According to some local properties of Lorentz transformation, Einstein stated: 'Vetheitiss greater than that of light have no possibility of existence.' He neglected to point out the applicable range of the sp...According to some local properties of Lorentz transformation, Einstein stated: 'Vetheitiss greater than that of light have no possibility of existence.' He neglected to point out the applicable range of the special theory of relativity. In fact, it could only be applied to the subluminal-speeds. This paper shows that if ones think of the possibility of the existence of the superluminal-speeds and redescribe the special theory of relativity following Einstein's way, it could be supposed that the physical spacetime is a Finsler spacetime, characterized by the metric ds4=gijkldxidxidxkdxl. If so, a new spactime transformation could be found by invariant ds4 and the theory of relativity is discussed on this transformation it is possible that the Finsler spacetime F(x,y) may be endowed with a catastrophic nature. Based on the different properties between the ds2 and ds4, it is discussed that the flat spacetime will also have the catastrophic nature on the Finsler metric ds4. The spacetime transformations and the Physical quantities will suddenly change at the catastrophe set of the spacetime, the light cone. It will be supposed that only the dual velocity of the superluminal-speeds could be observed. If so, a particle with the superluminal-speed v> c could be regarded as its anti-particle with the dual velocity v1=c2/ v< c. On the other hand, it could be assumed that the horizon of the field of the general relativity is also a catastrophic set. If so, a particle with the superluminal-speeds could be projected near the horizon of these fields, and the particle will move on the sauce-like curves. It is very interesting that, in the Schwarzschild fields, the theoretical calculation for the sauce-like curves should be in agreement with tie data of the superluminal expansion of extragalactic radio sources observed year after year. (see Gao, 1992b).The ca- tastrophe of spacetime has some deep cosmological means. According to the some interested subjects in the Process of evolution of the universe the catastrophe nature of the Finsler spacetime and its cosmological impli= cations are discussed. It is shown that the nature of the universal evolution could be attributed to the geometric features of the Finsler spacetime. (see Cao, 1993)展开更多
The first complete formulation of special relativity (SR) is that of Einstein who postulated the light speed invariance. The second level assumes the longitudinal length contractions and the slowing down of clock rate...The first complete formulation of special relativity (SR) is that of Einstein who postulated the light speed invariance. The second level assumes the longitudinal length contractions and the slowing down of clock rates by the same factor y-1. This level discusses the role of different synchronizations.In the third level SR is seen as a consequence of the spin motion of the elementary particles. It seems possible to detect the privileged system S for which the electromagnetic radiation due to the spin motion of all the electrons in the universe is isotropic.展开更多
Understanding the equation of state of cold dense matter,i.e.,those inside neutron stars,is a key problem in the multi-messenger astronomical era.In order to facilitate the scientific discussions between different com...Understanding the equation of state of cold dense matter,i.e.,those inside neutron stars,is a key problem in the multi-messenger astronomical era.In order to facilitate the scientific discussions between different commu-nities in the relevant fields,particularly between nuclear physicists and astrophysicists,we have organized the Dialo-gue at the Dream Field(DDF2024).The participants explored topics of various fields such as pulsar astrophysics,transient phenomena,hadronic and nuclear matter,supra-nuclear matter with quark degree of freedom,numerical relativity.This involved discussions on the mechanisms,model constructions,observational impacts,and introduc-tions of new facilities.In-depth exchanges were carried out through invited talks and free discussions,as well as a visit to view the FAST telescope.展开更多
An indoor location system based on multilayer artificial neural network（ANN） with area division is proposed.The characteristics of recorded signal strength（RSS）,or signal to noise ratio（SNR） from each available ...An indoor location system based on multilayer artificial neural network（ANN） with area division is proposed.The characteristics of recorded signal strength（RSS）,or signal to noise ratio（SNR） from each available access points（APs）,are utilized to establish the radio map in the off-line phase.And in the on-line phase,the two or three dimensional coordinates of mobile terminals（MTs） are estimated according to the similarity between the new recorded RSS or SNR and fingerprints pre-stored in radio map.Although the feed-forward ANN with three layers is sufficient to describe any nonlinear mapping relationship between inputs and outputs with finite discontinuous points,the efficient inputs for better training performances are difficult to be determined because of complex and dynamic indoor environment.Then,the discussion of distance relativity for different signal characteristics and optimal strategies for multi-mode phenomenon avoidance is presented.And also,the feasibility and effectiveness of this method are verified based on the experimental comparison with normal ANN without area division,K-nearest neighbor（KNN） and probability methods in typical office environment.展开更多
