1. Titel The Oldest Memory: The Echo of the Big Bang

2. What is the oldest memory? First question: What is the start of time? Creation of the universe – The Big Bang! Is there any „memory“ of this event?

3. 1965: Penzias & Wilson

4. Blackbody radiation

5. Cosmic Microwave Background 2,725 ± 0.002 K

6. What is the CMB? Universe is expanding (Hubble flow)- Doppler Effect: Expanding blackbody: Still a blackbody, but cooler CMB: The cooled down blackbody named Universe  Universe started in a hot, dense state CMB is „The Echo“ of this Big Bang (This was already predicted by Gamov in the 40‘s) Static sourceMoving source

7. Measuring the Anisotropy

8. WMAP: The „raw“ data

9. Subtracting the Doppler Dipole

10. Substracting the Galaxy

11. What to learn from the CMB? Anisotropies are caused by slight inhomogenities Inhomogenities interact with sound speed Cosmic expansion decouples light from matter  CMB shows „last scattering surface“ Results in length scale  allows to measure the geometry of the universe Geometry related to fundamental parameters

12. Results: Power Spectrum  The Universe is flat!

13. Fundamental Parameters Relative Abundance: „Usual“ (Baryonic) Matter: 4.4% ± 0.4% Total Matter:27.0% ± 4.0% Dark Energy:73.0% ± 4.0%  We only know about ~5% of our universe! So... Plenty of work to do! For more information: http://map.gsfc.nasa.gov/