data/train/batch_000027.jsonl

{"text": "##man and university physics : extended version with modern physics by hugh d. young. links to information about these books and others can be found at physicsbooks. org. successful physics study requires a great deal of research, which means knowledge of the properties of matter and energy. many of these properties have been already recorded for you to use in your research and calculations. a good source for physics data is the nist scientific and technical physics databases ( nist. gov. srd. physics. htm ), which contains data on atomic and molecular physics, fluids, crystal structure, thermophysical and thermochemical properties and more. online physics journals much of physics research information will come from the articles found inside physics journals. these journals present both established and cutting edge research in the various disciplines of physics. a convenient source of physics journals can be found online at the american institute of physics website at journals. alp. org. some of the journals they offer include applied physics letter, the journal of applied physics, the journal of mathematical physics, physics of fluids and applied physics reviews. other physics research tools the american institute of physics ( aip. org ) has more than just journal information. this comprehensive website features physics news, a physics career center, information about physics awards and prizes, statistical research information and more.", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6262342695777612, "token_count": 271, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:5d7ad155-790d-4f5a-a056-83b7dad39d50>", "chunk_index": 3, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:44.911061"}
{"text": "this monograph was reprinted by the american crystallographic association, successor to the american society for x - ray and electron diffraction, may, 1966. this monograph has two aspects. on the one hand, it is presented as a contribution to the study of structure factors \u2014 or fourier transforms \u2014 of atomic groupings which occur frequently in a wide variety of crystals, both organic and inorganic. thus special attention is given to such cases as tetrahedral, octahedral and hexagonal arrays of like atoms. a section on the structure factors of small crystals is also included. on the other hand, it is presented as a contribution to the x - ray analysis of megamolecular crystals as yet studied by few but destined, it would seem, to play an important role in the crystallography of the future. megamolecular crystals confront crystallography with a new problem, since the structure of the molecules and indeed, to some extent, even the composition of the molecules is unknown. it is the belief of the author that a systematic study of what may be called the language of structure factors is a necessary preliminary to the interpretation of the intensity maps of crystals made up of megamolecules of unknown structure. in the sequel the structure factors of distributions of different structural types are recorded. such mathematical facts provide material for the study of the relationship between distributions and their structure factors \u2014 the fundamental theme throughout this monograph. the marine biological laboratory woods hole, mass., august 1, 1945 appendix. fourier series and fourier ' s integral theorem", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6459231473706333, "token_count": 312, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:5435ddbe-02e0-4168-9373-7130d1226fe9>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:44.932622"}
{"text": "resurrection, ritual, sacrifice, salvation, sin, soul, spirituality, worship although many species are social, forming groups based on genetic ties, affection, self - defense, or shared food gathering and distribution, humans are distinguished by the variety and complexity of the institutions that they form, both for individual and group survival and for the preservation and development of technology and knowledge. group identity and acceptance can exert a powerful influence on individual behaviour, yet humans are also able to form and adapt to new groups. an individual may develop strong feelings of loyalty towards such groups. the human individual often develops a particularly strong attachment to a small group, typically including his closest biological relatives : his mother, father, and siblings. a similarly strong attachment may be forged with a small group of equals, resulting in peer groups of individuals of similar age, typically of the size of ten to twenty individuals, possibly related to the optimal size of a hunting party. group dynamics and peer pressure may substantially influence the behaviour of group members. ( see also asch conformity experiments. ) larger groups of humans can be unified by notions of common ancestry ( tribes, ethnicities, nations ) or common geographical location and material interests ( states ), which are often further divided into social classes and hierarchical structures. a tribe may consist of a few hundred individuals, while the largest modern state, china, contains over a billion. violent conflicts between states are called wars. loyalty to a larger group of this type is called nationalism or patriotism. in extreme cases, feelings of loyalty towards an institution or authority can become pathological, leading to mass hysteria or fascism. ( see also milgram experiment, stanford prison experiment. ) main articles : consciousness, human self - reflection, mind, mind - body problem, dualism, artificial intelligence, rationalism, empiricism, immanuel kant, david hume, philosophy of mind, epistemology, materialism, physicalism, reductionism, idealism. the way the world is experienced by an individual is the subject of much debate and research in philosophy, psychology, biology, neurology, and cognitive science. human and non - human animals are said to possess consciousness, self - awareness, or a mind, which gives rise to an individual ' s perception of his own existence, the passage of time, and his free will, though some philosophers argue that free will is an illusion. ( see also predestination, fatalism, determinism, social determinism and biological determinism ). there is debate about the", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6104503568767913, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:2396534e-9f1f-417a-bf63-e9df0b10d725>", "chunk_index": 12, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:45.003576"}
{"text": ". about. com / od / molecules... wflake. htm so one \u201c version of a designer \u201d is natural laws and as the site above shows this design can be explained scientifically. there is another type of design, for example the cell. the design clearly seen in it \u2019 s operation cannot be explained by natural laws alone. natural laws are in operation but are controlled by what are referred to as biological algorithms. algorithms by their very nature are the product of an outside agency. so the question is, what is that outside agency? this is a question that science is simply unable to answer because analytical science can only describe natural phenomena. so i have two \u201c versions of a designer \u201d. one science can describe and the other science cannot describe. now regarding the latter a description of this outside agency must naturally be a matter of belief and not science. that belief can be regarded as a religion or philosophy and therefore cannot be analysed by the scientific method. let me remind you that this discussion is about a scientific theory ( s ). now i can understand why you appear to want to move this debate on to belief systems because on a scientific basis the argument for species change ( origin ) by natural phenomena is being lost. all the arguments you are putting forward are based on a philosophical approach and not as i am arguing, a scientific one. some would regard that as a religious approach. the reality is, you don \u2019 t need to know what i believe, to show that what i state is scientifically incorrect. all you have to do is produce the evidence that rebuts my statements. so please tell, what are you doing making statements you claim are based on science and in a scientific forum if you are not prepared to support them with any recognised scientific evidence. ( although once again you contradict yourself because you refer to the grant studies of finches ) btw the standard theory i. e. \" decent from a common ancestor by random mutation and natural selection \" is quite a simple theory and one that my grandson understands. not sure about my grandmother! if something is factual you will be able to show it with evidence, if you cannot then it is a belief. why not just admit that what you have been arguing is based on a belief system. that would be a consistent way of presenting your point. new species created in lab. may 3 issue proceedings of national acadamy of sciences. i do not agree that religeous / phylosophical beliefs are beyond the reach of science.", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6140909906426425, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:82b91dab-83b8-41d6-a087-bc411c444c7a>", "chunk_index": 9, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:45.488150"}
{"text": "or cool, and the transformation of materials ( turning ore into metal, for example ). these things then deliver what human beings want \u2013 personal transport, a comfortable home, the ability to communicate, clothes and food. the paper sets up a four - stage chain. fuels are extracted or, in the case of renewables, collected and then converted in a machine that turns them into heat or other useful energy source. the process occurs in what the authors call a \u2018 passive system \u2019 such as a vehicle or a hot water system. the final service is something directly desired by the individual consumer or business, such as transport or comfort. there are efficiency losses in this stage in the chain. the paper estimates the volumes of energy being used by the world \u2019 s major energy conversion devices. the top six machines are as follows : | machine | | exajoules per year | these machines are directed towards producing about 233 exajoules of heat a year and about 175 exajoules of motion. the energy for motion will be accompanied by heat. for example, a car \u2019 s petrol engine produces far more heat than energy for motion. so, in the case of a diesel engine, the world \u2019 s most important energy conversion device, only about 25 % of the chemical energy in the fuel gets turned into energy to move the car. the service provided by the energy can then be described. table 2 shows the useful things we get from the 475 exajoules each year. | useful output from our energy use | | exajoules per year | | percentage of total | | thermal comfort ( heating and cooling ) | | 90 | | 19 % | | sustenance ( growing, preparation, storage, cooking of food ) | | 84 | | 18 % | | structure ( materials to provide structural support \u2013 a wall or a can for a drink or even a piece of paper to print on ) | | 68 | | 14 % | | hygiene ( hot water, clothes washing, appliances ) | | 56 | | 12 % | | communication ( digital and written communications \u2013 e. g. computers, phones, etc. ) | | 29 | | 6 % | let \u2019 s look each output in turn. how much can we expect to be able to save through well - understood energy efficiency options? ( almost all of the figures in the following section are my estimates and are not from the cullen / allwood paper. ) few buildings anywhere in the world are particularly well insulated. the typical british home loses around 250 watts per", "subdomain_id": "subdomain_quantum_thermodynamics", "similarity_score": 0.6093964590079937, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:2e431a8b-642e-4a95-b611-6732e0b57fd8>", "chunk_index": 1, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:45.688013"}
{"text": "disc 1 : classical genetics concept 1children resemble their parents. ( gregor mendel : introduction ) concept 2genes come in pairs. ( gregor mendel : genetic alleles ) concept 3genes don ' t blend. ( gregor mendel : inheritance ) concept 4some genes are dominant. ( gregor mendel : dominance ) concept 5genetic inheritance follows rules. concept 6genes are real things. ( rediscovery of mendel ' s laws ) concept 7all cells arise from preexisting cells. concept 8sex cells have one set of chromosomes ; body cells have two. concept 9specialized chromosomes determine gender. concept 10chromosomes carry genes. ( fruit fly genetics ) concept 11genes get shuffled when chromosomes exchange pieces. concept 12evolution begins with the inheritance of gene variations. ( early plant genetics, evolution ) concept 13mendelian laws apply to human beings. ( sexlinked genes, early human genetics ) concept 14mendelian genetics cannot fully explain human health and behavior. disc 2 : molecules of genetics concept 15dna and proteins are key molecules of the cell nucleus. ( dna and amino acid discovery and structure ) concept 16one gene makes one protein. ( relating genes and protein function ) concept 17a gene is made of dna. ( oswald avery : dna as the transforming principle ) concept 18bacteria and viruses have dna too. ( conjugation, hershey and chase experiment ) concept 19the dna molecule is shaped like a twisted ladder. ( watson and crick : 3d structure of dna ) concept 20a half dna ladder is a template for copying the whole. concept 21rna is an intermediary between dna and proteins. ( rna transcription, translation ) concept 22dna words are three letters long. ( genetic code, translation ) concept 23a gene is a discrete sequence of dna nucleotides. concept 24the rna message is sometimes edited. ( rna splicing, exons, introns ) concept 25some viruses store genetic information in rna. ( retroviruses, reverse transcriptase ) concept 26rna was the first genetic molecule. concept 27mutations are changes in genetic information. concept 28some types of mutations are automatically repaired. disc 3 : genetic organization and control concept 29dna is packaged in a chromosome. ( dna packaging, chromatin ) concept 30higher cells incorporate an ancient chromosome. concept 31some dna does not encode protein. ( noncoding, \" junk \" dna ) concept 32some dna can", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.64534043495111, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:8059df8a-8f3d-42c5-8a91-049dedad7cf4>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:45.821440"}
{"text": "looking at failures in a new two department of energy researchers at sandia national labs are taking a new approach to the study of how and why engineered systems fail. chris forsythe and caren wenner say that, instead of looking at all the things a person might possibly do wrong, they study identifying conditions and environmental factors that make the potential for human failure probable. \" mitigating these factors enhances the surety of engineered systems, such as nuclear weapons, \" says forsythe, a member of the lab ' s statistics and human factors department. \" the standard technique for preventing error is an analysis that attempts to establish an exhaustive list of everything that is likely to go wrong, \" says forsythe. \" after you ' ve done that a long time, you get good at it, but it can be labor intensive and you always miss some things. the problem that humans bring to systems is an infinite number of ways to fail. you can never anticipate all that can go wrong. \" the alternative method forsythe and wenner use is called an \" organic \" model. they believe that the introduction of humans into an engineered system causes the entire system to take on organic properties and that, to fully evaluate safety and security of a system, these properties must be considered. contact : ( 505 ) 844 - 5720. the big chill for computer chips michigan state university researchers believe their new material, a combination of cesium, bismuth, and tellurium, will someday double the speed at which computers operate. \" we ' ve demonstrated that the new material outperforms the current material in a given temperature range, \" says mercouri kanatzidis, a michigan state university professor of chemistry in whose laboratory the discovery was made. current thermoelectric materials drop their temperatures when jolted with electricity. the new material could drop the temperature even more. eventually, its applications could include cooling computer chips. currently, most computers use fans for cooling chips. according to the professor, fans will be insufficient. \" as chips become smaller and more powerful, they generate more heat. we ' ll need a more active way of removing the heat, \" says kanatzidis. the discovery stems from several years of research funded by a grant from the office of naval research. contact kanatzidis at ( 517 ) 355 - 4512, ext 174. bright idea for researchers stephen forrest and marc baldo from princeton university with colleague mark thomson of the university of southern california created a light - emitting", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6307380307756046, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:9356f59a-1f04-4753-b7b1-439b0dd65249>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:45.863691"}
