G******n
发帖数: 749 | 1 听说国内这方面现在做得不错，跟国际上的水平很接近了 | t**********m
发帖数: 205 | 2 超弦 will be dead and the world will be peaceful, no bubbles, life friendly. | S***p
发帖数: 19902 | | w******a
发帖数: 2592 | 4 by "close" you mean ～ light year, you got it
【在 G******n 的大作中提到】
: 听说国内这方面现在做得不错，跟国际上的水平很接近了
| g****t
发帖数: 31659 | 5 我觉得LQG更有希望。
【在 G******n 的大作中提到】
: 听说国内这方面现在做得不错，跟国际上的水平很接近了
| S***p
发帖数: 19902 | 6 恩，至少看着靠谱一点
【在 g****t 的大作中提到】
: 我觉得LQG更有希望。
| w******a
发帖数: 2592 | 7 我觉得说这话的就是既不了解弦论也不了解圈量子引力的
【在 g****t 的大作中提到】
: 我觉得LQG更有希望。
| c****e
发帖数: 2097 | 8 really? In which universe?
超弦的热点转向代数几何的研究了
★ Sent from iPhone App: iReader Mitbbs 6.0 - iPhone Lite
【在 S***p 的大作中提到】
: 超弦的热点转向代数几何的研究了
| c****e
发帖数: 2097 | 9 What's ur name, kitty? Bush?
超弦 will be dead and the world will be peaceful, no bubbles, life friendly.
★ Sent from iPhone App: iReader Mitbbs 6.0 - iPhone Lite
【在 t**********m 的大作中提到】
: 超弦 will be dead and the world will be peaceful, no bubbles, life friendly.
| h********0
发帖数: 12056 | 10 LQG is so boring! If you want to do fundamental physics,
go for string.
【在 g****t 的大作中提到】
: 我觉得LQG更有希望。
| | | S***p
发帖数: 19902 | 11 写点string theory的基本要点让我们学习一下吧
有什么难点要点，impressive的地方
【在 h********0 的大作中提到】
: LQG is so boring! If you want to do fundamental physics,
: go for string.
| c****e
发帖数: 2097 | 12 Lousy people will not get past G-string, so it's pointless to lecture to
them
写点string theory的基本要点让我们学习一下吧有什么难点要点，impressive的地方
★ Sent from iPhone App: iReader Mitbbs 6.0 - iPhone Lite
【在 S***p 的大作中提到】
: 写点string theory的基本要点让我们学习一下吧
: 有什么难点要点，impressive的地方
| o****d
发帖数: 5454 | 13 super string theory is not physics, it's only a mathematics structure
And only few people study it.
I guess only few people cares about it.
【在 G******n 的大作中提到】
: 听说国内这方面现在做得不错，跟国际上的水平很接近了
| w******a
发帖数: 2592 | 14 白痴年年有，今年特别多
【在 o****d 的大作中提到】
: super string theory is not physics, it's only a mathematics structure
: And only few people study it.
: I guess only few people cares about it.
| o****d
发帖数: 5454 | 15 你肯定不是物理专业的。
【在 w******a 的大作中提到】
: 白痴年年有，今年特别多
| F******n
发帖数: 160 | 16 Has superstring theory made any predictions that could be quantitatively
tested by experiments? If not, it should not be called real physics. Then
why would people care about it? Only for intelligence satisfaction, like
mathematics? This sounds familiar - did we recently hear of something called
"rational structure"? :)
【在 o****d 的大作中提到】
: super string theory is not physics, it's only a mathematics structure
: And only few people study it.
: I guess only few people cares about it.
| h********0
发帖数: 12056 | 17 people working in lqg are typically classified as
a bunch of crackpots, I think this is a bit too harsh.
But if you take a look at the article published in sci American (?)
where Witten's name is listed together with a few
obscure lqg names (fotini, lizi) as some most influential
theoretical physicists, then you know why these
people deserve the treatment. | b****s
发帖数: 1300 | | o****d
发帖数: 5454 | 19 既然你想的和我一样，为啥还要commet我呢？
called
【在 F******n 的大作中提到】
: Has superstring theory made any predictions that could be quantitatively
: tested by experiments? If not, it should not be called real physics. Then
: why would people care about it? Only for intelligence satisfaction, like
: mathematics? This sounds familiar - did we recently hear of something called
: "rational structure"? :)
| w******a
发帖数: 2592 | 20 your foolishness only exceeds by your abysmal ignorance
called
【在 F******n 的大作中提到】
: Has superstring theory made any predictions that could be quantitatively
: tested by experiments? If not, it should not be called real physics. Then
: why would people care about it? Only for intelligence satisfaction, like
: mathematics? This sounds familiar - did we recently hear of something called
: "rational structure"? :)
| | | h********0
发帖数: 12056 | 21 别和他生气，就一个文科傻妞。
【在 w******a 的大作中提到】
: your foolishness only exceeds by your abysmal ignorance
:
: called
| c****e
发帖数: 2097 | 22 The true question is, when will experimental physics reach Planck energy?
