主题：从狭义相对论公式看当物体超光速的时候，是否是会时光倒流？ -- 思想的行者
家园 从狭义相对论公式看当物体超光速的时候，是否是会时光倒流？ 综合本人在科学网上的回复：http://blog.sciencenet.cn/home.php?mod=space&uid=279604&do=blog&id=783984
由于实验无法对洛仑兹和爱因斯坦两个人的观点进行检验，因此看来对于狭义相对论的正确性依然有一些争议，但是不管如何，洛仑兹变换是没有争议，不管是洛仑兹的以太论和狭义相对论都需要用到洛仑兹变换。
因此我们仅仅从洛仑兹变换出发，看看当物体超光速的时候会发生什么？
首先，超光速现象已经被人们所发现，在爱因斯坦等人所提出的EPR佯谬中，指出量子力学隐含着两个分离的系统有着超光速的关联，而这一点，也应该已经被证实；
例如以下的中国科技大学的网页的消息
最近，由中国科学技术大学潘建伟院士领衔的自由空间量子通信团队的彭承志、张强研究小组，在国际上首次成功实现了无局域性漏洞的量子纠缠关联塌缩速度下限测量，结果表明在所有相对地球以千分之一光速或更低速度运行惯性参照系中，量子纠缠关联塌缩速度下限为光速的一万倍。该研究成果发表在近日出版的《物理评论快报》（Phys. Rev. Lett. 110, 260407 (2013)）上。http://news.ustc.edu.cn/xwbl/201307/t20130723_155137.html
那么当物质的速度超过了光速的时候会发生什么？
我们从洛仑兹变换来看，运动的参照系会发生尺缩钟慢效应这个尺缩钟慢效应是用sqrt(1-v**2/c**2)来衡量的，显然当V越来越大，越来越接近c的时候，这个式子的结果会越来越小，即尺缩钟慢效应越来越大。
但是我们考虑一下当v>c的时候，会发生什么呢？
这个式子会变成一个负数，即时间变成负数时间，即发生时光倒流吗？
不会，注意，前面的开方号即sqrt,-1的开方等于-1吗？中学数学就告诉我们，-1的开方=i
这意味着什么呢，这意味着当物体超光速的时候，物体进入了虚数时空，而不是时光倒流。
虚数时空一定不存在吗？
如果如果我们看量子力学的薛定谔方程，例如一维薛定谔方程http://baike.baidu.com/view/551078.htm的右边，注意在几率幅函数对时间的偏导数之外，还要乘以一个i。
薛定谔先生是靠猜的方式猜出那个方程，那个方程为什么会那个样子，他也不知道，对于为什么几率幅的时间偏导数还要乘以一个i，人们有很多解释，能够在一定程度上解释得通。
但更具有物理意义的解释应该是，我们所处的时空实际上是一个复数时空，当量子纠缠等效应超光速的时候，就进入了复数时空，因此薛定谔方程必须有一个i
家园 讨论超光速都在以光为研究物 有一种情况我想了好久。。。。不要笑我啊。。。。如果有一个直径40万公里的大轮子，在理想情况下，我拿住一点让它转起来，那么在我的对面点也同时发生了运动，是不是能说这种运动的传导是超光速的呢？纯粹靠个儿大实现。。。。。
家园 你问的问题不需要大球 小球就可以，只需要小球在旋转，旋转的线速度接近光速。
问题在于根据狭义相对论，当静止质量不为0的物体速度等于光速的时候，其质量无穷大，因而其能量也无穷大。
因此你的问题只能在静止质量为0的量子上有意义。
这个量子之间存在着一个所谓的纠缠，例如两个光子的偏振状态就存在着某种不约而同的纠缠，两个纠缠的光子，你改变一个光子的偏振状态，另一个光子的偏振状态也几乎是马上改变---最少是超光速的--中科大的团队证明这个马上发生的速度是光速的最少一万倍以上，人们正在根据这个量子纠缠的超光速特性研究量子计算机以实现即时通信。
为什么会发生这样的量子纠缠，你提的问题应该说是一个不错的问题
家园 多谢解惑 多谢各位答疑解惑，拱手答谢，花之
家园 不会马上动 相对论的预测是你对面不会马上动。不管你的轮子有多硬，怎么也得等个1.3秒以上。
在人类迄今所有对物理宇宙的认知中，还没有发现过任何超距相互作用。已知的四种相互作用都通过物质传递，传递速度都不超过真空中的光速。
我们触手可及的最大物体是地球。如果日本现在大地震，地球另一端的人在30毫秒内没有任何办法得知。
- 复 不会马上动
家园 建议你再去了解了解量子纠缠与EPR佯谬再说吧 量子纠缠导致的量子即时通信技术有多少团队在研究啊
家园 您是建议我了解一下无克隆定理或者无通信定理？ 这些都说明量子即时（我理解您所谓的即时就是瞬时，至少可以超过真空中的光速）通信是不可能的呀？您到底想说超光速通信可能还是不可能呀？
另外有哪些团队在研究量子即时通信啊？我是真心不知道。
研究量子测量，量子光学，量子纠缠，量子信息，量子计算，量子加密，量子通信的我见的多了，研究量子传态，量子通信复杂度的我也听说过，就是没见过研究量子即时通信的，更别说技术层面的了。这申请经费得多难哪。还是说有私人注资？虽然身边量子信息中心的人乌泱乌泱的，可从没听谁提过研究即时通信的团队。保险起见我还是认真上网搜了搜（我也真闲），确实没找到任何团队。您能不能在百忙中指点我一下，就一个团队就行，学校研究所名称也行，PI名字也行，代表论文也行，随便给个名儿。西太平洋大学的就算了。
家园 你见得多了，不见得你就了解了量子纠缠和量子通信之间的关系 不见得你就了解通过量子纠缠进行通信是不是光速通信。
你这样显摆自己认识多少人的回复是无意义回复。
不欢迎此类回复，投草一颗。
家园 Alice通过经典通道把测量结果告知bob:不可能超光速 "通过量子纠缠进行通信" is not about 超光速, it is about "量子纠缠" part.