{"text": "research. contact kanatzidis at ( 517 ) 355 - 4512, ext 174. bright idea for researchers stephen forrest and marc baldo from princeton university with colleague mark thomson of the university of southern california created a light - emitting material that they say improves the efficiency with which light is produced for flat panel displays found in laptop computer screens, car stereo displays, hand - held devices, cellular telephones, and elsewhere. the team combined the phenomena of fluorescence and phosphorescence in a way that allows the production of light that is four times more efficient than fluorescent materials. the result is an organic light - emitting diode ( oled ) made of thin films that emit light. the efficiency of light - emitting devices depends on how well molecules react in \" excited \" states called \" singlets \" and \" triplets. \" the material emits light when either singlets or triplets release their energy and return to a ground state. the researchers use phosphors to \" collect \" all the triplet states, convert them to usable singlets, and transfer them into fluorescent material. princeton applied for a patent on the work. fax : ( 609 ) 258 - 0119. switching faster than electronic optical transistors may soon offer designers greater bandwidth and speed than electronic transistors, according to panos datskos of oak ridge national laboratory ( ornl ). \" we are talking about using photons instead of electronics and creating transistors that are 100 times faster than any of today ' s transistors, \" says datskos. electronic transistors are used today as amplifiers, detectors, and switches in computers, telephones, and many other electronics components. optical switching by photon activation is analogous to a transistor with input photons controlling the signal photons. datskos and colleague slo rajic use a highly sensitive miniature light detection device called a micromechanical quantum detector. the optical switching technology uses a diode laser and optical absorption of its wavelength. if enough stress is created by the absorption of the light, it puts a strain on the material. by shifting the wavelength, it turns the switch on an off. \" it is similar to the electronic transistor, but incorporates the benefits of photonics, \" say rajic. call datskos at ( 865 ) 574 - 6205. optical power meter users, such as designers of optical fiber telecommunications equipment, and compact disc player manufacturers may now obtain several papers from the", "subdomain_id": "subdomain_quantum_optics", "similarity_score": 0.6431318392241772, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:9356f59a-1f04-4753-b7b1-439b0dd65249>", "chunk_index": 1, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:45.864605"}
{"text": "of photonics, \" say rajic. call datskos at ( 865 ) 574 - 6205. optical power meter users, such as designers of optical fiber telecommunications equipment, and compact disc player manufacturers may now obtain several papers from the national institute of standards and technology ( nist ) that pertain to measurement and calibration standards. the nist standards, known as standard reference materials ( srm ) fall into two categories for optical fibers : geometric properties and propagation characteristics. the standards allow description of a fiber based on either its physical dimensions or the way in which light propagates within it. for physical dimensions, nist offers srms for fiber cladding diameter, fiber coating diameter, connector ferrule ( for both inner and outer diameters ), and mode - field diameter. in the field of propagation characteristics, available srms include chromatic dispersion, polarization - mode dispersion, and polarization - dependent loss. copies of the paper \" nist artifact standards for fiber optic metrology \" ( no. 03 - 00 ) are available from sarabeth harris at firstname. lastname @ example. org or call ( 303 ) 497 - 3237. for more information on optical fiber artifacts and srms, contact lee best at email @ example. com. a research team at the university of north carolina at chapel hill and north carolina state university developed a new x - ray imaging method called diffraction enhanced imaging ( dei ) that produces better pictures of breast tissue than conventional x - rays. \" dei conceivably could be used not only in breast imaging, but in any medical and non - medical applications involving x - rays, \" says dale sayers, professor of physics at nc state. researchers there compared images and found tumor visibility was superior with dei in six of the seven specimens. with dei, an \" analyzing \" crystal is placed in the x - ray beam between the object being studied and an image - creating medium such as film, x - ray plate, or digital detector. the silicon crystal diffracts a particular wavelength of x - ray through the physics principle known as bragg ' s law. when the crystal is adjusted and two images taken and processed, a new image based on refraction is produced. refraction ( where light, including x - rays, deviates in angles ) happens because of differences in the atomic density of the materials through which it passes. \" in a tissue sample, if a tumor is embedded in normal tissue there is usually a density", "subdomain_id": "subdomain_quantum_metrology", "similarity_score": 0.63380696770348, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:9356f59a-1f04-4753-b7b1-439b0dd65249>", "chunk_index": 2, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:45.865487"}
{"text": "given figure a and figure b such that ar ( a ) = 20sq. units and ar ( b ) = 20 sq. a. figure a and b are congruent b. figure a and b are not congruent c. figure a and b are similar d. figure a and b may or may not be congruent write a factual description of the scene at the park in your locality in the morning hours i am given the following reaction : 2nh3 ( g ) - - - - - - - > n2 ( g ) + 3h2 ( g ) my question is : 6. 4 mols of ammonia gas has been put into a 1. 7 l flask and has been permitted to reach equilibrium in accordance to the reaction listed above. if the equilibrium mixture has 4. 2 mols of nitr... i want to apoligize. the equilibrium is 4hcl ( g ) + o2 ( g ) - - - > 2h2o ( g ) + 2cl2 ( g ) not 4hcl ( g ) + o2 ( g ) - - - > 2h2 ( g ) + 2cl2 ( g ). which quantum number, or quantum numbers, can be connected with the direction a particular orbital position points in space, regarding wave mechanics? what is the legend of kailashnath templee.. in kanchipuram.?? plzz reply.. need it urgently.. i checked dozens of web sites about the kailashnath temple and none mentions any legends. this is the most complete article i found about the temple. http : / / www. 4to40. com / discoverin... newspaper article review i was very impressed for further reading", "subdomain_id": "subdomain_quantum_simulation", "similarity_score": 0.6214965078806892, "token_count": 357, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:9dd35b05-0af2-44de-b89d-d2abb253e023>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:47.607329"}
{"text": "class 6, division 6. 1 \u2014 definitions. for the purpose of this subchapter, poisonous material ( division 6. 1 ) means a material, other than a gas, which is known to be so toxic to humans as to afford a hazard to health during transportation, or which, in the absence of adequate data on human toxicity : is presumed to be toxic to humans because it falls within any one of the following categories when tested on laboratory animals ( whenever possible, animal test data that has been reported in the chemical literature should be used ) : a liquid or solid with an ld50 for acute oral toxicity of not more than 300 mg / kg. a material with an ld50 for acute dermal toxicity of not more than 1000 mg / kg. a dust or mist with an lc50 for acute toxicity on inhalation of not more than 4 mg / l ; or a material with a saturated vapor concentration in air at 20 \u00b0c ( 68 \u00b0f ) greater than or equal to one - fifth of the lc50 for acute toxicity on inhalation of vapors and with an lc50 for acute toxicity on inhalation of vapors of not more than 5000 ml / m3 ; or is an irritating material, with properties similar to tear gas, which causes extreme irritation, especially in confined spaces. for the purposes of this subchapter \u2014 ld50 ( median lethal dose ) for acute oral toxicity is the statistically derived single dose of a substance that can be expected to cause death within 14 days in 50 % of young adult albino rats when administered by the oral route. the ld50 value is expressed in terms of mass of test substance per mass of test animal ( mg / kg ). ld50 for acute dermal toxicity means that dose of the material which, administered by continuous contact for 24 hours with the shaved intact skin ( avoiding abrading ) of an albino rabbit, causes death within 14 days in half of the animals tested. the number of animals tested must be sufficient to give statistically valid results and be in conformity with good pharmacological practices. the result is expressed in mg / kg body mass. lc50 for acute toxicity on inhalation means that concentration of vapor, mist, or dust which, administered by continuous inhalation for one hour to both male and female young adult albino rats, causes death within 14 days in half of the animals tested. if the material is administered to the animals as a dust or mist, more than 90 percent of the particles available for inhalation in", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6128367126908667, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:ccc80cb3-6e22-4ce2-a095-b6f5c8d19544>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:47.664587"}
{"text": "anand jagota ' s group web site deposition of cnts on surfaces we are developing techniques for controlled deposition of carbon nanotubes from an aqueous suspension onto a substrate. we typically work with dna - cnt dispersions and deposit onto silicon wafers coated with an organic self - assembled monolayer. we find that there are two possible phenomena that occur. nanotubes appear to deposit by hopping over an electrostatic potential barrier. under some conditions, it appears that nanotubes deposit randomly and are aligned by a passing meniscus. under other conditions, they appear to deposit aligned, and we have hypothesized that this is due to the formation of a liquid crystal sheet. drop of dna - cnt dispersion on a hydrophobic silicon substrate. deposition of dna - cnt onto a hydrophobic surface followed by re - alignment by a meniscus. interaction potential between dna - cnt and a surface : deposition is modeled as activated hopping over the electrostatic potential barrier. ( constantine khripin and ming zheng ) the figure below shows how we view the other possibility, that dna - cnt rods form an elastic liquid crystal sheet. what ' s this? \u2026.. it ' s the phase plane plot of a differential equation that describes the behavior of a sheet when matter can flow in and out of it to minimize free energy. it arises out of our work to understand how sheets of carbon nanotubes in solution might behave if subjected to external constraints and moments. ( constantine khripin & tian tang ) \u201c deformation of a liquid crystal with coupling between elasticity and concentration \u201d, constantine khripin, anand jagota tian tang, journal of physical chemistry c, accepted ( 2007 ). 610 758 4396", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6058435804774531, "token_count": 358, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:2560344d-fe5d-4f3a-8258-07f2c02e0e6e>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:47.711443"}
{"text": "interspecies feshbach resonances feshbach resonances are an extremely valuable tool for ultracold atom experiments. they occur, when the colliding atoms can couple to a bound molecular state belonging to a different atomic asymptote. this situation can be artificially brought about by applying a homogeneous magnetic field that introduces a zeeman energy due to the magnetic moment of the atoms. when the magnetic moment of a bound molecular state and the combined magnetic moment of the colliding atoms is different, the zeeman energy is different for the two states and they can be shifted relative to each other ( left image ). at the magnetic field that corresponds to energetic degeneracy, the scattering length of the system changes dramatically an can be tuned to any value between plus and minus infinity ( right image ). optical dipole trap in order to apply a homogeneous magnetic field, the atoms need to be loaded into a trap that does not use the magnetic field coils. we therefore use an optical dipole trap based on a 10w yb : yag fiber laser running at 1064 nm that is focussed onto the atomic clouds. since the light is far red - detuned from the atomic transitions, they only experience a potential energy proportional to the light intensity without scattering of photons. the magnetic field coils can then be used to apply the magnetic field. we use a horizontally crossed beam geometry in order to localize the atoms in the center of the magnetic field coils. since they are so small, field gradients across the cloud, reducing the magnetic field resolution, need to be considered. the image shows fermionic li atoms inside a single beam dipole trap with a long aspect ratio ( top ) and the crossed geometry where most atoms are in the crossing volume ( bottom ). feshbach resonances do not necessarily appear in all spin combinations. we therefore need to prepare the atoms in specific states, usually the absolute ground state, e. g. | 1, + 1 > for bosonic rubidium and lithium and | 1 / 2, + 1 / 2 > for fermionic lithium. this can be done with very efficiently by coupling e. g. the initial state | 2, + 2 > with radio frequency or microwave field to the desired lower state | 1, + 1 >. in case of 7li the frequency is about 803 mhz. by ramping this frequency across the resonance, nearly all atoms can be transferred into the absolute ground state. the transfer efficiency can be analyzed by", "subdomain_id": "subdomain_quantum_metrology", "similarity_score": 0.6690385768446458, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:b19b9582-1f3a-4486-af4b-0a5edcd9be59>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:48.504241"}
{"text": "lower state | 1, + 1 >. in case of 7li the frequency is about 803 mhz. by ramping this frequency across the resonance, nearly all atoms can be transferred into the absolute ground state. the transfer efficiency can be analyzed by a stern - gerlach experiment in which an magnetic field gradient is applied during free fall. the different magnetic momenta then cause a splitting of the cloud of atoms into the different magnetic substates. ( a ) a cloud of pure | 2, + 2 > li without any sweep. ( b ) after a sweep nearly 100 % of the atoms are in the | 1, + 1 > state. ( c ) applying the same sweep again restores the initial population distribution. 6li - 87rb feshbach resonances on july 5th 2007, we observed for the first time in the fermi - bose system feshbach resonances. this was achieved by monitoring the atom numbers after a fixed storage time at different magnetic fields. in the vicinity of a feshbach resonance, the collision rate increases thereby also increasing inelastic three - body recombination. for our conditions, li - rb - rb three - body collisions are the dominant loss channel. we found a narrow ( a ) and a broad ( b ) feshbach resonance in the magnetic field range from 0.. 1200g for 6li and 87rb atoms in their respective hyperfine ground states | f, mf = 1 / 2, + 1 / 2 > and | 1, + 1 >. the magnetic field values where they occur represent important benchmarks for an accurate determination of the interspecies interaction potentials. the broad resonance at 1067g can be used to accurately control the interspecies scattering length. 7li - 87rb feshbach resonances the first feshbach resonances in the bose - bose system were observed on march 23th 2008. five loss features were observed in total, four of which could be unambiguously assigned to heteronuclear interspecies feshbach resonances of the 7li - 87rb system. both atoms are in their absolute groundstate | f, mf = 1, + 1 >. of particular interest is the extremely broad s - wave feshbach resonance located at 649g with a tuning width of almost 200g making very precise control of the scattering parameters possible. catalytic enhancement of 6li p - wave feshbach resonances in the fermi - bose mixture, the fermions", "subdomain_id": "subdomain_quantum_metrology", "similarity_score": 0.6548183225448215, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:b19b9582-1f3a-4486-af4b-0a5edcd9be59>", "chunk_index": 1, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:48.505090"}
{"text": "##bach resonance located at 649g with a tuning width of almost 200g making very precise control of the scattering parameters possible. catalytic enhancement of 6li p - wave feshbach resonances in the fermi - bose mixture, the fermions are spin - polarized and do not interact through s - wave collisions due to the pauli exclusion principle. the next higher partial wave, the p - wave, is allowed, but due to its centrifugal barrier, these collisions are highly suppressed at ultracold temperatures. nonetheless, at 158g there occurs a p - wave resonance in the li subsystem that makes is possible to introduce strong li - li collisions through the p - wave channel. the presence of rb inside the trap introduces another loss mechanism through inelastic li - li - rb collisions ( right ), thereby enhancing the visibility of the p - wave resonance compared to a pure li cloud where only li - li - li collisions can occur ( left ). based in our measurements of the background scattering lengths as well as the positions of feshbach resonances, the interaction potentials were reconstructed to a high degree of precision. these calculations were performed both in the groups of eberhard tiemann ( u hannover ) and alejandro saenz ( hu berlin ). these potentials form the basis for scattering length tuning curves as well as for photoassociation schemes to produce deeply bound polar molecules.", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6475077707228754, "token_count": 290, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:b19b9582-1f3a-4486-af4b-0a5edcd9be59>", "chunk_index": 2, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:48.505706"}
