During the course of one year, I photographed 95 sunrises along the east bank of the Columbia River from my home on the west bank in Richland, WA (46.3° N latitude). I then calculated the seasonal phenomena listed in the title with the intention of explaining the variation of the photographed sunrises. The calculations use a simplified model of the Sun-Earth system and employ rotation matrices to predict the path of the Sun, as observed at any location in the northern hemisphere, throughout the year. These predictions are in good agreement with those listed by NOAA and also with the photographic data. The analysis presented here provides a novel way to calculate and understand the seasonal variations of visible sunlight.
{"title":"Using rotation matrices to calculate the locations of sunrise and sunset, the hours of daylight, observed path of the Sun, and its elevation angle for any latitude","authors":"M. S. Greenwood","doi":"10.1119/5.0095598","DOIUrl":"https://doi.org/10.1119/5.0095598","url":null,"abstract":"During the course of one year, I photographed 95 sunrises along the east bank of the Columbia River from my home on the west bank in Richland, WA (46.3° N latitude). I then calculated the seasonal phenomena listed in the title with the intention of explaining the variation of the photographed sunrises. The calculations use a simplified model of the Sun-Earth system and employ rotation matrices to predict the path of the Sun, as observed at any location in the northern hemisphere, throughout the year. These predictions are in good agreement with those listed by NOAA and also with the photographic data. The analysis presented here provides a novel way to calculate and understand the seasonal variations of visible sunlight.","PeriodicalId":7589,"journal":{"name":"American Journal of Physics","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48378042","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"教育学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Conway's classic game of life is a two-dimensional cellular automaton in which each cell is alive or dead and evolves according to simple rules that depend solely on the number of live cells in its immediate neighborhood. The emergence of complex multi-cellular objects provides a fascinating vehicle for exploration. A variant of the classic game of life is presented, the generalized semi-classical game of life, in which each cell contains a qubit that evolves by repeated application of birth, death, and survival operators. Species are characterized by just two parameters: a preferred neighborhood liveness representing the tendency to herd and a resilience parameter representing species' vulnerability to environmental changes. This generalized model provides the opportunity to model the fortune of species and to compare to available data. The model is shown to mimic environmental catastrophes and is illustrated by the model's prediction of a return to the pre-hunting level of the global whale population by 2140. A student-designed predator–prey model is shown to qualitatively describe the fate of strongly- and weakly coupled predator–prey systems (snowshoe hare/lynx and rabbit/fox, respectively) and sudden and slow predatory impact (dodo and diprotodon, respectively).
{"title":"The game of life as a species model","authors":"D. Faux, P. Bassom","doi":"10.1119/5.0150858","DOIUrl":"https://doi.org/10.1119/5.0150858","url":null,"abstract":"Conway's classic game of life is a two-dimensional cellular automaton in which each cell is alive or dead and evolves according to simple rules that depend solely on the number of live cells in its immediate neighborhood. The emergence of complex multi-cellular objects provides a fascinating vehicle for exploration. A variant of the classic game of life is presented, the generalized semi-classical game of life, in which each cell contains a qubit that evolves by repeated application of birth, death, and survival operators. Species are characterized by just two parameters: a preferred neighborhood liveness representing the tendency to herd and a resilience parameter representing species' vulnerability to environmental changes. This generalized model provides the opportunity to model the fortune of species and to compare to available data. The model is shown to mimic environmental catastrophes and is illustrated by the model's prediction of a return to the pre-hunting level of the global whale population by 2140. A student-designed predator–prey model is shown to qualitatively describe the fate of strongly- and weakly coupled predator–prey systems (snowshoe hare/lynx and rabbit/fox, respectively) and sudden and slow predatory impact (dodo and diprotodon, respectively).","PeriodicalId":7589,"journal":{"name":"American Journal of Physics","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49509492","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"教育学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Comment on “Thermodynamics of Benford's first digit law” [Am. J. Phys. 87, 787–790 (2019)]","authors":"X. Ren","doi":"10.1119/5.0149874","DOIUrl":"https://doi.org/10.1119/5.0149874","url":null,"abstract":"","PeriodicalId":7589,"journal":{"name":"American Journal of Physics","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44499106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"教育学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Localized surface plasmons (LSPs) in metal particles are used in medical, chemical, physical, and biological sensing applications. In this paper, we revisit the classical description of LSPs. We use the Drude model and the Quasi-Static approximation to describe the plasmon resonances in terms of the material and the size of the particles embedded in a dielectric host. We then incorporate the Clausius–Mossotti relation to include shape effects in the classical description. Finally, we incorporate surface damping and retardation effects to arrive at a unified, classical description providing an intuitive and realistic model of plasmonic resonances in metal particles.
