离开物理研究十年了，2004年底在网上看到一篇超导涡旋态的实验文章，
突然想到我能在我过去工作的基础上解释那篇文章的实验现象。
于是，在工作之余踏上了民科之路。做研究是民科的方式，投文章
也是民科的待遇，好几处碰得焦头烂额。哈哈，现在终于有杂志
接收了。于是，我成了快乐的民科。：-)

祝贺元江兄重归物理学！

谢谢：-)还得加点细节。

重归也谈不上，做个后备役，应个卯吧：-)

等弄完了还要请殷兄看看，我有些超导实验上的问题想问问殷兄。

元江兄，我对超导实验可毫不了解呀。
另外，我姓尹。

对不起，尹兄，把你的姓搞错了。
我是想问一些实验测量手段和技术。以后再讲吧，让我手上
这点事先做掉。

:: 让我手上这点事先做掉。

除了手上这点事，也祝元江兄脚上一点事早日搞定。:)

恭喜恭喜

这个快乐的民科还是你提议的呢：-)

呵呵，把兴趣当作职业的确很痛苦

啪啪啪，鼓掌。

Good.

I remember you also want to post it to the arXiv. Now your paper has been accepted, maybe you could write to them to see whether they will allow you to do it.

呵呵，恭喜恭喜

基础不够强，学术观点容易犯错，这些都不算民科。真正的民科是精神偏执狂，无法跟正常人交流沟通。本人基础薄弱，还喜欢好为人师、信口开河、经常犯错还自以为是，很有民科倾向，但是如果有谁说我是民科，我举双手反对（毕竟我搞研究的时候是另一回事，严肃多了），除非真的存在所谓“民科相对论”：在大牛眼里，小牛是民科；在大大牛眼里，普通大牛是民科。但是这样就乱套了，美化了“民科”这个名词，玷污了“科学家”这个称呼。

元江兄，如果涉及到有关微腔QED以及其它用光学手段探测的实验手段，我也许能够帮上忙。我现在比较熟悉的系统只有腔QED以及离子阱系统。

我很赞同星空浩淼兄的说法。学识不够，喜欢提一些疯狂的想法，以及不在正规的学术机构任职，这些都不成问题。关键是能够主动的学习，提高自己，对别人的意见能够做出客观正确的判断，虚心接受。一句话，对自己有自知之明。这样的人关注的是如何离真理更进一点，而不是发明耸人听闻的新理论博取名声。

：：呵呵，把兴趣当作职业的确很痛苦

===================================
呵呵，把职业当作兴趣的确很快乐

：：本人基础薄弱，还喜欢好为人师、信口开河
=========================================
貌似我就是这样的民科，自己掌嘴三十，啪啪啪……

回sage，等我修改完了我挂在奇迹文库。arXiv那里我试试看，反正它
那里现在架子大得很，挂不上也只好算了。

其实呢，民科也无所谓，这个称号也蛮好的。
举世滔滔，这里还有一个昌海办的小角落可以让我与
诸位共享研究的快乐，很不错啦。谢谢各位，谢谢昌海。

元江兄，你只要找到一位在arxiv的凝聚态方向贴过4篇以上的论文的人，让他给你通过一下，你就可以在arxiv上的凝聚态方向贴你的论文了。我就是找到了一位认识的教授让他给我通过后，才能在arxiv上量子物理方向贴论文的。

晕，在arxiv上贴论文原来还有限制啊？

对，需要一个所谓的endorcement。具体的说明见下面这个页面：

http://arxiv.org/help/endorsement

我也曾经写过一个中文的说明，见这个页面：

http://gezhi.org/node/217

元江兄，你只要找到一位在arxiv的凝聚态方向贴过4篇以上的论文的人，让他给你通过一下，你就可以在arxiv上的凝聚态方向贴你的论文了。我就是找到了一位认识的教授让他给我通过后，才能在arxiv上量子物理方向贴论文的。
---------------------------


尹兄，你知道我找谁？我找了约瑟夫逊，那个诺奖得主。：-)
他也回信了，跟我报怨说连他都被了，因为他现在研究的好像是
特异功能一类的，他贴过去的文章对被删掉。：-)
我想想我也不算冤了

