2. GBT in the Hills National Radio Astronomy Observatory Green Bank, WV

3. Measuring the Size and Age of the Universe Introduction

4. You are an astronomer who has just made this image of the sky. As you study this image, what questions do you ask?

5. Introduction What are these “fuzzy” objects? Are they moving? Are they part of a system? How far away are they? What are they made of? How were they formed?

6. galaxy data 1

7. Gas Spectra Neon Sodium Hydrogen

8. Radio Spectral Line Hydrogen NGC 628 Radio Spectra

9. Galaxy data 2

10. Doppler Shifts Doppler Shift

11. The Expanding Universe Expansion

12. If we assume: All spiral galaxies are similar in size to the Milky Way. Spiral galaxies are 10 kpc in radius. Then we can estimate the distance to these galaxies. Assumption s

13. TAN angle = Opposite Adjacent R Angular size Distance Galaxy distance Distance = Radius TAN angle = Radius Distance

14. Our dv graph

15. Hubble Constant 1/T = H 1/H = Time!!! Age of Univers e Slope = V/D T = 1 x D D

16. Hubble’s Data Hubble’s DV Graph

17. Calculating H and T

18. So, What is the Age of the Universe? About 11 BY answer

19. August, 1999 October, 1999 Sky&Tele 2

20. Distance Ladder