{"title":"Analytical calculation of plasmonic resonances in metal nanoparticles: A simple guide","authors":"Marco Locarno, Daan Brinks","doi":"10.1119/5.0094967","DOIUrl":"https://doi.org/10.1119/5.0094967","url":null,"abstract":"Localized surface plasmons (LSPs) in metal particles are used in medical, chemical, physical, and biological sensing applications. In this paper, we revisit the classical description of LSPs. We use the Drude model and the Quasi-Static approximation to describe the plasmon resonances in terms of the material and the size of the particles embedded in a dielectric host. We then incorporate the Clausius–Mossotti relation to include shape effects in the classical description. Finally, we incorporate surface damping and retardation effects to arrive at a unified, classical description providing an intuitive and realistic model of plasmonic resonances in metal particles.","PeriodicalId":7589,"journal":{"name":"American Journal of Physics","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42776393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"教育学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
An oblique collision of an object with a rigid surface involves an initial sliding phase that persists throughout the collision at glancing angles of incidence but which involves a subsequent grip phase at higher angles of incidence. The grip phase itself terminates towards the end of the collision if the contact region starts to slide backwards. Experimental evidence of the three separate stages of the collision process is presented using a high speed video camera to film the impact of a rubber disk on a rigid horizontal surface. A simplified model of the process is presented, providing analytical solutions that are at least qualitatively consistent with the experimental observations.
{"title":"Oblique collision of a soft rubber disk with a rigid surface","authors":"R. Cross","doi":"10.1119/5.0135633","DOIUrl":"https://doi.org/10.1119/5.0135633","url":null,"abstract":"An oblique collision of an object with a rigid surface involves an initial sliding phase that persists throughout the collision at glancing angles of incidence but which involves a subsequent grip phase at higher angles of incidence. The grip phase itself terminates towards the end of the collision if the contact region starts to slide backwards. Experimental evidence of the three separate stages of the collision process is presented using a high speed video camera to film the impact of a rubber disk on a rigid horizontal surface. A simplified model of the process is presented, providing analytical solutions that are at least qualitatively consistent with the experimental observations.","PeriodicalId":7589,"journal":{"name":"American Journal of Physics","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43471535","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"教育学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This fourth Resource Letter on the Manhattan Project comprises over 140 new sources to complement the 390 listed in the first three on this topic. Books, review papers, and journal articles are cited for the categories of general works; specific topics within the Manhattan Project; technical and historical works; biographies and autobiographies; international wartime programs, allied intelligence, and the use of the bombs; postwar developments; and educational materials. A separate section lists videos and websites.
{"title":"Resource Letter MP-4: The Manhattan Project and related nuclear research","authors":"B. Cameron Reed","doi":"10.1119/5.0149901","DOIUrl":"https://doi.org/10.1119/5.0149901","url":null,"abstract":"This fourth Resource Letter on the Manhattan Project comprises over 140 new sources to complement the 390 listed in the first three on this topic. Books, review papers, and journal articles are cited for the categories of general works; specific topics within the Manhattan Project; technical and historical works; biographies and autobiographies; international wartime programs, allied intelligence, and the use of the bombs; postwar developments; and educational materials. A separate section lists videos and websites.","PeriodicalId":7589,"journal":{"name":"American Journal of Physics","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135209920","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"教育学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. Marrache-Kikuchi, Guillaume Roux, J. Fischbach, B. Pilette
We present an intermediate-level course on sustainable physics, which combines lectures and student projects. Sustainable physics concepts are progressively introduced through both a global and a specialized perspective: climate change and building design. The lectures and hands-on activities on both topics show how they share common concepts and provide complementary points of view. Climate change mitigation and adaptation are touched on via student group projects, where they are asked to tackle a specific question of their choosing via reviews of the literature, modeling, or experiments.
{"title":"A course on climate change and sustainable building design","authors":"C. Marrache-Kikuchi, Guillaume Roux, J. Fischbach, B. Pilette","doi":"10.1119/5.0137570","DOIUrl":"https://doi.org/10.1119/5.0137570","url":null,"abstract":"We present an intermediate-level course on sustainable physics, which combines lectures and student projects. Sustainable physics concepts are progressively introduced through both a global and a specialized perspective: climate change and building design. The lectures and hands-on activities on both topics show how they share common concepts and provide complementary points of view. Climate change mitigation and adaptation are touched on via student group projects, where they are asked to tackle a specific question of their choosing via reviews of the literature, modeling, or experiments.","PeriodicalId":7589,"journal":{"name":"American Journal of Physics","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43332190","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"教育学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
F. Bouquet, J. Bobroff, Lou-Andreas Etienne, Clara Vardon
We developed a two-day physics class that uses a nearby forest as a teaching location. Using low-cost material, students design and carry out physics projects outside of the usual controlled environment that is a classroom. In this way, they come to realize that physics can be used to understand the real world. They organize and present their results in an original format, an exhibit they collectively build. This project is an introduction to the role physics can play in exploring environmental issues, incorporating a sensitive and positive aspect which is important in this time of environmental crisis.
