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A life-size—and moveable—cat figure in the garden of Huttenstrasse 9, Zurich, where Erwin Schrödinger lived 1921–1926. A visitor to the house cannot know in advance where the cat will be.

A life-size—and moveable—cat figure in the garden of Huttenstrasse 9, Zurich, where Erwin Schrödinger lived 1921–1926. A visitor to the house cannot know in advance where the cat will be.

Schrödinger intended his thought experiment as a discussion of the [[EPR paradox|EPR article]]—named after its authors [[Albert Einstein|Einstein]], [[Boris Podolsky|Podolsky]], and [[Nathan Rosen|Rosen]]—in 1935.<ref>[http://prola.aps.org/abstract/PR/v47/i10/p777_1 Can Quantum-Mechanical Description of Physical Reality Be Considered Complete?] {{webarchive|url=https://web.archive.org/web/20060208145129/http://prola.aps.org/abstract/PR/v47/i10/p777_1 |date=2006-02-08 }} A. Einstein, B. Podolsky, and N. Rosen, Phys. Rev. 47, 777 (1935)</ref> The EPR article highlighted the counterintuitive nature of [[quantum superposition]]s, in which a quantum system such as an [[atom]] or [[photon]] can exist as a combination of multiple states corresponding to different possible outcomes.

Schrödinger intended his thought experiment as a discussion of the [[EPR paradox|EPR article]]—named after its authors [[Albert Einstein|Einstein]], [[Boris Podolsky|Podolsky]], and [[Nathan Rosen|Rosen]]—in 1935.<ref>[http://prola.aps.org/abstract/PR/v47/i10/p777_1 Can Quantum-Mechanical Description of Physical Reality Be Considered Complete?] {{webarchive|url=https://web.archive.org/web/20060208145129/http://prola.aps.org/abstract/PR/v47/i10/p777_1 |date=2006-02-08 }} A. Einstein, B. Podolsky, and N. Rosen, Phys. Rev. 47, 777 (1935)</ref> The EPR article highlighted the counterintuitive nature of [[quantum superposition]]s, in which a quantum system such as an [[atom]] or [[photon]] can exist as a combination of multiple states corresponding to different possible outcomes.

Schrödinger intended his thought experiment as a discussion of the EPR article—named after its authors Einstein, Podolsky, and Rosen—in 1935. The EPR article highlighted the counterintuitive nature of quantum superpositions, in which a quantum system such as an atom or photon can exist as a combination of multiple states corresponding to different possible outcomes.

Schrödinger intended his thought experiment as a discussion of the EPR article—named after its authors Einstein, Podolsky, and Rosen—in 1935. The EPR article highlighted the counterintuitive nature of quantum superpositions, in which a quantum system such as an atom or photon can exist as a combination of multiple states corresponding to different possible outcomes.

薛定谔打算把他的思维实验作为对'''<font color="#ff8000">电子顺磁共振EPR</font>'''文章（以其作者爱因斯坦、波多尔斯基和罗森的名字命名）的讨论在1935年进行了讨论。EPR文章强调了量子叠加的反直觉性质，在量子叠加中，一个量子系统，比如原子或者光子，可以作为对应不同可能结果的多个状态的组合而存在。

1935年，薛定谔提出该思维实验是对'''<font color="#ff8000">EPR佯谬</font>'''论文（以其作者爱因斯坦、波多尔斯基和罗森英文首字母命名）的讨论。EPR文章强调了量子叠加的反直觉性质，在量子叠加中，一个量子系统，比如原子或者光子，可以作为对应不同可能结果的多个状态的组合而存在。

The prevailing theory, called the Copenhagen interpretation, says that a quantum system remains in superposition until it interacts with, or is observed by the external world. When this happens, the superposition collapses into one or another of the possible definite states. The EPR experiment shows that a system with multiple particles separated by large distances can be in such a superposition. Schrödinger and Einstein exchanged letters about Einstein's EPR article, in the course of which Einstein pointed out that the  state of an unstable keg of gunpowder will, after a while, contain a superposition of both exploded and unexploded states.

The prevailing theory, called the Copenhagen interpretation, says that a quantum system remains in superposition until it interacts with, or is observed by the external world. When this happens, the superposition collapses into one or another of the possible definite states. The EPR experiment shows that a system with multiple particles separated by large distances can be in such a superposition. Schrödinger and Einstein exchanged letters about Einstein's EPR article, in the course of which Einstein pointed out that the  state of an unstable keg of gunpowder will, after a while, contain a superposition of both exploded and unexploded states.