"量子即时（我理解您所谓的即时就是瞬时，至少可以超过真空中的光速）通信,超光速通信" is not what 量子通信 about, not at all. period.
still, this kind of discussions are very important in terms of learning about the related physics/math models behind it.
1.
as said before, the critical part of "通过量子纠缠进行通信" is (roughly speaking)
between alice and Bob, they can all 对自己的qutrit进行相应的么正变换, that part is known only between alice and bob;
2.
still, Alice has to 通过经典通道把测量结果告知bob, or she did some kind of 么正变换, to the "EPR thing", and bob could calculate what kind of 么正变换 alice did;
but there is no other transmission except for 经典通道, for Alice to tell Bob: I did something, done my part of the game, now it is your turn.
and that "game(and how alice and bob play the game)" is only known between alice and bob, there is no way for other people like Uncle sam to figure out what the hell is going on between the two 中共地下党员 of alice & bob(:).
"经典通道" transmission 不可能超光速, but it would not impact the 地下党 part of the game.
however, without "经典通道" transmission part, Bob can never complete his part of the game.
in that sense, 量子通信不可能超光速, period.
3.
obviously, "经典通道" transmission is not tricky at all, what is tricky ( in terms of how to do it in the macroscopic environment) is the making o f "量子纠缠" etc.
4.
still, 么正变换 is a super powerful concept in quantum physics, and in classical physics, we do have 正则变换, and I have posted before, folks need to learn 哈密顿力学/理论力学 first before learning QM/SR/GR, period.
5
even "通过量子纠缠进行通信" is and will be a technology challenge for long long time, the information processing theory behind it is already widely applied in many areas, such as 并行通信 brain model etc, as posted before.
in that sense, the fundamental concepts and the related modeling (logic and math language) are super important, regardless of what you actually do, in today's informational economy and politics (to some degree), that is a key part of "CORE algo" of the emerging global information and AI system.
and I have posted quite bit about the possible "apps" ideas in that sense.
otherwise, as an individual or as a nation, "文盲" of modern informational & AI version of 達爾文遊戲 will be cheated by those 氣功大師.
largely because of GFW and other political issues, TGchina is facing huge challenges in those area, but as an individual, that is not an excuse to fall behind.
period.
so, study English and physics, a must, if one is still capable of leaning.
although learning QM is hard (and learning without doing some lab work is even harder), for anybody.
nothing is easy, kind of why Chinese elite almost all support TG, 氣功大師 plays political game while making tons of money with it, in china mainland with 1.3 billion workers 听党的话跟党走 , what a beautiful life(:).
but nothing is free, somebody has to pay for that beautiful life of today's Chinese social elite. but who cares(:), let the suckers suck(:).damned.
6.
"量子即时（我理解您所谓的即时就是瞬时，至少可以超过真空中的光速）通信,超光速通信" is right in the sense of social physics: that "elite 通信 among elite themselves)" is 超光速通信, since "文盲" folks will be bypassed anyway, anywhere, US or china, china kind of the worse (but better than 印度?)