尹兄，你知道我找谁？我找了约瑟夫逊，那个诺奖得主。：-)
他也回信了，跟我报怨说连他都被了，因为他现在研究的好像是
特异功能一类的，他贴过去的文章对被删掉。：-)
我想想我也不算冤了
--------------------------------------------------------

这也太让人惊讶了！

既然你的论文已经被接收了，如果实在找不到人给你背书的话，
那放在奇迹预印本网站上也是一样的。

arxiv好象有规定，超过一定时间（若干年）没有在arxiv的某一领域发表文章的作者在该领域即便曾经是专家，或曾经有过发表权限，也会expire。约瑟夫逊或许是栽在了这一条上。他老人家找几个弟子推荐一下应该就行了。:)

我倒是不知道约瑟夫逊在研究特异功能，他最好请一位一流的魔术师协助研究。寸有所长、尺有所短，科学家肉眼凡胎，在这方面其实是很容易被欺骗的。而一旦被欺骗，“科学家”这三个字会成为欺骗者最好的护身符或广告词。

我倒是不知道约瑟夫逊在研究特异功能，他最好请一位一流的魔术师协助研究。寸有所长、尺有所短，科学家肉眼凡胎，在这方面其实是很容易被欺骗的。而一旦被欺骗，“科学家”这三个字会成为欺骗者最好的护身符或广告词。
=================================
约瑟夫逊确实在若干年前就研究特意功能了
和我们国家的老钱一样，成为特意功能宣传者的幌子

如果探讨脑电波这样的“特异功能”，或许还有点戏，其他都是骗人的。
国外已经研究出一种东西，残疾人只需眼睛看着用意念想，就可以遥控开关，这是电视新闻里面讲过的。

特异功能的事说起来象伪科学，可是我有时想到
量子力学中的糊涂处，觉得特异功能的事也不好说。
我不是说现在号称有特异功能的度是真的或可能的，
我的意思是好像不能排除那种特异功能的可能性。

对了，我现在对电子也是越来越糊涂，这到底是一个
颗粒性的粒子(无论多么小)，还是根本就不是一个
粒子啊？我好象记得丁肇中说测不到电子半径的。

对了，我现在对电子也是越来越糊涂，这到底是一个
颗粒性的粒子(无论多么小)，还是根本就不是一个
粒子啊？我好象记得丁肇中说测不到电子半径的。

=======================================================

It depends what to you mean by radius of electron. If you are asking whether electron has some substructure, the answer is that we have not seen any, so far. Therefore, we so far treat electron as a point like degree of freedom.

If you are asking whether you could think of electron as having some geometrical size, the answer is yes, it is roughly the inverse of electon mass.Such an intuition could be made more precise if you define electron radius with some kind of scattering experiments.

就是这个问题，似乎“电子到底是什么”这样的本原问题
是不再有答案的。有的只是“在这种情况下，你可以把它看成
这样的东西”：-)

>>对了，我现在对电子也是越来越糊涂，这到底是一个颗粒性的粒子(无论多么小)，还是根本就不是一个粒子啊？我好象记得丁肇中说测不到电子半径的。

In Tony Zee's "Fearful Symmetry" (written in 1986), he also commented that it was not known whether the electron has any substructure. As Sage pointed out, it's very unlikely that experimental physicists will be able to see any substructure at all.

I think the Wikipedia entry summarizes our current state of knowledge on the electron very well:

"The electron is currently described as a fundamental particle or an elementary particle. It has no substructure. Hence, for convenience, it is usually defined or assumed to be a point-like mathematical point charge, with no spatial extension. However, when a test particle is forced to approach an electron, we measure changes in its properties (charge and mass). This effect is common to all elementary particles: Current theory suggests that this effect is due to the influence of vacuum fluctuations in its local space, so that the properties measured from a significant distance are considered to be the sum of the bare properties and the vacuum effects (see renormalization)."

As for Yuan Jiang's comments, I used an analogy to help my understanding --- quantum mechanics views an electron's radius as zero (supported by the fact that modern particle physics experiments couldn't measure this radius) in a similar way to special relativity views a photon's rest mass as zero (a photon will be never be at rest, hence no way to measure its rest mass anyway). Correct me if I got it wrong, all "massless" particles are traveling at the speed of light, so we couldn't demand particle physicists to "prove" that mass is indeed zero like the fact that we couldn't really "prove" an electron's radius is zero.