In this paper we recall the different definitions of simultaneity, the coordinate time interval and the velocity. It is emphasized that the above second two definitions depend on the simultaneity. We review the test t...In this paper we recall the different definitions of simultaneity, the coordinate time interval and the velocity. It is emphasized that the above second two definitions depend on the simultaneity. We review the test theories on special relativity. It is shown that anisotropy (if possible) of one-way speed of light has not any ef- fects in the physical experiments. Therefore anisotropy of one-way speed of light cannot be determined by the experiments, except if an absolute (standard) simultaneity would be found.展开更多
The Galilei covariant generalizations of the EM field equations (1984) (including moving media), Schroedinger, and Dirac (1985, 1993) equations for inertial frames S(w) with substratum velocity w are re- viewed. By G...The Galilei covariant generalizations of the EM field equations (1984) (including moving media), Schroedinger, and Dirac (1985, 1993) equations for inertial frames S(w) with substratum velocity w are re- viewed. By G-covariant electrodynamics, physical variables, e.g., rod length, clock rate, particle mass, momentum, and energy are G-invariants, determined by the object velocity v-w= vo=G-inv relative to the substratum frame, So(w=0) [v=object velocity relative to observer in S(w)] Galilean measurements using standard (i) contracted rods and (ii) retarded clocks, anisotropic light propagation, and conservation of EM energy and momentum in IFs S(w) are discussed. Fundamental experiments are formulated which permit measurement of substratum (w) induced EM and charge fields, the substratum velocity w, and verification of the G-invariance of the magnetic field, B= Bo=G-inv. The G-invariant Lagrangian and Hamiltonian of a charged particle in EM fields, and the momentum and energy conservation equations in Particle collisions are given for velocities |v-w|<co. The EM Doppler effects for moving source or moving observer are shown to exhibit measurable substratum effects. The spectral lines from a recoiling atom exhibit superimposed Doppler and substratum (w) shifts. The measurable substratum effects in the (i) aberration of light and (ii) reflection of light from a moving mirror are evaluated. The EM fields of accelerated charges in the substratum flow w are given, and applied to the anisotropic emission of x-rays in IFs S(w). G-covariant electrodynamics is examined for subluminal and superluminal electron velocities. Both the Cerenkov effect in (i) dielectrics for Iv--wl> c(ro) and (ii) vacuum for |v-w| > co are relative to the substratum So, and demonstrate the anisotropy of the vacuum in IFs S(w). G-covariant electrodynamics (relative to substratum) contains Lorentz covariant electrodynamics (relative to observer) in the special case w = 0 (So).展开更多
In most multi-function phased array radar applications, multiple missions, including airspace searching and target tracking, are usually performed simultaneously by the digital beam-forming technique and the time divi...In most multi-function phased array radar applications, multiple missions, including airspace searching and target tracking, are usually performed simultaneously by the digital beam-forming technique and the time dividing method. This paper presents a novel method to classify pulses of different missions from an interleaved pulse sequence emitted by the same radar, which is significant in radar electronic reconnaissance and electronic support measure. Firstly, two hypotheses, i.e., pulse relativity within the same mission and pulse independence among different missions, are proposed by analyzing the antenna pattern and the beam scheduling method of the phased array radar. Based on the above two hypotheses, an optimal model for pulse classification is exploited with pulse amplitude series, where the absolute-value sum of second order difference is taken as the optimal kernel to measure sequence smooth continuity. Finally, several pieces of sequences under different numbers of missions and tracking data rates are simulated for algorithm verification. The simulation results show that the long data length and the high data rate will increase classification efficiency due to the validity of the two hypotheses in sufficient pulse amplitude sequence.展开更多
