分享關於「宇宙大爆炸」的一段話

科學知道自己的局限。很多不懂科學卻偏偏自以為懂科學的人們卻不知道科學的局限。

科學家們自己都搞不清楚的事情，貌似很多不懂科學卻偏偏自以為懂科學的人們已經搞懂了。


建議：
知道的就是知道的，不知道的就是不知道的。
搞得清楚的就搞清楚了再說，搞不清楚就不要自以為自己搞清楚了。同樣再摘錄一段：



While the Big Bang model is well established in cosmology, it is likely to be refined in the future. Little is known about the earliest moments of the Universe's history. The Penrose–Hawking singularity theorems require the existence of a singularity at the beginning of cosmic time. However, these theorems assume that general relativity is correct, but general relativity must break down before the Universe reaches the Planck temperature, and a correct treatment of quantum gravity may avoid the singularity.[62]
Some proposals, each of which entails untested hypotheses, are:
models including the Hartle–Hawking no-boundary condition in which the whole of space-time is finite; the Big Bang does represent the limit of time, but without the need for a singularity.[63]
brane cosmology models[64] in which inflation is due to the movement of branes in string theory; the pre-big bang model; the ekpyrotic model, in which the Big Bang is the result of a collision between branes; and the cyclic model, a variant of the ekpyrotic model in which collisions occur periodically. In the latter model, the Big Bang was preceded by a Big Crunch and the Universe endlessly cycles from one process to the other.[65][66][67]
chaotic inflation, in which universal inflation ends locally here and there in a random fashion, each end-point leading to a bubble universe expanding from its own big bang.[68][69][70]
Proposals in the last two categories see the Big Bang as an event in a much larger and older Universe, or multiverse, and not the literal beginning.

膜拜一下孔老夫子：知之為知之，不知為不知，是知也！

哈哈，貌似你很喜歡給別人帖標籤呀。好歹咱們也學過幾何，至少是有中學程度的。。。不過今天太晚啦，困死了。科學不科學的，明天再說吧。。。。

自由之靈 發表於 2011-3-7 14:22
哈哈，貌似你很喜歡給別人帖標籤呀。好歹咱們也學過幾何，至少是有中學程度的。。。不過今天太晚啦，困死了 ...

我不是要給誰貼標籤。我只是希望：大家發言之前要做點功課。

你不要學那個三七二十八的傢伙。

我不能確定有沒有「輪迴」，但是我100%肯定：假如有輪迴，這個輪迴也絕對不會是老七的那個令人懷疑的的「輪迴」轉世/靈童。

回復 pcless 5樓 的帖子

我覺得你們大家都跑題了，老嘁說了這麼多他自己也被拉得跑題了。其實他想說的並不是「輪迴是存在的」，他想說的是「基督教是明顯反科學的，這跟佛教是有區別的」，事實上佛教反科學確實不如基督教明顯，基督教不光是教義反科學，而是打著旗號反科學的。如此而已。

如此反覆來回跑題到宇宙大爆炸實在太誇張了，即便宇宙大爆炸被解密了，總會有我們人類不能觸及的自然領域，拿出來跟宗教一通攪和毫無意義。現代物理的數學模型所觸及的世界，在某種意義上來說，已經不是語言所能夠概括的了，即使你的數學好到可以理解，你也未必能用語文說清楚。最重要的是，大家應該明白你們對老嘁批評的同時，你們自己對科學並不象你們自己想像得這麼了解，至少我從貼子里看到的不是這樣。所以你們對老嘁還是寬容些吧，反基就是反基，我認為反基的原因就是因為我們都相信這世界不是單色調的。

看來大家的交集應該在反基，除了反基，也只能一拍兩散。

可是，基又有什麼好反的，輪來輪去還是那幾板斧，除了弊帚自珍，誰還提的起神兒來。

回復 王劍 6樓 的帖子

既然「反」了科學了，還有100%反和50%反的區別？

50100?

回復 在美一方 8樓 的帖子

反基督教和反科學好象是有區別的吧？

回復 在美一方 8樓 的帖子

我不知道我什麼時候說過反科學了？

回復 王劍 11樓 的帖子

"事實上佛教反科學確實不如基督教明顯"

回復 在美一方 12樓 的帖子

我們還是別跑題了，我意思是說老嘁反基督教是有原因的，這個原因我們大家都很明白，他不反佛教的原因我們也很明白。難道我們因為老嘁反基督教，就得逼著他反佛教？

我不反對任何人反佛教，對我來說有點多此一舉。

如此我對8樓也有答案了，是的，佛教和基督教是有區別的。

回復 王劍 13樓 的帖子

我的意思，「反」了什麼，就是180度的，哪裡有什麼程度之分？所謂佛教比基督教反科學程度低些，無非是在你們眼裡，佛教內容里反科學的成分也許比基督教的少些。【這裡加一句】一個臭雞蛋是臭雞蛋，三分之一個臭雞蛋依然是臭雞蛋。