{"text": "what are quantum computers good for? forget cracking crypto, think modelling reality itself to help build a better one the problem with trying to explain quantum computing to the public is that you end up either simplifying the story so far as to make it wrong, or running down so many metaphorical rabbit - burrows that you end up wrong. so the register is going to try and invert the usual approach, and try to describe quantum computing at a more materialistic level : how do you build one, and when it \u2019 s built, how do you use it? hopefully, a concrete framework will make it easier to understand quantum computing along the way. and we promise not to reiterate the story of schroedinger \u2018 s cat. not even once. the basic design actually, a quantum computer is very easy to design. its main systems are below. how to build a quantum computer. image, andy davies, the register the classical computer is something we ' re all familiar with. the main point of having it there is because you \u2013 as the human trying to use the quantum computer \u2013 need something to interact with. we haven \u2019 t quite got so far as a nice gui interface for what \u2019 s inside schroedinger \u2019 s box. the quantum computer is where the qubits live \u2013 those difficult creatures that, if we can control them properly, actually perform the quantum computation. that leaves us the bit in the middle \u2013 the quantum - classical interface. it \u2019 s the cutoff between the quantum world and the classical world, which is why researchers call it the \u201c heisenberg cut \u201d. it \u2019 s the place where classical information emerges out of quantum mechanics. when it comes to describing quantum computing, that interface can be both easy and difficult to explain. the mechanism for manipulating a qubit can be difficult to do ( that \u2019 s what this year \u2019 s nobel prize in physics was all about! ) but it isn \u2019 t that hard to understand : it may be as \u201c simple \u201d as manipulating a mirror or a polarising filter. but just how \u201c classicality \u201d emerges from the quantum world occupies a lot of theoretical attention \u2013 the kind that needs long and deep study, and \u2026 to be honest, it doesn \u2019 t matter all that much for this discussion. we know that classical emerges out of the quantum, because we \u2019 re here to argue about it. we can see that qubits behave like quantum phenomena : they exhibit entanglement and superposition, and those are the kinds of properties that give", "subdomain_id": "subdomain_quantum_computing", "similarity_score": 0.6922781749565597, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:de649ddf-57cb-4797-a2eb-ead8b68ec149>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:49.550367"}
{"text": "we know that classical emerges out of the quantum, because we \u2019 re here to argue about it. we can see that qubits behave like quantum phenomena : they exhibit entanglement and superposition, and those are the kinds of properties that give us quantum computers. next : the compiler there \u2019 s another reason to have a classical computer act as the intermediary between the user and the quantum computer : it makes the quantum computer more flexible, because it will carry out a step analogous to a compiler in conventional computing. the compiler \u2019 s job is to take the user \u2019 s program instructions, and determine things like the algorithm the program will use, and which quantum operators \u2013 qubit gates \u2013 are needed to execute the algorithm. constant vs balanced? to make quantum computers useful, we need to understand when they will clearly outperform classical algorithms \u2013 which is hard to explain convincingly, but lets try a simple example. let \u2019 s imagine a ( rather pointless ) guessing game : alice has two machines in front of her, comprising a keypad and a display that can show 0 or 1, and it \u2019 s her job to figure out which one is working correctly. the machines will accept any input between 1 and 1000 ( decimal, not binary ), and should display a 0 for 500 of the possible inputs, and a 1 for the other 500 \u2013 except that alice doesn \u2019 t know which inputs produce which results. all she is told is this : \u201c the faulty machine only displays 1, never 0 \u201d. the question is : is there an efficient way to test the machines? alice could simply grab one of the machines, and start punching in numbers. if alice chose the working machine, and if the association between numbers and 0 or 1 outputs is randomly distributed, she could find an answer fairly quickly that way. if she \u2019 s lucky. if she \u2019 s unlucky, alice might have to test 500 numbers on one machine before she sees the output change from 0 to 1 ( or vice versa ). similarly, if she \u2019 s unlucky, she chose the broken machine, and she will have to test 500 inputs to be certain. mathematically, what alice is trying to do is work out whether the unknown function \u2013 the one inside the working machine \u2013 is constant or balanced. computers can work this out \u2013 but the best known classical algorithm still gives us a worst - case complexity in which the required tests are always half the possible number of inputs. if the machines accepted numbers between 1 and 2000, then 1000 tests are needed", "subdomain_id": "subdomain_quantum_computing", "similarity_score": 0.6808500036887786, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:de649ddf-57cb-4797-a2eb-ead8b68ec149>", "chunk_index": 1, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:49.552016"}
{"text": ". computers can work this out \u2013 but the best known classical algorithm still gives us a worst - case complexity in which the required tests are always half the possible number of inputs. if the machines accepted numbers between 1 and 2000, then 1000 tests are needed in the worst case. in one of the earliest breakthroughs in quantum computing, deutsch and jozsa devised a simple quantum algorithm for solving this problem. they discovered that if you had a quantum version these gadgets, one which could have quantum bits as inputs and outputs, then this problem could be solved by a single query. the key to this quantum advantage is that much of the work that alice would have performed can be taken care of by quantum superpositions and interference. this algorithm is initialized by setting the input qubits and output qubit to 000 \u2026 0. then we apply some quantum gates that create a superposition over all possible inputs to the gadget. there is then a circuit element that feeds these inputs into the unknown gadget. finally, the same operation that created the superposition over all inputs is performed once again and all the qubits are measured. before we perform this measurement, the computation is in schroedinger \u2019 s box ( to borrow a metaphor ) and qubits exist in a superposition of 0 \u2019 s and 1 \u2019 s. when we \u201c open the box \u201d and destroy the superposition we will simply read out a string of 1 \u2019 s and 0 \u2019 s. now, because of the way in which this circuit is implemented, if the gadget was defective, that is, constant, then it will always give the answer 000 \u2026 0 with 100 percent. if the gadget was balanced \u2013 that is, not defective \u2013 then some of those output bits will definitely give the answer 1. for the working machine, there is 0 percent chance that we will read out a string of 0 \u2019 s. next : getting more complex it \u2019 s more complex than that, surely? of course \u2013 but this is, at least, an accurate enough framework to act as a starting point. for instance, more complex quantum algorithms are robust to noise. in the case of the deutsch - jozsa algorithm, if a small chance of failure exists then there is a classical algorithm that performs just as well as deutsch - jozsa. quantum circuits create finely tuned probability distributions. any noise makes our measurement that little bit uncertain : did we measure qubits superposed with the desired state, or did we merely observe", "subdomain_id": "subdomain_quantum_computing", "similarity_score": 0.7041238032426619, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:de649ddf-57cb-4797-a2eb-ead8b68ec149>", "chunk_index": 2, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:49.553404"}
{"text": "that performs just as well as deutsch - jozsa. quantum circuits create finely tuned probability distributions. any noise makes our measurement that little bit uncertain : did we measure qubits superposed with the desired state, or did we merely observe noise? the solution to this in more sophisticated algorithms, like shor \u2019 s famous factoring algorithm, is to repeat the process, and build up a distribution of the results, increasing the probability that we are observing an answer that is correct. in other words, the output register ( where we read the qubits ) becomes a probabilistic summary of all the possible output states permitted by the algorithm you \u2019 re using. of course, it \u2019 s quite possible to generate probability distributions with a classical computer \u2013 but as your number of possible outcomes increases, so does the length of time needed to generate the distributions. but at some point, as it seems for many problems in the famous complexity class np and for many of the problems that quantum computers are good for, a classical turing machine can \u2019 t get there in polynomial time. one of the reasons so much research is directed to how we handle and measure qubits is to give us more confidence in fewer measurements \u2013 without destroying the quantum states that we need for the quantum computer to work. that is, of course, if we \u2019 re positive that quantum mechanics is indeed complete. that \u2019 s the deepest theoretical question of quantum mechanics, a question that \u2019 s almost metaphysical. rather than seeking an ultimate, final, indisputable proof that quantum mechanics is right, it \u2019 s probably easier to do what we \u2019 re doing : continue the research to reach a point at which we can test a quantum computer of reasonable scale, and let the proof come along later. after all, we happily use quantum mechanics to build lasers! next : applications of quantum computing applications of quantum computing why bother? worldwide, a lot of research dollars are being poured into quantum computing, in spite of a widespread belief that it \u2019 s only application is to render today \u2019 s encryption algorithms useless. what \u2019 s the point of spending research dollars on a theoretical construct of such limited application? the idea that quantum computing is only good for large - number factoring is still widespread. but some of the standard tools of quantum computing are starting to chip away at this perception. let \u2019 s look at two. the fourier transform is one of the oldest : while the mathematics for representing a time - domain event in the frequency domain is well - understood, the more complex the wave", "subdomain_id": "subdomain_quantum_simulation", "similarity_score": 0.720265472180017, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:de649ddf-57cb-4797-a2eb-ead8b68ec149>", "chunk_index": 3, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:49.554675"}
{"text": "computing are starting to chip away at this perception. let \u2019 s look at two. the fourier transform is one of the oldest : while the mathematics for representing a time - domain event in the frequency domain is well - understood, the more complex the wave you \u2019 re trying to analyse, the bigger the calculation. in certain settings a quantum computer is exponentially more efficient at performing fourier transforms than a classical computer. this is very much a creature of the real world, spanning materials sciences, structural engineering, our understanding of waves, photonics, consumer electronics \u2026 the list goes on. another example is here : a quantum algorithm for solving linear equations ( where you have a matrix and a known vector, and wish to compute an unknown vector ). for some classes of linear equations, harrow, hassidim and lloyd have demonstrated that a classical computer \u2019 s runtime will be exponentially greater than that of a quantum computer. as we understand more about quantum algorithms, we \u2019 re learning more about the types of problems that quantum computers could be applied to. and as researcher scott aaronson describes in this blog post, it \u2019 s also becoming clear that one of the best applications for quantum computers is to help us simulate the quantum world. this post describes the limits of classical simulation, with the conjecture that even quantum computers based on linear optics are too complex to be simulated in a classical computer. simulating quantum systems is an application that today consumes a huge amount of the world \u2019 s supercomputer processor cycles \u2013 along with other big - science headliners like astrophysics, genetics, geoscience, materials science, meteorology, climate modelling and high - energy physics. why is so much effort expended on quantum simulation? because that \u2019 s where the world begins. quantum simulation helps us, for example, better understand what \u2019 s going on in the world of chemistry. that, in turn, leads to potential applications in materials science, genetics, and other disciplines. in this nature paper published last year, for example, european and canadian researchers propose using quantum computers to ( it sounds recursive ) simulate the states available to \u2026 a quantum computer. it \u2019 s neither silly nor trivial. as they explain in the abstract, the simulation is necessary so as to understand the equilibrium and static properties of the quantum system. but how many samples are needed for a researcher to be certain that they \u2019 ve fully characterized the quantum system \u2013 without making a \u201c list of everything \u201d? today, the problem is approached by sampling, using the metropolis algorithm on", "subdomain_id": "subdomain_quantum_simulation", "similarity_score": 0.6806506892911717, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:de649ddf-57cb-4797-a2eb-ead8b68ec149>", "chunk_index": 4, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:49.555688"}
{"text": "an event which occurs between the large quantities of oppositely - charged particles which were already present in matter. contact electrification is more like \" stretched atoms \" than anything else. if we could take some atoms and pull their electrons far away from their protons, we would have created an imbalance of charge or \" static it ' s true that during \" frictional electricity \" or contact electrification, it ' s * usually * only the negative electrons which are moved from one surface to the other. but this transferring of electrons then results in two areas of imbalanced charge, not one. as negative particles are pulled away from the positive particles, the positives and negatives are no longer near each other and are no longer are able to cancel each other. because of this, equal and opposite areas of imbalanced charge are always created during the un - cancelling. if you take away a neutral object ' s electrons, you leave its protons exposed. for a visual demonstration of this, see my red / green electricity article and although the negative charges did the moving, this doesn ' t mean the positive charges are unimportant! before the charges were separated, there were equal quantities of positive and negative charges present together within the materials. the positives null out the negatives, and the negatives null out the positives. after the separation of the charges complete, the positive charges are just as important as the negative. in one place you ' ll have more protons than electrons, and this place will have an overall positive charge. in the other spot you ' ll have more electrons than protons, for an overall negative charge in that region. you ' ve not caused a \" buildup of electrons \", you ' ve caused an imbalance, an un - cancelling, a stretching - apart, a separation of opposites which otherwise would cancel each other. in fact, one appropriate term for static electrification is charge separation. think for a moment : if you put the positive and negative imbalances back together, where does the \" buildup of electrons \" go? nowhere, there was no buildup there in the first place. putting the two polarities of charge back together eliminates the imbalance and forms normal uncharged matter again. on the contrary, everyday ' static electricity ' involves immense voltages. when two insulating surfaces are adhered ( or rubbed ) together, two opposite regions of imbalanced charge appear. when these surfaces are later pulled away from each other, a very strong \" electric field \" appears", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6294662576787946, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:bc368e7f-964c-4b40-89cd-5d4c85b191f3>", "chunk_index": 1, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:50.459357"}
