Ukuqonda kwethu imvelo futhi ikakhulukazi umlando we-physics kanye nemithetho elawulayo, isishintshe kakhulu kusukela ezinsukwini zezazi zefilosofi zemvelo zamaGreki asendulo, lapha kuyachazwa ukuthi lezi zinguquko zenzeka kanjani futhi kungani, ngokuhlolwa komlando kanye nemibono, ngesikhathi sabo, beyinguquko.
Umsuka kanye Nokuziphendukela kwemvelo kweFiziksi
Ngokuvumelana ne Isizinda esingokomlando se-physics kanye nefilosofi yemvelo, zazisetshenziswa ngokushintshana kwesayensi inhloso yayo ukutholwa kanye nokwakhiwa kwe Amandla Ayisisekelo Emvelo, Njengoba isayensi yesimanje yayikhula futhi iba isipesheli ngokwandayo, i-physics yasho ukuthi ingxenye yesayensi yemvelo yayingafakiwe kusayensi yezinkanyezi, ikhemistri, i-geology, nobunjiniyela.
Nokho, i-physics idlala indima ebalulekile kuyo yonke isayensi yemvelo, futhi yonke le mikhakha inamagatsha lapho imithetho yemvelo nezilinganiso zigcizelelwa ngokukhethekile, ngamagama afana ne-astrophysics, geophysics, biophysics, ngisho ne-psychophysics, i-physics can , at base , echazwa njengesayensi yento, ukunyakaza, namandla, imithetho yayo ngokuvamile ichazwa ngendlela engokomnotho nangokunemba ngolimi lwezibalo.
Umgomo omkhulu wefiziksi ukuthola isethi yemithetho ebumbene ebusa indaba, ukunyakaza, namandla ebangeni elincane le-subatomic, esikalini somuntu sempilo yansuku zonke, nasemabangeni amakhulu (ngokwesibonelo, lawo esikalini se-extragalactic). ) lo mgomo wokuvelela usufezeke kakhulu.
Nakuba itiyori ehlangene ngokuphelele yezenzakalo ezibonakalayo ingakafinyelelwa, isethi encane ngokuphawulekayo yemithetho yemvelo eyisisekelo ibonakala ikwazi ukulandisa ngazo zonke izenzakalo ezaziwayo.
Indikimba yefiziksi yathuthukiswa kwaze kwaba ngasekuqaleni kwekhulu lama-20, eyaziwa ngokuthi i-classical physics, ingachaza kakhulu ukunyakaza kwezinto ezimakhroscopic ezihamba kancane maqondana nejubane lokukhanya kanye nezimo ezinjengokushisa, umsindo, ugesi, uzibuthe kanye ukukhanya.
Intuthuko yesimanje ekuhlobaneni kanye ne-quantum mechanics iguqula le mithetho njengoba isebenza esivinini esiphezulu, ezintweni ezinkulu kakhulu, nasezicini ezincane ze-matter, njengama-electron, ama-proton, nama-neutron.
I-Physics Yasendulo
UThales wayeyisazi sefiziksi sokuqala futhi imibono yakhe yanikeza isiyalo igama layo, wayekholelwa ukuthi umhlaba, nakuba wenziwe ngezinto eziningi, empeleni wakhiwe ngento eyodwa, amanzi, ebizwa ngokuthi i-Physis ngesiGreki sasendulo.
Ukusebenzisana kwamanzi phakathi kwezigaba zokuqinile, uketshezi kanye negesi kwanikeza izinto ezibonakalayo izakhiwo ezihlukene, lena kwakuyincazelo yokuqala yokukhipha izenzakalo zemvelo endaweni yokuqondisa kwaphezulu kanye nendawo yemithetho nezincazelo zemvelo.
U-Anaximander, odume kakhulu nge-proto-evolutionary theory, waphikisana nemibono kaThales futhi waphakamisa ukuthi esikhundleni samanzi, into ebizwa ngokuthi i-Apeiron yayiyisakhiwo sayo yonke into, ngosizo lokubheka emuva kwesimanje singasho ukuthi lokhu kwakungomunye umcabango ohlakaniphile. ye-Anaximander futhi efana kakhulu nomqondo wokuthi i-hydrogen iyisakhiwo sazo zonke izinto ezisemkhathini wethu.
