关于尺缩,钟慢公式的使用

本文指出并分析了使用尺缩和钟慢公式时常出现的错误。     

光束“尺缩效应”的探讨

推导出在沿着或垂直于光束运动的参照系中,光束的长度和宽度的变化规律。并且得出以光速运动的几何尺度,在不同的参照系中也有着和光束相同的变化规律。我们比较了这种光束的尺缩效应与一般物体尺缩效应的不同之处,最后又推导出光束的体积在不同参照系中的变化公式。     

哪一个钟慢了?--关于相对论中钟慢效应的进一步讨论

通过例子阐明狭义相对论中钟慢效应是相互的道理。     

关于相对论中尺缩效应的相互性

通过例子对尺缩效应的相互性进行了阐明 .     

狭义相对论中动尺收缩效应之认识

动尺收缩是狭义相对论时空观的经典效应之一,本文从一道例题的错误解法出发,阐述狭义相对论中同时的相对性是形成动尺收缩效应的原因。     

狭义相对论中动尺收缩效应之认识

1905年,爱因斯坦创立了狭义相对论,从而把牛顿力学中对宏观低速物体的研究推广到高速运动的物体,得到了一套崭新的时空观.动尺收缩是狭义相对论时空观的经典效应,狭义相对论时空观的基础是同时的相对性.因此同时的相对性与动尺收缩效应存在必然的联系.     

狭义相对论学习中学生的错误理解研究概述

狭义相对论作为经典物理与近代物理的分水岭,对学生认识科学本质具有深远的影响.然而实际教学与研究显示,学生对狭义相对论存在许多错误理解.为了解决这一问题,本文梳理了国内外关于狭义相对论学习的相关研究.根据狭义相对论的知识框架,总结了学生在狭义相对论学习中普遍存在的错误理解,并分析其背后的原因,以期为未来狭义相对论的教学与研究提供借鉴.     

关于运动的钟变慢的讨论

"运动的钟变慢"是相互的.通过这个结论,本文进一步论证处在两个不同惯性系的两个时钟,它们的读数与观察者所处的惯性系无关.     

相对论的几何表述

相对论的几何表述②梁灿彬（北京师范大学物理系，北京１００８７５）２．４“尺缩”效应质点在三维语言中是空间的一点，在四维语言中是时空中的一条类时线（世界线）．同理，一把细尺在三维语言中是一段直线，在四维语言中则是一个二维面（称为世界面，是介于尺头、尺尾...     

对长度收缩的另一种看法

介绍对长度收缩的另一种看法,即被测量者如何看待别人的测量,并讨论产生不同看法的原因．     

Spatial measures in special relativity do not empirically determine simultaneity relations: A reply to Coleman and Korté

Coleman and Korté have restated and defended an earlier attempt to refute the traditional thesis of the conventionality of simultaneity within special relativity. Here we argue their attempt still fails and respond to criticisms of a paper in which we addressed the inadequacies of their earlier paper. The spatial criterion they use to argue for standard synchronization throughout an inertial frame is merely a definition and provides no demonstration that a unique distant simultaneity relation exists in nature.     

基于狭义相对论的同时性对长度收缩佯谬的认识

利用狭义相对论对同时性的理解,指出了关于一种长度收缩佯谬解释的不妥之处,并解释了改进后的关于长度收缩佯谬的提法,证明了在不同参照系上的观测者观测所得到的结论相同.     

