Chapter 17 The Beginning of Time Copyright 2009 Pearson Education Inc Copyright 2009 Pearson Education Inc 17 3 The Big Bang and Inflation Our goals for learning What aspects of the universe were originally unexplained by the Big Bang theory How does inflation explain these features of the universe How can we test the idea of inflation Copyright 2009 Pearson Education Inc What aspects of the universe were originally unexplained by the Big Bang theory Copyright 2009 Pearson Education Inc Mysteries Needing Explanation 1 Where does structure come from 2 Why is the overall distribution of matter so uniform 3 Why is the density of the universe so close to the critical density Copyright 2009 Pearson Education Inc Mysteries Needing Explanation 1 Where does structure come from 2 Why is the overall distribution of matter so uniform 3 Why is the density of the universe so close to the critical density An early episode of rapid inflation can solve all three mysteries Copyright 2009 Pearson Education Inc How does inflation explain these features of the universe Copyright 2009 Pearson Education Inc Inflation can make structure by stretching tiny quantum ripples to enormous sizes These ripples in density then become the seeds for all structure in the universe Copyright 2009 Pearson Education Inc How can microwave temperature be nearly identical on opposite sides of the sky Copyright 2009 Pearson Education Inc Regions now on opposite sides of the sky were close together before inflation pushed them far apart Copyright 2009 Pearson Education Inc Density Critical Density Critical Density Critical Copyright 2009 Pearson Education Inc The overall geometry of the universe is closely related to total density of matter and energy The inflation of the universe flattens the overall geometry like the inflation of a balloon causing overall density of matter plus energy to be very close to critical density Copyright 2009 Pearson Education Inc How can we test the idea of inflation Copyright 2009 Pearson Education Inc Patterns of structure observed by WMAP show us the seeds of the universe Copyright 2009 Pearson Education Inc Observed patterns of structure in the universe agree so far with the seeds that inflation would produce Copyright 2009 Pearson Education Inc Seeds Inferred from CMB Overall geometry is flat Total mass energy has critical density Ordinary matter 4 6 of total Total matter is 28 of total Dark matter is 23 of total Dark energy is 72 of total Age of 13 7 billion years Copyright 2009 Pearson Education Inc Seeds Inferred from CMB Overall geometry is flat Total mass energy has critical density Ordinary matter 4 6 of total Total matter is 28 of total Dark matter is 23 of total Dark energy is 72 of total Age of 13 7 billion years In excellent agreement with observations of present day universe and models involving inflation and WIMPs Copyright 2009 Pearson Education Inc What have we learned What aspects of the universe were originally unexplained by the Big Bang theory The origin of structure the smoothness of the universe on large scales the nearly critical density of the universe How does inflation explain these features of the universe Structure comes from inflated quantum ripples Observable universe became smooth before inflation when it was very tiny Inflation flattened the curvature of space bringing the expansion rate into balance with the overall density of mass energy Copyright 2009 Pearson Education Inc What have we learned How can we test the idea of inflation We can compare the structures we see in detailed observations of the microwave background with predictions for the seeds that should have been planted by inflation So far our observations of the universe agree well with models in which inflation planted the seeds Copyright 2009 Pearson Education Inc Mysteries Why no antimatter Where do the high energy cosmic rays come from What is the field producing the initial inflation and later dark energy What is dark energy What was the initial fluctuation What is time Copyright 2009 Pearson Education Inc The Ultimate Fate of the Universe Exponential acceleration The disapperance of the CMB The disapperance of the galaxies The Big Rip or the GNAB GIB and why Copyright 2009 Pearson Education Inc Quiz 5 Can science ever understand the moment of Creation Should it try Copyright 2009 Pearson Education Inc
View Full Document
Unlocking...