1. 1 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 3: Inflation Big Bang, Black Holes, No Math ASTR/PHYS 109 Dr. David Toback Lecture 27

2. Was due Today – L28 2 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 3: Inflation Reading & Pre-Lecture Reading Questions: –None End-of-Chapter Quizzes: –Chapter 19 Papers: –Paper 4: Stage 1 due Monday, Stage 2 the following Monday –Honors: Tonight at 11:55PM on eCampus Notes: –Today is the last day of class –All EOC quizzes will be due Monday May 11 th at 11:55PM. You cannot pass the course without doing all of them –Make sure you have turned in all papers (including Revisions) into turnitin. You will lose points if you don’t. –Won’t start calculating grades until the 11 th

3. 3 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation Unit 6 Going back in time and going forward in time Before the first millionth of a second and the Fate of the Universe

4. 4 Outline of Unit 6 1.Possible Fates of the Universe, Dark Matter and Dark Energy 2.Particle Physics, Dark Matter and the Very Early Universe 3.Inflation Last Topic

5. 5 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation Today’s Outline There are many pieces of evidence that point to something “odd” happening in the very early universe, but we’ll focus on the one piece that is easiest to understand A Universe where the particles have an energy that looks like temperature, and is the same in all directions Why this is “unexpected” Inflation in the VERY early Universe

6. 6 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation Problem Same Temperature Everywhere or said differently Why does the Universe look like it’s in Thermal Equilibrium or was in Thermal Equilibrium?

7. 7 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation Thermal Equilibrium? Up until now we’ve said the Universe essentially looks the same everywhere because it evolved from particles in thermal equilibrium Assumption: All the stuff in the Universe had enough time to come into thermal equilibrium

8. 8 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation How Uniform is It? Temperature Map of the Universe Uniform to 1 part in 10,000

9. 9 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation Problem According to General Relativity if the Universe expanded to have the speeds we see now then the “stuff” in the Universe would have expanded so quickly that it would never have had time to come into thermal equilibrium A cooler with ice and water will eventually come into thermal equilibrium, but it takes a while

10. 10 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation Why? The Speed of Light Particles can’t move faster than the speed of light to bang into each other and bring everything into equilibrium –Space would have separated the particles in the early Universe so quickly that they would never have been able to interact with each other enough to come into thermal equilibrium

11. 11 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation The Problem If the Universe didn’t have time to come into thermal equilibrium, how is it that it looks like it was in thermal equilibrium? In English: How did every part of the entire universe get to be so nearly the same temperature everywhere if big chunks of the Universe didn’t have time to interact?

12. 12 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation Is/Was the Universe in Thermal Equilibrium? Not from thermal equilibrium? The explosion we call the Big Bang would need to have to occurred in such a way that the Universe is almost EXACTLY the same in every direction –Ever seen a bomb/fireworks explode in exactly the same way in all directions? Seems unlikely Would also need to produce energy’s that look like a temperature distribution –Even harder to imagine…

13. 13 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation The Million Dollar Question The Universe we live in today appears to have been in Thermal Equilibrium at some point Question: How could this have happened? How did a Universe that didn’t have time to come into Thermal Equilibrium come to look like was in Thermal Equilibrium?

14. 14 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation Thermal Equilibrium Two main options: 1.Either there is a creator (or something else) that made the explosion look like it created a nearly perfect temperature distribution 2.There is something else going on and the Universe was in thermal equilibrium at some point

15. 15 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation Our best Hypothesis: Inflation Noto Bene: we don’t really understand what caused inflation yet Anyone want a Nobel Prize?

