W hen atoms crystallize, their energy levels split to fill wide bands. That spreading of the levels sets the crystal’s electronic properties, but it’s not the only factor. How the atoms arrange in space also counts, and in some rare cases, a crystal can possess certain symmetries that bestow the bands with “topological” features. Like electrons, phonons move about a crystal in ways prescribed by a band structure, which can also have topological features. Now, Jiade Li of China’s Institute of Physics and his collaborators have used a type of electron spectroscopy to demonstrate that graphene, which has already been shown to have topological electrons, has topological phonons [1].
{"title":"Graphene Has Topological Phonons","authors":"Charles Day","doi":"10.1103/physics.16.s126","DOIUrl":"https://doi.org/10.1103/physics.16.s126","url":null,"abstract":"W hen atoms crystallize, their energy levels split to fill wide bands. That spreading of the levels sets the crystal’s electronic properties, but it’s not the only factor. How the atoms arrange in space also counts, and in some rare cases, a crystal can possess certain symmetries that bestow the bands with “topological” features. Like electrons, phonons move about a crystal in ways prescribed by a band structure, which can also have topological features. Now, Jiade Li of China’s Institute of Physics and his collaborators have used a type of electron spectroscopy to demonstrate that graphene, which has already been shown to have topological electrons, has topological phonons [1].","PeriodicalId":20136,"journal":{"name":"Physics","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134971685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
E ven in our digital age, ballpoint pens are an irreplaceable tool for writing down flashes of inspiration or signing legally binding documents. The ink flowing through these everyday objects has always been a passive absorber of light, but Junyi Zhao fromWashington University in St. Louis and colleagues have now changed that [1]. The team has designed a ballpoint pen that writes with ink that produces light as a light emitting diode (LED).
{"title":"Handwritten LEDs Light Up the Page","authors":"Sarah Wells","doi":"10.1103/physics.16.158","DOIUrl":"https://doi.org/10.1103/physics.16.158","url":null,"abstract":"E ven in our digital age, ballpoint pens are an irreplaceable tool for writing down flashes of inspiration or signing legally binding documents. The ink flowing through these everyday objects has always been a passive absorber of light, but Junyi Zhao fromWashington University in St. Louis and colleagues have now changed that [1]. The team has designed a ballpoint pen that writes with ink that produces light as a light emitting diode (LED).","PeriodicalId":20136,"journal":{"name":"Physics","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134971687","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T he neural networks of animal brains are partly mirror symmetric, with asymmetries thought to be more common in more cognitively advanced species. This assumption stems from a long-standing theory that increased complexity of neural tasks can turn mirror-symmetric neural circuits into circuits existing in only one side of the brain. This hypothesis has now received support from amathematical model developed by Luís Seoane at the National Center for Biotechnology in Spain [1]. The researcher’s findings could help explain how the brain’s architecture is shaped not only by cognitively demanding tasks but also by damage or aging.
{"title":"Brain Asymmetry Driven by Task Complexity","authors":"Ryan Wilkinson","doi":"10.1103/physics.16.s133","DOIUrl":"https://doi.org/10.1103/physics.16.s133","url":null,"abstract":"T he neural networks of animal brains are partly mirror symmetric, with asymmetries thought to be more common in more cognitively advanced species. This assumption stems from a long-standing theory that increased complexity of neural tasks can turn mirror-symmetric neural circuits into circuits existing in only one side of the brain. This hypothesis has now received support from amathematical model developed by Luís Seoane at the National Center for Biotechnology in Spain [1]. The researcher’s findings could help explain how the brain’s architecture is shaped not only by cognitively demanding tasks but also by damage or aging.","PeriodicalId":20136,"journal":{"name":"Physics","volume":"78 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135786189","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A coalition of astronomers calls for renaming the Milky Way’s two brightest satellite galaxies, along with other astronomical objects and facilities that bear the name of a Portuguese explorer who murdered and enslaved Indigenous people.
{"title":"Astronomers Need to Rename the Magellanic Clouds","authors":"Mia de los Reyes","doi":"10.1103/physics.16.152","DOIUrl":"https://doi.org/10.1103/physics.16.152","url":null,"abstract":"A coalition of astronomers calls for renaming the Milky Way’s two brightest satellite galaxies, along with other astronomical objects and facilities that bear the name of a Portuguese explorer who murdered and enslaved Indigenous people.","PeriodicalId":20136,"journal":{"name":"Physics","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135886858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T he single-celled parameciumwhizzes through its aqueous habitat at a rate of 10 times its length a second, thanks to the coordinated undulation of hair-like structures, called cilia. Cilia are also found in human lungs where their motion helps to clear out mucus. Researchers in microfluidics would like to mimic cilia’s fluid-shifting ability for novel devices, but they have had trouble creating artificial cilia at the microscale. Now Jaap den Toonder of Eindhoven University of Technology in the Netherlands and his collaborators have demonstratedminiaturized artificial cilia that perform like real ones [1]. What’s more, their experiments clarified which aspects of the cilia’s motion are responsible for
{"title":"Making Miniature Artificial Cilia","authors":"Charles Day","doi":"10.1103/physics.16.156","DOIUrl":"https://doi.org/10.1103/physics.16.156","url":null,"abstract":"T he single-celled parameciumwhizzes through its aqueous habitat at a rate of 10 times its length a second, thanks to the coordinated undulation of hair-like structures, called cilia. Cilia are also found in human lungs where their motion helps to clear out mucus. Researchers in microfluidics would like to mimic cilia’s fluid-shifting ability for novel devices, but they have had trouble creating artificial cilia at the microscale. Now Jaap den Toonder of Eindhoven University of Technology in the Netherlands and his collaborators have demonstratedminiaturized artificial cilia that perform like real ones [1]. What’s more, their experiments clarified which aspects of the cilia’s motion are responsible for","PeriodicalId":20136,"journal":{"name":"Physics","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135886857","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The focus of this paper is on analyzing the role and the choice of parameters in sociophysics diffusion models by leveraging the potentialities of sociophysics from a mathematical programming perspective. We first present a generalised version of Galam’s opinion diffusion model. For a given selection of the coefficients in our model, this proposal yields the original Galam’s model. The generalised model suggests guidelines for possible alternative selection of its parameters that allow it to foster diffusion. Examples of the parameters selection process as steered by numerical optimisation, taking into account various objectives, are provided.