Omunye wezazi zefiziksi zasendulo ezaziwayo kwakunguLeucippus, owaphikisana ngokuqinile nombono wokungenelela kwaphezulu okuqondile endaweni yonke, lesi sazi sefilosofi saphakamisa ukuthi izenzakalo zemvelo zinembangela yemvelo. U-Leucippus kanye nomfundi wakhe, u-Democritus, bahlakulela i-theory yokuqala ye-athomu, bephikisana ngokuthi izinto azikwazi ukuhlukaniswa unomphela futhi ekugcineni zizofika zibe yizicucu ezingenakunqunywa.
ithiyori yokuqala ye-athomu
Kuwukuqagela kwefilosofi yasendulo ukuthi zonke izinto zingachazwa ngenhlanganisela engenakubalwa yezinhlayiya eziqinile, ezincane, ezingahlukaniseki ezinobukhulu obuhlukahlukene kodwa zezinto ezifanayo eziyisisekelo noma inkolelo-mbono yesimanje yesayensi yendaba ngokuvumelana nalokho izakhi zamakhemikhali ezihlanganayo ukuze zakhe u-A. izinto eziningi ezihlukahlukene zihlanganisa ukuhlanganisa kwamayunithi amancane afanayo, anesici se-nuclear and electronic substructure ye-elementi ngayinye.
I-Euclid nezibalo
Ukungalingani kwezincwadi ezihlukahlukene kanye namazinga ezibalo ahlukahlukene kungase kunikeze umbono wokuthi u-Euclid wayengeyena nje umhleli wezincwadi ezabhalwa ezinye izazi zezibalo, ngokwezinga elithile lokhu kuyiqiniso, nakuba cishe kungenakwenzeka ukunquma ukuthi yiziphi izingxenye ezingezakhe nokuthi yiziphi. Ukuzivumelanisa nabanduleli bayo. Abantu besikhathi sika-Euclid babheka umsebenzi wakhe wokugcina nonegunya, ukusho okuncane nje, njengokuphawula kwe-Elements.
I-Aristotelian Physics
Kuyathakazelisa ukuthi nakuba u-Aristotle ethathwa njengoyise wesayensi futhi wabasiza kahle Isifinyezo somlando weFiziksi nge-systematics kanye nokwenza kwakhe, empeleni wavimbela intuthuko ye-physics phakathi nezinkulungwane zeminyaka.
Naye ngokwakhe wenza iphutha ngokuthi ithiyori yezibalo nomhlaba wemvelo akuzange kuhambisane, igama eliyimfihlo lokuthembela ngokweqile olwazini. U-Aristotle wayefuna ukuveza izimfundiso ezinjengokunyakaza namandla adonsela phansi ngenkolelo-mbono yakhe yezakhi, okungeziwe ku-physics yasendulo eyadlulela naku-alchemy nemithi.
U-Aristotle wagomela ngokuqinile ukuthi yonke into yakhiwe inhlanganisela yezakhi ezinhlanu, umhlaba, umoya, umlilo, amanzi ne-ether engaphatheki, waqhubekisela phambili lokhu ngokugomela ngokuthi umbuso womhlaba uzungezwe umoya, ulandelwa imibuso yomlilo ne-ether. .
I-Physics emhlabeni wamaSulumane wenkathi ephakathi
I-Mechanics yayingenye yesayensi ethuthuke kakhulu okufanele iqhutshwe ngeNkathi Ephakathi, isebenza ngaphakathi kohlaka oluyisisekelo luka-Aristotle, izazi zefiziksi zenkathi ephakathi zagxeka futhi zazama ukuthuthukisa izici eziningi zefiziksi ka-Aristotle.
Inkinga yokunyakaza kwe-projectile yayibalulekile kumakhenikha e-Aristotelian, futhi ukuhlaziya le nkinga kumelela omunye weminikelo ehlaba umxhwele kakhulu yenkathi ephakathi ku-physics, ngenxa yokucabangela ukuthi ukuqhubeka kokunyakaza kudinga isenzo esiqhubekayo samandla okushayela, ukunyakaza okuqhubekayo iphrojekthi ngemva kokulahlekelwa ukuthintana neprojektha idinga incazelo.
