": 8, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:25.041293"}
{"text": "become a fan of h2g2 the word ' phlogiston ' 1 is derived from the greek language. it is the neuter form of the word phlogistos, meaning ' inflammable '. this word is in turn derived from phlogizein meaning ' to set on fire ', derived from phlox, or phlog -, meaning flame. burning, as can be seen, is at the root of this area of scientific thought. the theory of phlogiston arose in the late 17th century when it was proposed by johann becher ( who referred to it as ' inflammable earth ' ). it was continued in the work of georg stahl. the theory postulates that in all flammable materials the elusive substance phlogiston is present, a substance without colour, odour, taste or weight, which is given off when materials are burnt. all materials could have three basic parts : phlogiston, impurities and the purest form of the material. anything that could be burned to nothing would be considered to have been completely composed of phlogiston - such as charcoal or sulphur. so, for example, wood when burnt leaves ash. it was, therefore, deemed that wood was composed of pure wood ( ash ) and phlogiston. iron on the other hand consisted of rust, the pure form of the metal and phlogiston. the impurities arose where the remains could not be defined as either the pure material or phlogistonated air. gases that dissolved in water were a prime example of this kind of impurity, materials that did not meet the criteria of either pure base or phlogiston. the theory maintained its position in scientific thought for 100 years, though throughout that period loopholes were identified and then carefully patched up with new variations and terms, like the impurities of fixed and foul air. objections were consistently countered with new information from phlogistonists who were not keen to see their theories blown apart. ultimately it was the work of french scientist antoine laurent lavoiser, in the late 18th century, which led to the systematic tearing apart of the phlogiston theory. his astute and systematic experimentation gave weight to gathering force of the antiphlogistonist movement. what replaced it were theories around oxygen and the reactions experienced by materials in the presence of this life - giving gas. experiments switched from purely observational efforts to quantitative analysis that tried to qualify changes and reactions without giving in to notions of fancy expanded from what the eyes", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6550313060215972, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:fc986c49-6faf-4aca-b1c9-e3476e23ef91>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:25.280417"}
{"text": "in this module we need to be a little bit more precise about temperature and heat energy than we have been so far. heat energy is usually measured in terms of calories. the calorie was originally defined as the amount of energy required to raise one gram of water one degree celsius at a pressure of one atmosphere. this definition is not complete because the amount of energy required to raise one gram of water one degree celsius varies with the original temperature of the water by as much as one percent. since 1925 the calorie has been defined as 4. 184 joules, the amount of energy required to raise the temperature of one gram of water from 14. 5 degrees celsius to 15. 5 degrees celsius. for our purposes here we can ignore the fact that the effect of one calorie of energy varies depending on the temperature of the water. newton ' s model of cooling can be thought of, more precisely, as involving two steps. the picture above shows a brick whose length is four centimeters. we mentally divide the brick into two unequal pieces. the lefthand piece has a length of one centimeter and the righthand piece has a length of three centimeters. heat is flowing across the mental boundary between the two pieces from left to right at the rate of a calories per hour. as a result the average temperature of the lefthand piece is changing at the rate of - ka degrees celsius per hour. the constant k depends on the composition of the brick and its cross - sectional area. the average temperature of the righthand piece is changing at the rate of ka / 3 degrees celsius per hour. the three in the denominator comes from the fact that since the righthand piece is three times the length of the lefthand piece, its mass is three times as big.", "subdomain_id": "subdomain_quantum_thermodynamics", "similarity_score": 0.6509850149051808, "token_count": 371, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:a815ae2f-316e-4506-a921-7c7a166c371c>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T01:35:26.142461"}