7.
obviously, humanity as a whole, 科学技术是第一生产力, and to progress in that direction, humanity need to narrow the gap between "文盲" folks and 氣功大師, particularly in social science area, with help of 科学技术 itself.
to do that, globalization of information & AI system 24/7 in all kinds of language is the way to go, kind of why GOOG/FB are spending huge amount of their money in doing that, and of course 夹带私活 for themselves in the process.
constrained and restrained by GFW, TGchina's model has fundamental problems with it: if nothing else, Chinese companies and Chinese people themselves, will be facing "文盲" issue, with 文盲" defined by uncle sam's global power, soft and hard, in the global information/logic/value/AI network or platform, dominated by GOOG/FB/AAPL/MSFT/TSLA etc, eventually hitting TGchina from 太空, etc.
meanwhile, TGchina's 中国特色社会主义 (regardless of its logic if there is any): if it cannot be globalized, it is a piece of BS, making sense?
and how do you globalize 中国特色社会主义: what is your logic model? any time frame? what is the risk?
and how many generations of Chinese people's life will be gambled with 中国特色社会主义 in china first, then globally?
and if nothing else, with GFW, how can you globalize 中国特色社会主义 as a culture/vaule/logic model to the outside world?
with GFW, chairman X ideology 军 will more than likely=内战内行, and very likely 内战 is his goal anyway.
I would think, this line of logic is fairly straight forward, and many Chinese elite folks know about it too, but, hey, for now, good & easy money and good life, and all you need to do is to smile with uncle TG together, then why not(:)?
remember:
热力学第零定律- 维基百科，自由的百科全书
zh.wikipedia.org/zh-hk/热力学第零定律
第零定律是由英國物理學家福勒(R.H.Fowler)於1930年正式提出，比热力学第一定律和热力学第二定律晚了80餘年，但是第零定律是后面几个定律的基础，所以叫做 ...
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联合噪声下确定的安全量子通信 - 中国科学G辑
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它是经典机密共享的量子版. 在经典机密共享中, 发送方Alice 把她的私钥KA 劈裂. 成两块信息, 即KB 和KC, 并分别发送给她的两个代. 理Bob 和Charlie. 当且仅当Bob ...
[DOC]
正则变换（canonical congjugate）探究
course.zjnu.cn/qm/eWebEditor/.../201062919121641.DO...
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在哈密顿力学中，正则变换是一种正则坐标的转变，即将广义坐标变换为另一组广义坐标，或 ... 从式（11）可以看出：正则变换有赖于函数的选择，这个函数叫做母函数。
理论力学网络课程
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当前位置：学习内容 -第七章 正则方程. (3) 取pj，Qj，t为独立变量. 则有 (7.4.9). (4) 取pj，Pj，t为独立变量. 则有 (7.4.10). 以上讨论是显含时间的正则变换，即母函数F显 ...
家园 "一个国家的真正崛起，是意识形态的崛起" "一个国家的真正崛起，是意识形态的崛起，中国能举起自由民主的大旗，还举得的比美国更高么？绝无可能，那么中国要构建怎样的意识形态呢？是儒家，是佛教，还是毛主义？这将是决定中国未来的根本。"
http://www.ccthere.com/article/4001954
this is obviously a huge topic;
without getting sucked too much into it (obviously the whole china is pretty much sucked into this thing every day), I am just going to ask a few basic methodology type of questions or modeling issues, as food for thoughts, not really arguing, using some analogies.
1.
as we all know, in today's increasingly globalized world, 意识形态 is not one nation's thing, particularly for big country like china, it is a global thing, much like the a commercial service or product: what matters is not how much you like it yourself, it is all about: can you make other people or the whole world 1) knows or pay attention to your product; 2) eventually, like your product; 3) pay a good price (hopefully a premium) to use your product
do you have a plan or model to accomplish all the above? do you have resources? what is your time line?
and any further back up/hedge plan in case of things going wrong big time?
and we do know, in terms of social science, things do go wrong, often big time, and bloody.
if not, what are you going to do?
2.
as I posted before, for 意识形态, the above line of logic or modeling is even more important, because as a nation, you are basically gambling with your almost entire inventory of resources.
as I posted before, there are no easy answers/solutions for this almost life/death kind of 意识形态 challenge for Chinese as a nation, due to all kinds of reasons as I posted before;
what I am really talking about is modeling, should a person or nation start modeling process first, for any serious challenges, before jumping into river with your two foot, with "摸著石頭過河”
BS theory(:)?
3.
as posted before & because of many known reasons, the Chinese nation has this big family mentality: the political elite kind of lead & manages the Chinese people as the elites are parents, and ordinary people kind of like kids, 听大人话家长话, already for over 5k years?
中央在下一盘很大的棋, 我們的對手 is not uncle sam or jpy, we are doing....