The Global Positioning System (GPS) uses accurate atomic clocks in satellites and on the ground to provide world-wide position and time determination. These clocks have gravitational and motional frequency shifts whic...The Global Positioning System (GPS) uses accurate atomic clocks in satellites and on the ground to provide world-wide position and time determination. These clocks have gravitational and motional frequency shifts which are so large that, without properly accounting for relativistic effects, the system would not work. As a practical matter, therefore, many individuals who use the GPS need to understand how relativistic effects accounted for in the system. This paper discusses relativistic effects arising from both special relativity and general relativity, and how these effects are incorporated in GPS operations. Two introductory sections on kinematics in special and general relativity, respectively, are followed by a section which describes how relativistic effects should be accounted for. The concept of synchroization in the Earth-Centered Inertial frame is discussed in detail. Numerical and experimental examples are given, showing the sizes of the various effects. The treatment of special and general relativity is sufficiently complete that a person should be able to follow the development without much reference to external material, except that a few standard results have been quoted from textbooks without derivation.展开更多
Fundamental definitions of distance and velocity in radar measurement principle are examined and revised from strict theoretical point of view. Synchronization scheme - for clocks in uniform, translatory relative moti...Fundamental definitions of distance and velocity in radar measurement principle are examined and revised from strict theoretical point of view. Synchronization scheme - for clocks in uniform, translatory relative motion is introduced as theoretical foundation for GPS and GLONASS type navigation and positioning technology. Traditional definitions of two-way radar measurement, based on arithmetic mean vlaue concept, turn out to be special cases of revised definitions for one-way radar measurement, based on geometric mean concept, derived from synchronization of moving clocks in accordance with the principle of relativity. The essential physical meaning of Lorentz transformation is interpreted in terms of radar measured parameters. Invariance or absoluteness of four dimensional interval turns out to be invariance or absoluteness of geometric mean time interval. The Lorentz factor turns out to be ratio of geometric mean and arithmetic mean time intervals in terms of radar measured parameters. Theoretical results are illustrated transparently by numerical examples. A crucial experiment for direct testing of the second postulate of special relativity by means of GPS of GLONASS type technology is proposed in this paper.展开更多
基金The project was supported by National Natural Science Foundation of China.
文摘According to some local properties of Lorentz transformation, Einstein stated: 'Vetheitiss greater than that of light have no possibility of existence.' He neglected to point out the applicable range of the special theory of relativity. In fact, it could only be applied to the subluminal-speeds. This paper shows that if ones think of the possibility of the existence of the superluminal-speeds and redescribe the special theory of relativity following Einstein's way, it could be supposed that the physical spacetime is a Finsler spacetime, characterized by the metric ds4=gijkldxidxidxkdxl. If so, a new spactime transformation could be found by invariant ds4 and the theory of relativity is discussed on this transformation it is possible that the Finsler spacetime F(x,y) may be endowed with a catastrophic nature. Based on the different properties between the ds2 and ds4, it is discussed that the flat spacetime will also have the catastrophic nature on the Finsler metric ds4. The spacetime transformations and the Physical quantities will suddenly change at the catastrophe set of the spacetime, the light cone. It will be supposed that only the dual velocity of the superluminal-speeds could be observed. If so, a particle with the superluminal-speed v> c could be regarded as its anti-particle with the dual velocity v1=c2/ v< c. On the other hand, it could be assumed that the horizon of the field of the general relativity is also a catastrophic set. If so, a particle with the superluminal-speeds could be projected near the horizon of these fields, and the particle will move on the sauce-like curves. It is very interesting that, in the Schwarzschild fields, the theoretical calculation for the sauce-like curves should be in agreement with tie data of the superluminal expansion of extragalactic radio sources observed year after year. (see Gao, 1992b).The ca- tastrophe of spacetime has some deep cosmological means. According to the some interested subjects in the Process of evolution of the universe the catastrophe nature of the Finsler spacetime and its cosmological impli= cations are discussed. It is shown that the nature of the universal evolution could be attributed to the geometric features of the Finsler spacetime. (see Cao, 1993)
文摘The first complete formulation of special relativity (SR) is that of Einstein who postulated the light speed invariance. The second level assumes the longitudinal length contractions and the slowing down of clock rates by the same factor y-1. This level discusses the role of different synchronizations.In the third level SR is seen as a consequence of the spin motion of the elementary particles. It seems possible to detect the privileged system S for which the electromagnetic radiation due to the spin motion of all the electrons in the universe is isotropic.