哥本哈根诠释这一理论是当时流行的理论，它认为量子系统在与外部世界相互作用或被外部世界观察之前一直处于叠加状态。发生这种情况时，叠加态会坍缩成一种或另一种种可能的定态。电子顺磁共振(EPR)实验表明，具有多个相距较远距离的多个粒子的系统可能处于这种叠加状态。薛定谔和爱因斯坦就爱因斯坦的 EPR 文章互相通信。在此过程中，爱因斯坦指出，不稳定的火药桶的状态会在一段时间后包含爆炸状态和未爆炸状态的叠加。

哥本哈根诠释是主流理论，它认为量子系统在与外部世界相互作用或被外部世界观察之前一直处于叠加状态。发生这种情况时，叠加态会坍缩成一种或另一种可能的定态。EPR实验表明，具有多个相距较远的粒子的系统可能处于这种叠加状态。薛定谔和爱因斯坦就爱因斯坦的 EPR 佯谬论文通信，在信件中，爱因斯坦指出，不稳定的火药桶的状态会在一段时间后包含爆炸状态和未爆炸状态的叠加。

To further illustrate, Schrödinger described how one could, in principle, create a superposition in a large-scale system by making it dependent on a quantum particle that was in a superposition.  He proposed a scenario with a cat in a locked steel chamber, wherein the cat's life or death depended on the state of a radioactive atom, whether it had decayed and emitted radiation or not. According to Schrödinger, the Copenhagen interpretation implies that the cat remains both alive and dead until the state has been observed. Schrödinger did not wish to promote the idea of dead-and-alive cats as a serious possibility; on the contrary, he intended the example to illustrate the absurdity of the existing view of quantum mechanics.

To further illustrate, Schrödinger described how one could, in principle, create a superposition in a large-scale system by making it dependent on a quantum particle that was in a superposition.  He proposed a scenario with a cat in a locked steel chamber, wherein the cat's life or death depended on the state of a radioactive atom, whether it had decayed and emitted radiation or not. According to Schrödinger, the Copenhagen interpretation implies that the cat remains both alive and dead until the state has been observed. Schrödinger did not wish to promote the idea of dead-and-alive cats as a serious possibility; on the contrary, he intended the example to illustrate the absurdity of the existing view of quantum mechanics.

  ——Solitude（讨论）该句意译  

  ——Solitude（讨论）该句意译  

However, since Schrödinger's time, other interpretations of the mathematics of quantum mechanics have been advanced by physicists, some of which regard the "alive and dead" cat superposition as quite real.    Intended as a critique of the Copenhagen interpretation (the prevailing orthodoxy in 1935), the Schrödinger's cat thought experiment remains a defining touchstone for modern interpretations of quantum mechanics. Physicists often use the way each interpretation deals with Schrödinger's cat as a way of illustrating and comparing the particular features, strengths, and weaknesses of each interpretation.

However, since Schrödinger's time, other interpretations of the mathematics of quantum mechanics have been advanced by physicists, some of which regard the "alive and dead" cat superposition as quite real.    Intended as a critique of the Copenhagen interpretation (the prevailing orthodoxy in 1935), the Schrödinger's cat thought experiment remains a defining touchstone for modern interpretations of quantum mechanics. Physicists often use the way each interpretation deals with Schrödinger's cat as a way of illustrating and comparing the particular features, strengths, and weaknesses of each interpretation.

但是，自从薛定谔时代以来，物理学家对'''<font color=”#ff8000”>量子力学数学mathematics of quantum mechanics</font>'''进行了其他解释，其中一些解释认为“活死”的猫的叠加是十分真实的。作为对哥本哈根诠释的批判(1935年盛行的正统观念) ，薛定谔的猫这一思维实验仍然是现代量子力学诠释的决定性的试金石。物理学家经常使用每种解释处理薛定谔猫的方式来说明和比较每种解释的特点、优缺点。

但是，自从薛定谔时代以来，物理学家提出了诸多其他'''<font color=”#ff8000”>量子力学quantucsm mechanics</font>'''的数学解释，其中一些解释认为处于“活且死”叠加态的猫是十分真实的。薛定谔的猫意在批判哥本哈根诠释(1935年的主流正统学说) ，至今仍是各种现代量子力学诠释的决定性的试金石。物理学家经常使用每种诠释处理薛定谔猫的方式来说明和比较每种解释的特点、优点和缺点。