{"text": "electricity ' involves immense voltages. when two insulating surfaces are adhered ( or rubbed ) together, two opposite regions of imbalanced charge appear. when these surfaces are later pulled away from each other, a very strong \" electric field \" appears between them, and this e - field can raise hair, attract lint, etc. in addition, this e - field is an example of pure voltage, or voltage without current. the strength of this e - field is incredibly large when compared to the voltage of batteries and of common electronic circuitry. it is thousands of times stronger, sometimes hundreds of thousands of times stronger. everyday \" static electricity \" involves immense voltages. the tiniest \" static spark \" is caused by about 1000 volts. longer \" car door sparks \" and \" doorknob sparks \" can involve as much as 10, 000 volts. for more info, see : actually, all neutral objects are made out of charge we always talk of matter as if it only had passing relation to electrical effects. yet if we look in detail into the nature of matter, we find physical substances, made of molecules, made of atoms, made of positive and negative electric charge. matter is not electrical? no, quite the opposite : electric charge is the major component of all atoms. therefor matter is * made out of cancelled electric charge. * if we cancel out some opposite charge by placing positive charge together with negative charge, do we get nothing? no, instead we get material substance. positive protons plus negative electrons equals neutral atoms. physical objects normally have no charge? wrong. the physical objects * are * the electricity is energy? wrong. \" electricity \" is a catch - all word with many meanings. unfortunately these meanings are contradictory, and this leads to the unsettling fact that there is no single substance or energy called \" electricity. \" and the problem is not as simple as having different kinds of electricity. instead, we wrongly use the word \" electricity \" to name completely different things. when we say \" quantity of electricity, \" we could be talking about quantities of electrons or quantities of electrical energy.... or quantity of potential, or forces, fields, net charge, current, power, or even talking about classes of electrical phenomena or fields of science. all of these are found under the definition of the word \" electricity. \" this is a major mistake, it ' s like saying that miles, pounds, and degrees are measures of the same single \" stuff. \" and can you have a cup full", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6341757840664113, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:bc368e7f-964c-4b40-89cd-5d4c85b191f3>", "chunk_index": 2, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:50.461462"}
{"text": "all of these are found under the definition of the word \" electricity. \" this is a major mistake, it ' s like saying that miles, pounds, and degrees are measures of the same single \" stuff. \" and can you have a cup full of \" weather \" or a bucket of \" geology? \" part of this problem would if we used the word \" electricity \" only to designate a field of science or class of phenomena ; in the same way we use the words \" physics \" or \" optics. \" we do use it this way occasionally. but then we immediately turn around and do the equivalent of teaching our kids that \" optics \" is a substance which comes out of light bulbs, or that cars can move because they are filled with \" physics \"! that ' s how we misuse the actually electricity does not exist! see : what is here are a few examples of errors caused by the contradictory meanings. - well, jus exzactaly which one of them is the \" electricity? \" : electric circuits the * charges * sit in one place and wiggle back and forth, but the * energy * moves continuously forward. this is analogous to the way that sound in air moves continuously forward, while the air itself just wiggles back and forth. by applying contradictory definitions to the the term \" electricity, \" we teach that electricity ( charge ) sits in one spot in the wires and wiggles, but at the same time electricity ( energy ) moves forward rapidly. garbage! how can anyone possibly understand this?! it ' s like saying that sound and wind are the same thing! and the error is directly traceable to the bogus, contradictory \" electricity \" - another : there are two forms of electricity, positive electricity and negative electricity. no, the two forms of electricity are static and no, there are many forms of electricity : triboelectricity, bioelectricity, myoelectricity, piezoelectricity. no, there is only one electricity, the form of energy called electromagnetism. no, electricity is energy flow, haven ' t you ever heard of \" watts of electricity? \"... which one of the above is right? all of them. and none, because the word \" electricity \" has more than one contradictory definition, and the experts cannot agree. none are since there is no \" electricity \" which can be the charge, energy, and phenomena all at once. and all these statements are correct, because the word \" electricity \" is commonly used to name", "subdomain_id": "subdomain_quantum_optics", "similarity_score": 0.6237316840540729, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:bc368e7f-964c-4b40-89cd-5d4c85b191f3>", "chunk_index": 3, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:50.462898"}
{"text": "contradictory definition, and the experts cannot agree. none are since there is no \" electricity \" which can be the charge, energy, and phenomena all at once. and all these statements are correct, because the word \" electricity \" is commonly used to name all these different things, and dictionaries support this. volts of electricity. amperes of electricity. kilowatt - hours of electricity. watts of electricity. coulombs of electricity. it ' s all totally meaningless and confusing when yet it ' s inextrictably entwined in hundreds of textbooks, dictionaries, and encyclopedias. the solution? say \" amperes of electric current \", not amperes of electricity. say \" kilowatt - hours of energy \", and \" coulombs of charge \", and \" watts of power. \" to greatly imporve the clarity of your explanations, simply don ' t mention ' electricity ' at all. ' charging ' a capacitor fills it with charge? capacitors store electric charge? no! the word \" charge \" has more than one contradictory meaning, so if you ' re using it, you ' re probably creating misconceptions. \" charge \" refers to several things : to net - charge, to quantities of charged particles, and to \" charges \" of energy. no, because ' charged ' and ' uncharged ' capacitors actually contain the exact same amount of charge. - for example, even when a metal object is totally neutral, it contains vast quantities of movable electrons. you can imagine that all metals are soaked with a sort of \" electric fluid \" made of negative particles which are wandering among the \" solid \" positive copper ions. if copper is like a wet sponge, then the sponge is the protons in the atom nuclei, and the water is the movable electrons. on the other hand, since the positives and negatives cancel, could we say that wires contain no charge at all? or should we say the opposite : that they contain immense quantities of charge because they are constructed from electrons and protons? are they \" charged \" because they ' re partly composed of \" liquid \" electric charges, or are they \" uncharged \" because they contain exactly equal quantities of opposite charges... which all which is ' right? ' i don ' t know the answer. maybe it ' s better to abandon the word \" charged \", and use other, less misleading terms. don ' t say \" charged \", say \" electrified. \" speak of", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.640574542294235, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:bc368e7f-964c-4b40-89cd-5d4c85b191f3>", "chunk_index": 4, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:50.464125"}
{"text": "by the misleading term \" charge. \" those rare people who figure it out become experts. but it ' s not hard to be an expert when nearly universal confusion rules a field of study. ' static ' is rare? no. if you believe typical explanations of \" static electricity \", you will come to see \" static \" as a fairly rare phenomena that has little connection with the rest of the world. yes, yes, lightning is impressive, and copiers and laser printers are convenient, but if \" static \" didn ' t exist, the world wouldn ' t be much different, would it? in fact, ' static electricity ' is actually as common as matter in fact, electrostatics is a bit more important than we commonly assume. contrary to popular belief, standard \" electric current \" circuits are deeply connected with electrostatics. for one thing, it is the electrostatic force that drives electric current! \" voltage \" is an electrostatic phenomena, voltage is electrostatic fields. without electrostatics, there could be no voltage, hence no current and no electrical devices. it is totally wrong to build a false wall between \" static \" and \" current \", it ' s as silly as teaching that \" pressure \" and \" movement \" are two separate types of water. \" static \" and \" current \" are two fields of study, not two substances or energies. they are subject areas which were created entirely by humans, they don ' t * really * exist separately in the real \" static electricity \" is important in many other places besides lightning, photocopiers, and doorknob sparks. for example, your muscles are driven by long - chain molecules which are forced to slide across each other. this sliding is performed by electrostatic attraction and repulsion between parts of the molecule, and so your muscles are electrostatic motors! they are \" linear motors \", as opposed to the rotary electrostatic \" pop bottle \" motor found elsewhere on my website. another example : nerves function as tiny capacitors, with charge pumps to electrify them, and ion gates to discharge them. imagine a nerve as being a long tubular \" leyden jar \" having billions of tiny \" vandegraaff generators \" scattered across its surface, and with billions of \" spark gaps \" which always close in sequence as the nerve impulse another one : when uranium atoms are hit by neutrons and their nuclei split, the main source of released energy is the repulsion between alike - charged positive protons in the fragments of the nucleus. therefor,", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6071030096342864, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:bc368e7f-964c-4b40-89cd-5d4c85b191f3>", "chunk_index": 6, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:50.467105"}
{"text": "close in sequence as the nerve impulse another one : when uranium atoms are hit by neutrons and their nuclei split, the main source of released energy is the repulsion between alike - charged positive protons in the fragments of the nucleus. therefor, nuclear reactors release the electrostatic energy of uranium nuclei. a plutonium bomb is actually a \" static electric \" repulsion another : when dissimilar materials touch, charge is separated. when dissimilar semiconductors touch, we get \" contact potential \", a microscopic electrostatic phenomenon which makes numerous devices possible : leds, solar cells, thermocouples,... and diodes, transistors, computers, radios, television, internet, etc. semiconductor electrostatics is essential to another : one type of transistor in particular, the fet or \" field effect transistor \", is purely an electrostatic device. electrostatic fields within it are used to open and close the conductive channel which regulates current. see \" charge detector \" for some suggested experiments. are these sorts of transistors rare? no. every single transistor in the memory, cpu, and io chips of modern pcs are fet transistors. most of the transistors in modern tvs and stereos are fets. few people realize that \" static electric \" devices have taken over the electronics industry, or that pcs are made from microscopic electrostatic components, or that all the data in all the computers all over the world is stored as tiny patterns of electrostatic charges. \" atp \" is the fuel which drives living things, from bacteria to humans. one part of the 1997 nobel prize in chemistry was awarded to the researchers boyer and walker who discovered how energy is placed into atp. it turns out that atp is assembled by an enzyme which is run by a tiny rotating electrostatic motor! the \" spring \" in each atp is \" cocked \" by a little rotating molecular machine run by electrostatics. the reaction is reversible, and atp can drive the motor, changing it into an electrostatic typical human body contains around 10 ^ 16 of these rotary electrostatic a big one next. the world is molecules. and molecules are atoms, and atoms are themselves composed of positive and negative charged particles. atoms are held together by electrostatic attraction. if matter is made of little dots, then the \" bars \" that connect all the dots together are made electrostatic fields. also, atoms are connected to each other through chemical bonding, and chemical bonding is", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6329180803047447, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:bc368e7f-964c-4b40-89cd-5d4c85b191f3>", "chunk_index": 7, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:50.468111"}
{"text": "atoms are held together by electrostatic attraction. if matter is made of little dots, then the \" bars \" that connect all the dots together are made electrostatic fields. also, atoms are connected to each other through chemical bonding, and chemical bonding is based upon electrostatic attraction / repulsion forces. without \" static electricity \" there would be no chemistry, no living things. without \" static electricity \", solids and liquids would be gas, the molecules of the gas would fall apart into atoms, and the atoms would turn separate electrons and nuclei. without electrostatics, the entire universe would be a boring, featureless cloud of neutral - particle gas. some people consider electrostatics to be boring. on the contrary, electrostatics is the very thing that lets this universe be an interesting no, electrostatics does not involve \" electricity at rest. \" first let ' s look at an analogy which might help clear up our thinking. within the science of hydraulics there are sections called hydrodynamics and hydrostatics. hydrostatics is the study of fluid pressure and forces. it ' s not the study of static water, it ' s the study of water pressure. when pressurized pipes are swelling, or when a piston is driving water ahead of it, those are situations involving hydrostatics. if you draw maps of the distribution of pressure upon a surface, that ' s does hydrostatics involve water at rest? no, because fluid forces still exist even when water is moving. just because water starts flowing, that doesn ' t mean that hydrostatic pressure must vanish. does hydrostatics involve a special kind of water called \" static water? \" no, that ' s just silly. \" static water \" is a field of science otherwise known as hydrostatics. hydrostatics is not a stuff! ok, now look at the science called \" electricity. \" it has sections called \" electrodynamics \" and \" electrostatics. \" is electrostatics the study of non - moving electricity? first think about hydrostatics before you try to answer this question. as you suspect, electrostatics is similar to hydrostatics : it is the study of electric forces and the electric charge which creates those forces. it is the study of imbalanced charges in matter, and of voltage and electric fields. notice that i didn ' t say anything about \" charges at rest. \" this is intentional, since electrostatic forces don ' t go away when the charges start flowing in a current. and while", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6036112305775044, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:bc368e7f-964c-4b40-89cd-5d4c85b191f3>", "chunk_index": 8, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:50.471528"}
{"text": "charges in matter, and of voltage and electric fields. notice that i didn ' t say anything about \" charges at rest. \" this is intentional, since electrostatic forces don ' t go away when the charges start flowing in a current. and while electric voltage falls under the heading \" electrostatics, \" electric voltage is intimately involved with flowing charges. ( analogy : water pressure is intimately involved with water flow. ) is there a kind of electricity called \" static electricity? \" no. that ' s just silly. it ' s just as silly as believing in a special kind of water called static water. there ' s a field of science called electrostatics or \" static electricity, \" but there ' s no such stuff as \" static. \" where did this crazy misconception about \" motionless charges \" come from? there are hundreds, perhaps thousands of books which blatantly state \" electrostatics is the study of charges at rest. \" how can they say such things? i have a good idea. look at the difference between hydrodynamics and hydrostatics. hydrostatics ignores the changing parts and concentrates only on and the distribution of forces. on the other hand hydrodynamics ignores the unchanging parts ; it studies changing or \" dynamic \" events like fluid flow patterns, turbulence, etc. if we became slightly confused, we might decide that hydrodynamics was all about moving water while hydrostatics was only about motionless water. easy mistake. yet it ' s a serious one, since the actual difference between \" statics \" and \" dynamics \" is something made up by human minds, not something that really exists out in the real world. it has almost nothing to do with water ' s movement. for example, if i look at a river and i ignore the flowing water while only observing the fluid forces, then i ' ve made that moving river become a \" hydrostatic \" system. if hydrostatics was motionless water alone, then i couldn ' t think about common hydrostatic topics such as the pressure in a moving river or the forces applied by curving flows. back to electricity again : \" statics \" and \" dynamics \" are viewpoints, and they have almost nothing to do with motionless or flowing charges. i can look at a flashlight and, if i concentrate on voltage and electrical forces while ignoring electric current, i can transform it into an \" electrostatic \" device with my mind. \" electrostatics \" is a way of thinking ; a kind of viewpoint. it ' s", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6008089450080202, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:bc368e7f-964c-4b40-89cd-5d4c85b191f3>", "chunk_index": 9, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:50.472870"}