Distance and the conventionality of simultaneity in special relativity

The conventionality of simultaneity within inertial frames is presented in a general formalism that clarifies the relationship of spatial measures to the choice of simultaneity. A number of claims that such measures undermine the conventional nature of simultaneity are presented and shown to be unfounded. In particular, a recent claim by Coleman and Korte [9] that such measures empirically establish a unique simultaneity relationship is shown to be in error. In addition, the general formalism enables the empirical status of simultaneity within an inertial frame to be clarified by presenting the choice of simultaneity as a gauge choice.1. Recent introductions to the literature have been given by Redhead [35], Ungar [47], Havas [21], and Vetharaniam and Stedman [48].2. The conventionalist position is by no means a uniform one, and in particular, it is worth noting an important distinction exemplified in the respective positions of Reichenbach and Grünbaum. For Reichenbach [37, p. 144f.] we have no empirical access to the one-way speed of light due to the nature of light as a first signal, and the conventionality comes from our absence ofknowledge about the one-way speed of light. For Grünbaum the one-way speed of light is actually objectively undetermined, and the physical attributes that sustain a speed in a given direction are non-existent. See, for example, [16, p. 87] and [17, p. 352]. Discussions of the differences between the positions of Reichenbach and Grünbaum may be found in [14] and [35]. Naturally, one may adhere to a position espoused by Reichenbach without the added ontological commitment of Grünbaum.3. Our is equivalent to (1 - 2), where is the symbol introduced by Reichenbach and customarily used in the discussions of the conventionality of simultaneity.4. An exposition of this argument may be found in the recent text by Lucas and Hodgson [28].5. Schrödinger [42, p. 78] has aptly labeled this quantity the distance of simultaneity.6. Examples of previous uses space-dependent synchrony parameters may be found in studies by Clifton [8], Havas [21], Anderson and Stedman [1], and Stedman [43; 44, § 2].7. This approach has been reviewed by Basri in [4] and [3].8. A number of faulty assessments of the empirical status of the conventionality of simultaneity may be similarly traced at least in part to overly simplistic assumptions on the nature of as Havas [21] and Clifton [8], for example, have had occasion to point out.9. See, for example, [1]. Kinematic formula relating other quantities in a treatment of STR without the standard convention on the one-way speed of light were first derived by Winnie [53].10. In comparison to other space dependent treatments of the synchrony parameter, ourh is analogous to defined by Clifton in Eq. (15) of [8], and equivalent to -f defined by Havas in Eq. (A1) of [21] and to defined in Eq. (6) of our earlier treatment in [1]. We take this opportunity to mention that the irrotational property ofh was inadvertently referred to as solenoidal in this work.11. Equation (26) is equivalent to Møller's expression in § 8.8 of [32] for the speed of light in terms of the metric components where our-h _i is equivalent to Møller's _i (g _i0)/ .12. Note as well, the expression of this operation in standard texts on STR by Rindler [38, pp. 27–28] and Mermin [30, p. 79] respectively: To measure the rod's length in any inertial frame in which it moves longitudinally, its end-point must be observed simultaneously... and, ...a measurement of the length of a moving meter stick involves determining how far apart the two ends areat the same time. In the same context of determining the length of moving rods, Mermin [30, p. 185] proposes that the sense of length entailing the concept of being determined at simultaneous times is inherent in the notion of rods: ...it is precisely the lines of constant time that determine whatA orB means by the stick. For the notion of the stick includes implicitly the assumption that all the points of matter making up the stick exist at the same moment.13. In many ways the claim that the special properties of proper lengths with Einstein synchronization undermines the conventionality of simultaneity is analogous to the claim that the correspondence of the slow-clock transport method of synchronization with that of Einstein synchronization provides an empirical determination of synchronization. The use of clock transport as a means for synchronization was discussed by Reichenbach [37, p. 133f], while the proposal that slow transport of clocks provides a unique form of synchronization was first argued for by Eddington [10]. Arguments that it undermines any significant sense of the conventionality in the one-way speed of light have been given by Ellis and Bowman [13] with responses by Grünbaum [19] and Salmon [41, 40].14. Coleman and Korte [9, pp. 423–425] claim their method is free from any assumptions on the one-way speed of light; however, they assume that is a constant 3-vector.15. Reichenbach explicitly mentioned in [36, § 43] that a condition equivalent to Eq. (13) is a sufficient condition for a constant roundtrip speed of light.16. The remarks of one of the referees have served to alert us to the need to emphasize both of these points.17. The manner in which gravity may be viewed as a gauge theory has been the subject of considerable discussion (see, for example, the discussion in [23] and [24]). We note that the manner in which we are takingh as a potential differs from the sense in which the Christoffel symbols as affine connections may be seen to play a role of gauge potentials in GTR.18. A discussion of the significance of Weyl's work and the importance of the round-trip measurements may be found in works by Yang [56] and Mills [31].19. In the context only of time orthogonal coordinates, an example of the fiber structure we are imposing on space and time may be found in [26, p. 71f]. Again we note that in a more general treatment, where the Christoffel symbols are considered as connections, the fiber structure instead consists of a bundle of linear frames of Riemannian spacetime (see, for example, the presentations in [46] and [23]).20. Our position is not unlike Göckeler and Schücker's [15, p. 75] claim that Einstein's particular choice of coordinates in GTR masks the general gauge structure of the theory.     