文摘Understanding the equation of state of cold dense matter,i.e.,those inside neutron stars,is a key problem in the multi-messenger astronomical era.In order to facilitate the scientific discussions between different commu-nities in the relevant fields,particularly between nuclear physicists and astrophysicists,we have organized the Dialo-gue at the Dream Field(DDF2024).The participants explored topics of various fields such as pulsar astrophysics,transient phenomena,hadronic and nuclear matter,supra-nuclear matter with quark degree of freedom,numerical relativity.This involved discussions on the mechanisms,model constructions,observational impacts,and introduc-tions of new facilities.In-depth exchanges were carried out through invited talks and free discussions,as well as a visit to view the FAST telescope.
基金supported by the National High Technology Research and Development Program of China (863 Program)(2008AA12Z305)
文摘An indoor location system based on multilayer artificial neural network（ANN） with area division is proposed.The characteristics of recorded signal strength（RSS）,or signal to noise ratio（SNR） from each available access points（APs）,are utilized to establish the radio map in the off-line phase.And in the on-line phase,the two or three dimensional coordinates of mobile terminals（MTs） are estimated according to the similarity between the new recorded RSS or SNR and fingerprints pre-stored in radio map.Although the feed-forward ANN with three layers is sufficient to describe any nonlinear mapping relationship between inputs and outputs with finite discontinuous points,the efficient inputs for better training performances are difficult to be determined because of complex and dynamic indoor environment.Then,the discussion of distance relativity for different signal characteristics and optimal strategies for multi-mode phenomenon avoidance is presented.And also,the feasibility and effectiveness of this method are verified based on the experimental comparison with normal ANN without area division,K-nearest neighbor（KNN） and probability methods in typical office environment.
文摘In this paper we recall the different definitions of simultaneity, the coordinate time interval and the velocity. It is emphasized that the above second two definitions depend on the simultaneity. We review the test theories on special relativity. It is shown that anisotropy (if possible) of one-way speed of light has not any ef- fects in the physical experiments. Therefore anisotropy of one-way speed of light cannot be determined by the experiments, except if an absolute (standard) simultaneity would be found.