{"text": "have been killed at any moment, and if lightning had actually hit his kite, today he would be regarded as a colonial politician who was killed by stupidity, not as a famous scientist who founded a major new research area. ok, so what is static electricity?!!! 1. static electricity is a field of science. some people call it \" electrostatics. \" same thing. so, if static electricity is a kind of science, then it can ' t be made by generators. in a similar way, you can dissect a dead frog, but you ' ll never find any biology. and rocks don ' t contain any tiny pieces of \" geology. \" remember : hydrostatics is the study of fluid pressure, newtonian statics is the study of physical forces, and static electricity is the study of charge, voltage, and electrical forces. where can we find static electricity? in physics books... and in buildings at the 2. static electricity is a set of events which humans have grouped sparks and lightning are \" static electricity, \" even though sparks and lightning are about the most dynamic things imaginable. also, \" dryer cling \" is static electricity. the cling effect, that is the electricity. after all, \" electricity \" can mean \" a class of phenomenon, \" and having your socks stick to the back of your sweater is certainly a phenomenon. where does static electricity come from? from human minds : same as with \" weather \" and \" bureaucracy \" and other classes of phenomenon. 3. static electricity is another word for high voltage. whenever we have high voltage, then we also have electrostatic attraction and repulsion. high voltage can attract lint or tiny bits of paper, and it can make hair stand up. with high voltage we also get long sparks, crackling noises, and blue glows and flashes. high voltage makes ozone ; the stuff that gives that funny chlorine smell. these things are the hallmarks of static electricity, but they are never caused by the \" static - ness \" of electric charges. instead they are caused by intense e - fields. intense e - fields are another way of saying \" high votlage. \" if you can scuff your shoes on the carpet and then zap people with your finger, then you ' ve been charging your body to several thousand volts. 4. static electricity means an imbalance of electric charge electrically neutral matter contains closely - spaced electrons and protons. the \" positives \" and the \" negatives", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6007858680477074, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:bc368e7f-964c-4b40-89cd-5d4c85b191f3>", "chunk_index": 13, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:50.480880"}
{"text": "correlations out of masses of data. i can ' t possibly imagine how he comes to that conclusion. correlations are a way of catching a scientist ' s attention, but the models and mechanisms that explain them are how we make the predictions that not only advance science, but generate practical applications. one only needs to look at a promising field that lacks a strong theoretical foundation \u2014 high - temperature superconductivity springs to mind \u2014 to see how badly the lack of a theory can impact progress. put in more practical terms, would anderson be willing to help test a drug that was based on a poorly understood correlation pulled out of a datamine? these days, we like our drugs to have known targets and mechanisms of action and, to get there, we need standard science. anderson does provide two examples that he feels support his position, but they actually appear to undercut it. he notes that we know quantum mechanics is wrong on some level, but have been unable to craft a replacement theory after decades of work. but he neglects to mention two key things : without the testable predictions made by the theory, we ' ll never be able to tell how precisely it is wrong and, in those decades where we ' ve failed to find a replacement, the predictions of quantum mechanics have been used to create the modern electronics industry, with the data cloud being a consequence of that. if anything, his second example is worse. we can now perform large - scale genetic surveys of the life present in remote environments, such as the far reaches of the pacific. doing so has informed us that there ' s a lot of unexplored biodiversity on the bacterial level ; fragments of sequence hint at organisms we ' ve never encountered under a microscope. but as anderson himself notes, the only thing we can do is make a few guesses as to the properties of the organisms based on who their relatives are, an activity that actually requires a working scientific theory, namely evolution. to do more than that, we need to deploy models of metabolism and ecology against the bacteria themselves. overall, the foundation of the argument for a replacement for science is correct : the data cloud is changing science, and leaving us in many cases with a google - level understanding of the connections between things. where anderson stumbles is in his conclusions about what this means for science. the fact is that we couldn ' t have even reached this google - level understanding without the models and mechanisms that he suggests are doomed to irrelevance. but, more importantly, nobody, including anderson himself if", "subdomain_id": "subdomain_quantum_thermodynamics", "similarity_score": 0.6628698442627141, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:ce63cc82-d538-4652-80e1-60e4e5426cd0>", "chunk_index": 1, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:50.520132"}
{"text": "click one of the letters above to advance the page to terms beginning with that letter. - an organicrefers to the branch of chemistry that studies compounds containing carbon, usually in combination with hydrogen and other elements such as o, n, s, and p. certain small ions and compounds containing carbon ( such as carbonate ions and carbon dioxide ) are not considered to be organic, but rather are classed as inorganic. compounda substance made up of two or more elements and having those elements present in definite proportions ; a compound can be decomposed into two or more different substances. consisting of a purine or pyrimidine basein arrhenius theory, a substance that increases the concentration of hydroxide ions in an aqueous solution. in bronsted - lowry theory, a hydrogen - ion ( proton ) acceptor. in lewis theory, a species that donates a pair of electrons to form a covalent bond. bonded to a sugara small carbohydrate that either contains five or six carbon atoms or is a dimer of two units, each containing five or six carbon atoms. that is bonded to a phosphate groupthose elements that comprise a single column of the periodic table. also called family. ; a monomerone of the units that joins with other units to form a polymer. for dnaabbreviation for deoxyribonucleic acid ; the polymer of nucleotides that constitutes the genetic material of chromosomes. or rnaabbreviation for ribonucleic acid ; a biological polymer of nucleotides that is involved in protein synthesis..", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6631583787166282, "token_count": 328, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:69705712-7756-4e2d-a7df-ec4081faf306>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:50.893498"}
{"text": "elements, including : aluminium ; barium ; chromium ; copper ; iron ; magnesium ; manganese ; strontium ; titanium ; and vanadium. its crystallography is orthorhombic. its hardness is 4. 5 \u2013 5. 5, quite soft for a gemstone, and its specific gravity is 2. 60 \u2013 2. 85. the refractive index of canadian material ( as measured via sodium light, 589. 3 nm ) is as follows : \u03b1 1. 522 ; \u03b2 1. 672 \u2013 1. 673 ; \u03b3 1. 676 \u2013 1. 679 ; biaxial negative. under ultraviolet light, ammolite may fluoresce a mustard yellow. an iridescent opal - like play of color is shown in fine specimens, mostly in shades of green and red ; all the spectral colors are possible, however. the iridescence is due to the microstructure of the aragonite : unlike most other gems, whose colors come from light absorption, the iridescent color of ammolite comes from interference with the light that rebounds from stacked layers of thin platelets that make up the aragonite. the thicker the layers, the more reds and greens are produced ; the thinner the layers, the more blues and violets predominate. reds and greens are the most commonly seen colors, owing to the greater fragility of the finer layers responsible for the blues. when freshly quarried, these colors are not especially dramatic ; the material requires polishing and possibly other treatments in order to reveal the colors ' full potential. the ammolite itself is actually a very thin sheet, ca. 0. 5 \u2013 0. 8 millimeters ( 0. 02 \u2013 0. 03 inches ) in thickness. rarely is ammolite without its matrix, which is typically a grey to brown shale, chalky clay, or limestone. so - called \" frost shattering \" is common ; exposed to the elements and compressed by sediments, the thin ammolite tends to crack and flake ; prolonged exposure to sunlight can also lead to bleaching. the cracking results in a tessellated appearance, sometimes described as a \" dragon skin \" or \" stained glass window \" pattern. ammolite mined from deeper deposits may be entirely smooth or with a rippled surface. occasionally a complete ammonite shell is recovered with its structure well - preserved : fine, convoluted lines delineate the shell chambers, and the overall shape is suggestive of a", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6174954781801559, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:2683a553-b9d8-4e06-b4da-6a928019f233>", "chunk_index": 1, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:51.169460"}
{"text": "power electronics ( pe ) play a critical role in transforming the current electric grid into the next - generation grid. pe enable utilities to deliver power to their customers effectively while providing increased reliability, security, and flexibility to the electric power system. while approximately 30 % of all power generation utilize pe somewhere between the point of generation and its end use today, by 2030 it is expected that up to 80 % of generated electricity will utilize pe [ power electronics for distributed energy systems and transmission and distribution applications, ornl, 2005 ]. increased pe integration into the electric grid provides : ( 1 ) increased grid reliability ; ( 2 ) compelling cost savings ; and ( 3 ) large environmental benefits and energy savings. furthermore, power electronics will enable increased productivity, complement increased renewables - to - grid integration, and empower consumers in the residential, industrial and commercial sectors. existing silicon - based power electronics enable conversion from dc to ac and the movement of electricity from higher voltage transmission to lower voltage distribution. however, silicon ( si ) - based semiconductor technology cannot handle the power levels and switching frequencies anticipated by next generation utility applications. pe based on wide bandgap ( wbg ) semiconductor materials, such as silicon carbide ( sic ), gallium nitride ( gan ), and diamond, could increase the reliability and efficiency of the next generation electric grid. these materials are capable of routing power more quickly and handling higher voltages. a number of barriers and challenges exist in utilizing wbg semiconductor based pe to their full potential, including identifying and designing new types of devices that best exploit wbg semiconductor properties and creating cost - effective high - volume manufacturing processes for those devices. the power electronics multi - year plan ( april 2011 ) describes office of electricity delivery and energy reliability \u2019 s ( oe ) strategy for the development of power electronics that will be able to handle the high power levels envisioned for the next generation electric grid. the doe oe de - foa - 0000461 ( march 2011 ) was a national call seeking applications focused on developing power electronic devices with the power levels and switching frequencies required for future high - power, next generation utility applications. technical papers published from oe \u2019 s gan initiative for grid application ( giga ) seedling project can be found at : lu, b. ; saadat o. i. ; palacios, t. \u201c high - performance integrated dual - gate algan / gan enhancement - mode transistor \u201d electron device letters, ieee. sept 2010 lu, b. ; palacios,", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6168879328938144, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:d847d1d8-c939-4fd3-bf21-08fd1fa81040>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:51.575702"}
{"text": "shadow technique improves measurement of micro holes june 2, 2005 contact : gail porter sometimes seeing a shadow can be as good or better than seeing the real thing. a new measurement method * developed by researchers working at the national institute of standards and technology ( nist ) is a case in point. the method uses the shadow cast by a small glass probe to infer the dimensions of tiny, microscale holes or other micrometer - sized components. the technique may provide an improved quality control method for measuring the interior dimensions of fuel nozzles, fiber optic connectors, biomedical stents, ink jet cartridges and other precision - engineered products. designed to be implemented with the type of coordinate measuring machine ( cmm ) routinely used in precision manufacturing settings, the method uses a flexible glass fiber with a microsphere attached on one end. the glass probe is attached to the cmm ' s positioning system, inserted into the part to be measured, and systematically touched to the part ' s interior walls in multiple locations. a light - emitting diode is used to illuminate the glass fiber. while the microsphere inside the part is not visible, the shadow of the attached fiber \u2014 with a bright band of light at its center \u2014 shows the amount of deflection in the probe each time the part ' s interior is touched. a camera records the shadow positions. based on prior calibration of the force required to bend the probe a specific distance, the part ' s dimensions can be determined with an uncertainty of about 35 nanometers ( nm ). the method can be used for holes as small as 100 micrometers in diameter. \" our probe has a much smaller measurement uncertainty than other available methods and it is very cost effective to make, \" says bala muralikrishnan, a nist guest researcher from the university of north carolina at charlotte. the thin, glass fiber is about 20 millimeters long and 50 micrometers in diameter, making it especially useful for measuring relatively deep holes not easily measured with other methods. replacement probes cost about $ 100 compared to about $ 1, 000 for those manufactured using silicon micromachining techniques. * b. muralikrishnan, j. a. stone and j. r. stoup. measuring internal geometry of fiber ferrules. presented at the sme micromanufacturing conference, minneapolis, minn., may 4 - 5, 2005.", "subdomain_id": "subdomain_quantum_metrology", "similarity_score": 0.6207547015822051, "token_count": 490, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:cb1401ad-38ed-4bc6-993f-03cf0a470f48>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:52.193319"}
{"text": "company goals. ( shrink ) emphasis in business ethics texts and courses has generally focused on corporate and other relatively high - level ethical issues. however, business school graduates in early career stages report ethical dilemmas involving individual - level decisions, often including influence attempts from one or more members of their work role sets. this paper proposes the use of role set analysis as a pedagogical technique for helping individuals to anticipate and deal with early - career ethical issues. locke consistently argues for the importance of cosmopolitan identity, i. e., cultural - citizenship. paradoxically, he also argues for the importance of particular, local, and racial / ethnic identities. people have a natural instinct that locke terms a consciousness of kind, to bond with persons in relatively closed communities. communities are not natural social groups for locke, but historical social constructions. i argue that locke ' ' s ethical and conceptual paradox is revolved by considering the relationship between instincts and particular social groups as asymmetrical ; that groups are (... ) inherently constructed, and thus require continual revaluation. particular communities are, at best, gemeinschaft. ( shrink ) the conventional wisdom among many sociologists is ( 1 ) that it is their prerogative to define, document, and explain the inequalities that exist in society and ( 2 ) that there are two general theoretical perspectives useful for studying inequality : functionalism and conflict theory. some scholars have recently challenged the latter portion of this view by advocating the development of more interpretive, interactionist approaches. however, these scholars ' ' agendas often tend to perpetuate the first half of the conventional wisdom. while interactionists ( and other constructionist (... ) scholars ) can choose to study inequality in any number of ways, i argue that the most distinctive contribution they can make is to focus on the meanings that inequalities have for people in everyday life, as well as how those meanings are achieved. ( shrink ) urquhart and mendez and salto claim to establish completeness theorems for the system c and two of its negation extensions. in this note, we do the following three things : ( 1 ) provide a counterexample to all of these alleged completeness theorems, ( 2 ) attempt to diagnose the mistakes in the reported completeness proofs, and ( 3 ) provide complete axiomatizations of the desired systems. intuitionists and classical logicians use in common a large number of the logical axioms, even though they supposedly", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6106481579945868, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:d1e25020-c22c-486c-9f63-9c29e87ed515>", "chunk_index": 7, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:52.426665"}