我從來沒有說，誰要是批駁基督教反科學的話，也必須批駁佛教反科學，而我向來是反對這種做法的。誰愛批駁什麼，是誰個人的自由。

回復 在美一方 14樓 的帖子

對我來說，在態度上不針鋒相對跟舉著大旗要去學校教神創論是有明顯區別的，是不是臭雞蛋，有沒有臭雞蛋，跟到處去販賣臭雞蛋還是有區別的。所以我的結論：佛教和基督教在科學態度上還是有區別的。因為這是個人文問題。

跑題跑得厲害啊！

要反什麼都是個人的自由，這是肯定的。

但是，不管反什麼，發言要有嚴謹的治學態度。

什麼叫嚴謹？請參考我論證科學和基督教矛盾的帖子：

剖析科學與基督教信仰的一個矛盾
http://truth-truth.blog.sohu.com/36105265.html

回復 王劍 15樓 的帖子

我不計較態度，只看文字事實

老七， 看來對你來說，最有說服力的大概是Wiki上的東西。但是在你引的那一段之前，有一句是說這些模型都是「untested"的. 我不知道你為什麼沒有把這句話加上？

以下是Wiki對Cyclic Models 的結果：

Cyclic model

A cyclic model is any of several cosmological models in which the universe follows infinite, self-sustaining cycles. For example, the oscillating universe theory briefly considered by Albert Einstein in 1930 theorized a universe following an eternal series of oscillations, each beginning with a big bang and ending with a big crunch; in the interim, the universe would expand for a period of time before the gravitational attraction of matter causes it to collapse back in and undergo a bounce.


Overview

In the 1930s, theoretical physicists, most notably Albert Einstein, considered the possibility of a cyclic model for the universe as an (everlasting) alternative to the model of an expanding universe. However, work by Richard C. Tolman in 1934 showed that these early attempts failed because of the entropy problem: according to the Second Law of Thermodynamics, entropy can only increase.[1] This implies that successive cycles grow longer and larger. Extrapolating back in time, cycles before the present one become shorter and smaller culminating again in a Big Bang and thus not replacing it.

This puzzling situation remained for many decades until the early 21st century when the recently discovered dark energy component provided new hope for a consistent cyclic cosmology.[2]

One new cyclic model is a brane cosmology model of the creation of the universe, derived from the earlier ekpyrotic model. It was proposed in 2001 by Paul Steinhardt of Princeton University and Neil Turok of Cambridge University. The theory describes a universe exploding into existence not just once, but repeatedly over time.[3][4] The theory could potentially explain why a mysterious repulsive form of energy known as the "cosmological constant", and which is accelerating the expansion of the universe, is several orders of magnitude smaller than predicted by the standard Big Bang model.

A different cyclic model relying on the notion of phantom energy was proposed in 2007 by Lauris Baum and Paul Frampton of the University of North Carolina at Chapel Hill.[5]

The Steinhardt–Turok model In this cyclic model, two parallel orbifold planes or M-branes collide periodically in a higher dimensional space.[6] The visible four-dimensional universe lies on one of these branes. The collisions correspond to a reversal from contraction to expansion, or a big crunch followed immediately by a big bang. The matter and radiation we see today were generated during the most recent collision in a pattern dictated by quantum fluctuations created before the branes. Eventually, the universe reached the state we observe today, before beginning to contract again many billions of years in the future. Dark energy corresponds to a force between the branes, and serves the crucial role of solving the monopole, horizon, and flatness problems. Moreover the cycles can continue indefinitely into the past and the future, and the solution is an attractor, so it can provide a complete history of the universe.

As Richard C. Tolman showed, the earlier cyclic model failed because the universe would undergo inevitable thermodynamic heat death.[1] However, the newer cyclic model evades this by having a net expansion each cycle, preventing entropy from building up. However, there are major problems with the model. Foremost among them is that colliding branes are not understood by string theorists, and nobody knows if the scale invariant spectrum will be destroyed by the big crunch. Moreover, like cosmic inflation, while the general character of the forces (in the ekpyrotic scenario, a force between branes) required to create the vacuum fluctuations is known, there is no candidate from particle physics. [7]

