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宇宙的最初三分鐘

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。.

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宇宙的最初三分鐘

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  1. 宇宙的最初三分鐘

  2. 宇宙的起源? • 宇宙是永恒存在的，還是有起始的？

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

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

  5. 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。

  6. At t<=0 • Gravitational singularity • Quantum tunnelling

  7. 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

  8. 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。

  9. Fundamental Force • Strong interaction • Mediator : Gluon • Relative Magnitude : 1 • Behavior : 1/r7 • Range : 1.4 x 10-15 m

  10. Fundamental Force • Electromagnetic interaction • Mediator : Photon • Relative Magnitude : 1/137 • Behavior : 1/r2 • Range : ∞

  11. Fundamental Force • Weak interaction • Mediator : W and Z bosons • Relative Magnitude : 10-13 • Behavior : 1/r5 to 1/r7 • Range : 10-18 m

  12. Fundamental Force • Gravitational interaction • Mediator : Graviton (perhaps) • Relative Magnitude : 10-39 • Behavior : 1/r2 • Range : ∞

  13. Planck time(0<t<=10-43s) • 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

  14. T~10-43 s • 1032 K. • No electrons , atoms. • matter and antimatter existed in almost equal amounts • All but gravitational force were unified

  15. Phase Transition • Example:ice water steam Phasetransition: • ice water Phasetransition: • water steam

  16. Phase transitions in the early Universe • GUT phasetransition:As the temperature drops below ~ 1029K, 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

  17. Phase transitions in the early Universe • Electroweak phase transition: • As the temperature drops below ~ 1015K, 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

  18. GUT Phase transition10-35s< T < 10-32s • 1028 K , 10-25 meters • baryonic matter formed • all that existed during this time were quarks. • rapid inflation expanded to nearly 10+25 meters • Strong Nuclear force separated from ElectroWeak force

  19. T~ 10-11 sthe time it takes light to travel half-way across an eraser at the top of a pencil • 1016 K • EM-force and Weak force separated

  20. T~10-6 s(light travels 3 football fields) • 1013 K • cooled enough to form leptons • (e.g. neutrinos , electrons) • baryons , e.g. protons , neutrons • Mesons

  21. T~ 1 s • 1010 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

  22. T~3 mins • 109 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

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

  24. Reference(Wikipedia) • http://zh.wikipedia.org/wiki/%E5%9F%BA%E6%9C%AC%E7%9B%B8%E4%BA%92%E4%BD%9C%E7%94%A8 • http://en.wikipedia.org/wiki/The_Big_Bang • http://en.wikipedia.org/wiki/Static_universe • http://en.wikipedia.org/wiki/Steady_state_theory • http://en.wikipedia.org/wiki/Quasi-steady_state_cosmology • http://en.wikipedia.org/wiki/Fundamental_particles

  25. Reference • http://en.wikipedia.org/wiki/Fundamental_force • http://en.wikipedia.org/wiki/Strong_interaction • http://en.wikipedia.org/wiki/Weak_interaction • http://en.wikipedia.org/wiki/Electromagnetism • http://en.wikipedia.org/wiki/Gravity

  26. Reference • http://en.wikipedia.org/wiki/Planck_epoch • http://en.wikipedia.org/wiki/Cosmic_microwave_background_radiation

  27. Reference • http://en.wikipedia.org/wiki/Hydrogen • http://en.wikipedia.org/wiki/Deuterium • http://en.wikipedia.org/wiki/Tritium • http://en.wikipedia.org/wiki/Helium

  28. References(Articles & Lectures) • Errors in the Steady State and Quasi-SS Models: • http://www.astro.ucla.edu/~wright/stdystat.htm • Astronomy 201 Cosmology - Lecture 41: • http://www.aip.de/People/MSteinmetz/classes/Cosmology_201/PDF/Lecture_41.pdf • History of The Universe : • http://home.cwru.edu/~sjr16/advanced/cosmos_history.html

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

  30. 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

  31. ~The End~

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