16. 16 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation What is “Inflation”? Can explain this “problem” (and many others) if there was a sudden “inflation” when the Universe was very young This would be an expansion of space-time that is much more extreme than that predicted by the simple Big Bang theory

17. Overview Example 17 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation Brief History of Time 1.Universe grows slowly for awhile 2.Then grows really quickly for awhile 3.Then grows at the rate we see now Our Universe Now Our Universe right after the bang

18. 18 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation An “Inflationary” Version of History 1.The Big Bang occurs, the universe expands and cools much more slowly than it does today –For the first 10 -35 seconds the expansion is SO SLOW that the Universe comes into thermal equilibrium 2.The Universe starts expanding VERY RAPIDLY for a really short time –Call this time period “Inflation” –Grows by between 10 20 and 10 30 times 3.After inflation is done, the Universe grows with the rate consistent with what we observe today

19. 19 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation Put this in Perspective Before Inflation: The visible Universe was about the size of an atom During Inflation: It grew to about the size of a cherry pit After Inflation: Continued with a “slower” expansion to its current size

20. 20 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation Aside on Relativity Remember: No THING can travel THROUGH SPACE faster than the speed of light However: General Relativity doesn’t place a limit on the speed at which Space-Time can stretch

21. 21 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation How does this make the Universe look like it’s in Thermal Equilibrium? Before inflation the Universe was really small  The stuff in it had plenty of time to come into Thermal Equilibrium After inflation all that occurs is the expansion of a Universe that at one point was in thermal equilibrium Thus, you live in a universe with the same temperature in all directions

22. Quantum Fluctuations and Inflation 22 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation The quantum fluctuations in the early universe are what provided the seeds for galaxy formation Fluctuations occurred in the universe BEFORE inflation (when universe was small enough for quantum mechanics to be important) Just “stayed in place” during the rapid expansion –Same temperature everywhere, even though not in thermal equilibrium today

23. 23 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation Now we are able to explain all the major stages of the the Evolution of The Universe

24. 24 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation Inflation The problem with the model

25. 25 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation What Caused Inflation? Don’t really know SHU Chapters 12 and 13 present some ideas, but its not clear they’re right The reading “Cosmology in the 21 st Century” is closer to our current guess Scientists are still working on this…

26. End of the Semester Pre-Lecture Reading Questions: –Unit 6 Revision (if desired), Stage 1: Due Monday Dec 7 th at 4:10PM Papers: –Paper 4: Stage 1: Due Friday Dec 4 th at 4:10PM Stage 2: Due Friday Dec 11 th at 4:10PM EOC Quizzes: –All EOC quizzes will be due Wednesday Dec 16 th at 11:55PM. You cannot pass the course without doing all of them Honors Paper: –Stages 1 & 2 must be approved explicitly –Final paper due Wednesday Dec 9 th at 11:55PM in eCampus Other Notes: –Make sure you have turned in all papers (including Revisions) into turnitin. You will lose points if you don’t. –Won’t start calculating grades until the 17 th –Please do the Course Evaluations 26 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 3: Inflation

27. Interested in learning more next semester? Take Astronomy 111 27

28. That’s it! Best of luck finishing all the papers and quizzes Best of luck on finals! Thanks for listening! 28 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation

29. 29 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation

30. Fixes for this year Water cooler and remove flatness. Grid for expansion. Burnt orange cmb 30 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 3: Inflation

31. 31 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation Today’s Outline Two pieces of evidence: 1.A Universe with the Critical Density and a Flat space-time 2.A Universe where the Temperature is the same in all directions Why these are “unexpected” Inflation in the VERY early Universe

32. 32 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation First Problem Universe appears to have exactly the critical density

33. 33 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation Density of the Universe and General Relativity General Relativity teaches us that the Density of the Universe determines the Curvature of Space-Time Remember, we’re not talking about local curvature, but the curvature of the entire universe

34. Early Times & Fate of the Universe Topic 1: Possibilities 34 Look at the Spots We know what the size of the spots should be back during recombination, but we can ask how much the light was lensed as it moved through space Big Crunch Critical Density Expands Forever

35. 35 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation Critical Universe  Flat Space Time CrunchCritical Forever? Data points to a Universe with the critical density and flat space- time The Data

36. 36 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation Flatness and General Relativity General Relativity tells what the Bang must have been like to evolve into something that gives a flat space-time AND has the speed we observe This isn’t a problem… BUT it also tells us that if the Universe were “slightly different” from that at the beginning it would become VERY un-flat now, or would have collapsed already