Schrödinger's famous thought experiment poses the question, "when does a quantum system stop existing as a superposition of states and become one or the other?"  (More technically, when does the actual quantum state stop being a non-trivial linear combination of states, each of which resembles different classical states, and instead begin to have a unique classical description?) If the cat survives, it remembers only being alive. But explanations of the EPR experiments that are consistent with standard microscopic quantum mechanics require that macroscopic objects, such as cats and notebooks, do not always have unique classical descriptions. The thought experiment illustrates this apparent paradox. Our intuition says that no observer can be in a mixture of states—yet the cat, it seems from the thought experiment, can be such a mixture. Is the cat required to be an observer, or does its existence in a single well-defined classical state require another external observer? Each alternative seemed absurd to Einstein, who was impressed by the ability of the thought experiment to highlight these issues. In a letter to Schrödinger dated 1950, he wrote:

Schrödinger's famous thought experiment poses the question, "when does a quantum system stop existing as a superposition of states and become one or the other?"  (More technically, when does the actual quantum state stop being a non-trivial linear combination of states, each of which resembles different classical states, and instead begin to have a unique classical description?) If the cat survives, it remembers only being alive. But explanations of the EPR experiments that are consistent with standard microscopic quantum mechanics require that macroscopic objects, such as cats and notebooks, do not always have unique classical descriptions. The thought experiment illustrates this apparent paradox. Our intuition says that no observer can be in a mixture of states—yet the cat, it seems from the thought experiment, can be such a mixture. Is the cat required to be an observer, or does its existence in a single well-defined classical state require another external observer? Each alternative seemed absurd to Einstein, who was impressed by the ability of the thought experiment to highlight these issues. In a letter to Schrödinger dated 1950, he wrote:

薛定谔著名的思维实验提出了这样一个问题: “量子系统何时会停止作为叠加态而成为其中之一? ”(从技术上讲，什么时候实际的量子态不再是非平凡的线性组合状态，而是开始有一个独特的经典描述?)如果猫活下来了，它只记得活着。但是，与标准微观量子力学相一致的EPR实验的解释要求宏观物体，例如猫和笔记本，并不总是具有独特的经典描述。这个思维实验说明了这个明显的悖论。我们的直觉告诉我们，任何观察者都不可能处于混合的状态——然而，从思维实验来看，猫可能是这样的状态。这只猫是否需要成为观察者，或者它在一个定义明确的经典状态下的存在是否需要其他外部观察者？对爱因斯坦来说，每一种选择都是荒谬的，他对思维实验突出这些问题的能力印象深刻。在1950年写给薛定谔的一封信中，他写道:

薛定谔著名的思维实验提出了一个问题: “量子系统何时会脱离叠加态转而塌缩为其中一个状态? ”（更严格地说，从何时起实际的量子态不再是多个经典态的非平凡线性组合，而是开始有一个唯一的经典描述？）如果猫还活者，那么它只记得活着的状态。但是，EPR实验的解释与标准的微观量子力学都要求宏观物体（如猫和笔记本）并不总是有唯一的经典描述。薛定谔的思维实验说明了这一明显的悖论。我们的直觉告诉我们，没有观察者可以处于混合状态——然而，上诉思维实验却表明，猫可以处于既生又死的状态。猫是否需要成为观察者，或者猫需要另外一个外部观察者使其能够存在一个定义明确的经典状态中？爱因斯坦认为每一种选择都很荒谬，他对思维实验突出这些问题的能力印象深刻。在1950年写给薛定谔的一封信中，他写道:

{{Quote|You are the only contemporary physicist, besides [[Max von Laue|Laue]], who sees that one cannot get around the assumption of reality, if only one is honest. Most of them simply do not see what sort of risky game they are playing with reality—reality as something independent of what is experimentally established. Their interpretation is, however, refuted most elegantly by your system of radioactive atom + amplifier + charge of gun powder + cat in a box, in which the psi-function of the system contains both the cat alive and blown to bits. Nobody really doubts that the presence or absence of the cat is something independent of the act of observation.<ref>{{cite journal|title=Induction and Scientific Realism: Einstein versus van Fraassen Part Three: Einstein, Aim-Oriented Empiricism and the Discovery of Special and General Relativity|first=Nicholas|last=Maxwell|date=1 January 1993|volume=44|issue=2|pages=275–305|doi=10.1093/bjps/44.2.275|jstor=687649|journal=The British Journal for the Philosophy of Science}}</ref>}}<br>

