不会。

中国科学技术大学或北京大学。

could be. It’s not hard to think of problems in quantum gravity which still need explanation even if holographic principle is really universal.

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

我不知道华罗庚先生说过没有, 我亲耳听杨振宁先生说过好几次.

我不了解，在看到他们捧出的大部头“著作”的时候就直接晕掉了

No,this is of course not .this opinion you raised is not softly comparable to that you raised in previous post .
well, you can see back what you said in previous post.

就好象说:

a = b x c x d x e

现在你说, a 用的是天然单位, 所以 e 也一定是天然单位. 可是还有 b, c, 和 d 呢? 它们用的是什么单位? 没关系, 什么都行?

the meaning of two examples you raised above are very different.

you say :if a=b*c*d

it’s clear that b \ c \ d are all multiplied as a factor which have independent unit .
this relation is very different from that bellow

毛泽东的寿命 = 83 * 年

You can only say ,if 毛泽东的寿命 = b*c*d
and the unit （83 年）of 寿命 is determinated naturly ,and how about b \ c and d .
if that case ,then i can give you a answer to this question as the same as what i replied in my previous post.
b \c \d ’s units must be determinated naturly as the same as the determination of the unit of “年”

well,i think i must stop here now .
since i find this is a not essential problem .

我相信holographic principle比AdS/CFT更普适，理解holographic principle和如何formulate holographic principle应该是最重要的事情。

shan-qin wang,

Don’t forget the automorphic forms in counting extremal blackhole entropy. Also people looking for vacua, the superpotential and other algebraic constraints can be studied using algebraic number theory. Also how about the geometric langlands program?

if a=b*c*d.
the unit of a is determnated naturly,b must be the same as well,i think .
this connection could be in spite of the determnation of the unit of c and d.

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

任何两个时间都可以用
a = b *c
联系起来. 比如:
毛泽东的寿命 = 83 * 年
所以如果年是自然单位, 毛泽东的寿命也是?

无聊:

我考他的这个是小儿科, 但凭他这不读书却啥也不在话下的架势, 他未必知道.

到目前为止，holographic principle是我们发现的唯一的比较可靠的东西。我也同意也许还有更深刻的原理等着我们去发现。

I agree
I do not see any mistake about this point of view
if unit of the day is determinated naturly, unit of the seconds must be also determinated naturly.

A example:
as 多年前 said, if a=b*c*d.
the unit of a is determnated naturly,b must be the same as well,i think .
this connection could be in spite of the determnation of the unit of c and d.

For the dimension of spacetime, i saw a paper written by a student discussed this many years ago .
according to what he said in that paper, maybe the conclusion the number of dimension of our universe is ten (if string theory is successed) can be obtained as well without Holographic principle, in mathematic ,there are some symmetric groups have some particular properties about the number of ten
but i do not know whether what he said is correct or not utill there is explicit evidence given by experiments.

However, from my personal viewpoint , i do not trust greatly that all the things about universe including the self-consistency of physical theories have to need Holographic principle.
Maybe there are many better theories or other better ways that are not discovered by human utill now to understand this universe

哈哈, 有趣的数字游戏! 283!

不过,不用人择原理, 137也只是大自然的巧合吧了…….

不过,不用人择原理, 137也知识大自然的巧合吧了…….

至于纽结在二维, 三维和四维不同性质的讨论, 是个 well known 的事实, 不始于你, 也不始于李政道先生.

问你个问题, 你知道 R4 上有多少个不同的微分结构吗?

一个小时60分，一分60秒，就这60，就是人为的。如果这个不人为，那么一英尺12英寸，一码3英尺，一英里1760码同样不人为，英制现在只有美国人用。

不是任何无量纲的量都是自然的，如果这样，天底下就没有不自然的数了，欧拉常数e是自然的，因为它出现在很多重要的数学关系中，如级数展开，微分关系，甚至这个著名的等式。而10不自然，因为另一个文明完全可以用20进制，对于他们来说20就是10。

本来一句开玩笑的话，居然引出这么多的争论出来，我正式宣布收回人类的妊娠期的说法

One example is you can not make a tight knot in either 2-D space or 4-D space. In 2-D, knots simple do not exist. In 4-D, any knot simply unwinds itself. 两维空间下没有办法打结，四维空间下打的任何结都是活结，只有
三维空间下，才有办法打死结。

For example, if you use the electron charge as a unit of charge, then your unit is a natural unit. If you use 10^6 times the electron charge as the unit, it is still a natural unit. Or, if you want, define the charge unit as exactly PI* electron charge, it is still a natural unit. But if you define charge unit as 1/1.602×10^-19 of an electron charge. And the number comes out of no where, has no mathematics origin, and is purely a number determined by experiment and by some arbitrary set unit, then it is an anthropic unit, not a natural one.

Meter is an anthropic unit, since its origin is roughly 1/4×10^107 of the circumference of the earth’s equator. Kilogram originated as the mass of one cubic decimeter of water, and is now defined as the mass of one piece of alloy metal stored in Paris. There can’t be a more anthropic unit than the kilogram.

金观涛说: “你把一天分成24小说，一小时分成60分钟，一分钟分成60秒，秒就是这样从天推导而来的。” 这个好象还可以接受. 他又说: “如果你说天是天然单位，那么秒也是天然单位，如果天是人为单位，那么秒也是人为的。” 这个我就听不懂了.

就好象说:

a = b x c x d x e

现在你说, a 用的是天然单位, 所以 e 也一定是天然单位. 可是还有 b, c, 和 d 呢? 它们用的是什么单位? 没关系, 什么都行?

Come on!

