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主题:【原创】关于粒子性和波动性 -- witten1

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呵呵
家园 打断一下关于dirac电子为光速

我找到了一个网页,兄台可以看看

http://www.physicsforums.com/showthread.php?t=215338

引用一部分相关内容

Re: What is the velocity of a relativistic electron?

On 2008-02-13, Juan R. Gonzàlez-lvarez <[email protected]> wrote:

> I find different answers:

>

> ((Classical electrodynamics))

>

> v < c

>

> ((Relativistic Quantum Mechanics))

>

> v = c using Dirac equation for |PSI>.

Eh, no.

You are confused by an archaic paradox. The paradox consists of identifying the operator c*alpha (in the usual 3+1 Dirac equationnotation) with the physical velocity, which quite obviously doesn't work. For a modern discussion of the Dirac electron's velocity operator,see [1] where the author discusses the Foldy-Wouthuysen transformation and how to use it to get the correct operator obeservable. See also [2]for some more discussion and references.

The velocity operator thus obtained, satisfies the Heisenberg equationsof motion v = dx/dt and the well known relation v = p/m in the non-relativistic limit. Note, here x is not the spatial argument of the usual Dirac wave function. It is also obtained through the Foldy-Wouthuysen transformation, or from the formula given by Newton andWigner (again, see [2]). Once a particular time axis has been chosen,this operator x is unique (up to translations of the origin ofcoordinates).

这里的说法似乎有些不同,我就偷懒不去看,等你的评论了

去搜这个是因为我觉得你的Dirac电子‘瞬时’速度为光速的‘解释’,不是很有物理意义撒。

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