狭义相对论中同时性的研究

本文对狭义相对论中＂同时性＂的基础和＂尺缩钟慢＂效应的本质进行了深入探讨.＂绝对同时＂和＂绝对静止＂一样是不存在的,＂同时＂和＂静止＂都具有相对性.以此为出发点,本文对一个不能直接应用＂尺缩钟慢＂效应解决的物理问题进行了深入研究.结果表明只要找到与正在发生的事件始终保持相对静止的惯性参考系,我们就可以引入＂固有时间＂的概念,再结合＂尺缩钟慢＂效应得到相应事件相对于地面参考系的时间变化规律.     

狭义相对论教学中的几个问题

本文讨论了相对论教学中几个方面的问题,包括常见例子的问题,洛伦兹变换的方便形式,同时相对性例子在另一参考系的讨论,长度测量在另一参考系看到的现象,时间延缓及运动参考系各点时间不同和光的多普勒效应的简单推导.通过不同过程在不同参考系中的讨论,掌握在运动系讨论问题的方法,以及同一过程在不同惯性系内的不同表现,而所有现象的测量结论在洛伦兹变换下保持不变.     

On attempts to rescue the conventionality thesis of distant simultaneity in str

Recently, some conventionalists have tried to rescue the conventionality of distant simultaneity by introducing a spatially dependent (x,y,z), where {1,2,3}. In this paper, we show that this attempt fails by providing a detailed analysis of the coordinate independent and non-conventional procedure for directly measuring the metricd _M ² on eventspace with respect to a physical radar coordinate system. The measuredd _M ² in turn provides the empirical basis for uniquely determining the hyperplanes of space for a given inertial observer in a way that makes absolutely no reference whatsoever to any kind of synchrony, whether spatially dependent or not except for the sole purpose of assigning physical coordinates to events.     

Beltrami-de Sitter时空和de Sitter不变的狭义相对论

分析了在相对论体系中狭义相对性原理和宇宙学原理之间的关系以及Beltrami-de Sitter -陆启铿疑难.指出可以把狭义相对性原理推广到非零常曲率时空，在具有Beltrami度规 的de Sitter/反de Sitter时空中建立狭义相对论的运动学和粒子动力学. 在这类狭义相对 论中,相对于Beltrami坐标同时性，Beltrami坐标系就是惯性坐标系，相应的观测者为惯 性观测者; 对于自由粒子和光讯号, 惯性定律成立;可以定义可观测量,它们不但守恒而且还 满足推广的爱因斯坦关系.除了Beltrami坐标时同时性之外，对于共动观测, 还可以取固 有时同时性;此时，Beltrami度规成为Robertson-Walker型的度规，其3维空间是闭的,对 于平坦的偏离为宇宙学常数的量级.这表明,在这类狭义相对论中,相对性原理与“完美”宇 宙学原理之间存在内在联系,并不存在那些问题.进而,基于最新观测事实，重述了Mach原 理；指出对于Beltrami-de Sitter/反de Sitter时空，宇宙学常数恰恰给出惯性运动的起 源. 关键词： 狭义相对性原理 宇宙学原理 de Sitter不变的狭义相对论 Beltrami-de Sitter时空 同时性 Mach原理     

基于相对性原理的多普勒效应公式推导

“大学物理”旨在向学生传递“联系”与“统一”的思想,但众多的教材在推导多普勒效应公式时却没有深入探寻“相对运动”与“频率变化”之间的联系和统一.作者从波长的定义着手,基于相对性原理,应用伽利略变换式对机械波的多普勒效应公式进行推导和应用验证;采用洛伦兹变化式对电磁波的多普勒效应公式进行推导.通过推导机械波和电磁波的多普勒效应公式,揭示了多普勒效应的频率变化实际是在不同惯性系中的测量结果.