李淼又错了。秒和天是紧密相联的单位，怎么可能一个是人为，一个是
自然的呢。你把一天分成24小说，一小时分成60分钟，一分钟分成60秒，
秒就是这样从天推导而来的。如果你说天是天然单位，那么秒也是天然
单位，如果天是人为单位，那么秒也是人为的。

天是人为单位，不是天然单位，虽然我们选择地球日夜更替周期为一天。
注意，地球的自转周期不是一天，而是略短。这个单位是人为的选择，
没有什么天然的理由。为什么要用地球而不是其他行星的自转周期呢？
地球自转周期并且不是不变的，一直在变慢。那么为什么一点要用我们
这个时代的地球转动周期做一天，而不是几亿年前或者几亿年后的一天呢？
这些都是人为的约定。

金观涛
Quantoken

不幸的是紧化让我们失去了弦理论的唯一性，所以有了 landscape 和人择原理在弦论中的应用．其实在弦论之前，对人择原理的讨论更多是侧重于它能给理论带来什么限制等方面，并不是真用它来从一大堆理论中来选一个合理的理论．

杨振宁说, 读书有个过程, 你要先把一本书读厚了, 再把它读薄. 这样来看，弦论 (及弦landscape) 把我们从理论的匮乏带到了理论的过剩. 应该是一个进步. 我们现在就处于把书读厚的过程中, 哪天这本书被读薄了, TOE 也就有了. 中国人没有把这书读厚, 希望能把它读薄. 看你们的了!

同意你说的。

我个人目前的选择是，在研究弦论本身的理论问题的同时，要注重实验，也许那块启发弦论家的石子是实验家在我们的前面丢下来的。

要联系弦理论和现实世界，一些奇怪的数字似乎总要和我们不期而遇。比如紧化半径和弦长度标度的比值，又或者蜷曲因子。如何理解这些数字也许会是联系弦理论和现实世界的桥梁。在string landscape中稳定性原理不足以帮助我们解释这些数字。那么自恰性原理会再一次给我们带来惊奇吗？

弦理论到底离我们有多远？

如果现在的string landscape是我们努力的终点，如果非要有人择原理，那么我们有理由相信弦理论家的命运也许是岌岌可危的。：）

好问题。

秒是人为的单位，天是地球自转的单位，不那么人为。

谢谢提示。

Hui已经回答你了。

http://yanfeng.org/blog/647/

It’s my pleasure.

谢谢。

test:

我在正帖里用的就是

看来跟帖不起作用。

Exactly.

多年前：

当Ramanujan研究物理，他就成了Eddington。

我是开玩笑, 没有非要你写的意思. 我哪敢对你指手画脚呀!

也许你是对的，我还没有去具体计算小数点。即使如此，282.6经过4舍5入后还是283

shanqin-wang ：

谢谢。

FengCJ ：

《触不到的恋人》很好看，尤其是全智贤。 你没有看过也知道音乐，不错。

duality：

当然有关了，人类的怀孕期不会是一个随机数的。

多年前：

Polyakov不好写，因为我私人方面不认识他，只能写他的物理了。

Phiphy：

用数论做弦论的比我好不了多少，也许我的研究更简明易懂

hehe…..interesting

Maybe the front one above is determinated by holographic principle as well.

“Release me,
I know the only way to reach me,
that is the way that it should be
So free me from all your memories
I know we must say goodbye
We must say goodbye

If you belong in this world
Then I know we’ll take the step to every road
Now alone, I realize you’re far ahead
Without knowing you we’re there still in my heart
I know we must say goodbye
We must say goodbye

Can’t we belong in this world
Then I’m sure you’d take me to your every road
Just one thin,not realizing you were there
Without knowing you were there still in your heart
I know you must say goodbye
We must say goodbye

I know we must say goodbye ”

凄凉、伤感、无奈的感触中却也不免体会到一点点的解脱的心境。真想有空看看这部片子－－《触不到的恋人》

Using the true natural units I proposed, the numbers can be calculated pretty easily:

Mass of universe = PI*N^2
Radius of universe = PI*N
Lambda = Mass/Volume = PI*N^2/(4*PI/3 *(PI*N)^3)
= 3/(4*PI^3) * 1/N

Mean while Planck mass = sqrt(1/G) = sqrt(2*N). Thus
Lambda/Mp^4 = 3/(4*PI^3) * 1/N * 1/(2*N)^2
= 3/(16*PI^3*N^3)

With N the universal constant:
N = PI*exp(2/(3*alpha)) = 1.48982536×10^40

(alpha is the fine structure constant)

Therefore

Lambda = 3/(16*PI^3*N^3) Mp^4
= 3/(16*PI^3*(1.48982536×10^40)^3) Mp^4
= 1.828713×10^-123 Mp^4
= exp(-282.614254) Mp^4

That’s where it came from: from the universal constant, which in term comes from the big ALPHA. Even G also comes from ALPHA since G = 1/(2N).

金观涛
Quantoken

Why would any one calculate using the unit eV? It is so anthropic since eV is a particular unit selected by human beings:

1.Human picked the arbitrary length unit of one meter, and mass unit of one kilogram. These two are anthropic units, so are any derived unit, like one Newton of force, or one joules of energy.

2.Faraday defines the unit of electrical current Ampere, by requiring that when one amperes current flows through two parallel conductive wires separated by one meter, the magnetic force between them shall be 10^-7 newton per meter. Thus Ampere is also an anthropic unit.

3.The unit of electric charge, Couloumb, is defined as one ampere times one second of time, another anthropic unit. And Volt is defined as one joule divided by one couloumb. So Volt is an anthropic unit. The electron charge e is natural unit, But eV is anthropic since V is defined anthropicly.

金观涛
Quantoken

你太人择了，居然用人类特有的10进位。

所以我才是民科大师…