这是一篇有关外星智能探索的最新报道。Are we alone in thegalaxy?从早期的无线电信号到现代的大型望远镜阵,人类对地外文明探索的脚步从未停止过。科技空前发展、资金相对充足,笑容不仅洋溢在科学家的脸上,希望也会在每一个相信地外...这是一篇有关外星智能探索的最新报道。Are we alone in thegalaxy?从早期的无线电信号到现代的大型望远镜阵,人类对地外文明探索的脚步从未停止过。科技空前发展、资金相对充足,笑容不仅洋溢在科学家的脸上,希望也会在每一个相信地外文明存在的人心中升起。展开更多
As we continue searching for exoplanets, we wonder if life and technological species capable of communicating with us exists on any of them. As geoscientists, we can also wonder how important is the presence or absenc...As we continue searching for exoplanets, we wonder if life and technological species capable of communicating with us exists on any of them. As geoscientists, we can also wonder how important is the presence or absence of plate tectonics for the evolution of technological species. This essay considers this question, focusing on tectonically active roclw （silicate） planets, like Earth, Venus, and Mars. The development of technological species on Earth provides key insights for understanding evolution on exoplanets, including the likely role that plate tectonics may play. An Earth-sized silicate planet is likely to experience several tectonic styles over its lifetime, as it cools and its lithosphere thickens, strengthens, and becomes denser. These include magma ocean, various styles of stagnant lid, and perhaps plate tectonics. Abundant liquid water favors both life and plate tectonics. Ocean is required for early evolution of diverse single-celled organisms, then colonies of cells which specialized further to form guts, ap- pendages, and sensory organisms up to the complexity of fish （central nervous system, appendages, eyes）. Large expanses of dry land also begin in the ocean, today produced above subduction zones in juvenile arcs and by their coalescence to form continents, although it is not clear that plate tectonics was required to create continental crust on Earth. Dry land of continents is required for further evolution of technological species, where modification of appendages for grasping and manipulating, and improve- ment of eyes and central nervous system could be perfected. These bioassets allowed intelligent crea- tures to examine the night sky and wonder, the beginning of abstract thinking, including religion and science. Technology arises from the exigencies of daily living such as tool-making, agriculture, clothing, and weapons, but the pace of innovation accelerates once it is allied with science. Finally, the importance of plate tectonics for developing a technological species is examined via a thought experiment using two otherwise identical planets： one with plate tectonics and the other without. A planet with oceans, continents, and plate tectonics maximizes opportunities for speciation and natural selection, whereas a similar planet without plate tectonics provides fewer such opportunities. Plate tectonics exerts envi- ronmental pressures that drive evolution without being capable of extinguishing all life. Plate tectonic processes such as the redistribution of continents, growth of mountain ranges, formation of land bridges, and opening and closing of oceans provide a continuous but moderate environmental pressure that stimulates populations to adapt and evolve. Plate tectonics may not be needed in order for life to begin, but evolution of technological species is favored on planets with oceans, continents, plate tectonics, and intermittently clear night sky.展开更多
The Drake formula is a statistical method of forecasting the possible number N of technically evolved extraterrestrial and galactic civilizations able to communicate with the human species. It is based on seven differ...The Drake formula is a statistical method of forecasting the possible number N of technically evolved extraterrestrial and galactic civilizations able to communicate with the human species. It is based on seven different factors that can be grouped into factors of type A, f<sub>A</sub> (“Astrophysicist”) and type B, f<sub>B</sub> (“Astrobiological”). The quantitative analysis of these factors at the time of the presentation of the formula was subjective and highly variable for both factors f<sub>A</sub> and f<sub>B</sub>. Current scientifical and technological development has made it possible to refine the quantitative estimates of the f<sub>A</sub> group whose definition is now less uncertain. In group f<sub>A</sub> the parameter n<sub>e</sub> is understood as the number of planets capable of sustaining life. By means of n<sub>e</sub> Drake defines this possibility exclusively from the geometric point of view. In particular, the planet’s orbit must be included in the circumstellar space in which the planetary temperature allows the presence of liquid water. This is not enough because, for liquid (and gaseous) water to be present on the planet’s surface, it is also essential that the planet has a magnetic field of adequate intensity to shield the flow of charged particles coming from its star (solar wind). The solar wind is able to break up and disperse the liquid and gaseous water molecules and any organic molecules in times much shorter than theoretically necessary for the formation of life and above all, except for singularities, than necessary for evolution to arrive at intelligent life. Here the planetary magnetic field parameter n<sub>m</sub> is introduced into the Drake formula and its statistical probability of existence is discussed.展开更多
The inherent unpredictability of the maritime environment leads to low rates of survival during accidents.Life jackets serve as a crucial safety measure in underwater environments.Nonetheless,most conventional life ja...The inherent unpredictability of the maritime environment leads to low rates of survival during accidents.Life jackets serve as a crucial safety measure in underwater environments.Nonetheless,most conventional life jackets lack the capability to monitor the wearer's underwater body movements,impeding their effectiveness in rescue operations.Here,we present an intelligent self-powered life jacket system(SPLJ)composed of a wireless body area sensing network,a set of deep learning analytics,and a human condition detection platform.Six coaxial core-shell structure triboelectric fiber sensors with high sensitivity,stretchability,and flexibility are integrated into this system.Addi-tionally,a portable integrated circuit module is incorporated into the SPLJ to facilitate real-time monitoring of the wearer's movement.Moreover,by leveraging the deep-learning-assisted data analytics and establishing a robust correlation between the wearer's movements and condition,we have developed a comprehensive system for monitoring drowning individuals,achieving an outstanding recognition accuracy of 100%.This groundbreaking work intro-duces a fresh approach to underwater intelligent survival devices,offering promising prospects for advancing underwater smart wearable devices in rescue operations and the development of ocean industry.展开更多
