西安金翅鸟演艺广场:广义相对论的基础！！

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转载自 天地无用 2010年07月12日 13:36 阅读(0) 评论(0) 分类：论文转载 权限: 公开

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广义相对论的基础   

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广义相对论是爱因斯坦继狭义相对论之后，深入研究引力理论，于1913年提出的引力场的相对论理论。这一理论完全不同于牛顿的引力论，它把引力场归结为物体周围的时空弯曲，把物体受引力作用而运动，归结为物体在弯曲时空中沿短程线的自由运动。因此，广义相对论亦称时空几何动力学，即把引力归结为时空的几何特性。  

如何理解广义相对论的时空弯曲呢？这里我们借用一个模型式的比拟来加以说明。假如有两个质量很大的钢球，按牛顿的看法，它们因万有引力相互吸引，将彼此接近。而爱因斯坦的广义相对论则并不认为这两个钢球间存在吸引力。它们之所以相互靠近，是由于没有钢球出现时，周围的时空犹如一张拉平的网，现在两个钢球把这张时空网压弯了，于是两个钢球就沿着弯曲的网滚到一起来了。这就相当于因时空弯曲物体沿短程线的运动。所以，爱因斯坦的广义相对论是不存在“引力”的引力理论。  

进一步说，这个理论是建立在等效原理及广义协变原理这两个基本假设之上的。等效原理是从物体的惯性质量与引力质量相等这个基本事实出发，认为引力与加速系中的惯性力等效，两者原则上是无法区分的；广义协变原理，可以认为是等效原理的一种数学表示，即认为反映物理规律的一切微分方程应当在所有参考系中保持形式不变，也可以说认为一切参考系是平等的，从而打破了狭义相对论中惯性系的特殊地位，由于参考系选择的任意性而得名为广义相对论。  

我们知道，牛顿的万有引力定律认为，一切有质量的物体均相互吸引，这是一种静态的超距作用。  

在广义相对论中物质产生引力场的规律由爱因斯坦场方程表示，它所反映的引力作用是动态的，以光速来传递的。  

广义相对论是比牛顿引力论更一般的理论，牛顿引力论只是广义相对论的弱场近似。所谓弱场是指物体在引力场中的引力能远小于固有能，力场中，才显示出两者的差别，这时必须应用广义相对论才能正确处理引力问题。  

广义相对论在1915年建立后，爱因斯坦就提出了可以从三个方面来检验其正确性，即所谓三大实验验证。这就是光线在太阳附近的偏折，水星近日点的进动以及光谱线在引力场中的频移，这些不久即为当时的实验观测所证实。以后又有人设计了雷达回波时间延迟实验，很快在更高精度上证实了广义相对论。60年代天文学上的一系列新发现：3K微波背景辐射、脉冲星、类星体、X射电源等新的天体物理观测都有力地支持了广义相对论，从而使人们对广义相对论的兴趣由冷转热。特别是应用广义相对论来研究天体物理和宇宙学，已成为物理学中的一个热门前沿。  

爱因斯坦一直把广义相对论看作是自己一生中最重要的科学成果，他说过，“要是我没有发现狭义相对论，也会有别人发现的，问题已经成熟。但是我认为，广义相对论不一样。”确实，广义相对论比狭义相对论包含了更加深刻的思想，这一全新的引力理论至今仍是一个最美好的引力理论。没有大胆的革新精神和不屈不挠的毅力，没有敏锐的理论直觉能力和坚实的数学基础，是不可能建立起广义相对论的。伟大的科学家汤姆逊曾经把广义相对论称作为人类历史上最伟大的成就之一。

英文： the basis of general relativity
  Following the general theory of relativity Einstein's special theory of relativity are after-depth study of the gravitational theory, in 1913 proposed the relativistic gravitational field theory. This theory is completely different from Newton's gravitational theory, it comes down to the gravitational field of space-time bending around objects, put objects by the gravitational effects of exercise, reduced to objects in space and time along the curved lines of free short-term exercise. Thus, also known as space-time geometry of general relativity dynamics, that is attributed to the gravitational properties of space-time geometry.

How to understand general relativity space-time bending it? Here we use a model of analogy to illustrate. If both have a lot of quality ball, according to Newton's view, they attract each other due to gravity will be near each other. Einstein's general theory of relativity and then do not think that exist between the two ball Attraction. They are close to each other because we do not have the ball appears, the space-time around the Net like a draw, and now put two balls this time and space bending Net, so the ball both on the Net roll bending down up to 1. This is equivalent to a result of bending space-time line of objects along the short-range exercise. Therefore, Einstein's general theory of relativity there is no "gravity" theory of gravity.

Furthermore, this theory is built on the equivalence principle and the principle of the generalized covariant basic assumptions on which the two. Objects are from the equivalence principle of inertial mass and gravitational mass equal to the basic facts that the Department of gravity and speed up the equivalent of the inertial force, which in principle can not distinguish; generalized covariant principle of equivalence principle can be considered a math that the physical laws that reflect all the differential equations at all the reference system should be to maintain the same form can also be said that the reference system are all equal, thus breaking the special theory of relativity in the special status of inertial system, because reference system of the arbitrary selection of the above-mentioned known as general relativity.

We know that Newton's law of gravity that all objects have the quality of both the mutual attraction, which is a static role of ultra-distance.

General relativity in the material produced in the gravitational field of the law by the Einstein field equations that reflect the gravity of its role is dynamic, with the speed of light to convey.

General relativity is Newton's gravitational theory than the more general theory, Newton's gravitational theory of general relativity is only a weak field approximation. Refers to the so-called weak-field gravitational objects in the gravitational field can be far less than the intrinsic energy, force field, the only difference between the two shows, when the application of general relativity must be right to deal with the gravitational problem.

Set up in 1915 in general relativity, the Einstein proposed that can be tested from three of its correctness, the so-called three experiments. This is the light deflection near the sun, Mercury precession, as well as spectral lines in the gravitational field of the frequency shift, which at that time is soon confirmed by the experimental observation. It was designed after the time delay of radar echo experiments soon confirmed on a more high-precision general relativity. 60's on a series of astronomical discoveries: 3K microwave background radiation, pulsars, quasars, X-launched a new power supply, such as astrophysical observations have vigorously supported the general theory of relativity, so that the interest of the general theory of relativity from cold to hot . In particular the application of general relativity to study astrophysics and cosmology, physics has become a popular front.

Einstein's general theory of relativity has put his own life as the most important scientific achievements, he said, "If I do not see the special theory of relativity, would have found someone else, the question is ripe. But in my opinion, not the same as general relativity . "Indeed, the general theory of relativity special theory of relativity contains more than deep thought, the new theory of gravity is still a best theory of gravity. NOT bold innovation and indomitable perseverance, there is no sharp instincts and a solid theory of basic math, it is impossible to establish a general theory of relativity. Thomson great scientist once said that as a general theory of relativity put up the history of mankind's greatest achievements.