3. How Big is the Universe? Really big! The Sun is 8 light minutes away. There are 10 11 stars in our galaxy. COBE/DIRBE satellite image The center of our Galaxy is 25,000 light years away. The Milky Way in infrared emission.

4. From Hubble STScI/NASA Field & Levay 10 11 Galaxies in Observable Universe

5. The Universe is Expanding Hubble observed that the further away a galaxy is the faster it is moving away. Us Galaxy We are not (that!) special, all observers see the same. A neighbor We should think about this as “making space” since the Big Bang, not as an explosion in a preexisting space. The Universe appears the same from all vantages.

6. The Universe is Infinite. We live in a “Hubble Patch” Diameter set by: 2 (speed of light) x (age of universe) Observable Universe or Hubble Patch “Edge” of the observable universe Ignore the expansion and imagine being able to go anywhere in the “whole universe” instantaneously

7. Because the Speed of Light is Finite, Telescopes Are Like Time Machines We see distant objects as they were when they were younger. “Edge” of the observable universe Still ignoring the expansion Younger

8. Now Add The Expansion Light from the “edge” was emitted when the universe was much more compact. The expansion of space stretches wavelengths. “Edge” of the observable universe Younger

9. The Standard Model of Cosmology Surface of last scattering at “decoupling.” “Reionization”

10. Decoupling of the CMB The universe expands and cools from its fiery beginning. When the temperature of the Universe is roughly half the temperature of the Sun, atoms of hydrogen can form. This is called the epoch of decoupling and it occurred 379,000 years after the Big Bang. - e - e - e - e Neutral atoms Ionized plasma Universe cools CMB proton

11. The Standard Cosmological Model Surface of last scattering at “decoupling.” “Reionization”

12. Mark Subbarao & SDSS Collaboration

13. How Do We Measure the CMB? With the expansion of the universe, the CMB has cooled to -270 o C, or 2.725 o C above absolute zero. The CMB is about 1000 times cooler than the Sun and so “shines” in the microwave regime. TV Channel 69 broadcasts at 800 MHz CMB approx 1% of TV noise! You’ve all detected the CMB!

14. (COBE announcement, 4/92) Dave Wilkinson Wilkinson Microwave Anisotropy Probe.

15. UBC Mark Halpern JPL Olivier Dore NASA/GSFC Bob Hill Gary Hinshaw Al Kogut Nils Odegard Janet Weiland Ed Wollack Princeton Norm Jarosik Lyman Page Kendrick Smith David Spergel Chicago Stephan Meyer Hiranya Peiris Brown Greg Tucker UCLA Ned Wright Science Team: WMAP A partnership between NASA/GSFC and Princeton Johns Hopkins Chuck Bennett (PI) Ben Gold David Larson Cornell Rachel Bean Microsoft Chris Barnes CITA Mike Nolta ICE Licia Verde UT Austin Eiichiro Komatsu Oxford Jo Dunkley Columbia Michele Limon

16. K Band, 22 GHz, 1.4 cm

17. Ka Band, 33 GHz, 1 cm

18. Q Band, 41 GHz, 0.7 cm

19. V Band, 61 GHz, 0.5 cm

20. W Band, 94 GHz, 0.3 cm

22. 5º5º

23. How do we get hot and cold patches? Gravitational landscape--just like hills and valleys. Colder Hotter Spot size = [speed plasma ( ) travels]x[age of universe at decoupling] 1 degree in angle W. Hu

24. The “fundamental mode” acts as a fundamental “footprint” or yardstick at the edge of the observable universe. This allows us to determine the size of the observable universe. Us (12,000 stacked hot spots.)  deg Cosmic Paleontology

25. From the standard yardstick, we can deduce the distance to the edge of the universe. Knowing this distance, and the speed of light, we deduce that the age of the universe is: t U =13.75 +/- 0.13 Gyr

26. Basic model (with only six parameters) agrees with virtually all cosmological measurements. Parameters of the Model 4.6%22.6%72.8%

27. The “dark energy” has no foundation in any fundamental theory of nature. It is as though the vacuum has an energy associated with it that drives the universe apart, like antigravity. Most feel that “dark energy” represents a missing piece of theory as opposed to a substance.

28. The Standard Cosmological Model At a very early time a “quantum field” impressed on the universe a gravitational landscape. We measure characteristics of this field. Abbreviated This is a picture of a quantum field from the birth of the universe. Matter fell into the valleys to form eventually “structure.” But only 1/6 of this matter is familiar to us. The dynamics of the universe is now driven not so much by the matter but by an apparent