{"title":"Teaching physics in the woods","authors":"F. Bouquet, J. Bobroff, Lou-Andreas Etienne, Clara Vardon","doi":"10.1119/5.0143470","DOIUrl":"https://doi.org/10.1119/5.0143470","url":null,"abstract":"We developed a two-day physics class that uses a nearby forest as a teaching location. Using low-cost material, students design and carry out physics projects outside of the usual controlled environment that is a classroom. In this way, they come to realize that physics can be used to understand the real world. They organize and present their results in an original format, an exhibit they collectively build. This project is an introduction to the role physics can play in exploring environmental issues, incorporating a sensitive and positive aspect which is important in this time of environmental crisis.","PeriodicalId":7589,"journal":{"name":"American Journal of Physics","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48507722","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"教育学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
David L. Tran, P. Shirazi, M. Panduranga, G. Carman
A cost-effective method for the quantitative characterization of the magnetostrictive effect in thin films is presented. In this method, a sample's magnetostriction is extrapolated from the tip displacement of a thin-film magnetostrictive cantilever. The tip displacement is measured by monitoring the position of a reflected laser beam using two differentially coupled photodiode positioning sensors. In contrast with alternative optical deflection-angle devices designed for educational purposes, the detection limit of our setup resolves submicron-level displacements from nanoscale thin films. The efficacy of the system is demonstrated through measurements using amorphous 200-nm thick Terfenol-D/Si (100) bimorph cantilevers. In these measurements, magnetostriction values of 106 ± 3.5 ppm at ±4300 Oe applied field were attained, where the voltage noise floor was ±0.05 V (a cantilever displacement uncertainty of ±70 nm). In-plane (IP) and out-of-plane (OOP) magnetization curves and crystallographic x-ray diffraction (XRD) were performed to determine the magnetic behavior and confirm the amorphous nature of the films, respectively. The experimental methods and material characterization systems demonstrated here enhance the understanding of complex magnetic phenomena and introduce common measurement techniques to better equip students with the skills for insightful analysis of fundamental magnetic physics.
{"title":"Cost-effective measurement of magnetostriction in nanoscale thin films through an optical cantilever displacement method","authors":"David L. Tran, P. Shirazi, M. Panduranga, G. Carman","doi":"10.1119/5.0134187","DOIUrl":"https://doi.org/10.1119/5.0134187","url":null,"abstract":"A cost-effective method for the quantitative characterization of the magnetostrictive effect in thin films is presented. In this method, a sample's magnetostriction is extrapolated from the tip displacement of a thin-film magnetostrictive cantilever. The tip displacement is measured by monitoring the position of a reflected laser beam using two differentially coupled photodiode positioning sensors. In contrast with alternative optical deflection-angle devices designed for educational purposes, the detection limit of our setup resolves submicron-level displacements from nanoscale thin films. The efficacy of the system is demonstrated through measurements using amorphous 200-nm thick Terfenol-D/Si (100) bimorph cantilevers. In these measurements, magnetostriction values of 106 ± 3.5 ppm at ±4300 Oe applied field were attained, where the voltage noise floor was ±0.05 V (a cantilever displacement uncertainty of ±70 nm). In-plane (IP) and out-of-plane (OOP) magnetization curves and crystallographic x-ray diffraction (XRD) were performed to determine the magnetic behavior and confirm the amorphous nature of the films, respectively. The experimental methods and material characterization systems demonstrated here enhance the understanding of complex magnetic phenomena and introduce common measurement techniques to better equip students with the skills for insightful analysis of fundamental magnetic physics.","PeriodicalId":7589,"journal":{"name":"American Journal of Physics","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42424914","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"教育学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Erratum: “A compact disc under skimming light rays” [Am. J. Phys.\u0000 86(3), 169 (2018)]","authors":"R. De Luca, M. Di Mauro, O. Fiore, A. Naddeo","doi":"10.1119/5.0146809","DOIUrl":"https://doi.org/10.1119/5.0146809","url":null,"abstract":"","PeriodicalId":7589,"journal":{"name":"American Journal of Physics","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47094710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"教育学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：