{{Quote|You are the only contemporary physicist, besides [[Max von Laue|Laue]], who sees that one cannot get around the assumption of reality, if only one is honest. Most of them simply do not see what sort of risky game they are playing with reality—reality as something independent of what is experimentally established. Their interpretation is, however, refuted most elegantly by your system of radioactive atom + amplifier + charge of gun powder + cat in a box, in which the psi-function of the system contains both the cat alive and blown to bits. Nobody really doubts that the presence or absence of the cat is something independent of the act of observation.<ref>{{cite journal|title=Induction and Scientific Realism: Einstein versus van Fraassen Part Three: Einstein, Aim-Oriented Empiricism and the Discovery of Special and General Relativity|first=Nicholas|last=Maxwell|date=1 January 1993|volume=44|issue=2|pages=275–305|doi=10.1093/bjps/44.2.275|jstor=687649|journal=The British Journal for the Philosophy of Science}}</ref>}}<br>

Note that the charge of gunpowder is not mentioned in Schrödinger's setup, which uses a Geiger counter as an amplifier and hydrocyanic poison instead of gunpowder. The gunpowder had been mentioned in Einstein's original suggestion to Schrödinger 15 years before, and Einstein carried it forward to the present discussion.

Note that the charge of gunpowder is not mentioned in Schrödinger's setup, which uses a Geiger counter as an amplifier and hydrocyanic poison instead of gunpowder. The gunpowder had been mentioned in Einstein's original suggestion to Schrödinger 15 years before, and Einstein carried it forward to the present discussion.

Since Schrödinger's time, other interpretations of quantum mechanics have been proposed that give different answers to the questions posed by Schrödinger's cat of how long superpositions last and when (or whether) they collapse.

Since Schrödinger's time, other interpretations of quantum mechanics have been proposed that give different answers to the questions posed by Schrödinger's cat of how long superpositions last and when (or whether) they collapse.

A commonly held interpretation of quantum mechanics is the Copenhagen interpretation.  In the Copenhagen interpretation, a system stops being a superposition of states and becomes either one or the other when an observation takes place. This thought experiment makes apparent the fact that the nature of measurement, or observation, is not well-defined in this interpretation. The experiment can be interpreted to mean that while the box is closed, the system simultaneously exists in a superposition of the states "decayed nucleus/dead cat" and "undecayed nucleus/living cat", and that only when the box is opened and an observation performed does the wave function collapse into one of the two states.

A commonly held interpretation of quantum mechanics is the Copenhagen interpretation.  In the Copenhagen interpretation, a system stops being a superposition of states and becomes either one or the other when an observation takes place. This thought experiment makes apparent the fact that the nature of measurement, or observation, is not well-defined in this interpretation. The experiment can be interpreted to mean that while the box is closed, the system simultaneously exists in a superposition of the states "decayed nucleus/dead cat" and "undecayed nucleus/living cat", and that only when the box is opened and an observation performed does the wave function collapse into one of the two states.

对量子力学的一个普遍的诠释是哥本哈根诠释。在哥本哈根诠释中，一个系统不再是状态的叠加，而是在观测发生时成为一个或另一个。这个思维实验清楚地表明，测量或观察的本质在这个诠释中并没有被明确定义。实验可以解释为，当盒子关闭时，系统同时处于“衰变核 / 死猫”和“未衰变核 / 活猫”两种状态的叠加状态，只有当盒子被打开并进行观测时，波函数才坍缩为两种状态之一。

是哥本哈根诠释是量子力学的主流诠释。根据哥本哈根诠释，当观测时，一个系统将不再处于叠加态，而是塌缩为其中任意一种状态。薛定谔的思维实验清楚地表明，在哥本哈根诠释中，测量或观察并没有被明确定义。实验可以解释为，盒子关闭时，系统处于“衰变的原子核 / 死猫”和“未衰变的原子核 / 活猫”叠加状中，只有打开盒子进行观测时，波函数才会塌缩成这两种状态之一。