文摘The Galilei covariant generalizations of the EM field equations (1984) (including moving media), Schroedinger, and Dirac (1985, 1993) equations for inertial frames S(w) with substratum velocity w are re- viewed. By G-covariant electrodynamics, physical variables, e.g., rod length, clock rate, particle mass, momentum, and energy are G-invariants, determined by the object velocity v-w= vo=G-inv relative to the substratum frame, So(w=0) [v=object velocity relative to observer in S(w)] Galilean measurements using standard (i) contracted rods and (ii) retarded clocks, anisotropic light propagation, and conservation of EM energy and momentum in IFs S(w) are discussed. Fundamental experiments are formulated which permit measurement of substratum (w) induced EM and charge fields, the substratum velocity w, and verification of the G-invariance of the magnetic field, B= Bo=G-inv. The G-invariant Lagrangian and Hamiltonian of a charged particle in EM fields, and the momentum and energy conservation equations in Particle collisions are given for velocities |v-w|<co. The EM Doppler effects for moving source or moving observer are shown to exhibit measurable substratum effects. The spectral lines from a recoiling atom exhibit superimposed Doppler and substratum (w) shifts. The measurable substratum effects in the (i) aberration of light and (ii) reflection of light from a moving mirror are evaluated. The EM fields of accelerated charges in the substratum flow w are given, and applied to the anisotropic emission of x-rays in IFs S(w). G-covariant electrodynamics is examined for subluminal and superluminal electron velocities. Both the Cerenkov effect in (i) dielectrics for Iv--wl> c(ro) and (ii) vacuum for |v-w| > co are relative to the substratum So, and demonstrate the anisotropy of the vacuum in IFs S(w). G-covariant electrodynamics (relative to substratum) contains Lorentz covariant electrodynamics (relative to observer) in the special case w = 0 (So).
文摘In most multi-function phased array radar applications, multiple missions, including airspace searching and target tracking, are usually performed simultaneously by the digital beam-forming technique and the time dividing method. This paper presents a novel method to classify pulses of different missions from an interleaved pulse sequence emitted by the same radar, which is significant in radar electronic reconnaissance and electronic support measure. Firstly, two hypotheses, i.e., pulse relativity within the same mission and pulse independence among different missions, are proposed by analyzing the antenna pattern and the beam scheduling method of the phased array radar. Based on the above two hypotheses, an optimal model for pulse classification is exploited with pulse amplitude series, where the absolute-value sum of second order difference is taken as the optimal kernel to measure sequence smooth continuity. Finally, several pieces of sequences under different numbers of missions and tracking data rates are simulated for algorithm verification. The simulation results show that the long data length and the high data rate will increase classification efficiency due to the validity of the two hypotheses in sufficient pulse amplitude sequence.
基金This work was supported in pert by NIST Contract No. 40RANB9B8112.
文摘The Global Positioning System (GPS) uses accurate atomic clocks in satellites and on the ground to provide world-wide position and time determination. These clocks have gravitational and motional frequency shifts which are so large that, without properly accounting for relativistic effects, the system would not work. As a practical matter, therefore, many individuals who use the GPS need to understand how relativistic effects accounted for in the system. This paper discusses relativistic effects arising from both special relativity and general relativity, and how these effects are incorporated in GPS operations. Two introductory sections on kinematics in special and general relativity, respectively, are followed by a section which describes how relativistic effects should be accounted for. The concept of synchroization in the Earth-Centered Inertial frame is discussed in detail. Numerical and experimental examples are given, showing the sizes of the various effects. The treatment of special and general relativity is sufficiently complete that a person should be able to follow the development without much reference to external material, except that a few standard results have been quoted from textbooks without derivation.
文摘Fundamental definitions of distance and velocity in radar measurement principle are examined and revised from strict theoretical point of view. Synchronization scheme - for clocks in uniform, translatory relative motion is introduced as theoretical foundation for GPS and GLONASS type navigation and positioning technology. Traditional definitions of two-way radar measurement, based on arithmetic mean vlaue concept, turn out to be special cases of revised definitions for one-way radar measurement, based on geometric mean concept, derived from synchronization of moving clocks in accordance with the principle of relativity. The essential physical meaning of Lorentz transformation is interpreted in terms of radar measured parameters. Invariance or absoluteness of four dimensional interval turns out to be invariance or absoluteness of geometric mean time interval. The Lorentz factor turns out to be ratio of geometric mean and arithmetic mean time intervals in terms of radar measured parameters. Theoretical results are illustrated transparently by numerical examples. A crucial experiment for direct testing of the second postulate of special relativity by means of GPS of GLONASS type technology is proposed in this paper.
