ASTR 1102 002 2008 Fall Semester Joel E Tohline Alumni Professor Office 247 Nicholson Hall Slides from Lecture23 Chapter 26 Cosmology and Chapter 27 Exploring the Universe Implications of Big Bang Era of recombination and Cosmic Microwave Background CMB Origin of the Elements Non uniformities in the Early Universe and the Origin of Galaxies At the time of recombination the temperature was a few thousand degrees everywhere But from our point of view now this radiation has been significantly redshifted due to expansion of the universe so the spectrum should look like a black body of a much cooler temperature Remember Black body spectrum from Chapter 5 At the time of recombination the temperature was a few thousand degrees everywhere But from our point of view now this radiation has been significantly redshifted due to expansion of the universe so the spectrum should look like a black body of a much cooler temperature From Einstein s theory Dicke Peebles Princeton University predict T 3 K At the time of recombination the temperature was a few thousand degrees everywhere But from our point of view now this radiation has been significantly redshifted due to expansion of the universe so the spectrum should look like a black body of a much cooler temperature From Einstein s theory Dicke Peebles Princeton University predict T 3 K What would a 3 K spectrum look like Remember Black body spectrum from Chapter 5 Penzias Wilson discover CMB radiation awarded 1978 Nobel Prize Uniformity of CMB COBE satellite measurements which improved on discovery of Penzias Wilson show CMB temperature is 2 725 K Exactly the same temperature no matter which direction you look in the sky at the time of recombination the universe was extremely uniform Slight Doppler shift due to Earth s motion through space Otherwise only very tiny fluctuations smaller than 200 micro Kelvin K Uniformity of CMB COBE satellite measurements which improved on discovery of Penzias Wilson show CMB temperature is 2 725 K Exactly the same temperature no matter which direction you look in the sky at the time of recombination the universe was extremely uniform Slight Doppler shift due to Earth s motion through space Otherwise only very tiny fluctuations smaller than 200 micro Kelvin K Uniformity of CMB COBE satellite measurements which improved on discovery of Penzias Wilson show CMB temperature is 2 725 K Exactly the same temperature no matter which direction you look in the sky at the time of recombination the universe was extremely uniform Slight Doppler shift due to Earth s motion through space Otherwise only very tiny fluctuations smaller than 200 micro Kelvin K Uniformity of CMB COBE satellite measurements which improved on discovery of Penzias Wilson show CMB temperature is 2 725 K Exactly the same temperature no matter which direction you look in the sky at the time of recombination the universe was extremely uniform Slight Doppler shift due to Earth s motion through space Otherwise only very tiny fluctuations smaller than 200 micro Kelvin K Uniformity of CMB COBE satellite measurements which improved on discovery of Penzias Wilson show CMB temperature is 2 725 K Exactly the same temperature no matter which direction you look in the sky at the time of recombination the universe was extremely uniform Slight Doppler shift due to Earth s motion through space Otherwise only very tiny fluctuations smaller than 200 micro Kelvin K confirmed by WMAP spacecraft Implications of Big Bang Era of recombination and Cosmic Microwave Background CMB Origin of the Elements Non uniformities in the Early Universe and the Origin of Galaxies Implications of Big Bang Era of recombination and Cosmic Microwave Background CMB Origin of the Elements Non uniformities in the Early Universe and the Origin of Galaxies Origin of the Elements Looking back even further in time before recombination the universe was even hotter At a sufficiently early epoch it was too hot for any atomic nuclei heavier than Hydrogen to have existed When did the first elements form and which ones were able to form ANS In the first 3 minutes and only Helium Origin of the Elements Looking back even further in time before recombination the universe was even hotter At a sufficiently early epoch it was too hot for any atomic nuclei heavier than Hydrogen to have existed When did the first elements form and which ones were able to form ANS In the first 3 minutes and only Helium Origin of the Elements Looking back even further in time before recombination the universe was even hotter At a sufficiently early epoch it was too hot for any atomic nuclei heavier than Hydrogen to have existed When did the first elements form and which ones were able to form Origin of the Elements Looking back even further in time before recombination the universe was even hotter At a sufficiently early epoch it was too hot for any atomic nuclei heavier than Hydrogen to have existed When did the first elements form and which ones were able to form ANS In the first 3 minutes and only Helium How Do We Measure 0 Measure count up all the matter density in the universe 0 and compare the value to c Measure distances and redshifts of even more distant galaxies and look for deviations in the Hubble diagram Modern Hubble Law implies 0 m