37. 37 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation Critical Density It’s as if we threw up a ball on the Earth 13.5 billion years ago with exactly the right speed such that now it’s in outer space now with EXACTLY zero speed Slightly too dense? Would expand and then quickly collapse back onto itself

38. Another Analogy: Kicking a Football Kick the ball from the 50 yard line to within the region from the end zone to the 25 yard line –1 part in 2 Kick the ball from the 50 yard line to within 10 yards of the goal –1 part in 5 From the 50 yard line to within 1 yard of the goal –1 part in 50 Hit the goal line itself  About 1 in 100 Land on a dime on the goal line  1 in a thousand Land on a hair on the goal line  1 in 10 5 38 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation

39. 39 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation How close to perfect? We observe the Universe to be within 1 part in 10,000 (10 5 ) of being flat now –Could be exactly flat –Actually, making the Universe flat isn’t as easy as kicking a ball. Closer to trying to putt a golf ball down a mountain into a hole at the bottom Unless something special happened RIGHT AFTER the Big Bang the Universe would have had to be in exactly the right configuration to 1 part in ~10 50 to have evolved to be as flat as we observe now

40. 40 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation Flatness and Temperature Problems How did we get from a Universe of Infinite Curvature at the Big Bang to one with almost EXACTLY no curvature now?

41. 41 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation Flatness Think about two options: 1.Either there is a creator (or something else) that “tuned” the explosion perfectly 2.There is something else going on to make the Universe flat Lucky for us the Universe is flat; life as we know it couldn’t exist otherwise

42. 42 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation How does this Help Flatness? The sudden inflation would have forced whatever curvature there was in the universe towards zero –Like inflating a balloon  makes a small spot on its surface flatter –Smoothes out any wrinkles Thus, you live in a Universe that is almost perfectly flat because of that sudden inflation long ago

43. End of Semester Part 2 Papers: –Paper 4 Revision (if desired): Stage 1 due Wednesday night at 11:55PM Stage 2 due Friday night at 11:55PM Grades: –All paper and PLRQ grades are in CPR and won’t get ported to eCampus –Will start calculating grades after all the revisions are done (may take awhile) Please do the Course Evaluations 43 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation

44. 44 Was Due Today– L2 Reading & Pre-Lecture Reading Questions: –None End-of-Chapter Quizzes: –If we finished Chapter 19, then Chapter 19 (if not, then just Chapter 18) Papers: –Paper 4: Stage 2 Notes: –Monday is the last day of class –All EOC quizzes will be due before Finals Week. You cannot pass the course without doing all of them –Make sure you have turned in all papers into turnitin. You will lose points if you don’t.

45. 45 Was Due Today– L2 Reading & Pre-Lecture Reading Questions: –None End-of-Chapter Quizzes: –If we finished Chapter 19, then Chapter 19 (if not, then just Chapter 18) Papers: –Paper 4: Stage 2 Notes: –Monday is the last day of class –All EOC quizzes will be due before Finals Week. You cannot pass the course without doing all of them –Make sure you have turned in all papers into turnitin. You will lose points if you don’t.

46. 46 Prep For Next Time – L12 Note: May change depending on how far we get in lecture Reading: –BBBHNM: All reading through Chapter 20 Reading Questions: –All reading questions through 20 eLearning Quizzes: –If we finished Chapter 18 then end-of-chapter quiz 18 (else just through Chapter 17) Papers: –Text of Paper 4 assignment due Wednesday at 11:55PM –Calibrations, Reviews and Self-assessment due before class on Monday

47. Prep for Next Time – P26 47 Reading –BBBHNM 22 Reading questions –Chapter 22 End-of-Chapter Quizzes –If we finished Chapter 20 then end-of-chapter quiz 20 (else just 19) Papers –Paper 1, 2 or 3: Misgraded? Let us know –Paper 3 revision: Due tonight at Midnight –Paper 4: Due tonight at Midnight