The Baum–Frampton model This more recent cyclic model of 2007 makes a different technical assumption concerning the equation of state of the dark energy which relates pressure and density through a parameter w.[5][8] It assumes w < −1 (a condition called phantom energy) throughout a cycle, including at present. (By contrast, Steinhardt–Turok assume w is never less than −1.) In the Baum–Frampton model, a septillionth (or less) of a second before the would-be Big Rip, a turnaround occurs and only one causal patch is retained as our universe. The generic patch contains no quark, lepton or force carrier; only dark energy – and its entropy thereby vanishes. The adiabatic process of contraction of this much smaller universe takes place with constant vanishing entropy and with no matter including no black holes which disintegrated before turnaround. The idea that the universe "comes back empty" is a central new idea of this cyclic model, and avoids many difficulties confronting matter in a contracting phase such as excessive structure formation, proliferation and expansion of black holes, as well as going through phase transitions such as those of QCD and electroweak symmetry restoration. Any of these would tend strongly to produce an unwanted premature bounce, simply to avoid violation of the second law of thermodynamics. The surprising w < −1 condition may be logically inevitable in a truly infinitely cyclic cosmology because of the entropy problem. Nevertheless, many technical back up calculations are necessary to confirm consistency of the approach. Although the model borrows ideas from string theory, it is not necessarily committed to strings, or to higher dimensions, yet such speculative devices may provide the most expeditious methods to investigate the internal consistency. The value of w in the Baum–Frampton model can be made arbitrarily close to, but must be less than, −1.



Notes^ a b R.C. Tolman (1987) [1934]. Relativity, Thermodynamics, and Cosmology. New York: Dover. ISBN 0486653838. LCCN 34032023-{{{3}}}.  
^ P.H. Frampton (2006). "On Cyclic Universes". arΧiv:astro-ph/0612243 [astro-ph].  
^ P.J. Steinhardt, N. Turok (2001). "Cosmic Evolution in a Cyclic Universe". arΧiv:hep-th/0111098 [hep-th].  
^ P.J. Steinhardt, N. Turok (2001). "A Cyclic Model of the Universe". arΧiv:hep-th/0111030 [hep-th].  
^ a b L. Baum, P.H. Frampton (2007). "Entropy of Contracting Universe in Cyclic Cosmology". arΧiv:hep-th/0703162 [hep-th].  
^ P.J. Steinhardt, N. Turok (2004). "The Cyclic Model Simplified". arΧiv:astro-ph/0404480 [astro-ph].  
^ P. Woit (2006). Not Even Wrong. London: Random House. ISBN 97800994488644.  
^ L. Baum and P.H. Frampton (2007). "Turnaround in Cyclic Cosmology". Physical Review Letters 98 (7): 071301. doi:10.1103/PhysRevLett.98.071301. PMID 17359014. arXiv:hep-th/0610213.  
[edit] See alsoCosmology
Richard Tolman
Big Bounce
Cosmological constant
Conformal Cyclic Cosmology
Cycles of time in Hinduism
[edit] Further readingP.J. Steinhardt, N. Turok (2007). Endless Universe. New York: Doubleday. ISBN 9780385509640.  
R.C. Tolman (1987) [1934]. Relativity, Thermodynamics, and Cosmology. New York: Dover. ISBN 0486653838. LCCN 34032023-{{{3}}}.  
L. Baum and P.H. Frampton (2007). "Turnaround in Cyclic Cosmology". Physical Review Letters 98 (7): 071301. doi:10.1103/PhysRevLett.98.071301. PMID 17359014. arXiv:hep-th/0610213.  
R. H. Dicke, P. J. E. Peebles, P. G. Roll and D. T. Wilkinson, "Cosmic Black-Body Radiation," Astrophysical Journal 142 (1965), 414. This paper discussed the oscillatory universe as one of the main cosmological possibilities of the time.
S. W. Hawking and G. F. R. Ellis, The large-scale structure of space-time (Cambridge, 1973).
[edit] External linksPaul J. Steinhardt, Department of Physics, Princeton University
Paul H. Frampton, Department of Physics and Astronomy, The University of North Carolina at Chapel Hill
Cyclic universe on arxiv.org
"The Cyclic Universe": A Talk with Neil Turok

Wiki 已經指出，早在1934年，你說的那種循環理論就被證偽了。其他所有在這裡列出的循環理論都是在2007年以前發表的。而NASA 的衛星WMAP直到2008年才公布黑色能量五年的數據。我盡量用最新的結果給你解釋，很奇怪你居然不去看，卻要給別人扣帽子。你說你有什麼科學精神？

自由之靈 發表於 2011-3-12 01:50
這裡已經指出，早在1943年，你說的那種循環理論就被偽證了。其他所有在這裡列出的循環理論都是在2007年以前 ...

我說的那種？我從來不關心哪一種！

我只關心：cyclic model 被證偽了嗎？