基金supported by a generous grant from the Gordon and Betty Moore Foundation
文摘As we continue searching for exoplanets, we wonder if life and technological species capable of communicating with us exists on any of them. As geoscientists, we can also wonder how important is the presence or absence of plate tectonics for the evolution of technological species. This essay considers this question, focusing on tectonically active roclw （silicate） planets, like Earth, Venus, and Mars. The development of technological species on Earth provides key insights for understanding evolution on exoplanets, including the likely role that plate tectonics may play. An Earth-sized silicate planet is likely to experience several tectonic styles over its lifetime, as it cools and its lithosphere thickens, strengthens, and becomes denser. These include magma ocean, various styles of stagnant lid, and perhaps plate tectonics. Abundant liquid water favors both life and plate tectonics. Ocean is required for early evolution of diverse single-celled organisms, then colonies of cells which specialized further to form guts, ap- pendages, and sensory organisms up to the complexity of fish （central nervous system, appendages, eyes）. Large expanses of dry land also begin in the ocean, today produced above subduction zones in juvenile arcs and by their coalescence to form continents, although it is not clear that plate tectonics was required to create continental crust on Earth. Dry land of continents is required for further evolution of technological species, where modification of appendages for grasping and manipulating, and improve- ment of eyes and central nervous system could be perfected. These bioassets allowed intelligent crea- tures to examine the night sky and wonder, the beginning of abstract thinking, including religion and science. Technology arises from the exigencies of daily living such as tool-making, agriculture, clothing, and weapons, but the pace of innovation accelerates once it is allied with science. Finally, the importance of plate tectonics for developing a technological species is examined via a thought experiment using two otherwise identical planets： one with plate tectonics and the other without. A planet with oceans, continents, and plate tectonics maximizes opportunities for speciation and natural selection, whereas a similar planet without plate tectonics provides fewer such opportunities. Plate tectonics exerts envi- ronmental pressures that drive evolution without being capable of extinguishing all life. Plate tectonic processes such as the redistribution of continents, growth of mountain ranges, formation of land bridges, and opening and closing of oceans provide a continuous but moderate environmental pressure that stimulates populations to adapt and evolve. Plate tectonics may not be needed in order for life to begin, but evolution of technological species is favored on planets with oceans, continents, plate tectonics, and intermittently clear night sky.
文摘The Drake formula is a statistical method of forecasting the possible number N of technically evolved extraterrestrial and galactic civilizations able to communicate with the human species. It is based on seven different factors that can be grouped into factors of type A, f<sub>A</sub> (“Astrophysicist”) and type B, f<sub>B</sub> (“Astrobiological”). The quantitative analysis of these factors at the time of the presentation of the formula was subjective and highly variable for both factors f<sub>A</sub> and f<sub>B</sub>. Current scientifical and technological development has made it possible to refine the quantitative estimates of the f<sub>A</sub> group whose definition is now less uncertain. In group f<sub>A</sub> the parameter n<sub>e</sub> is understood as the number of planets capable of sustaining life. By means of n<sub>e</sub> Drake defines this possibility exclusively from the geometric point of view. In particular, the planet’s orbit must be included in the circumstellar space in which the planetary temperature allows the presence of liquid water. This is not enough because, for liquid (and gaseous) water to be present on the planet’s surface, it is also essential that the planet has a magnetic field of adequate intensity to shield the flow of charged particles coming from its star (solar wind). The solar wind is able to break up and disperse the liquid and gaseous water molecules and any organic molecules in times much shorter than theoretically necessary for the formation of life and above all, except for singularities, than necessary for evolution to arrive at intelligent life. Here the planetary magnetic field parameter n<sub>m</sub> is introduced into the Drake formula and its statistical probability of existence is discussed.
基金support received from the Natural Science Foundation of the Beijing Municipality(grant nos.L222037,2212052)the National Natura Science Foundation of China(grant no.22109012)the Fundamental Research Funds for the Central Universities(grant no.E1E46805).
文摘The inherent unpredictability of the maritime environment leads to low rates of survival during accidents.Life jackets serve as a crucial safety measure in underwater environments.Nonetheless,most conventional life jackets lack the capability to monitor the wearer's underwater body movements,impeding their effectiveness in rescue operations.Here,we present an intelligent self-powered life jacket system(SPLJ)composed of a wireless body area sensing network,a set of deep learning analytics,and a human condition detection platform.Six coaxial core-shell structure triboelectric fiber sensors with high sensitivity,stretchability,and flexibility are integrated into this system.Addi-tionally,a portable integrated circuit module is incorporated into the SPLJ to facilitate real-time monitoring of the wearer's movement.Moreover,by leveraging the deep-learning-assisted data analytics and establishing a robust correlation between the wearer's movements and condition,we have developed a comprehensive system for monitoring drowning individuals,achieving an outstanding recognition accuracy of 100%.This groundbreaking work intro-duces a fresh approach to underwater intelligent survival devices,offering promising prospects for advancing underwater smart wearable devices in rescue operations and the development of ocean industry.