团结 under 中央, 天大的困难也能战胜...
what a world, again, as I said, today more & more people don't really care: what they really want to is to suck their share of money out of TG"中央在下一盘很大的棋".
why not?(:)
then how do you 提高劳动生产率 as a nation if everybody wants to make quick and dirty money out of the system by 套利交易?
yes, we are going to 改革, again, where is your model of logic? not just a bunch of emotion invoking slogans.
4.
for the foreseeable future, TG is going to keep working on 构建中国的意识形态/中国特色社会主义 anyway, regardless, with GFW as some kind of 絕熱近似 from the rest of the world, or TGchina may fall apart yesterday;
with GFW, TG senior elite traders are going to 套利交易 in & out of GFW, sucking tons of money out of TGchina system, as they have been doing.
5.
I have read many good posts here, really helpful, and I hope my 2 cents can be food for thoughts as well for others, again, in terms of modeling.
家园 微观系统"絕熱": "超光速"意義不同 1.
first of all, "量子纠缠与EPR佯谬" is still bothering humanity, obviously, it had bothered Einstein until his death, etc.
those are still of 微观系统 物理现象, even "global", in terms of "幺正操作", etc.
2.
罗化生：从狭义相对论公式看当物体超光速的时候，是否是会时光倒流？
in terms of macroscopic physics, that type of 时光倒流questions are meaningless, there is no 宏观物体超光速, period.
of course, you could say you mean "微观"物体超光速, but what is a "微观"物体? blabla
3.
in QM/QFT, often 微观系统 is "絕熱":therefore system is 么正, 绝热过程可逆 etc, and we have 么正算子（unitary operator), such as "量子计算与量子逻辑门 操作上为所有可能的幺正变换，因而，对态的操作应是幺正的、 可逆的，无能量的", no media (we are trying to find that workable media, obviously) involved, "超光速", etc.
and further into QFT, we have "虛光子", "off shell", many seemingly "超光速" stuff, many in the sense of 相位 field etc, which itself is still a work progress in QFT;
the concept of 相位, 么正算子（unitary operator）in qm originally started with Dirac'work.
and obviously, "物体" in QM is not "物体" as we know in terms of macroscopic physics;
4.
it is very hard to find a real physics system of "絕熱" in the macroscopic environment, and physics as an "emerging physics", "物体" is well behaved according to 狭义相对论, & largely GR as well, when "物体" emerged into macroscopic environment from microscopic environment, where "物体"超光速, "时光倒流" do "happen", but more of "mathematical physics" (for lack of better word description, we need to get into QFT for more "accurate" descriptions , etc).
it's often difficult for people to tell the difference between the macroscopic physics and microscopic physics, with many same or similar terminologies used in both field but often with totally different meanings.
and out of a particular context, even general verbal discussion of general concepts and models is difficult, if not meaningless.
yes, this is a public forum.
5.
because of non-"絕熱" properties of macroscopic environment, "量子计算与量子逻辑门 操作上为所有可能的幺正变换，因而，对态的操作应是幺正的、 可逆的，无能量的"
is still a largely a research-in-progress thing, no one knows whether it is ever possible as a real "app".
and obviously, because of non-"絕熱" properties of macroscopic environment, china is facing a struggle in terms of its "normalization" with global "heatbath", 顏色革命 etc, which is obviously a very important parameter of china modeling, for chairman X & his team, as we know.
by the way, no offense to you or anybody, just trying to clarify some basic concepts/terminologies.
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量子力学相位因子 - 物理
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由 李华钟 著作 - 2001 - 被引用 10 次 - 相關文章
量子力学相位因子3. 李华钟. 中山大学高等学术研究中心及物理系广州. / 量子化对称和相位因子) ) ). 世纪物理学的主旋律0. ) ) ) 引自杨振宁在中国科学院成立.
家园 不可能同时，物质不可能是绝对刚性的 家园 传导速度仅仅是该材料中的声波速度而已。 家园 轮子再大，如果角速度不够大的话，线速度也不会大 狭义相对论所说的速度是线速度
线速度等于角速度乘以一个半径
问题在于你这么大的轮子，其角速度很小。
你说的轮子其实在宇宙间到处都是，例如地球的周长貌似是4万公里，地球的半径就有6000多公里，比地球半径大几十倍的天体是很多的，地球在自转，比地球大几十倍的天体自转的应该也有不少。
家园 这种运动传导会比光速慢很多，因为不存在“绝对刚体”。 你说的你在一边推动轮子，40万公里外的另一边“同时”跟着转动，避开惯性的问题不谈，实现这个“同时”的前提是，这个轮子是绝对刚体制造的，也就是说绝对不会有变形，一端被施加的力，不需要时间就传递到了另一端。这样的东西是不可能存在的。力是靠形变传递的。
民科有种证明超光速的说法跟你这个异曲同工：拿根31万公里长的棍子捅那一头的人。理由完全一样。