{"title":"Mathematical Programming for the Dynamics of Opinion Diffusion","authors":"Andrea Ellero, Giovanni Fasano, Daniela Favaretto","doi":"10.3390/physics5030061","DOIUrl":"https://doi.org/10.3390/physics5030061","url":null,"abstract":"The focus of this paper is on analyzing the role and the choice of parameters in sociophysics diffusion models by leveraging the potentialities of sociophysics from a mathematical programming perspective. We first present a generalised version of Galam’s opinion diffusion model. For a given selection of the coefficients in our model, this proposal yields the original Galam’s model. The generalised model suggests guidelines for possible alternative selection of its parameters that allow it to foster diffusion. Examples of the parameters selection process as steered by numerical optimisation, taking into account various objectives, are provided.","PeriodicalId":20136,"journal":{"name":"Physics","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135938095","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A lthough a crystal is a highly ordered structure, it is never at rest: its atoms are constantly vibrating about their equilibrium positions—even down to zero temperature. Such vibrations are called phonons, and their interaction with the electrons that hold the crystal together is partly responsible for the crystal’s optical properties, its ability to conduct heat or electricity, and even its vanishing electrical resistance if it is superconducting. Predicting, or at least understanding, such properties requires an accurate description of the interplay of electrons and phonons. This task is formidable given that the
{"title":"Toward a Complete Theory of Crystal Vibrations","authors":"Jan Berges","doi":"10.1103/physics.16.151","DOIUrl":"https://doi.org/10.1103/physics.16.151","url":null,"abstract":"A lthough a crystal is a highly ordered structure, it is never at rest: its atoms are constantly vibrating about their equilibrium positions—even down to zero temperature. Such vibrations are called phonons, and their interaction with the electrons that hold the crystal together is partly responsible for the crystal’s optical properties, its ability to conduct heat or electricity, and even its vanishing electrical resistance if it is superconducting. Predicting, or at least understanding, such properties requires an accurate description of the interplay of electrons and phonons. This task is formidable given that the","PeriodicalId":20136,"journal":{"name":"Physics","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136025528","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
I f you could quickly predict the reactivity of a material in different scenarios using only its atomic-level geometry, you’d hold the golden ticket to finding application-specific catalytic materials. Somemethods exist for making these predictions, but they require detailed knowledge about the arrangement of the atoms and are computationally expensive to perform and thus slow to run. Now Evan Miu and his colleagues at the University of Pittsburgh have developed a method that requires only information about the connectivity of the atoms, is computationally cheap, and is quick to run [1]. Their method accurately predicts howmetal oxides interact with hydrogen in a reaction important to energy storage and catalysis.
{"title":"Global Connectivity Predicts Reactivity","authors":"Rachel Berkowitz","doi":"10.1103/physics.16.s123","DOIUrl":"https://doi.org/10.1103/physics.16.s123","url":null,"abstract":"I f you could quickly predict the reactivity of a material in different scenarios using only its atomic-level geometry, you’d hold the golden ticket to finding application-specific catalytic materials. Somemethods exist for making these predictions, but they require detailed knowledge about the arrangement of the atoms and are computationally expensive to perform and thus slow to run. Now Evan Miu and his colleagues at the University of Pittsburgh have developed a method that requires only information about the connectivity of the atoms, is computationally cheap, and is quick to run [1]. Their method accurately predicts howmetal oxides interact with hydrogen in a reaction important to energy storage and catalysis.","PeriodicalId":20136,"journal":{"name":"Physics","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135096423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T he printing press has been called the greatest invention of the last thousand years. The credit is often given to the 15th century German craftsman Johannes Gutenberg. However, a Korean collection of Buddhist teachings, the Jikji Simchi Yojeol,was printed with a press 78 years before Gutenberg produced his first Bible. What are the similarities and differences in the methods employed for printing the Jikji and the Gutenberg Bible? As part of a collaborative research project, researchers are addressing this question using an x-ray probe at SLAC National Accelerator Laboratory in California. What they learn about the chemical composition of ancient Eastern and Western texts will provide insight into how knowledge sharing between cultures shaped the technological evolution of printing.
{"title":"The History of the Printing Press under an X-Ray Microscope","authors":"Rachel Berkowitz","doi":"10.1103/physics.16.154","DOIUrl":"https://doi.org/10.1103/physics.16.154","url":null,"abstract":"T he printing press has been called the greatest invention of the last thousand years. The credit is often given to the 15th century German craftsman Johannes Gutenberg. However, a Korean collection of Buddhist teachings, the Jikji Simchi Yojeol,was printed with a press 78 years before Gutenberg produced his first Bible. What are the similarities and differences in the methods employed for printing the Jikji and the Gutenberg Bible? As part of a collaborative research project, researchers are addressing this question using an x-ray probe at SLAC National Accelerator Laboratory in California. What they learn about the chemical composition of ancient Eastern and Western texts will provide insight into how knowledge sharing between cultures shaped the technological evolution of printing.","PeriodicalId":20136,"journal":{"name":"Physics","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135097852","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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