U-Aristotle ngokwakhe wayehlongoze izincazelo zokuqhubeka kokunyakaza kwe-projectile ngokuya ngesenzo se-medium, umlingiswa walezi zincazelo ozenza zingagculisi kubahlaziyi abaningi benkathi ephakathi, okwathi, nokho, bagcina ukucabangela okuyisisekelo kokuthi ukunyakaza kwe-projectile okuqhubekayo kudinga imbangela eqhubekayo.
Phakathi neminyaka yawo-1300, izazi ezithile zase-Oxford zazindla ngenkinga yefilosofi yokuthi ingaluchaza kanjani ushintsho olwenzeka lapho izimfanelo zanda noma zehla ngomfutho, futhi zaqala ukucabangela izici ze-kinematic zokunyakaza.
I-Ptolemy kanye nemodeli ye-geocentric
Futhi ebizwa ngokuthi i-geocentric system, imodeli yezibalo yendawo yonke eyakhiwe isazi sezinkanyezi kanye nesazi sezibalo u-Alexandrinus Ptolemy futhi eyabhalwa nguye ku-Almagest and Planetary hypotheses, uhlelo lwePtolemaic luyi-cosmology ye-geocentric, okungukuthi, iqala ngokuthatha ukuthi uMhlaba umile futhi eNkabeni yendawo yonke.
i-classical physics
I-Classic physics yaqala ukwakheka lapho uNewton ephakamisa inkolelo-mbono yakhe yamandla adonsela phansi kanye nezibalo esizazi ngokuvamile ngokuthi i-calculus esebenzisana nezibalo. Ukuthuthukiswa Komlando KweFiziksi, I-Newtonian physics yayinezinhlangothi ezintathu, ububanzi, ubude nokujula, eminyakeni engamakhulu amathathu edlule, u-Isaac Newton wamemezela ukuthi indawo nesikhathi kuyizithako zaphakade nezingaguquki ekwakhiweni kwendawo yonke, izakhiwo ezihlanzekile ezidlula imingcele yombuzo kanye incazelo.
UNewton wabhala ku-principal mathematics:
"Isikhala esiphelele emvelweni yaso ngaphandle kokuhlobana nanoma yini yangaphandle sihlala sifana futhi asinyakazi, isikhathi esiphelele, esiyiqiniso nesezibalo ngokwaso futhi imvelo yaso igeleza ngokulinganayo ngaphandle kokuhlobana nanoma yini yangaphandle."
Imibono kaNewton mayelana nendawo yonke, nakuba u-Einstein angabonisa ukuthi ayinembile, isayensi yakhonza amakhulu eminyaka, naphezu kokushiyeka kwayo, yavumela ukuthuthukiswa kwezobuchwepheshe kwenguquko yezimboni, inkolelo-mbono iyimodeli ehambisanayo eqondisa imicabango, iqoqo lemibono engase ilungiswe kuze kube yilapho kuthuthukiswa ithiyori engcono.
Imibono kaNewton yayihlanganisa inkolelo-mbono yakhe yamandla adonsela phansi ayenzela i-calculus ukuze ayichaze, umqondo wakhe wobukhulu obuthathu endaweni yonke engapheli, inkolelo-mbono yakhe yokukhanya, kanye nenkolelo yakhe eyisisekelo esekelwe ezimfundisweni zakhe zokuthi, eqinisweni, kwakunemigqa eqondile. imvelo, imibuzo kaNewton mayelana ne-physics yokukhanya yaphumela embonweni yezinhlayiyana zokukhanya, okungukuthi, umsebe wokukhanya ngamunye wawuhamba umugqa oqondile futhi ube nesisindo esincane ngendlela emangalisayo.
ILanga njengenkaba yendawo yonke
AmaGreki asendulo, isibonelo, ayebheka ukuthi amaplanethi ahlanganisa iLanga, uMhlaba wawuphakathi kwakho konke (i-geocentric), ngalezi planethi ezizungezile, lokhu kwaba okubaluleke kakhulu esikweni kangangokuthi izinsuku zesonto zaziphethe igama. konkulunkulu, abamelelwa yilezi zindawo zokukhanya eziyisikhombisa ezihambayo.
Imithetho yemvelo kaNewton
Ukuxhumana phakathi kwamandla asebenza emzimbeni kanye nokunyakaza komzimba, kwavezwa okokuqala yisazi sefiziksi saseNgilandi kanye nesazi sezibalo u-Isaac Newton, ngokusho kwe Isaac Newton Biography imithetho efanayo yavela okokuqala emsebenzini wakhe ngonyaka we-1687, ngokuvamile owaziwa ngokuthi i-Principia.