String theory computes many things observed in real world
Has superstring theory made any predictions that could be quantitatively
tested by exper........
★ Sent from iPhone App: iReader Mitbbs 6.0 - iPhone Lite
【在 F******n 的大作中提到】
: Has superstring theory made any predictions that could be quantitatively
: tested by experiments? If not, it should not be called real physics. Then
: why would people care about it? Only for intelligence satisfaction, like
: mathematics? This sounds familiar - did we recently hear of something called
: "rational structure"? :)
| F******n
发帖数: 160 | 23 我是门外汉, 不懂, 所以随便问问.
"如果"超弦没有定量可证伪的预测, 那就和"上帝"相似, 不是真正意义上的物理科学.
我最后一句是开玩笑. 对超弦的peer review肯定远多过"理性结构", 所以两者并不能
真正相提并论. 当然, 这所有都是基于前提"如果超弦没有定量可证伪的预测".
反过来,"如果"超弦有定量可证伪的预测, 原理上实验有可能实现, 只是现在实验技术
达不到, 那你的和我的前面的论断就不成立.
所以, 基于"我是门外汉,不懂", 我的核心问题是关于前提的, 超弦导电有没有定量可
证伪的预测? 抱歉我说的不够清楚, 还额外加了很多观点性的调侃.
【在 o****d 的大作中提到】
: 既然你想的和我一样，为啥还要commet我呢？
:
: called
| F******n
发帖数: 160 | 24 I am a layman on super-string theory, so I am not embarrassed at all by my
foolishness on this subject.
My main question was my first question - has superstring theory made any
predictions that could be quantitatively tested by experiments? Obviously
you didn't have any intention to talk to me logically and intelligently
about this question. That is ok. Is that called the "liberal-art" manner
talking to other people?
By the way, I apologize for any extra comment that stirred up your nerve...
8-)
【在 w******a 的大作中提到】
: your foolishness only exceeds by your abysmal ignorance
:
: called
| F******n
发帖数: 160 | 25 Those are valid points.
As to your first point, I don't know the answer. If I understood your
question correctly, you implied superstring indeed had some quantitative
prediction(s), which could be tested or falsified by experiments (at least
in principle)? If so, what were they?
As to your second point, it only means superstring theory can *explain* many
observed things in real world. This is again a valid point, as it can
explain more and more real world phenomena under strict peer reviews, it is
more likely a valid theory. However, only should superstring theory be
quantitatively tested/falsified by experiment, it would establish its
scientific foundation as a real physics - this is what your first point is
concerned about.
【在 c****e 的大作中提到】
: The true question is, when will experimental physics reach Planck energy?
: String theory computes many things observed in real world
:
: Has superstring theory made any predictions that could be quantitatively
: tested by exper........
: ★ Sent from iPhone App: iReader Mitbbs 6.0 - iPhone Lite
| F******n
发帖数: 160 | 26 嗯, "超弦导电", 很强大的汉字输入法
.
【在 F******n 的大作中提到】
: 我是门外汉, 不懂, 所以随便问问.
: "如果"超弦没有定量可证伪的预测, 那就和"上帝"相似, 不是真正意义上的物理科学.
: 我最后一句是开玩笑. 对超弦的peer review肯定远多过"理性结构", 所以两者并不能
: 真正相提并论. 当然, 这所有都是基于前提"如果超弦没有定量可证伪的预测".
: 反过来,"如果"超弦有定量可证伪的预测, 原理上实验有可能实现, 只是现在实验技术
: 达不到, 那你的和我的前面的论断就不成立.
: 所以, 基于"我是门外汉,不懂", 我的核心问题是关于前提的, 超弦导电有没有定量可
: 证伪的预测? 抱歉我说的不够清楚, 还额外加了很多观点性的调侃.
| c****e
发帖数: 2097 | 27 all consistent quantatitive theories have quantatitive predictions. even
inconsistent ones have outputs. wwhich however cannot be called predictions.
this includes for example much current work on lqg. esp. work by the
famously incompetent lee smolin.
note toobthat stupidity on part of present theorists also does not mean a
theory cannot predict sharp results for all phenomena in its purpoted realm
of validity. for example we do not know the existence of stable solutions of
the navier stokes equation. this in itself does nit mean the eq stops
applying. esp in case of dynamical questions, it is hard to answer sometimes
. string theory predicts to great precision certain quantities in quantum
field theories, that such field theories may not be the exact model of
nature is again not saying string theory has no fundamental significance,
just like that many field theories did not turn out to be the standard model
never would suggest the particle physics model should not be field theory,
as we know now it is. optimistically speaking string theory faces issues of
two kinds, one is to be more similar to our own world, two is to calculate
all principally calculable quantities. verybbasic things are not known at
present, such as string theory in general curved backgrounds. however, one
nontheless sees this as a problem of implentation and notbof principle, as
we know well enough nowadays certain examples such as isotropic universe
with negative cosmological constant. string world sheet calculation is
required and completed in order to find the right answer in agreement with
field thoery.
many
is
【在 F******n 的大作中提到】
: Those are valid points.
