宇宙的最初三分鐘

宇宙的起源 ? 宇宙是永恒存在的，還是有起始的？

穩恆態宇宙 The Steady-State Theory Quasi-steady state cosmology (QSS)

Entropy ( 熵 ) For any closed system Where S is entropy Universe is a closed system

大爆炸假說 (The Big-bang) 宇宙目前約 140 億歲 由一個密度極大且溫度極高的狀態演變 而來的。 在這個起始狀態中，宇宙的物質和能量 的溫度和密度極高。

At t<=0 Gravitational singularity Quantum tunnelling

Gravitational singularity ( 引力奇點 ) The Big Bang cosmological model at the start of time (t=0). the density of the universe and the curvature of space-time infinite. Predicted in Relativity

Quantum tunnelling ( 穿隧效應 ) 宇宙是由 “ 無 ” 誕生的嗎？ 宇宙是從沒有時間、沒有空間、沒有物 質，也沒有能量的 “ 無 ” 開始，因量子力 學的 “ 穿隧效應 ” 而突然誕生的。

Fundamental Force Strong interaction Mediator : Gluon Relative Magnitude : 1 Behavior : 1/r 7 Range : 1.4 x m

Fundamental Force Electromagnetic interaction Mediator : Photon Relative Magnitude : 1/137 Behavior : 1/r 2 Range : ∞

Fundamental Force Weak interaction Mediator : W and Z bosons Relative Magnitude : Behavior : 1/r 5 to 1/r 7 Range : m

Fundamental Force Gravitational interaction Mediator : Graviton (perhaps) Relative Magnitude : Behavior : 1/r 2 Range : ∞

Planck time (0<t<= s) all four fundamental forces were unified and elementary particles did not exist It is meaningless to speak of durations shorter than Planck time there is no generally accepted theory that unifies quantum mechanics and relativistic gravity p.s. 張 sir 話太深

T~ s K. No electrons, atoms. matter and antimatter existed in almost equal amounts All but gravitational force were unified

Phase Transition Example: ice water steam Phase transition: ice water Phase transition: water steam

Phase transitions in the early Universe GUT phase transition: As the temperature drops below ~ 10 29K, GUT force separates into the strong nuclear force and the electroweak force T > 1029K: GUT T < 1029K: electroweak force, strong nuclear force One of the candidates for inflation Other candidates: specifically designed inflaton fields

Phase transitions in the early Universe Electroweak phase transition: As the temperature drops below ~ 10 15K, the electroweak force separates into electromagnetism and the weak nuclear force T > 1015K: electroweak force T < 1015K: electromagnetism, weak nuclear force but to moderate a phase transition to trigger inflation

GUT Phase transition s < T < s K, meters baryonic matter formedbaryonic all that existed during this time were quarks. rapid inflation expanded to nearly meters Strong Nuclear force separated from ElectroWeak force

T~ s T~ s the time it takes light to travel half-way across an eraser at the top of a pencil K EM-force and Weak force separated

T~10 -6 s T~10 -6 s (light travels 3 football fields) K cooled enough to form leptons (e.g. neutrinos, electrons) baryons, e.g. protons, neutrons Mesons

T~ 1 s K not hot enough to form P,N Too hot to form atoms 1000 times hotter than the core of the sun. for every 1000 protons, there were 223 neutrons. free neutrons undergo beta decay

T~3 mins 10 9 K light atomic nuclei could form mainly of just one, two, three, or four particles H-1, H-2, H-3, He-3, He-4, Li-7 # of neutrons / # of protons = 0.164

Big Bang Nucleosynthesis It only lasted for about three minutes No elements heavier than beryllium formed

Reference (Wikipedia) %9B%B8%E4%BA%92%E4%BD%9C%E7%94%A8http://zh.wikipedia.org/wiki/%E5%9F%BA%E6%9C%AC%E7 %9B%B8%E4%BA%92%E4%BD%9C%E7%94%A

Reference

Reference ackground_radiationhttp://en.wikipedia.org/wiki/Cosmic_microwave_b ackground_radiation

Reference

References (Articles & Lectures) Errors in the Steady State and Quasi-SS Models: Astronomy 201 Cosmology - Lecture 41: 201/PDF/Lecture_41.pdfhttp:// 201/PDF/Lecture_41.pdf History of The Universe : mlhttp://home.cwru.edu/~sjr16/advanced/cosmos_history.ht ml

References (Articles & Lectures) 宇宙的起源 nce/universe/inside/001.htmlhttp://big5.china.com/gate/big5/tech.china.com/zh_cn/scie nce/universe/inside/001.html 宇宙誕生的最初三分鐘 nce/universe/inside/002.htmlhttp://big5.china.com/gate/big5/tech.china.com/zh_cn/scie nce/universe/inside/002.html 宇宙有始無終 nce/universe/inside/003.htmlhttp://big5.china.com/gate/big5/tech.china.com/zh_cn/scie nce/universe/inside/003.html

Reference (Books) 最初三分鐘 大霹靂之後 The First Three Minutes By Steven Weinberg University Physics Sixth Edition By Francis W.Sears, Mark W. Zemansky, Hugh D.Young

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