Wikipedia also states that:

http://en.wikipedia.org/wiki/Classical_electron_radius

"The classical electron radius is 2.8179 × 10^−15 m. This is the radius that is inferred from the electron's electric charge, by using the classical theory of electrodynamics alone, ignoring quantum mechanics. Classical electrodynamics (Maxwell's electrodynamics) is the older concept that is widely used for practical applications of electricity, electrical engineering, semiconductor physics, and electromagnetics; quantum electrodynamics, on the other hand, is useful for applications involving modern particle physics and some aspects of optical, laser and quantum physics."

"In simple terms, the classical electron radius is roughly the size the electron would need to have for its mass to be completely due to its electrostatic potential energy - not taking quantum mechanics into account. We now know that quantum mechanics, indeed quantum field theory, is needed to understand the behavior of electrons at such short distance scales, thus the classical electron radius is no longer regarded as the actual size of an electron. In fact, modern particle physics experiments indicate that the electron is a point particle, i.e. it has no size and its radius is zero. Still, the classical electron radius is used in modern classical-limit theories involving the electron, such as non-relativistic Thomson scattering and the relativistic Klein-Nishina formula. Also, the classical electron radius is roughly the length scale at which renormalization becomes important in quantum electrodynamics."

So in general cases, quantum mechanics' view that an electron has zero radius supersedes the classcial physics' inference of the electron radius value (which is still of some limited practical use in special cases).

How could one possibly give a precise definition of "the radius" of something in a world where self-interference is the basic rule of life?

Quantum mechanics tells us that elementary particles are neither point-like nor something with substructure, they are entities described by wavefunctions or field operators. It's simply illegitimate to seek an ontological answer to questions such as the volume of the electron. Therefore, the values of all classical parameters are context-dependent,i.e., the value of radius, or, of velocity, or, of energy, etc, may vary depending on your method of measurement.

In the opinion of many practical researchers, any (classical) geometric parameters such as radius, length, area, volume etc, lose their original basic meaning in quantum mechanics.

One way out of this conundrum is obvious: get rid of quantum mechanics. However, who knows when this would happen or would it happen at all, even in principle?

The more fundamental problem is that one has to invent a better theory on consciousness, particularly on how human mind acquires geometrical sense.

>In Tony Zee's "Fearful Symmetry" (written in 1986), he also commented that it >was not known whether the electron has any substructure. As Sage pointed out, >it's very unlikely that experimental physicists will be able to see any >substructure at all.

This is not what I want to say. I just pointed out that so far, we have not seen any substructure. It is fully possible that we will see it in the near future. And, looking at a book from 1986 is dangerous since experiments have progressed since then.

>I think the Wikipedia entry summarizes our current state of knowledge on the >electron very well:

Actually not very well. It is not clear, to say the least, why the quantum effect is relevant.

>"The electron is currently described as a fundamental particle or an elementary >particle. It has no substructure. Hence, for convenience, it is usually defined >or assumed to be a point-like mathematical point charge, with no spatial >extension. However, when a test particle is forced to approach an electron, we >measure changes in its properties (charge and mass). This effect is common to >all elementary particles: Current theory suggests that this effect is due to >the influence of vacuum fluctuations in its local space, so that the properties >measured from a significant distance are considered to be the sum of the bare >properties and the vacuum effects (see renormalization)."

>As for Yuan Jiang's comments, I used an analogy to help my understanding --- >quantum mechanics views an electron's radius as zero (supported by the fact >that modern particle physics experiments couldn't measure this radius) in a >similar way to special relativity views a photon's rest mass as zero

Not quite the same. There is nothing tell me that electron must have no substructure. However, an unbroken U(1) symmetry tell me that photon is massless

>(a photon >will be never be at rest, hence no way to measure its rest mass >anyway).

This is circular in logic. If it is massless, it can not be at rest.

>Correct me if I got it wrong, all "massless" particles are traveling at the >speed of light, so we couldn't demand particle physicists to "prove" that mass >is indeed zero
No, there is a burden of proof as to why the photon mass is zero. In fact, it has not been completely proven yet.