{"text": "another. for example, if someone injures a finger or pricks one part of the body with a pin, the whole body is immediately disturbed everywhere and not just in that part where the injury and so, since every soul is in contact with the universal soul, it is not possible to find in this case the same effects which occur in bodies which do not mutually penetrate into each other. rather, for spiritual substances, a different comparison is needed. for instance, if innumerable lamps are lit, they all act together as though they were one light, and no one light impedes or reflects or excludes another. the same thing happens when many voices are diffused through the same air, or if many visible rays, to use the common saying, spread out to reveal the same visible whole. all these rays pass through the same medium, and while some move in straight lines and others obliquely, they do not interfere with each other. in the same way, innumerable spirits and souls, when spread out through the same space, do not interfere with each other such that the diffusion of one would affect the diffusion of an infinity of others. this power belongs not only to the soul but also to certain accidents, like sound, light and vision. the reason is that the whole soul is located in the whole body and in every part of the body, and that the whole soul apprehends all things, however diverse and distant, which are around it outside of its body. this is a sign that the soul is not included in the body as its first act and substance, and that it is not circumscribed by the body. rather, in itself and by itself, it should be understood only as a second act. this principle is the cause of innumerable marvellous effects, although its nature and power need to be investigated. this soul and divine substance cannot be inferior to the accidents which issue from it as its effects, traces and shadows. i declare that if the voice operates outside the body which produces it, and enters as a whole into innumerable ears on all sides, then why cannot the whole substance, which produces the voice which is tied to certain organs of the body, be located in different places and parts? furthermore, it must be noted that occult intelligence is not heard or understood in all languages. for the voices spoken by humans are not heard in the same way as the voices of nature. as a result, poetry, especially of the tragic type ( as plotinus says ),", "subdomain_id": "subdomain_quantum_optics", "similarity_score": 0.6035953390644996, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:545bc4f6-d4d7-44d0-b97f-3e0808ef4e2d>", "chunk_index": 7, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:52.709534"}
{"text": "as is found in the four elements. a sign of this is that when a piece of iron touches a magnet, it acquires the same power of attracting other pieces of iron. this could not happen if this were due to an elementary quality. for when heat and coldness are accidentally present in a subject, they quickly disappear when the source of heat is removed. therefore, one must explain this in terms of the emission of parts or of a spiritual substance which flows from the magnet into the iron. it is diycult to imagine any other or even a similar cause of these effects. also from this perspective, which is fully self - consistent, it is easy to evaluate the various fantasies and dreams which others have mentioned as the causes of this attraction. this same explanation and cause accounts for the fact that diamonds are said to block such an attraction, and similar types of explanation account for various other things. for the outflow of a specific power can weaken another power, or actuate and sharpen certain other powers. thus, it is said that diamonds confer magnanimity on those who wear them.... on the bonding of spirits as was said above, some spirits reside in more subtle matter, others in more dense matter ; some reside in composite bodies, others in more simple bodies ; some in observable bodies, others in unobservable bodies. as a result, the operations of the soul are sometimes easier, sometimes more difficult, sometimes weaker, sometimes well adapted, sometimes impossible. some spirits operate within one genus, others act more efficaciously in another... [ evil demons ] freely distort things and play with humans by counterfeiting illusions of fear, anger, religion and such things. they understand languages and the sciences, but never make any firm assertions. and so these hateful demons introduce confusion and doubt into the human mind and senses. there are also ethereal spirits which are pure and luminous. all agree that they are hostile to no one and are completely good and friendly to virtuous men. but the airy spirits are friendly to some, and hostile and hateful to others. the aqueous and terrestrial spirits are hostile, or at least are not friendly, since they are less rational and more fearful. in accordance with the saying, \u2018 they hate what they fear, \u2019 they deliberately cause injury. but the spirits of fire, which are more properly called heroes and gods, are said to be the ministers of god. the cabalists call them fissi", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6335487766648416, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:545bc4f6-d4d7-44d0-b97f-3e0808ef4e2d>", "chunk_index": 16, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:52.718323"}
{"text": "change of combinations and actualizations. parallel to the various actualizations, which arise from the various compositions of things, there are various loves and hates. as was said, everything desires to remain in its present state of existence and does not comprehend, or even think about, any other new state of being. therefore, there is, in general, a bonding of reciprocal love of a soul for its own body, and of that body ( in its own way ) for its soul. thus, the diversity of natures and drives gives rise to a variety of bonds which affect both spirits and bodies. we will discuss these bonds immediately after we have first defined the analogy between spirits and composites. on the analogy of spirits porphyry, plotinus and the other platonists assign bodies to spirits as follows. the best and purest spirits, which are also called \u2018 gods \u2019, have bodies of fire, which is the purest and simplest substance. the spirits which have denser elementary bodies exist only by sharing in a more subtle element. thus, airy spirits have bodies mixed with air and fire ; aqueous spirits have bodies mixed with air and fire ; terrestrial spirits have bodies mixed with water, air and fire. these substances are invisible because of their thinness. furthermore, terrestrial and aqueous spirits sometimes choose to make themselves visible by means of dense and concrete vapours, and they appear in the purer regions, where the air is more calm and quiet. i, myself, have seen them at mount libero and at mount lauro. and they have appeared not just to me, but frequently to the local inhabitants to whom they are sometimes hostile ( but only moderately so ), by stealing and hiding the local animals, which they later return in a few days to their it is well - known and widely accepted as true that these spirits have also frequently appeared to workers in gold mines and in other underground places, for example, in the mountains of gebenna. these spirits sometimes harmed them, sometimes helped them and sometimes predicted events. this same type of spirit is found near nola in a desolate place near the temple of portus, and under a certain cliff at the foot of mount cicada, which was once used as a cemetery for plague victims. i myself, as well as many others, have personally experienced them while walking through that place at night. i was bombarded with many stones which violently exploded at a very short distance from my head and other parts of my body, and this continued in", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6180413581843521, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:545bc4f6-d4d7-44d0-b97f-3e0808ef4e2d>", "chunk_index": 18, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:52.720121"}
{"text": "to occur in the world, three conditions are required : ( 1 ) an active power in the agent ; ( 2 ) a passive power or disposition in a subject or patient, which is an aptitude in it not to resist or to render the action impossible ( which reduces to one phrase, namely, the potency of matter ) ; and ( \u2022 ) an appropriate application, which is subject to the circumstances of time, place and other conditions. in the absence of these three conditions, all actions are, simply speaking, always blocked. for even if a flute player is perfect, he is blocked by a broken flute, and the application of the former to the latter is useless. thus, a lack of power in the matter makes an agent impotent and an application unfitting. this is what was meant when we said that an absence of these three conditions, strictly speaking, always blocks an action. closer examination may show that the defect is due to only two, or even only one, of these conditions. but a defect in any one of them should be understood as meaning a defect in all three, as when the flute player and his performance are perfect but the flute is defective, or when the player and the flute are perfect but the performance is interrupted. if the whole meaning of efficient action is taken to consist in the application, then the first condition merges with the third, for the agent is nothing other than the applicator, and to do something is nothing other than to apply something. not all things are by nature passive, or active, in relation to all other things. rather, as is said in the physics, every passion is from a contrary, and every action is on a contrary, or more specifically, on a disposed contrary, as is stated in the common saying, \u2018 active powers act on a properly disposed patient \u2019. from this, it is clear that water mingles and mixes with water because of a similarity or awareness or sympathy, such that after they have united, no device can separate the one from the other. indeed, pure or unmingled wine also easily mixes with water, and vice versa, thus forming a mixture. but the parts of the wine contain some amount of heat and air and spirits, and thus the wine is not completely sympathetic with the water. as a result, they do not mix at the smallest level but survive separately to a noticeable degree in a heterogeneous compound, so that they can be separated again in various ways. the same thing happens to sea water, which yields fresh", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6356564965121242, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:545bc4f6-d4d7-44d0-b97f-3e0808ef4e2d>", "chunk_index": 24, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:52.728493"}
{"text": "more profoundly, we find that, indeed, it does exist in the body, and it consists of a certain physical bond, but, like the soul whose powers reveal its condition, it does not occupy any specific part of the body. indeed, even though the amorous effects of love may arise from the eyes or the mouth or the complexion, nevertheless it is clear that it is not found in them alone, nor does it arise from them alone. for the eyes, considered separately and by themselves, do not have the same force when they are not united with the other parts of the face. the same is true of the mouth, the nose and the complexion, which are not beautiful when depicted separately by a painter. as a result, the nature of beauty is indefinite and quite indescribable, and the same is true of the nature of goodness and cheerfulness. the complete nature of a bond is to be found not just in the object itself, but also in another equally important place, i. e., in the one who is bound. whether food is greedily consumed or is returned uneaten after a meal, this makes no difference at all as far as the substance and quality of the food is concerned. and the bonds of love, which were intense before sexual intercourse, become relaxed when the seed is ejaculated and the fire becomes moderated, even though the beautiful object remains the same. therefore, the whole nature of a bond cannot be found in the object. * the predispositions of the bonding agent. the bonding agent is said to be predisposed to bonding in three ways : by its order ; by its measure ; and by its type. the order is the interrelation of its parts ; the measure is its quantity ; and its type is designated by its shapes, its outlines and its colours. for example, in a bonding of sounds the order consists of a rising and falling through high, low and intermediate notes ; the measure is the use of thirds, fourths, fifths, sixths, etc., and the progression of tones and semitones ; the type is the harmony, softness and clarity. in all things which are predisposed to bonding, whether they be simple or composite, all three of these factors are present in a proportional way. * the diversity of predispositions. regarding the bonds themselves, there is another predisposition : the signs and vestiges which reveal how well developed the soul is. these move the soul to seek out only the", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6084872338655135, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:545bc4f6-d4d7-44d0-b97f-3e0808ef4e2d>", "chunk_index": 41, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:52.749175"}
{"text": "there are four things which rotate around god, or universal nature, or the universal good, or absolute beauty. they rotate in such a way that they cannot abandon that centre, otherwise they would be annihilated, and in such a way that they can be separated from that centre only by the distance of each of their circumferences from its proper centre. these four things, i say, move in a circle around their bonding agent in such a way that they maintain the same order forever. according to the platonists, they are mind, soul, nature and matter. mind, in itself, is stable ; soul, in itself, is mobile ; nature is partly stable and partly mobile ; and matter, as a whole, is both mobile and stable. * the condition of that which can be bound. nothing is bound unless it is very suitably predisposed, for that brightness is not communicated to all things in the same way. * the form of that which can be bound. everything which is bound has an awareness in some sense, and in the nature of that awareness, one finds a certain type of knowledge and of appetite, just as a magnet attracts or repels different kinds of things. hence, he who wishes to bind ought to focus in some way on the awareness in that which can be bound. for, indeed, a bond accompanies the awareness of a thing just like a shadow follows a body. * the comparison of things which can be bound. let us note that humans are more open to bonding than are animals, and ignorant and stupid men are very much less suited for heroic bonds than are those who have developed an illustrious soul. in regard to natural bonds, the common person is much more susceptible than is the philosopher ; as the proverb says, the wise rule over the stars. in regard to the intermediate type of bonds, it happens that the greedy person might boast of being temperate, and the lustful person of being moderate. * the distinction of things which can be bound. from what has just been said, it must be noted that the strength of one bond makes another type of bond less forceful or more mild. thus, a german is less agitated by venus, an italian by drunkenness ; a spaniard is more prone to love, a frenchman to * the seed or incitement of the capacity to be bound. a thing is bound in the strongest way when part of it is in the bonding agent, or when the bonding agent controls it by one of its parts. to", "subdomain_id": "subdomain_quantum_field_theory", "similarity_score": 0.6156332842588144, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:545bc4f6-d4d7-44d0-b97f-3e0808ef4e2d>", "chunk_index": 47, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:52.754859"}