: As to your first point, I don't know the answer. If I understood your
: question correctly, you implied superstring indeed had some quantitative
: prediction(s), which could be tested or falsified by experiments (at least
: in principle)? If so, what were they?
: As to your second point, it only means superstring theory can *explain* many
: observed things in real world. This is again a valid point, as it can
: explain more and more real world phenomena under strict peer reviews, it is
: more likely a valid theory. However, only should superstring theory be
: quantitatively tested/falsified by experiment, it would establish its
| c****e
发帖数: 2097 | 28 note that formal theoretical high energy thoery is mostly carried out by
string thoerists. it however clarifies the relations to distinguish between
what string theorists do and string theory itself.
for example. conformal field theory, which among many things has been shown
by more than one fields medalists to describe things as everyday as
percolation or magnetism, was mostly developedbby string theorists esp.
polyakov, zamolodchikov brothers, knizhknik, verlinde, or people who were
string theorists back then such as di francesco, and john cardy.
while conformal field theory has its own historic importance and scientific
role describing many critical phenomena, in string theory it is merely pure
consistency which requires the two dimensional string dynamics to be
conformal, there is no other way. with this understood, we proceed to
explain that cft is a tool for doing a string theory calculation, wherein
classical or asymptoticbstates of the string is constructed from the
building blocks of conformal fields, and then propagated by the conformal
field theory green functions. a cft person can stop at this step, as he had
his answer already, here comes first distinction ofba string theorist, who
has to go further and do more.
namely by instruction of path integral as formulated by feynman, string
theorists must integrate the answer over internal states, which are nothing
but all coupling constantsbof the conformal field theories. this calculation
is the precise criterion or hallmark of a string theory calculation, and a
basic reason why correctly calculating nontrivial things in string theory is
hard.
it also explains why only some string theorists calculate whole answers of
string theory oncebin a while, individual building blocks such as a
conformal block is an active subject in which mathematicians become famous
ifbthey know how to compute particular examples. this includes first rate
people such as kac, frenkel, feigin, and many many many others.
many
is
【在 F******n 的大作中提到】
: Those are valid points.
: As to your first point, I don't know the answer. If I understood your
: question correctly, you implied superstring indeed had some quantitative
: prediction(s), which could be tested or falsified by experiments (at least
: in principle)? If so, what were they?
: As to your second point, it only means superstring theory can *explain* many
: observed things in real world. This is again a valid point, as it can
: explain more and more real world phenomena under strict peer reviews, it is
: more likely a valid theory. However, only should superstring theory be
: quantitatively tested/falsified by experiment, it would establish its
| w******a
发帖数: 2592 | 29 其实这点我倒是同意的——如果没有“现实上”的prediction，就不算物理，不管它有
多自洽或者有多重要
当然，虽然string model building是绝大多数人厌恶的东西，但是并不是没有意义
predictions.
realm
of
sometimes
【在 c****e 的大作中提到】
: all consistent quantatitive theories have quantatitive predictions. even
: inconsistent ones have outputs. wwhich however cannot be called predictions.
: this includes for example much current work on lqg. esp. work by the
: famously incompetent lee smolin.
: note toobthat stupidity on part of present theorists also does not mean a
: theory cannot predict sharp results for all phenomena in its purpoted realm
: of validity. for example we do not know the existence of stable solutions of
: the navier stokes equation. this in itself does nit mean the eq stops
: applying. esp in case of dynamical questions, it is hard to answer sometimes
: . string theory predicts to great precision certain quantities in quantum
| b****s
发帖数: 1300 | 30 老co，this is a short but very good description of certain facts that 民科
and lots of hep/gr laymen and douche-bags on the board should know.
between
shown
scientific
pure
【在 c****e 的大作中提到】
: note that formal theoretical high energy thoery is mostly carried out by
: string thoerists. it however clarifies the relations to distinguish between
: what string theorists do and string theory itself.
: for example. conformal field theory, which among many things has been shown
: by more than one fields medalists to describe things as everyday as
: percolation or magnetism, was mostly developedbby string theorists esp.
: polyakov, zamolodchikov brothers, knizhknik, verlinde, or people who were
: string theorists back then such as di francesco, and john cardy.
: while conformal field theory has its own historic importance and scientific
: role describing many critical phenomena, in string theory it is merely pure
| | | c****e
发帖数: 2097 | 31 If they did, there would be no crack pots.
老co，this is a short but very good description of certain facts that 民科
and lots of hep/g........
★ Sent from iPhone App: iReader Mitbbs 6.0 - iPhone Lite
【在 b****s 的大作中提到】
: 老co，this is a short but very good description of certain facts that 民科
: and lots of hep/gr laymen and douche-bags on the board should know.
:
: between
: shown
: scientific
: pure
| r******y
发帖数: 3838 | 32 ideas of LQG are more interesting。
【在 h********0 的大作中提到】
: LQG is so boring! If you want to do fundamental physics,
: go for string.
| c****e
发帖数: 2097 | 33 the idea that i am the only being in the universe is even more interesting.
【在 r******y 的大作中提到】
: ideas of LQG are more interesting。
|
|