48. 48 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation The Reading for Unit 6 Full reading for Unit 6: BBBHNM: Chaps. 18-22 SHU: 8 (159-164) BHOT: 11 (122-137), 12 Seeds (Cosmology in the 21 st Century, Web Handout) Full reading through Unit 6: BBBHNM: Chaps. 1-22 TFTM: Chaps. 1-5 BHOT: Chaps. 1-7, 8 (68-76), 9 and 11 (117-137), 12 SHU: Chaps. 1-3, 4(77-86), 5(95-114), 6-8 (up-to- page 164) TOE: Chaps. 1-3 Seeds (Cosmology in the 21 st Century)

49. Papers & End of Semester Last day of class Cancelled the last paper Paper 4: –CPR due on Monday (no class, attend Friday class) –Will finish grades shortly after that Let us know if you see problems –Only doing text revisions: Email ASAP to be considered Honors papers: –Due tonight at midnight if you want to do a revision –You can turn it in on Monday, but with no chance for revision End of Chapter quizzes for all chapters due Monday –Can’t pass the course without them 49

50. 50 Prep for Today (Is now due) – L26 Reading: –BBBHNM 22 Reading questions: –Chapter 22 End-of-Chapter Quizzes: –Chapter 20 Paper Stuff –Paper 1, 2 or 3: Misgraded? Let us know –Paper 3 revision: CPR due Monday –Paper 4: CPR due Monday

51. 51 Course Evaluations Course evaluations will be done online via the Department of Physics On-Line Course Evaluation System You should have gotten an email about this already The Fall 2011 evaluation period will: Began on November 18 Ends on Friday, December 23 at 8AM Please do these ASAP… won’t take long

52. 52 Schedule from Here on Out Thursday: Dec 3 rd Chapter 21 –The rest of the reading is now due –Be working on eLearning Unit 6 stuff Tuesday: Dec 8 th Chapter 22 –Paper due at midnight Thursday Dec 10 th, No classes, Reading period Tuesday 15 th : Finals week, no final –Paper revisions due

53. 53 Last Paper Due last day of class Dark Matter Paper Or Research Paper Turn in at eLearning like usual

54. 54 Writing Assignments Short Assignments 1, 2 & 3 Re-do’s are still possible. Want to revise again? Talk to me eLearning: Unit 5 past due Need to be working on Unit 6

55. 55 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation Schedule from Here on Out Mon April 27 th : 25 th lecture –The rest of the reading is now due –Stage 1 Research Topic Proposal must be approved –WebCT Unit 6 stuff Wed April 29 th : 26 th lecture Mon May 4 th : Class cancelled –Research paper due at noon on Tuesday May 5 th Wed May 6 th : No classes, Reading period Mon May 8 th : Finals week, no final –Paper revisions due

56. 56 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation Why? The Speed of Light Objects can’t move faster than the speed of light to bang into each other and come to equilibrium –Objects separated by even a small one angular degree in the sky would have separated so quickly that they would never have been able to interact with each other and come into thermal equilibrium

57. 57 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation Schedule from Here on Out Next time: Finish the story of the Evolution of the Universe Dark Energy Wed Nov 19 th : 25 th lecture: –Recitation for Paper 2 Will be checked off at the end of class as your in-class quiz –Inflation Mon Nov 24th: 26 th lecture: Dark Energy Wed Nov 26th: No class –Research paper and 2 nd short paper due at midnight –Day before Thanksgiving. Class cancelled Dec 1 st : No classes redefined day Dec 3 rd : Reading period, no classes Dec 8 th : Finals week, no final

58. 58 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation The $64,000 Question Question: Why is the Universe SO flat and Isotropic? –The Flatness problem –The Isotropy problem Start by explaining why these issues should concern us

59. 59 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation Today’s Lecture: Inflation The story described so far doesn’t really explain the observed flatness and Isotropy of the Universe How “Inflation” helps (and what the word “Inflation” means here) A few words on what might have caused inflation –We don’t know what caused inflation –Any one want a Nobel Prize?