{"text": "the material substrate of natural things. it is not a bodily mass, and it has no bulk. nor can it rotate around a mass and through the whole of space, for not just large things, but also small ones, are seen to be beautiful. in the same species, large things are deformed and small things are beautiful, but the opposite also occurs, and it often happens that beauty is lost when something remains the same in quantity, and is preserved when that quantity is changed. the most beautiful baby or child is pleasing but does not bind until he is an adolescent of a certain age. then he has some size, and this is true even if his form and figure and complexion have not changed at all. from this we conclude that social types of bonding require a degree of size on which the form and the power of the bond depends. it refers, i think, to gestures, words, clothing, habits, sense of humour, and the other signs of human feelings. * the origin of a bond. some platonists define a bond as arising from a certain proportionality of parts accompanied by a certain pleasantness of colouring. but to those who consider the matter more fully, it is at least as clear that it is not just composite things and things consisting of parts that bind, but that colour alone and sound alone also bind. furthermore, nothing slips away and ages faster than beauty, and nothing changes more slowly than the form and figure which shine forth from the composition of parts. hence, it seems that the bond of beauty must be sought elsewhere than in the figure and in the proportionality of parts. indeed, sometimes love passes away after the flowering of the object loved, but the same beauty and figure still remain. as a result, the nature of a bond consists chiefly in a certain mutual orientation between a captor and a captive. indeed, it sometimes happens that even though we have no grounds to complain reasonably about a girl \u2019 s beauty, or in a social setting to criticize someone \u2019 s conversation, speech, habits or actions in general, still they do not please us. on the other hand, something, or even many things, may displease us in someone, yet we still love that person. and, indeed, it would be rather stupid to identify colour as a bond without distinguishing between colour and the things associated with colour. for does colour in itself bind when a brighter colour is displeasing and rejected by an old man, while a duller colour binds and captures a young man?", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6411453429499663, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:545bc4f6-d4d7-44d0-b97f-3e0808ef4e2d>", "chunk_index": 55, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:52.764705"}
{"text": "document type doctoral thesis author sedumedi, thomas dipogiso tshipa email @ example. com urn etd - 10172008 - 170856 document title first - year students ' use of prior knowledge in the learning of acids and bases degree phd department curriculum studies supervisor advisor name title prof a hattingh supervisor keywords - accessing knowledge - knowledge restructuring - incomplete knowledge - quality of knowledge - generate meaning - knowledge construction - inhibiting effects - prior knowledge - error prevention - types of knowledge date 2008 - 09 - 03 availability unrestricted abstract science has been perceived as difficult to learn because of its nature and the methods by which it is usually taught. most first - year science students entering higher education in south africa today come from disadvantaged teaching and learning backgrounds. these students bring different \u201c knowledge, skills or abilities \u201d into the learning process. this knowledge, referred to as prior knowledge \u2013 or what the student already knows \u2013 is the single most important factor influencing learning ( ausubel, 1968 ). it is on the basis of this influence of prior knowledge on learning that the focus in this study is on understanding its manifestation in learning. prior knowledge has both facilitating and inhibiting effects in learning. however, the focus in this study was only on inhibiting effects of prior knowledge on learning. to better understand prior knowledge qualitative methods ( interview, observation, document review and the prior knowledge state test ) were used. the aim was to specifically establish how students used their understanding of selected acid - base concepts and processes to construct understanding and to generate meaning of new concepts and / or knowledge. the study managed to highlight important aspects of the quality of prior knowledge and their manifestation in learning. the findings generally indicated that : - the quality of the knowledge that students possessed was in most instances incomplete. that is, in their description of concepts, students preferred to use summary and informal descriptions without understanding the meaning of the concepts they were describing. - the quality of knowledge ( e. g. incomplete knowledge ) affected their ability to construct understanding and / or generate meaning as this knowledge was insufficient to access for the construction of scientifically valid meanings of concepts. - the quality of students \u2019 knowledge impeded their ability to reflect and / or to be aware of the knowledge they possessed. this made it difficult for students to access knowledge and to restructure it in order to construct new knowledge or prevent errors in their learning. the study culminated in the development of a framework that may in future be used to assess prior knowledge and enhance meaningful teaching and learning based on", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.610647114973532, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:025fb90e-911d-4188-9474-729334756534>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:52.895888"}
{"text": "discussion of all aspects of biological molecules, biochemical processes and laboratory procedures in the field. 5 posts \u2022 page 1 of 1 although biology is the science of life, biologists have not yet been able to define \u201c life \u201d. although molecular gene is the foundational atom of modern biology, the \u201c gene \u201d also remains undefined. likewise \u201c species \u201d is the foundation of evolutionary biology, but evolutionists ( including darwin ) have not been able to define \u201c species \u201d yet. it is without knowing these, biology is \u2018 advancing \u2019. is biology on the right track? if it is, why we are unable to get clear understanding of these things in spite of substantial research already done in biology? we do not pause to ponder over this issue. it is high time we at least doubted something is fundamentally wrong in biology. it is without knowing what \u201c life \u201d is, we are trying to create life. the basic reason why we cannot define or understand the phenomenon of life is the erroneous concept of biological information. molecular gene ( genome ) concept is wrong. biological program responsible for life and the functioning of an organism is not encoded by a chemical molecule ( dna ). by treating dna as the molecule of life, we are superimposing biological information over chemical information. this implies that dna is the only molecule in the whole universe that carries biological information over and above chemical information. this is wrong. the molecular gene concept is therefore flawed and is scientifically untenable. it is violation of chemical principles. the scriptures lend a helping hand to resolve the issue. just because the help comes from scriptures, we should not reject it. that is unscientific. but if the scriptural revelation cannot be proved scientifically we can reject it. the quran and bible reveal that life is nonmaterial phenomenon validating the original proposal of \u2018 nonphysical gene \u2019 by wilhelm johannsen in 1909. he warned against two things while proposing the gene concept ; one is against treating gene as material entity, and the other is against assigning gene for particular character. both these warnings have been since proved correct. the nonphysical biological information can be conceived on the lines of computer model of the organism. phenomena of life and death can be defined and explained in the light of the quranic revelation based on the computer model of organism. the quran informs that god created adam by \u201c breathing rooh into a clay model of man \u201d ( q. 15 : 28 - 29 ). the term nafs is also used in place of rooh in the quran", "subdomain_id": "subdomain_quantum_mechanics", "similarity_score": 0.6405713155286943, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:8019964c-c8b6-47b8-95c1-fe61843aba2e>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:53.613639"}
{"text": "water droplets and light form the basis of all rainbows, which are circular arcs of color with a common center. because only water and light are required for rainbows, one will see them in rain, spray, or even fog. a raindrop acts like a prism and separates sunlight into its individual color components through refraction, as light will do when it passes from one medium to another. when the white light of the sun strikes the surface of the raindrop, the light waves are bent to varying degrees depending on their wavelength. these wavelengths are reflected on the far surface of the water drop and will bend again as they exit. if the light reflects off the droplet only once, a single rainbow occurs. if the rays bounce inside and reflect twice, two rainbows will appear : a primary and a secondary. the second one will appear fainter because there is less light energy present. it will also occur at a higher angle. not all the light that enters the raindrop will form a rainbow. some of the light, that which hits the droplet directly at its center, will simply pass through the other side. the rays that strike the extreme lower portions of the drop will produce the secondary bow, and those that enter at the top will produce the primary bow. the formation of the arc was first discussed by rene descartes in 1637. he calculated the deviation for a ray of red light to be about 138 degrees. although light rays may exit the drop in more than one direction, a concentration of rays emerges near the minimum deviation from the direction of the incoming rays. therefore the viewer sees the highest intensity looking at the rays that have minimum deviation, which form a cone with the vertex in the observer ' s eye and with the axis passing through the sun. the color sequence of the rainbow is also due to refraction. it was sir isaac newton, however, 30 years after descartes, who discovered that white light was made up of different wavelengths. red light, with the longest wavelength, bends the least, while violet, being the shortest wavelength, bends the most. the vertical angle above the horizon will be a little less than 41\u00b0 for the violet ( about 40\u00b0 ) and a little more for the red ( about 42\u00b0 ). the secondary rainbow has an angular radius of about 50\u00b0 and its color sequence is reversed from the primary. it is universally accepted that there are seven rainbow colors, which appear in the order : red, orange, yellow, green, blue, indigo, and violet. however, the", "subdomain_id": "subdomain_quantum_optics", "similarity_score": 0.6111501776423046, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:4a788f83-20a2-4475-abe8-5151df6d6219>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:54.001052"}
{"text": "students engage in several online simulations and in - class investigations related to the density of liquids, solids, and gases. they apply new understanding about density to the design and construction of hot air balloons. they make informed predictions about the variables that may affect the launch of their homemade hot air balloons and test them. the finale is the \u201c got gas? \u201d rally where students display their balloons and use multimedia presentations to demonstrate the principles of density used in the construction of their hot air balloons. view how a variety of student - centered assessments are used in the density : got gas? unit plan. these assessments help students and teachers set goals ; monitor student progress ; provide feedback ; assess thinking, processes, performances, and products ; and reflect on learning throughout the learning cycle. present the essential question, how is science applied in the real world? hold a general discussion on this question. discuss properties of matter, such as color, shape, flexibility, strength, and as many other properties that students can brainstorm and why the properties might be important. tell students that for the next few weeks, they will be investigating the property of density. have them write everything they know about density and why density might be important. have students investigate specific properties of matter with the layered liquids lab. in this lab, students layer mystery liquids and compare their relative densities. give each team one set of equipment ( see materials on the lab worksheet ). the liquids are as follows : each group should have 5 ml of each unknown liquid. directions for the students are given in the \" procedure \" section on the lab sheet. ( note that this procedure can also be done as a teacher - only demonstration. ) explain that students will move from comparing the density of liquids to investigating the density of solids. have students navigate to density *, an online simulation that encourages students to experiment with different variables and determine the effects of mass and volume on density. a teacher \u2019 s guide and related materials are included on the site. for extended learning, students can complete the buoyancy lab *, an online simulation that helps students further explore density properties by adjusting the density of a liquid to determine the effects on buoyancy of a solid object. related handouts and materials are included on the site. through these online simulations, students should make a connection between the layered liquids lab and the online density labs. after the labs, discuss the content question, what are the relationships among mass, volume, and density? expand on the investigations from the online density labs by discussing operational definitions and how to calculate", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6400502056601717, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:7c629a89-048e-4606-9c2e-a27cfd7612fd>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:54.397559"}
{"text": "connection between the layered liquids lab and the online density labs. after the labs, discuss the content question, what are the relationships among mass, volume, and density? expand on the investigations from the online density labs by discussing operational definitions and how to calculate density using the how dense? lab. explain to students that they will measure the absolute densities of liquids from the layered liquids lab. note that the liquids are the same as those compared in the layering liquids lab. each group ' s lab setup requires 25 ml of each sample liquid. discuss procedures and data collection in advance of the activity. explain to students that a bar graph would be appropriate for this type of data. also, this would be a good opportunity to use a spreadsheet program to input the data and make various types of graphs. this would allow students to quickly see which types of graphs are most revealing and useful. for further investigation, students can navigate to determination of density of a solid *, an online labs simulation that allows students to determine the density of various solids by using a virtual spring balance and a measuring cylinder. before beginning, ask students what they learned about comparing the density of fluids that might help them think about measuring the density of a solid. ( mass is determined by comparing an object of unknown mass to an object of known mass, using a balance scale. ) you may wish to review the lab animation * and answer any questions before students enter the simulator. after completing the simulation, have students complete the online quiz * to check for understanding. if you have limited internet access or computing equipment, you can use the optional solids lab procedure instead. following the procedures outlined in the document, students should be able to find the density of a variety of objects using the appropriate method by the end of this session. note that students will need two cubes made from different materials ( for example, steel and aluminum ) and an irregular sample of either steel or aluminum to complete this lab. ask students, if you put hot and cold water together, what will happen? discuss predictions and then do the following hot / cold density demonstration : ask students what the explanation might be for what was observed. have students write or discuss what ways temperature affects density. use online simulations to demonstrate what happens to gas molecules under different temperatures. some recommended simulations include : discuss scientific modeling and explain how molecules have been modeled in different ways over time. discuss the density of gases as compared to solids and liquids. applying density concepts to hot air balloons students are now ready to apply their knowledge about density in the construction of", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6162279263921453, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:7c629a89-048e-4606-9c2e-a27cfd7612fd>", "chunk_index": 1, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:54.399112"}