Inguquko yesayensi
Umbono omusha wemvelo wazalwa phakathi neNguquko Yesayensi, esikhundleni sendlela yamaGreki eyayinqobe isayensi iminyaka eminingi, isayensi yaba indlela yamahhala, ehlukile kufilosofi nobuchwepheshe, okwagcina kubhekwe ukuthi inezinjongo ezinhle.
Ekupheleni kwalesi sikhathi, kungase kungabi okuningi kakhulu ukusho ukuthi isayensi yayithathe indawo yobuKristu njengesizinda sempucuko yaseYurophu, ekuvundeni kweNkathi Yokuvuselela kanye neNguquko kwavela umbono omusha wesayensi lapho, okwenza lokhu okulandelayo: ukuguqulwa , ukufundiswa kabusha komqondo ovamile ovuna ukucabanga okungabonakali, ukufakwa esikhundleni sobuningi ngombono wekhwalithi wemvelo.
Umbono wemvelo njengomshini esikhundleni sento ephilayo, ukuthuthukiswa kwendlela yokuhlola nesayensi eyayifuna izimpendulo eziqondile emibuzweni ethile elinganiselwe eyakhiwe ngaphakathi kohlaka lwemibono ethile, kanye nokwamukelwa kwezinqubo ezintsha zencazelo, kugcizelela ukuthi «kanjani esikhundleni salokho. ethi "kungani" eyayiveze ukufuna kuka-Aristotle izimbangela zokugcina.
I-Thermodynamics ne-Optics
Uma i-hydrodynamics noma i-theory of elasticity ingeyona isithakazelo esisheshayo sokutadisha i-quantum theory, khona-ke nge-optics isimo sihluke ngokuphelele, njengoba inqubekelaphambili yayo ihlobene eduze nokuthuthukiswa kwe-physics yesimanje, efana nezimo ezenzeka ngokuqinile futhi. imizimba ewuketshezi, izenzakalo ezikhanyayo nazo zidonse ukunaka kwabantu kusukela ezikhathini zasendulo, kodwa kuphela ngekhulu le-XNUMX.
I-Optics yaqala ukwakha isayensi yangempela. Phakathi nalesi sikhathi, u-Descartes wenza imithetho yokuphikisa nokubonakaliswa kokukhanya futhi uFermat wahlongoza isimiso sakhe, esiqukethe wonke ama-geometrical optics, phakathi naso sonke lesi sikhathi sokuthuthukiswa kwe-optics, umqondo wemisebe yokukhanya wadlala indima ebalulekile kuwo. ukusakazeka kwe-rectilinear kwemisebe yokukhanya ku-vacuum noma kumidiya efanayo, ukuboniswa kwayo kusuka endaweni ethile ekhethekile, kanye nokuhlehla ngesikhathi soshintsho ukusuka endaweni eyodwa ukuya kwenye.
I-Electromagnetism kanye neSakhiwo se-Atomic
Imishini kanye nemikhakha ehlobene, kanye ne-acoustics ne-optics, yavela kudala, ngoba ifunda izenzakalo umuntu ahlangabezana nazo njalo ekuphileni kwakhe kwansuku zonke, isayensi kagesi, ngakolunye uhlangothi, ivele muva nje.
Yiqiniso, amanye amaqiniso, njengokufakwa kukagesi kwemizimba ngokungqubuzana noma izakhiwo zikazibuthe bemvelo, ayesevele aziwa ngaphambili, izenzakalo zemvelo zinkulu futhi ziyinqaba njengoba iziphepho zikagesi zingenakuhluleka ukudonsa ukunaka.
Kodwa-ke, akunakwenzeka ukuthi la maqiniso afundwa ngokwanele futhi aqhathaniswa kwaze kwaba sekupheleni kwekhulu le-XNUMX futhi cishe akekho owayecabanga ngokucacile ngaleso sikhathi ukuthi kwakuyoba into yokucwaninga isayensi entsha, eyakha enye yezindawo ezibaluleke kakhulu. ye-physics yesimanje, lokhu kwacaca kuphela ngasekupheleni kwekhulu le-XNUMX nasekuqaleni kwekhulu le-XNUMX.