>like the fact that we couldn't really "prove" an electron's >radius is zero.

There is a burden of proof here as well.

>Wikipedia also states that:
>http://en.wikipedia.org/wiki/Classical_electron_radius
>"The classical electron radius is 2.8179 × 10^−15 m. This is the radius that is >inferred from the electron's electric charge,

Not charge, but its mass.

>by using the classical theory of electrodynamics alone, ignoring quantum >mechanics.

Quantum mechanics gives a similar result, by considering photon scattering off electron.

>Classical electrodynamics (Maxwell's electrodynamics) is the older concept >that is widely used for practical applications of electricity, electrical >engineering, semiconductor >physics, and electromagnetics; quantum >electrodynamics, on the other hand, is useful for applications involving >modern particle physics and some aspects of optical, laser and quantum >physics."

Whatever.

>"In simple terms, the classical electron radius is roughly the size the >electron would need to have for its mass to be completely due to its >electrostatic potential energy - not taking quantum mechanics into account.

Again, including quantum effect won't change this a lot.

>We now know that quantum mechanics, indeed quantum field theory, is needed to >understand the behavior of electrons at such short distance scales, thus the >classical electron radius is no longer regarded as the actual size of an >electron. In fact, modern particle physics experiments indicate that the >electron is a point particle, i.e. it has no size and its radius is zero.

Not in the same sense as a sort of semi-classical radius does not exist.


>Still, the classical electron radius is used in modern classical-limit theories >involving the electron, such as non-relativistic Thomson scattering and the >relativistic Klein-Nishina formula. Also, the classical electron radius is >roughly the length scale at which renormalization becomes important in quantum >electrodynamics."

So, for all intensive purposes, this is a "radius"

>So in general cases, quantum mechanics' view that an electron has zero radius >supersedes the classcial physics' inference of the electron radius value (which >is still of some limited practical use in special cases).

This is not the correct conclusion.

Anyway, this shows not everybody is qualified to write a wiki.

我的文章还在排版，不过我接到通知，文章已在网上，可以下载PDF。
http://dx.doi.org/10.1016/j.physc.2007.01.010

问题是这个地点是要用户认证的，大概只有订户才能下载。
不知道sage学校里能不能上这个地方，如能下载PDF，希望能下载
后给我一份。我在PDF文件和25份预印本的两个选择中选了后者。

I just downloaded a copy for you, please check your Gmail account. Your figures look nice, which software package did you use to generate these graphs esp. the contour diagrams? GNU-Plot? Congratulations!

谢谢，我回去检查。

我的那些图有的是Gnuplot，有的是Mathematica，那个CountorPlot就是Mathematica画的，
是审稿人建议加这些图，我原来的稿子上没有。

omni,

下面这个网站上有我用来计算的实验数据。你可以去看看这些实验
中的涡旋态。我的计算和实验定性定量都符合。


http://www.physics.nist.gov/Divisions/Div841/Gp3/Projects/STM/supercond.html

元江大哥都自比为快乐无比的民科,哪,哪小弟等只能先学会当民科,再搞学术了.--------------------呵呵，把兴趣当作职业的确很痛苦
---------------------------------------------------------------------------------季候风大哥讲得太有道理了.以后要好好反省反省才对.

呵呵，民科难啊，难过专业的。

民科在科研界没混个脸熟，少人帮忖，要做出成绩来非常不容易。
如果是专业的，抓住什么热门的，大家都还不懂的题目，胡乱说
几句，也能出文章啊。：-)


祝大伙儿春节愉快

快乐民科的文章登出来了。谢谢Omni，他帮我下载了一份PDF格式的
文章。有愿意看一下并进行讨论的可以给我来email，我把文件寄过去。

byuan2004@gmail.com

看到你的论文了，也看到了你所解释的实验突破。
祝贺你，元江兄！

谢谢，这个工作的本征值计算部分，我十多年前就得到了。
本征值中间那段一看，平的，等于1。这就回到Abrikosov的理论了，没有深究。
三年前看到实验，突然发现这个实验是在否定Abrikosov理论，至少
是在显示Abrikosov理论的不完善。按Abrikosov理论，只有三角点阵才能出现，
因为三角点阵对应自由能极小值。因此，要么Abrikosov理论有错，要么
还有其它的物理机制也能确定涡旋点阵的对称性，但是没
有包括在Abrikosov理论中。我因为在以前的超晶格涡旋态计算中早
有Abrikosov理论不完整的看法，所以我想拿我的程式来试试。试成功了。