{"text": ": discuss scientific modeling and explain how molecules have been modeled in different ways over time. discuss the density of gases as compared to solids and liquids. applying density concepts to hot air balloons students are now ready to apply their knowledge about density in the construction of a hot air balloon. present the unit questions : how does the density of specific matter affect the construction process? and what principles of density are applied in hot air balloons? divide students into small groups. announce that the class will be hosting the \u201c got gas \u201d? hot air balloon rally. the students \u2019 task is to construct hot air balloons that will give riders the smoothest and longest flight. the students will work in groups and research how hot air balloons work and which variables to consider when constructing balloons. guide this activity with the balloon research worksheet. have groups create a balloon name and list as many variables that affect flight time as they can. discuss these variables as a class, and have students expand and modify notes accordingly. give each student an experiment data sheet, and present the problem, what causes some hot air balloons to have longer flight times than others? instruct students to discuss this within their groups, and write hypothesis and prediction statements. ( help narrow the choices of independent variables to those relating to balloon weight, temperature difference inside and outside the balloon, wind speed, and direction. ) have each group make a chart showing independent, dependent, and constant variables. instruct students to research the materials needed to build their balloons using the internet sources listed. students should consider the density of each of their chosen materials ( such as straws, plastic sheeting, string, paper cups, and so forth ) and provide a rationale for their choices. have groups turn in a list of supplies needed to build their balloon and have those supplies ready by the next class or have students bring in their own supplies. a pattern of a hot air balloon is included as an example, or each group can find or make their own pattern. students are now ready for construction day. explain that groups should document the density of each type of material used in their hot air balloon and the rationale for choosing the material. they should also describe how they used principles of density to ensure a long flight time and smooth ride. hold the \u201c got gas? \u201d hot air balloon rally! assign each group a designated flight time. flight is judged by time, integrity of materials, and smoothness of ride. tell students to set up a data table and graph while waiting for flight times, and work on their presentations by drawing", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6026959633383221, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:7c629a89-048e-4606-9c2e-a27cfd7612fd>", "chunk_index": 2, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:54.400175"}
{"text": "balloon rally! assign each group a designated flight time. flight is judged by time, integrity of materials, and smoothness of ride. tell students to set up a data table and graph while waiting for flight times, and work on their presentations by drawing illustrations of their project to scan into later publications and / or taking pictures. students can also use photo editing software or online drawing programs to create high - quality visual representations of their project. share the student example slideshow and discuss the criteria for the presentations. introduce the presentation rubric and keeping track brochure checklist. explain that students are to complete two presentation projects : have groups present their multimedia presentations and display their brochures. have students self - and peer - assess their collaboration skills using the peer rubric and their presentations using the presentation rubric. note : in addition to the student brochure and slideshow presentations, students may develop a class wiki * on the topic of density. students use the density test practice to review the concepts of the density lessons and prepare for the short - answer and practical exam. present the essential question again, how is science applied in the real world? use density as the focus this time. encourage students to further investigate this question by researching other examples when knowing the density of matter is applied to other situations ( such as density of gold to identify fool \u2019 s gold, packaging material, body density, all construction projects, and so forth ). english language learner gina aldridge participated in the intel\u00ae teach program, which resulted in this idea for a classroom project. a team of teachers expanded the plan into the example you see here. grade level : 6 - 9 subject ( s ) : physical science topics : properties of matter higher - order thinking skills : analysis, experimental inquiry key learnings : density, scientific method time needed : 4 weeks, 50 - minute lessons, daily background : from the classroom in mesa, arizona, united states", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6163882741374498, "token_count": 389, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:7c629a89-048e-4606-9c2e-a27cfd7612fd>", "chunk_index": 3, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:54.401197"}
{"text": "fri january 18, 2013 inventors design lamp powered entirely by gravity flora lichtman, host : this is science friday. i ' m flora lichtman, filling in for ira flatow today. solar wind, geothermal - now there ' s a new renewable energy source to add to that list. it ' s free, completely reliable and totally unlimited : the force of gravity. two british designers have invented a lamp that runs on gravity alone. their gravitylight - yes, that ' s its name, aptly named - uses, you guessed it, the pull of gravity on a weight to generate up to 30 minutes of light. to turn the lamp on, you lift a weighted bag up, and voila, as the bag slowly descends, led illumination. so how does this work? how hard is it to make? my next guest is here to tell us. martin riddiford is one of the inventors of the gravitylight and founder of the design company therefore. he joins me by phone from london, england. welcome to the program. martin riddiford : hi, flora. lichtman : hi. tell us what this gravitylight looks like, and then take us under the hood and tell us how it works. riddiford : ok. so gravitylight is a project which we started, because we were working with a charity trying to find an alternative to kerosene lamps for the developing world. and we were working with solar power at the time, and we were doing a lamp which used led bulbs and a battery. and we - you had to charge it through solar panels. and we found out that the cost of the unit was too expensive for people in africa to buy, because they have very, very limited finances. and there ' s no micro - financing in africa. so the lowest possible bum ( ph ) cost, or purchase cost, was absolutely essential in the project. so we came out of a meeting when we presented our - the latest work we ' d done with the battery powered device, and thought, we ' ve got to find a cheaper way of doing this. lichtman : now, how did you come up with the idea of - how did gravity come to mind? riddiford : well, we realized that there were two components, the led and the battery, and, obviously, the means of charging it. and there are various means of charging devices like this, with hand cranks and things like that. but they generally always involve a battery, and", "subdomain_id": "subdomain_quantum_optics", "similarity_score": 0.6034004553176492, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:b8a189a5-842b-467b-9552-3ccd208ff16d>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:54.500964"}
{"text": "joined : 16 mar 2004 | posted : tue aug 25, 2009 12 : 33 pm post subject : nanoparticles go bob bob bobbin \u2019 | nanoparticles go bob bob bobbin \u2019, create controllable surface patterns in a finding that could speed the use of sensors or barcodes at the nanoscale, north carolina state university engineers have shown that certain types of tiny organic particles, when heated to the proper temperature, bob to the surface of a layer of a thin polymer film and then can reversibly recede below the surface when heated a second time. selectively bringing a number of particles to a surface and then sinking them back below it results in controllable surface patterns. according to nc state researchers involved in the project, patterning surfaces is one of the holy grails of current nanotechnology research, and is difficult to do with certain particles. they add that the finding could result in tiny reusable bar codes, or in small fluorescent features that turn off when they sense too much heat or the presence of a certain chemical. dr. jan genzer, professor of chemical and biomolecular engineering, and dr. richard spontak, professor of chemical and biomolecular engineering and materials science and engineering, published their finding along with graduate students arif gozen and bin wei in the journal nano letters. they worked with engineers who designed the unique particles at the university of melbourne in australia. the researchers used a special type of organic nanoparticle called a core - shell microgel in which the core of a cross - linked, or networked, polymer is surrounded by a shell of a different polymer. \" most polymers are chain - like macromolecules that are like very long, cooked spaghetti noodles, but these special core - shell particles are shaped more like squash balls of one polymer with a fuzzy surface of a different polymer, \" spontak says. heating these approximately 30 - nanometer particles \u2013 which are hundreds of times smaller than a human hair \u2013 allows them to break through a polymer / polymer interface like a submarine coming to the surface of water. reheating the particles at a polymer surface sinks them back below the surface. \" this technique allows us to place the particles right where we want them \u2013 on the surface of a thin film, \" genzer says. \" it can be used to create a reusable bar code, for instance, or other functional polymer surfaces. \"", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6405084111524528, "token_count": 499, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:c9fb3b31-c2ad-43ac-b11c-095840933f7d>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:54.675201"}
{"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. polymer science and engineering : the shifting research frontiers stability in air at 240\u00b0c to permit blending and processing with conventional polymers. the oxidative and hydrolytic stability is significantly increased when the conducting polymer is used in the form of blends with conventional polymers. clearly, research to improve the stability of conducting polymers is essential to commercial applications in the future. polyaniline is currently the leading conducting polymer used in technological applications and is commercially available in quantity. polypyrrole and derivatives of polythiophene and poly ( phenylene vinylene ) also have significant potential technological applications. rechargeable polyaniline batteries and high - capacity polypyrrole capacitors are in commercial production. ironically conducting polymers are now being used in batteries and electrochromic displays. however, even though conductivities of greater than 10 - 3 s / cm are now achievable with gel electrolytes, the goal of preparing single - ion ( and specifically cation ) conductors with comparable conductivities has remained elusive. tight ion pairing between li + and polymer - bound anions ( usually sulfonates ) is responsible for the significantly lower conductivities. also, new approaches for the synthesis of polymer electrolytes as thin films directly on electrodes ( via, for example, photopolymerization ) are needed to complement novel multilayer battery fabrication technology. along these lines, a key goal is the design of multifunctional polymers capable of transporting only cations, stabilizing a battery system against overcharging, and exhibiting low reactivity at alkali metal and metal oxide electrodes. perhaps most important, electrode - polymer electrolyte reactions need to be examined from a fundamental point of view because these represent a major problem for battery cyclability and overall stability. the field of sensors is diverse, reflecting our need to control increasingly complex systems \u2014 including environments, processes, equipment, vehicles, and biomedical procedures \u2014 that are characterized by high levels of automation. the key to the success of such automated systems is the measurement technology, which demands rapid, reliable, quantitative measurement of the required control parameters. these parameters include temperature, pressure, humidity, radiation, electric charge or potential, light, shock and acoustic waves, and the concentrations of specific chemicals in any environment, to name just a few. obviously,", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6215666772459385, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:ecebaa44-8935-4957-91d2-76b4c2d54ff6>", "chunk_index": 0, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:54.810422"}
{"text": "the university of illinois at urbana - champaign have devised a dynamic and reversible way to assemble nanoscale structures and have used it to encrypt a morse code message. the team started with a template of dna origami \u2015 multiple strands of dna woven into a tile. they \u201c wrote \u201d their message in the dna template by attaching biotin - bound dna strands to specific locations on the tiles that would light up as dots or dashes. scientists in australia are perfecting a technique that may help see nanodiamonds used in biomedical applications. they have been processing the raw diamonds so that they might be used as a tag for biological molecules and as a probe for single - molecule interactions. with the help of an international team, these diamonds have recently been optically trapped and manipulated in three dimensions \u2014 the first time this has been achieved. in systemic lupus erythematosus, the body attacks itself for largely mysterious reasons, leading to serious tissue inflammation and organ damage. current drug treatments address symptoms only and can require life - long daily use at toxic doses. now, scientists at yale university have designed and tested a drug delivery system that uses biodegradable nanoparticles to deliver low drug doses. the method shows early promise for improved treatment of lupus and other chronic, uncured autoimmune diseases. a new study has examined how bacteria clog medical devices, and the result isn \u2019 t pretty. the microbes join to create slimey ribbons that tangle and trap other passing bacteria, creating a full blockage in a startlingly short period of time. the finding could help shape strategies for preventing clogging of devices such as stents and water filters many researchers have been investigating the potential of tiny particles filled with drugs to treat cancer. a team of scientists in sweden have recently made an advance in this area of research by developing \u201c theranostic \u201d nanoparticles, which combine therapy and diagnostics in the same nanomaterial. they are trackable through magnetic resonance. just like electronics, living cells use electrons for energy and information transfer. but cell membranes have thus far prevented us from \u201c plugging \u201d in cells to our computers. to get around this barrier that tightly controls charge balance, a research group at lawrence berkeley national laboratory \u2019 s molecular foundry has engineered < em > e. coli < / em > as a testbed for cellular - electrode communication. they have now demonstrated that these bacterial strains can generate measurable current at an anode. a new study provides details of the", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6135598870582795, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:f1436846-69bb-4dc4-b3c4-2a1a48404566>", "chunk_index": 2, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:55.252876"}
{"text": "s molecular foundry has engineered < em > e. coli < / em > as a testbed for cellular - electrode communication. they have now demonstrated that these bacterial strains can generate measurable current at an anode. a new study provides details of the structure and tissue properties of the remora fish ' s unique adhesion system. the researchers plan to use this information to create an engineered reversible adhesive inspired by the remora that could be used to create pain - and residue - free bandages, attach sensors to objects in aquatic or military reconnaissance environments, replace surgical clamps, and help robots climb. researchers from north carolina state university have, for the first time, successfully coated polymer implants with a bioactive film. the discovery should improve the success rate of such implants. the polymer used in these implants, called peek, does not bond well with bone or other tissues in the body. this can result in the implant rubbing against surrounding tissues, which can lead to medical complications and the need for additional surgeries. biomembranes consist of a mosaic of individual, densely packed lipid molecules. these molecules are formed inside the cells. but how do these building blocks move to the correct part of the membrane? researchers in germany have discovered the bilayer structural mechanism that demonstrates how this is done. a team of materials scientists at harvard university and the university of exeter have invented a new fiber that changes color when stretched. inspired by nature, the researchers identified and replicated the unique structural elements that create the bright iridescent blue color of a tropical plant ' s fruit. researchers in switzerland have designed tiny vessels that are capable of releasing active agents in the body. these \u201c nanovehicles \u201d are made from a liposome just 100 to 200 nm in diameter. by attaching magnetic iron oxide nanoparticles to the surface, scientists are able to target the vessel, heating it up to release the drug. scientists at arizona state university are celebrating their recent success on the path to understanding what makes the fiber that spiders spin \u2014 weight for weight \u2014 at least five times as strong as piano wire. they have found a way to obtain a wide variety of elastic properties of the silk of several intact spiders ' webs using a sophisticated but non \u2013 invasive laser light scattering technique. a university of british columbia researcher has helped create a gel \u2014 based on the mussel ' s knack for clinging to rocks, piers, and boat hulls - that can be painted onto the walls of blood vessels and stay put, forming a protective", "subdomain_id": "subdomain_quantum_materials", "similarity_score": 0.6161203368057877, "token_count": 512, "source_dataset": "HuggingFaceFW/fineweb-edu", "source_id": "<urn:uuid:f1436846-69bb-4dc4-b3c4-2a1a48404566>", "chunk_index": 3, "filtering_threshold": 0.6, "created_at": "2025-12-26T05:22:55.253940"}