Kuyathakazelisa ukuqaphela ukuthi ngesikhathi esifanayo izenzakalo zokuphazanyiswa zatholwa futhi inkolelo-mbono yamagagasi yakhiwa, lesi sikhathi esiphawulekayo emlandweni wokuthuthukiswa kwesayensi, lapho kwavela i-wave optics kanye nenkolelo-mbono yesimanje kagesi, kwakungenxa ye-physics ye-macroscopic. iminyaka engu-50 edlule kwakungeye-atomic physics.
I-physics yesimanje
Ifiziksi yesimanje ivamise ukubandakanya incazelo ethuthukisiwe yemvelo ngokusebenzisa imibono emisha eyayihlukile ezincazelweni zakudala futhi ehlanganisa izici ze-quantum mechanics kanye nokuhlobana kuka-Einstein, isibonelo imiphumela ye-quantum ngokuvamile ihilela amabanga ahlobene nama-athomu , ngakolunye uhlangothi, imiphumela yokuhlobana ngokuvamile ihilela isivinini uma kuqhathaniswa. ngesivinini sokukhanya.
Amandla
Izazi zefiziksi zisebenzisa igama elithi amandla ukuze zibonise amandla okushintsha isimo noma ukukhiqiza umsebenzi obangela ukunyakaza noma okhiqiza imisebe ye-electromagnetic, isibonelo, ekukhanyeni noma ekushiseni, igama livela kwelesiGreek futhi lisho "isenzo samandla."
Ohlelweni lwamazwe ngamazwe, amandla avezwa ngama-joules, kodwa ngokwemibandela evamile, avame ukuvezwa ngama-kilowatt-amahora (kWh), ngokuqondene nethani likawoyela elilingana (izinzwane), ngokuvamile livumela imithombo ehlukene ukuba iqhathaniswe. wamandla komunye nomunye, kufanele kuqashelwe ukuthi, ngokomthetho wokuqala we-thermodynamics, amandla esistimu evaliwe ayagcinwa.
I-Thermodynamics
Isekelwe emthethweni wokuqala nowesibili, okungukuthi, ukulondolozwa kwamandla kanye nokwanda kwe-entropy, le mithetho ibeka imingcele eqinile kunoma iyiphi imodeli yendawo yonke, ngaphezu kwalokho, ezinye izakhiwo zesikhala nesikhathi zivela ngomqondo we-thermodynamic. .
Ngakho-ke, le mibono akufanele ithathwe njengezakhiwo eziyisisekelo zokusebenzisana okuyisisekelo, ngalo mqondo, isikhathi sendawo es I-thermodynamic, ngaphezu kwalokho, uma umuntu evuma ukufaka izimpikiswano zezibalo, umuntu kufanele abuze ukuthi amandla omkhathi mhlawumbe angama-thermodynamic, indawo yonke yethu ingabuswa amandla e-entropic kunokuba ibuswe amandla aphelele.
Ugesi
Zisekelwe kumbono kaMaxwell wamagagasi kanye nezibalo zawo, kodwa aziqondwa kahle kakhulu kunalezi zinkolelo-mbono, azisekelwe ekuchazeni kwakhe ubudlelwano phakathi kwezinkambu ze-E no-B, kodwa zikaLudvig Lorenz, uMaxwell angavumelananga nazo.
UMaxwell wacabanga ukuthi lezi zinkambu ezimbili kufanele zenziwe ngomjikelezo ukuze isivinini sokukhanya sigcinwe, ngokungafani no-Lorenz, owacabanga ukuthi zombili izinkambu kufanele zithole ukuqina kwazo okuphezulu ngesikhathi esifanayo ukuze kugcinwe leso sivinini, izibalo ezivumela kokubili ukuphimisela amagama.
I-Quantum Mechanics
Umhlaba we-quantum wama-athomu nezinhlayiya ze-subatomic uyamangalisa, inhlayiya eyodwa ingaziphatha njengokungathi isendaweni ezimbili ngesikhathi esisodwa, futhi izinhlayiya ezimbili, emikhawulweni ehlukene yendawo yonke, ngandlela-thile zingaziphatha njengento eyodwa.
