夏加坤

传说中的高老庄就是这里？

夏加坤

大一那年，宋江在校报上发表处女作《哲学是张图》轰动校园，被誉为该校史上最年轻的哲学家。大学时代的宋江看上去比其他同学成熟，西装革履，鲜红领带，韩版眼镜，左手托腮，若有所思，摆拍成照，放到网上当头像。
------------------
原型是菜农
zoufeng_1234 发表于 2010-8-31 08:49

猪兄不厚道，
含沙射影，
暗箭伤人，
缺乏绅士风范。

夏加坤

大一那年，宋江在校报上发表处女作《哲学是张图》轰动校园，被誉为该校史上最年轻的哲学家。大学时代的宋江看上去比其他同学成熟，西装革履，鲜红领带，韩版眼镜，左手托腮，若有所思，摆拍成照，放到网上当头像。

好像不是。12d" />
WIND 发表于 2010-8-31 08:55

WIND又开心了。
这不是明摆着影射三个人嘛。
宋江在校报上发表处女作《哲学是张图》轰动校园，被誉为该校史上最年轻的哲学家：菜农。
西装革履，鲜红领带：章星球
韩版眼镜，左手托腮，若有所思，摆拍成照，放到网上当头像：当然就是偶了。

夏加坤

著名美评家顾大嫂，盛赞宋江其文，堪比李敖大师《阳痿美国》。
确切地说，宋江不是五毛，他看不起五毛，水平太低，只会转贴和人身攻击。宋江则不然，能用英文反美，网上辩论保持绅士风度，不急不恼。宋江这么做，有两个目的。一是想引起有关用人部门注意，有这么一个爱国青年，胸怀人类，为国分忧，对美说NO。
、、、、、、、、、、、、、、、、
把顾准的女儿顾大嫂也扯进来了。还堪比李敖大师，宋江真牛。

夏加坤

西装革履，鲜红领带：章星球
================
这个我还真没有想到。哈哈
WIND 发表于 2010-9-1 08:07

去相册里找找。
看看还有谁是西装革履，鲜红领带的。

夏加坤

夏加坤

梦子总是和乌搞有着不得不说的故事。
酸菜估计没有，臭豆腐还有一碟。

夏加坤

看这个贴比较紧张，不知道什么时候被影射。
zoufeng_1234 发表于 2010-9-9 16:57

一贵，天庭饱满，二贵，气宇轩昂，三贵，头无重发，四贵，印堂发亮，五贵，哎呀，五贵冲天，鸿运当头。
看，已经被映射了。

夏加坤

小说完了吗？
WIND 发表于 2010-9-20 13:02

没完，你可以继续。

夏加坤

我写小说的水平你又不是不知道？比你拯救地球的文章还令人可笑。
WIND 发表于 2010-9-21 12:57

偶拯救地球是知其不可而为之，不搞笑一点，岂不是让人笑话？

夏加坤

宇宙比可观测宇宙至少大250倍

　　宇宙的年龄是140亿年，因此咋一想可能会认为我们只能看到140亿光年外的物体。事实上这并不正确。因为宇宙是膨胀的，我们能观测到的最远天体远远超过140亿光年。实际上，宇宙微波背景辐射中的光子是经过450亿光年才飞抵地球。这意味着可观测宇宙的半径有450亿光年，直径900亿光年。真实的宇宙应该比可观测宇宙更大。但到底有多大？
http://www.technologyreview.com/blog/arxiv/26333/

Cosmos At Least 250x Bigger Than Visible Universe, Say Cosmologists
The universe is much bigger than it looks, according to a study of the latest observations.

kfc 02/01/2011

51 Comments
When we look out into the Universe, the stuff we can see must be close enough for light to have reached us since the Universe began. The universe is about 14 billion years old, so at first glance it's easy to think that we cannot see things more than 14 billion light years away.

That's not quite right, however. Because the Universe is expanding, the most distant visible things are much further away than that. In fact, the photons in the cosmic microwave background have travelled a cool 45 billion light years to get here. That makes the visible universe some 90 billion light years across.

That's big but the universe is almost certainly much bigger. The question than many cosmologists have pondered is how much bigger. Today we have an answer thanks to some interesting statistical analysis by Mihran Vardanyan at the University of Oxford and a couple of buddies.

Obviously, we can't directly measure the size of the universe but cosmologists have various models that suggest how big it ought to be. For example, one line of thinking is that if the universe expanded at the speed of light during inflation, then it ought to be 10^23 times bigger than the visible universe.

Other estimates depend on a number factors and in particular on the curvature of the Universe: whether it is closed, like a sphere, flat or open. In the latter two cases, the Universe must be infinite.

If you can measure the curvature of the Universe, you can then place limits on how big it must be.

It turns out that in recent years, astronomers have various ingenious ways of measuring the curvature of the Universe. One is to search for a distant object of known size and measure how big it looks. If it's bigger than it ought to be, the Universe is closed; if it's the right size, the universe is flat and if it's smaller, the Universe is open.

Astronomers know of one type of object that fits the bill: waves in the early universe that became frozen in the cosmic microwave background. They can measure the size of these waves, called baryonic acoustic oscillations, using space observatories such as WMAP.

There are also other indicators, such as the luminosity of type 1A supernovas in distant galaxies.

But when cosmologists examine all this data, different models of the Universe give different answers to the question of its curvature and size. Which to choose?

The breakthrough that Vardanyan and pals have made is to find a way to average the results of all the data in the simplest possible way. The technique they use is called Bayesian model averaging and it is much more sophisticated than the usual curve fitting that scientists often use to explain their data.

A useful analogy is with early models of the Solar System. With the Earth at the centre of the Solar System, it gradually became harder and harder to fit the observational data to this model. But astronomers found ways to do it by introducing ever more complex systems, the wheels-within-wheels model of the solar system.

We know now that this approach was entirely wrong. One worry for cosmologists is that a similar process is going on now with models of the Universe.

Bayesian model averaging automatically guards against this. Instead of asking how well the model fits the data, its asks a different question: given the data, how likely is the model to be correct. This approach is automatically biased against complex models--it's a kind of statistical Occam's razor.

In applying it to various cosmological models of the universe, Vardanyan and co are able to place important constraints on the curvature and size of the Universe. In fact, it turns out that their constraints are much stricter than is possible with other approaches.

They say that the curvature of the Universe is tightly constrained around 0. In other words, the most likely model is that the Universe is flat. A flat Universe would also be infinite and their calculations are consistent with this too. These show that the Universe is at least 250 times bigger than the Hubble volume. (The Hubble volume is similar to the size of the observable universe.)

That's big, but actually more tightly constrained than many other models.

And the fact that it comes from such an elegant statistical method means this work is likely to have broad appeal. If so, it may well end up being used to fine tune and constraint other areas of cosmology too.