均匀超导体中的涡旋点阵对称性确定至少还有一个磁通量
守恒的要求要考虑，在我的这个工作中，其实是磁通量守恒
的要求压过了自由能极小的热力学要求，所以才有这种涡旋点
阵对称性的连续变化。

我还有些想法没在文章中讨论，怕审稿时招来麻烦。
我在写一本超导笔记(中文)，以后可以在那里边探讨。

我也想问你一个问题，你看我的文章，能看懂么？
我问这个问题的原因有两个。一个是我通常觉得看别人
的理论文章很费劲，如果是不懂的领域也就算了，有些
领域我也是知道的，可就是看不太懂，把握不住要点。
不知道你看我的文章感觉怎样。

第二个原因是这样的。我以为现在的物理理论研究太玄了，
不是我当年能欣赏能热爱的物理。我不否认有好手能在这非常
繁复的局面中游刃自如，但是对大多数一般的聪明人而言，
这是一个生命和职业的陷阱。所以我很关注实验物理，我自己
曾经在跟实验物理学家交换数据和看法的过程中受益非浅。
所以，我希望我的文章能让实验物理学家看懂。

可以说是系统的实验数据核对才让我有信心去探索与传统理论
不同的新的理论框架。

我在这个坛子上也经常看到网友沉迷在“形式物理”上。
我以为这是很危险的。

元江兄，我看不懂你的论文，因为我对超导这个领域基本没有了解。但是我能看出你的理论分析所画出的图与实验得到的像非常象。现在看到你的对你的工作解释后，我想从新再读读你的论文，也许能够多了解一点。

关于如何做理论物理，我的想法与你的有些类似。我目前的研究方向是与实验联系很紧密的：提出一些有可能实现的理论方案，供实验组参考，用于实现量子计算。但由于自己缺乏与实验组的交流，所以对自己做的理论方案也有些底气不足。自己虽然经常看本领域的实验论文，有些论文读后感觉做得非常棒，很有感觉，但是大部分论文无法深入理解。

我对纯理论物理研究兴趣不大，感觉自己的能力也不足以做纯理论。我最感兴趣的一个方向是量子模拟：在实验室中模拟一些无法观测或者控制的实际物理系统，比如宇宙演化过程，文小刚的“人工光子”理论。这个方向能够把一些纯粹的理论物理预言和研究结果在实验室中检验，是很值得做的方向。虽然这种模拟并不是在真实的物理系统中做实验，可是在目前却是检验某些极端系统下物理理论的唯一办法。

在凝聚态系统中做宇宙学实验，可以看看这篇发表在Phys. Rep.上的综述：http://arxiv.org/abs/cond-mat/9607135
在实验室中验证“人工光子”理论的一个方案，可以看看这篇文献：http://link.aps.org/abstract/PRL/v97/e200401

元江兄，你是做凝聚态物理的，我的背景是量子光学，所以你应该比我更容易理解这两篇文献。

那篇关于人工光子的PRL也可以从预印本网站上下载：arXiv:cond-mat/0605154

非常敬佩元江前辈！
记得卢站长曾经说过，判断是否民科不是根据他的职业，而是根据他的思维方式和研究方法。你现在当然绝对不是啥民科，而应该叫做“业余科学家”，就象爱因斯坦在专利局的那些岁月的状态！哈哈

谢谢你的夸奖。

民科的道路越走越宽广了。我的那篇文章四月份发表后不几天，有家
出版社的主编来找我，说他正准备编一本超导进展的书，邀请我写
一篇文章，随便我写综述还是研究文章都可。我就回信问，总结我发表
过的的几个涡旋态解，起名“非均匀超导体中的涡旋态理论”怎么样？
这位主编毫无异议。后来我就大忙了，赶了一个多月，写出一个统一
的理论框架，四种非均匀情况下的应用，作为一章。现在已经接受，
大约年底可出版。这位主编还在等其它作者的章节，我也不知道是那
些人。都应该比我有名吧：-)