Nakuba kungase kubonakale kungenakwenzeka ukusonga izingqondo zethu ngobungako obungaka, lokhu kulandelana kwezinkulumo kuhamba indlela ende ekudambiseni umhlaba we-quantum, kusinikeza ukuqonda okuqinile “kuma-cogs namasondo” ahehayo okuthi ama-athomu asebenza kanjani.
Big Bang
Ngomzuzwana wokuqala wokuba khona kwendawo yonke, ukuqonda kwethu okwenzekayo kuhle ngokumangalisayo. Siyazi ukuthi imiqondo yesikhathi, indawo kanye nemithetho ye-physics yaqina ngokushesha okukhulu, ukusuka lapho, ukuhleleka kwaqala ukuvela ezinxushunxushwini, ezokuqala ezavela kwakuyizinhlayiya ze-subatomic ezifana nama-quarks.
Khona-ke izinhlayiya ezinkulu njengama-proton ne-neutron, cishe emizuzwini emithathu kamuva indawo yonke yase iphole yaba yisigidi sezigidi ze-°C. Lokhu kwenza ukuba ama-proton ne-neutron ahlangane ngokuhlangana futhi akhe ama-nuclei, i-nuclei egcwele ama-athomu.
Ukuhlobana
Imibono efinyelela kude engokwenyama eyathuthukiswa isazi sefiziksi saseJalimane u-Albert Einstein, kanye nemibono yakhe yokuhlobana okukhethekile ngo-1905 kanye nokuhlobana okujwayelekile, u-Einstein wabeka eceleni ukuphawula okuningi ngemibono yangaphambilini yomzimba, esebenza kule nqubo emicabangweni eyisisekelo yendawo, isikhathi, udaba. , amandla namandla adonsela phansi.
I-nuclear physics
Leli gatsha le-physics libhekene nesakhiwo senucleus ye-athomu kanye nemisebe ye-nuclei engazinzile.
amandla e-athomu
Njengama-athomu ajabulile, i-nuclei ekhipha imisebe engazinzile (ekhiqizwa ngokwemvelo noma ekhiqizwe ngokwenziwa) ingakhipha imisebe kazibuthe, ama-photon enuzi anamandla abizwa ngokuthi imisebe ye-gamma. Ama-nuclei e-radioactive aphinde akhiphe ezinye izinhlayiya, ama-electron angalungile nama-positive (imisebe ye-beta), ehambisana ne-neutrinos ne-helium nuclei (imisebe ye-alpha).
Amandla angaphakathi ku-nucleus
Ku-radioactivity kanye nasekushayisaneni okuholela ekuqhekekeni kwe-nuclear, ubunikazi bekhemikhali bethagethi yenuzi buyashintshwa ngaso sonke isikhathi lapho kuba noshintsho ekushayweni kwe-nuclear, ekuhlukaneni kwe-nuclear nokuhlangana lapho i-nuclei engazinzile ihlukana khona, ngokulandelana, ibe yi-nuclei encane noma ihlanganiswe ibe enkulu. i-nuclei, ukukhululwa kwamandla kukhulu kakhulu kunanoma yikuphi ukusabela kwamakhemikhali.
Intuthuko yakamuva ku-physics
Eminyakeni yamuva nje kuye kwaba nokutholwayo okuvumela intuthuko ku-physics, njengaleyo echazwe ngezansi:
I-laser
I-laser yayingeke yenzeke ngaphandle kokwazi ukuthi ukukhanya kuwumfanekiso wemisebe ye-electromagnetic. UMax Planck uthole uMklomelo KaNobel kuPhysics ngokuthola kwakhe i-quanta yamandla eyisisekelo, njengaku I-Quantum Planck Theory wayesebenzela i-thermodynamics, efuna ukukhombisa ukuthi kungani imisebe "yemnyama", into ecwilisa wonke amaza okukhanya, ayizange ikhiphe konke ukuphindaphinda kokukhanya ngokulinganayo lapho icasukile.
I-Hadron Collider Enkulu
Eminyakeni eyishumi ngemva kokuqala kokusebenza kwe-Large Hadron Collider, enye yezinto eziyinkimbinkimbi kunazo zonke ezake zabonwa, iyinhlayiya enkulu kunazo zonke emhlabeni, engcwatshwe amamitha angu-100 ngaphansi kwenkundla yesiFulentshi neSwitzerland enomjikelezo wamamayela angu-17 .