60. 60 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation The Universe we live in today appears to have a remarkably Flat space- time and is incredibly Isotropic (the same everywhere)

61. 61 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation What type of Universe? It’s as if we threw up a ball on the Earth 15 billion years ago with exactly the right speed such that now it’s in outer space with EXACTLY zero speed Not perfect? In a Closed Universe it expands and then collapses back onto itself

62. 62 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation Small Aside What if it didn’t have this “perfect” initial condition? Example problem: If the rate of expansion (or amount of “stuff” in the universe) was too small then the whole thing could collapse again Wouldn’t need to be too far off for the Universe to collapse REALLY quickly

63. 63 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation Paper 2 Notes Big Picture: This is a paper about particle physics and COSMOLOGY Answer the question: “Why would the experimental discovery of Supersymmetric particles help us understand the Universe?”

64. 64 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation Common Paper 2 Problems Forgot to mention about WHY we are asking for money –Can't just say "build experiments to study Dark Matter“ –How would experiments study it? –What would we need money to DO? Can’t just answer the question “Why do we believe in Dark Matter?” Can’t just say that the goal is to solve the Dark Matter “problem” (that’s an astronomy problem). Need to explain how understanding the Dark Matter tell us about the origin and evolution of the universe Didn’t explain how supersymmetry could provide a Dark Matter candidate

65. 65 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation Schedule from Here on Out Wed Nov 28 th (today): 27 th lecture –Finish up Inflation and Dark Energy –Research paper due at midnight Dec 3rd: No classes redefined day Dec 5th: Reading period, no classes. Meet at the Chicken Dec 10th: Finals week, no final All paper revisions due by Dec 12th

66. 66 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation Aside… Sometimes small happenings can have big effects Sometimes a butterfly flapping its wings in China can affect the weather in Chicago

67. 67 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation What Caused Inflation? Perhaps Inflation was caused by the sudden energy release from the decoupling of the strong and electroweak forces

68. 68 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation The Isotropy Problem While it’s nice to think that the Universe exploded in such a way that the Universe is almost EXACTLY the same in every direction (isotropic) this also seem unlikely –Ever seen a bomb explode in exactly the same way in all directions?

69. 69 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation More on the Isotropy Problem Said differently: Since the particles can only travel through the Universe at the speed of light then different parts of the Universe wouldn’t have been able to come into Thermal Equilibrium EVERYWHERE and show the same temperature of the Cosmic Background Radiation

70. 70 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation Summarizing the Data so Far 1.Hubble Constant gives us the speed of expansion fairly accurately 2.The Universe appears really isotropic 3.The measured density of the “stars and stuff” is about 4% of the critical density 4.The measured Curvature of the Universe is consistent with being exactly flat  Density is 100% of the critical density Something is inconsistent…

71. 71 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation Next Two Topics We can use the evidence that we live in a Flat, Homogenous and Isotropic Universe as evidence for two main things 1.Inflation (Today) 2.Other Mass/Energy in the Universe (Next Time) There is other evidence that this story is correct

72. 72 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation Not sure what to do with these pictures yet!

73. 73 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation Galaxy Formation t 1 s 10  7 s Quantum Gravity 500 M yrs SUSY Relic 10  43 s 10  11 s Relic Radiation Decouples: WMAP t = 14 billion years

74. 74 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation

75. 75 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation This is some text… { What happened here?

76. 76 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation when it became so cool atht the EWK and Strong force began to disconnect from each other and behave in very different ways This released tremendous energy, which suddently inflated the universe by a factor between 1020 and 1030

77. 77 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation SHU 12 cont… Tiny vacuum “popped” into existence. Has a small amount of energy… How does it become all the matter in the universe? What would happen if the tiny vacuum of energy somehow popped into existence, expanded rapidly, and failed to pop OUT of existence again? Would the expansion of the energy continue and be sustained enough long enough to allow for the emergence of a universe full of matter anything like the one we observe today?

78. 78 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation SHU 12 cont… Suppose all the energy in the vacuum was released, rather like the gas in a carbonated drink when the bottle is opened. In the drink, many bubbles of gas, not just one big bubble, rush to the top of the bottle when the cap is unscrewed and the pressure is released Why not imagine that the energy in the vacuum breaks up into billions of tiny bubble in a similar way; and that only one of these bubbles expands to become our universe?

79. 79 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation Question: What about the other bubbles? If each bubble becomes a universe, then we’d never see them… oh well… Other observable consequences? Somewhere there has to be an infinite number of universes… So rather than saying ours is special, it says ours is just one of many… However this is un-predictive…

80. 80 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation SHU 13 Not really inflation but… Smolin’s idea: What if lots of universes were created, but only one of them were “fit” enough (like Darwin’s ideas) to develop into what we see today. Or perhaps lots exist (parallel to ours) but ours is special in that it allows life. Not predictive, but interesting to think about…

81. 81 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation BHOT 8, SHU 12

82. 82 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation Galaxy Formation t 1 s 10  7 s Quantum Gravity http://www.damtp.cam.ac.uk/user/gr/public/bb_history.html 500 M yrs SUSY Relic 10  43 s 10  11 s Relic Radiation Decouples: WMAP t = 14 billion years

83. 83 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation

84. 84 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation

85. 85 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation Outline We really should say SOMETHING about inflation… not really sure what… TOE 5. Does this go as part of Evolution of the universe or as part of speculations? SHU 12, starting on page 241

86. 86 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation BHOT 8 There is some stuff in BHOT 8 about this stuff (page 74) Inflation is important in the evolution of the universe

87. 87 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation SHU 12 What might have caused the rapid expansion of the early universe? Why do we think there was a rapid expansion (faster than the speed of light) of the early universe? There is no way the universe could end up at its present size, with the rate of expansion we observe today…

88. 88 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation SHU 14 Hawkings ‘No boundary’ solution. People still think about this?? There are no boundaries marking the end of space or time, even though the universe as a whole has a finite size. Example: Think about walking on the earth. You will never meet a boundary… You can’t tell if you are on the inside or outside of a balloon.

89. 89 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation TOE 5 P97-107 is really just a quick summary of the evolution of the universe stuff we’ve already done Inflation: More on why we need it… TOE is pretty unclear. SHU better? Inflation says that the early universe had a period of very rapid (exponential) expansion The size of the universe expanded much faster than the speed of light in a tiny fraction of a second Relativity only talks about the speed of objects, SPACE is allowed to expand as quickly as it wants

90. 90 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation TOE 5 cont… Not really a good chapter…

91. 91 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation BHOT 8 The universe (according to Friedmann models) has a beginning at about 13.7 Billion years ago I.e., the distance between neighboring galaxies must have been zero First set of problems: Theories of space time is smooth and flat That means our theories break down at the big bang: a space-time with infinite density means infinite curvature so it isn’t flat! This means we cannot predict what happened BEFORE the big bang

92. 92 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation Isotropy problem The CMB is isotropic to at least one part in 1000. Yet when you look at the background radiation coming from two points in the sky separated by more than a degree, you look at two parts of the big bang that were not “causally connected” when the radiation was emitted. Said differently, when recombination occurred and the gas of the big bang became transparent to the radiation, the universe was not old enough for any signal to have traveled from one of these regions to the other.

93. 93 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation Thus, the two spots you look at did not have time to exchange heat and even out their temperatures

94. 94 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation BHOT 8 cont… “In the hot big bang model there was not enough time in the early universe for heat to have flowed from one region to another This means that the initial state of the universe would have had exactly the same temperature everywhere in order to account for the fact that the microwave background has the same temperature everywhere we look

95. 95 Big Bang, Black Holes, No Math Early Times & Fate of The Universe Topic 4: Inflation Why does this help explain things? all the irregularities would have been smoothed out by the expansion (kind of like wrinkles in a balloon smooth out when you blow it up)